JP5251413B2 - Synchronous motor drive device - Google Patents

Description

  The present invention relates to a driving apparatus for a synchronous motor in which a stator coil is star-connected.

  Conventionally, as shown in Patent Document 1, for example, this type of drive device includes an inverter circuit that outputs a three-phase alternating current to a stator coil and a control circuit that controls the inverter circuit.

  The inverter circuit is arranged in parallel between three switching elements arranged in parallel between the neutral point of the stator coil of the three-phase AC motor and the positive side bus, and in parallel between the neutral point and the negative side bus Three switching elements. A battery is disposed between the positive side bus and the negative side bus.

  The control circuit switches the six switching elements of the inverter circuit to output a three-phase alternating current from the inverter circuit to the three-phase alternating current motor based on the output voltage of the battery. As a result, a rotating magnetic field is generated in the stator coil, and the rotor rotates in synchronization with the rotating magnetic field.

  The inverter circuit is provided with a current sensor that detects a current flowing through the negative bus. For example, when a ground fault or the like that short-circuits between the stator coil and the ground occurs and the detected current value of the current sensor exceeds a predetermined value, the control circuit turns off all six switching elements.

Thus, the output of current from the inverter circuit to the stator coil can be stopped. Therefore, it is possible to stop the current from flowing from the stator coil to the ground.
JP 2001-231266 A

  In the above-described synchronous motor drive device, instead of connecting the battery between the positive side bus and the negative side bus, when the battery is connected between the neutral point of the stator coil and the negative side bus, Even when all of the six switching elements are turned off when a ground fault of the stator coil occurs, it is not possible to stop the current from flowing from the battery to the ground through the stator coil.

  In addition, when the switching element between the neutral point of the stator coil and the negative-side bus in the inverter circuit is short-circuited and current flows from the battery to the negative-side bus through the switching element, all of the six switching elements Even if the switch is turned off, it cannot be stopped that the current flows from the battery to the negative bus through the switching element.

  Further, when the battery is connected between the neutral point of the stator coil and the positive side bus, the same problem as when the battery is connected between the neutral point of the stator coil and the negative side bus occurs.

  In view of the above points, the present invention provides a synchronous motor drive device in which a battery is connected to a neutral point of a stator coil. When a short circuit failure of a switching element or a ground fault of a stator coil occurs, The purpose is to stop the flow of current.

  In order to achieve the above object, according to the first aspect of the present invention, the DC power supply means (81) among the plurality of switching elements is connected when the failure determination means determines the one failure. Blowing current control means (flowing current control means) for causing one of the bus-side switching elements to be energized to blow the first fuse (83) from the DC power supply means (81) to the first fuse (83). S210).

  As a result, even when a short-circuit failure of the switching element or a ground fault of the stator coil occurs and a current that does not blow the fuse flows into the fuse, the fuse and the stator coil are forcibly blown. Can be blocked. For this reason, it can stop that an electric current flows from a battery.

  Conventionally, an electromagnetic relay is arranged between the battery and the stator coil, and the battery and the stator coil are blocked by this electromagnetic relay. In this case, when the vibration is generated, the electromagnetic relay may malfunction, and the battery and the stator coil may not be disconnected.

  On the other hand, in the present invention, since a fuse is used to cut off between the battery and the stator coil, no malfunction occurs when vibration occurs.

In the invention according to claim 2, the DC power supply means (81) is disposed between the negative side bus (31) and the neutral point (15x) of the stator coil (15),
The capacitor (40) is disposed between the positive side bus (32) and a neutral point (15x) of the stator coil (15).

In the invention according to claim 3, the DC power source means (81) is disposed between the negative side bus (31) and the neutral point (15x) of the stator coil (15),
The capacitor (40) is arranged between the positive side bus (32) and the negative side bus (31).

  The invention according to claim 4 is characterized in that the first fuse (83) is disposed between the DC power source means (81) and a neutral point (15x) of the stator coil (15). And

In the invention according to claim 5, the first fuse (83) connected in series between the DC power source means (81) and the neutral point (15x) of the stator coil (15). With two fuses (85),
The first fuse (83) is set so that the first fuse (83) is blown when a current greater than or equal to a first threshold flows through the first fuse (83).
The second fuse (85) is set so that the second fuse (85) is blown when a current of a second threshold value or more flows through the second fuse (85);
Of the first and second fuses (83, 85), when one of the bus-side switching elements connected to the DC power source means (81) is energized by the fusing current control means (S210). The first and second threshold values are set so that only one fuse is blown.

  In the invention according to claim 6, when one of the bus-side switching elements connected to the DC power supply means (81) is energized by the fusing current control means (S <b> 210), the fuse as the one fuse is used. The second threshold value is set to be smaller than the first threshold value so that only the second fuse (85) is blown.

In the invention according to claim 7, the first fuse (83) connected in series between the DC power source means (81) and the neutral point (15x) of the stator coil (15). With two fuses (85),
The first fuse (83) is set to blow when a current flows through the first fuse (83) to reach a first melting temperature or higher,
The second fuse (85) is set so that the second fuse (85) is blown when a current flows through the second fuse (85) and becomes equal to or higher than a second blowing temperature,
When one of the bus-side switching elements connected to the DC power supply means (81) is energized by the fuse control means (S210), one fuse of the first and second fuses (85). The first and second fusing temperatures are set so that only the fusing is performed.

  In the invention according to claim 8, when the fusing current control means (S210) energizes one bus-side switching element connected to the DC power supply means (81), the fuse as the one fuse is operated. The second fusing temperature is set lower than the first fusing temperature so that only the second fuse (85) is blown.

In the invention according to claim 9, the short circuit failure of one bus side switching element connected to the DC power source means (81) is a short circuit fault of the negative side bus side switching element (U2, V2, W2), Current detection means (50) for detecting a current flowing from the DC power supply means (81) to the neutral point (15x) of the stator coil (15);
The failure determination means determines whether or not the detection value of the current detection means (50) is equal to or greater than a predetermined value, whereby a short-circuit failure of the negative-side bus-side switching element (U2, V2, W2) and the It is characterized by determining whether at least one failure has occurred among the ground faults of the stator coil (15).

In the invention which concerns on Claim 10, the short circuit failure of one bus side switching element to which the said DC power supply means (81) is connected is a short circuit fault of the negative side bus side switching element (U2, V2, W2),
Current detection means (50) for detecting a current flowing from the capacitor (40) to the positive-side bus (32);
When the detection value of the current detection means (50) is not less than the upper limit value and when the detection value of the current detection means (50) is less than the lower limit value, the failure determination means is either It is determined that at least one of the short-circuit failure of the negative-side bus-side switching element (U2, V2, W2) and the ground fault of the stator coil (15) has occurred.

In the invention which concerns on Claim 11, the short circuit failure of one bus side switching element to which the said DC power supply means (81) is connected is a short circuit fault of the negative side bus side switching element (U2, V2, W2),
Current detection means (50) for detecting a current flowing from the negative electrode bus (31) to the DC power supply means (81);
The failure determination means determines whether or not the detection value of the current detection means (50) is equal to or greater than a predetermined value, whereby a short-circuit failure of the negative-side bus-side switching element (U2, V2, W2) and the It is characterized by determining whether at least one failure has occurred among the ground faults of the stator coil (15).

  In the invention according to claim 12, the fusing current control means (S210) includes a short circuit failure of the negative side bus side switching element (U2, V2, W2) and a ground fault of the stator coil (15). When the failure determination means determines that at least one failure has occurred, among the plurality of switching elements (U1, V1, W1, U2, V2, W2), the negative-side bus-side switching element (U2, V2 and W2) are all energized and the fusing current flows from the DC power source means (81) to the first fuse (83).

In the invention according to claim 13, whether or not a short-circuit failure has occurred in the negative-side bus-side switching elements (U2, V2, W2) connected to the negative-side bus (31) among the plurality of switching elements. A negative-side short-circuit failure determination means for determining
When the failure determination means determines that at least one of the short-circuit failure of the negative-side bus-side switching element (U2, V2, W2) and the ground fault of the stator coil (15) has occurred, The fusing current control means (S210) energizes the negative-side bus-side switching elements (U2, V2, W2) determined by the negative-side short-circuit fault judging means that the short-circuit fault has not occurred, thereby causing the DC power source to operate. The fusing current is passed from the means (81) to the first fuse (83).

  In the invention according to claim 14, when at least one of the short-circuit fault of the negative-side bus-side switching element (U2, V2, W2) and the ground fault of the stator coil (15) occurs, the fault When the determination means determines, all of the positive-side bus-side switching elements (U1, V1, W1) are stopped from the plurality of the switching elements (U1, V1, W1, U2, V2, W2). A switching control means (S200) is provided.

In the invention which concerns on Claim 15, the positive electrode side short circuit fault determination which determines whether the short circuit fault has arisen in the positive electrode side bus side switching element (U1, V1, W1) connected to the said positive electrode side bus line (32). Means (S117a);
When the positive-side short-circuit fault determination means (S117a) determines that a short-circuit fault has occurred in the positive-side bus-side switching element (U1, V1, W1), the negative-side bus-side switching element (U2, V2, And switching control means (S210) for energizing all of the positive side bus side switching elements (U1, V1, W1) after stopping all of W2).

In the invention which concerns on Claim 16, whether the short circuit fault has arisen in the positive electrode side bus line side switching element (U1, V1, W1) connected to the said positive electrode side bus line (32) among these several switching elements. Positive-side short-circuit fault determining means (S117a) for determining
When the positive-side short-circuit fault determination means (S117a) determines that a short-circuit fault has occurred in the positive-side bus-side switching element (U1, V1, W1), the negative-side bus-side switching element (U2, V2, Switching control for energizing the positive-side bus-side switching elements (U1, V1, W1) determined by the positive-side short-circuit failure determination means (S117a) that the short-circuit failure has not occurred after stopping all of W2) Means (S240).

In the invention which concerns on Claim 17, the said DC power supply means (81) is arrange | positioned between the neutral point (15x) of the said positive electrode side bus | bath (32) and the said stator coil (15),
The capacitor (40) is arranged between the positive side bus (32) and the negative side bus (31).

In the invention which concerns on Claim 18, the said DC power supply means (81) is arrange | positioned between the neutral point (15x) of the said positive electrode side bus-line (32) and the said stator coil (15),
The capacitor (40) is arranged between the negative side bus (31) and a neutral point (15x) of the stator coil (15).

  The invention according to claim 19 is characterized in that the first fuse (83) is disposed between the DC power supply means (81) and the positive-side bus (32).

In the invention according to Claim 20, the second fuse (85) connected in series with the first fuse (83) between the DC power supply means (81) and the positive-side bus (32). With
The second fuse (85) is set so that the second fuse (85) is blown when a current of a second threshold value or more flows through the second fuse (85);
The first fuse (83) is set so that the first fuse (83) is blown when a current greater than or equal to a first threshold flows through the first fuse (83).
Of the first and second fuses (83, 85), when one of the bus-side switching elements connected to the DC power source means (81) is energized by the fusing current control means (S210). The first and second threshold values are set so that only one fuse is blown.

  In the invention according to Claim 21, when the one bus-side switching element connected to the DC power source means (81) is energized by the fusing current control means (S210), the fuse as the one fuse is operated. The second threshold value is set to be smaller than the first threshold value so that only the second fuse (85) is blown.

In the invention according to Claim 22, a second fuse (85) connected in series with the first fuse (83) between the DC power supply means (81) and the positive-side bus (32). With
The first fuse (83) is set to blow when a current flows through the first fuse (83) to reach a first melting temperature or higher,
The second fuse (85) is set so that the second fuse (85) is blown when a current flows through the second fuse (85) and becomes equal to or higher than a second blowing temperature,
When one bus-side switching element connected to the DC power supply means (81) is energized by the fusing current control means (S210), one of the first and second fuses (85) is operated. The first and second fusing temperatures are set so that only the fuse blows.

  In the invention according to Claim 23, when the one bus-side switching element connected to the DC power source means (81) is energized by the fusing current control means (S210), the fuse as the one fuse is operated. The second fusing temperature is set lower than the first fusing temperature so that only the second fuse (85) is blown.

In the invention according to claim 24, the short circuit failure of one bus side switching element connected to the DC power source means (81) is a short circuit fault of the positive side bus side switching element (U1, V1, W1),
Current detection means (50) for detecting current flowing from the DC power supply means (81) to the positive-side bus (32);
The failure determination means determines whether the detected value of the current detection means (50) is equal to or greater than a predetermined value, thereby causing a short-circuit failure of the positive-side bus-side switching element (U1, V1, W1) and the It is characterized by determining whether at least one failure has occurred among the ground faults of the stator coil (15).

In the invention which concerns on Claim 25, the short circuit failure of the one bus side switching element to which the said DC power supply means (81) is connected is a short circuit fault of the positive electrode side bus side switching element (U1, V1, W1),
Current detection means (50) for detecting current flowing from the neutral point (15x) of the stator coil (15) to the DC power supply means (81);
The failure determination means determines whether or not the detection value of the current detection means (50) is less than a predetermined value, thereby causing a short-circuit failure of the positive-side bus-side switching element (U1, V1, W1) and the It is characterized in that it is determined whether or not at least one of the ground faults of the stator coil (15) has occurred.

  In the invention according to claim 26, if at least one of the short-circuit fault of the positive-side bus-side switching element (U1, V1, W1) and the ground fault of the stator coil (15) occurs, the fault When the determination means determines, the fusing current control means (S210) is configured to select the positive-side bus-side switching element (U1, V2) among the plurality of switching elements (U1, V1, W1, U2, V2, W2). V1 and W1) are all energized and the fusing current flows from the DC power source means (81) to the first fuse (83).

In the invention which concerns on Claim 27, it has the positive electrode side short circuit fault determination means which determines whether the short circuit fault has arisen in the said positive electrode side bus line side switching element (U1, V1, W1),
The positive-side short-circuit fault determination means determines that at least one of the short-circuit fault of the positive-side bus-side switching element (U1, V1, W1) and the ground fault of the stator coil (15) has occurred. The fusing current control means (S210) energizes the positive-side bus-side switching elements (U1, V1, W1) determined by the positive-side short-circuit fault determination means that the short-circuit fault has not occurred. The fusing current is allowed to flow from the DC power supply means (81) to the first fuse (83).
In the invention according to claim 28, if at least one of the short-circuit fault of the positive-side bus-side switching element (U1, V1, W1) and the ground fault of the stator coil (15) occurs, the fault When the determination means determines, all of the negative-side bus-side switching elements (U2, V2, W2) are stopped among the plurality of switching elements (U1, V1, W1, U2, V2, W2). A switching control means is provided.
In the invention according to Claim 29, whether or not a short-circuit failure has occurred in the negative-side bus-side switching elements (U2, V2, W2) connected to the negative-side bus (31) among the plurality of switching elements. Negative-side short-circuit fault judging means for judging about,
When the negative-side short-circuit fault determining means determines that a short-circuit fault has occurred in the negative-side bus-side switching element (U2, V2, W2), the positive-side bus-side switching element (U1, V1, W1) And switching control means (S210) for energizing all of the negative-side bus-side switching elements (U2, V2, W2) after all are turned off.

In the invention which concerns on Claim 30, whether the short circuit fault has arisen in the negative electrode side bus line side switching element (U2, V2, W2) connected to the said negative electrode side bus line (31) among these switching elements. Negative-side short-circuit fault determination means for determining
When the negative-side short-circuit fault determining means determines that a short-circuit fault has occurred in the negative-side bus-side switching element (U2, V2, W2), the positive-side bus-side switching element (U1, V1, W1) Switching control means (S210) for energizing only the negative-side bus-side switching elements (U2, V2, W2) determined by the negative-side short-circuit fault determination means that the short-circuit fault has not occurred after all of them are turned off; It is characterized by providing.

In the invention according to claim 31, the inverter circuit control means (73) outputs a control signal to the plurality of switching elements (U1, V1, W1, U2, V2, W2) to provide the plurality of switching elements. (U1, V1, W1, U2, V2, W2) are to be switched,
For each switching element, a current flowing between the neutral point (15x) of the stator coil (15) and the negative-side bus-side switching element (U2, V2, W2) and flowing through the negative-side bus (31). Comprising first current detecting means (50a, 50b, 50c) for detecting,
The inverter circuit control means (73) outputs the control signal for stopping energization of the negative side bus side switching elements (U2, V2, W2) to the negative side bus side switching elements (U2, V2, W2). Sometimes, when the detected value of the first current detecting means (50a, 50b, 50c) is less than a predetermined value, the short circuit failure occurs in the negative side bus side switching element (U2, V2, W2). If not, the negative-side short-circuit fault judging means judges.

In the invention according to Claim 32, the current flowing through the neutral point (15x) of the stator coil (15) through the positive side bus (32) and the positive side bus switching element (U1, V1, W1). Second current detecting means (51a, 51b, 51c) for detecting each switching element,
The inverter circuit control means (73) outputs the control signal for stopping energization of the positive-side bus-side switching elements (U1, V1, W1) to the positive-side bus-side switching elements (U1, V1, W1). Sometimes, when the detection value of the second current detection means (51a, 51b, 51c) is less than a predetermined value, the short-circuit failure occurs in the positive-side bus-side switching element (U1, V1, W1). If not, the positive-side short-circuit failure determination means (S117a) determines.

In the invention according to Claim 33, one of the positive side bus (32) and the negative side bus (31) to which the DC power source means (81) is connected and the neutral of the stator coil (15). A third fuse (86a, 86b, 86c) connected in series to the one bus-side switching element between the point (15x) and
The third fuse (86a, 86b, 86c) is set to be blown when a current of a third threshold value or more flows through the third fuse,
The first fuse (83) is set so that the first fuse (83) is blown when a current greater than or equal to a first threshold flows through the first fuse (83).
When the one bus-side switching element connected to the DC power supply means (81) is energized by the fusing current control means (S210), the first and third fuses (83, 86a, 86b, 86c), the first and third threshold values are set so that only one fuse is blown.

  In the invention according to claim 34, when the one bus-side switching element connected to the DC power supply means (81) is energized by the fusing current control means (S210), the fuse as the one fuse is operated. The third threshold value is set to a value smaller than the first threshold value so that only the third fuse (86a, 86b, 86c) is blown.

In the invention according to claim 35, one of the positive side bus (32) and the negative side bus (31) to which the DC power supply means (81) is connected and the neutral of the stator coil (15). A third fuse (86a, 86b, 86c) connected in series to the one bus-side switching element between the point (15x) and
The third fuse (86a, 86b, 86c) is set to be blown when a current flows through the third fuse and exceeds a third blowing temperature,
The first fuse (83) is set to blow when a current flows through the first fuse (83) to reach a first melting temperature or higher,
When the one bus-side switching element connected to the DC power supply means (81) is energized by the fusing current control means (S210), the first and third fuses (83, 86a, 86b, 86c), the first and third fusing temperatures are set so that only one fuse is blown.

  In the invention according to claim 36, when the fusing current control means (S210) energizes one bus-side switching element connected to the DC power supply means (81), the fuse as the one fuse is operated. The third fusing temperature is set to a temperature lower than the first fusing temperature so that only the third fuses (86a, 86b, 86c) are blown.

The invention according to claim 37 includes a fourth fuse (87b) connected to the negative-side bus (31), and when a current equal to or greater than a fourth threshold flows through the fourth fuse (87b), 4 fuses are set to blow,
The first fuse (83) is set so that the first fuse (83) is blown when a current greater than or equal to a first threshold flows through the first fuse (83).
Of the first and fourth fuses (83, 87b), when the fusing current control means (S210) energizes one bus side switching element connected to the DC power supply means (81). The first and fourth threshold values are set so that only one fuse is blown.

  In the invention according to claim 38, when the one bus-side switching element connected to the DC power supply means (81) is energized by the fusing current control means (S210), the fuse as the one fuse is operated. The fourth threshold value is set to a threshold value smaller than the first fusing temperature so that only the fourth fuse (87b) is blown.

The invention according to claim 39 includes first voltage detection means (90) for detecting a voltage between the positive electrode and the negative electrode of the capacitor (40),
The failure determination means (S113) determines whether or not the detection value of the first voltage detection means is less than a predetermined value, whereby a short-circuit failure of the one bus-side switching element and the stator coil (15 ) To determine whether at least one of the faults has occurred.

In the invention according to claim 40, first voltage detecting means (90) for detecting a voltage between the positive electrode and the negative electrode of the capacitor (40);
Second voltage detection means (91) for detecting a voltage between the positive electrode and the negative electrode of the DC power supply means (81),
The failure determination means determines whether the absolute value of the difference between the detection value of the first voltage detection means (90) and the detection value of the second voltage detection means (91) is less than a predetermined value. It is determined whether or not at least one of the short-circuit fault of the one bus side switching element and the ground fault of the stator coil (15) has occurred.

In the invention which concerns on Claim 41, it comprises the temperature detection means (51) which detects the temperature of the said stator coil (15),
The failure determination means (S114) determines whether the detected value of the temperature detection means (51) is equal to or higher than a predetermined temperature, whereby a short-circuit failure of the one bus side switching element and the stator coil (15 ) To determine whether at least one of the faults has occurred.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
1, 2 and 3 show a first embodiment of an electric compressor for a vehicle air conditioner to which a drive device for a three-phase synchronous motor according to the present invention is applied. FIG. 1 is a mounting diagram of an electric compressor, and FIG. 2 is a diagram showing an internal configuration of the electric compressor.

  As shown in FIG. 1, the electric compressor 1 is disposed on the vehicle front side of the traveling engine 2 of the automobile, and the electric compressor 1 is supported on the vehicle front wall of the traveling engine 2. The electric compressor 1 constitutes a refrigeration cycle device for a vehicle air conditioner together with a condenser, a decompressor, and an evaporator.

  The electric compressor 1 includes a motor 10, a drive device 20, and a compression mechanism 30.

  The motor 10 is a three-phase synchronous motor including a housing 11, a rotating shaft 12, a rotor 13, a stator core 14, and a stator coil 15. The housing 11 is made of a conductive metal such as aluminum and is formed in a substantially cylindrical shape.

The housing 11 is provided with a suction port 11a and a discharge port 11b. The housing 11 is fastened to the vehicle front wall of the traveling engine 2 by bolts (not shown). A mounting surface 11 d is provided on the upper side of the outer wall of the housing 11.
A driving device 20 is disposed on the mounting surface 11d.

  The rotating shaft 12 is disposed in the housing 11 and is rotatably supported by bearings 12a and 12b. The rotating shaft 12 transmits the rotational driving force received from the rotor 13 to the compression mechanism 30.

The rotor 13 is formed in a cylindrical shape with a permanent magnet embedded therein, and is fixed to the rotating shaft 12. The stator core 14 is made of a magnetic material such as ferrite, and is disposed on the radially outer peripheral side with respect to the rotor 13.
A coolant channel 18a is formed between the stator core 14 and the housing 11 on the mounting surface 11d side. A refrigerant flow path 18 b is formed between the stator core 14 and the rotor 13.

  The stator coil 15 is a U-phase coil, a V-phase coil, and a W-phase coil that are star-connected, and is wound around the stator core 14. The stator coil 15 is connected to the drive device 20 via the terminal 17. The terminal 17 is fitted in the opening 11 c of the housing 11.

  The compression mechanism 30 is a scroll type compressor, and is rotated by the rotational driving force from the rotating shaft 12 of the motor 10 to suck, compress, and discharge the refrigerant. Lubricating oil is dissolved in the refrigerant. In the present embodiment, R134 is used as the refrigerant. As the lubricating oil, for example, POE (Polyol ester) oil is used.

  The driving device 20 is disposed on the outer surface of the housing 11. The driving device 20 constitutes an electric circuit that drives the motor 10. Hereinafter, a specific electric circuit configuration of the driving device 20 will be described with reference to FIG. FIG. 3 is a diagram illustrating an electric circuit configuration of the driving device 20.

  The drive device 20 includes an inverter circuit 30, a capacitor 40, current sensors 50, 55, 60, and a control circuit 70.

  The inverter circuit 30 includes switching elements U1, U2, V1, V2, W1, and W2 and diodes D1, D2, D3, D4, D5, and D6.

The switching elements U1 and U2 are connected in series between the negative electrode bus 31 and the positive electrode bus 32, and the switching elements V1 and V2 are connected in series between the negative electrode bus 31 and the positive electrode bus 32. W1 and W2 are connected in series between the negative side bus 31 and the positive side bus 32.

  The common connection point T1 of the switching elements U1 and U2 is connected to the U-phase coil 15a of the stator coil 15, and the common connection point T2 of the switching elements V1 and V2 is connected to the V-phase coil 15b of the stator coil 15. A common connection point T3 of W1 and W2 is connected to a W-phase coil 15c of the stator coil 15.

  As the switching elements U1, U2, V1, V2, W1, and W2, for example, semiconductor switching elements such as insulated gate bipolar transistors and field effect transistors are used.

  The diodes D1, D2, D3, D4, D5, and D6 are disposed so as to be in antiparallel to the corresponding switching elements among the switching elements U1, U2, V1, V2, W1, and W2.

  The capacitor 40 supplies power to the inverter circuit 30 together with the DC power source 80. The plus electrode of the capacitor 40 is connected to the positive bus 32 of the inverter circuit 30, and the minus electrode of the capacitor 40 is connected to the neutral point 15 x of the stator coil 15.

  The DC power supply 80 is disposed on the vehicle body side of the automobile, and includes a battery 81, a capacitor 82, and a current fuse 83. The battery 81 and the capacitor 82 are arranged in parallel between the neutral point 15x of the stator coil 15 and the ground. Capacitor 82 stabilizes the voltage applied from battery 81 to neutral point 15 x of stator coil 15.

  The current fuse 83 includes a fuse element connected between a terminal connected to the plus electrode side of the battery 81 and a terminal connected to the capacitor 82 plus electrode side. The fuse element blows when a current exceeding a predetermined value (hereinafter referred to as a fusing current value) flows. That is, the current fuse 83 is set to blow when a current equal to or greater than the fusing current value flows through the current fuse 83.

  The current sensor 50 is a sensor that detects a current flowing from the DC power source 80 to the neutral point 15x of the stator coil 15. The current sensor 60 is a sensor that detects a U-phase current, a V-phase current, and a W-phase current. The U-phase current is a current that flows from the common connection point T1 of the switching elements U1 and U2 to the U-phase coil 15a. The V-phase current is a current that flows from the common connection point T2 of the switching elements V1 and V2 to the V-phase coil 15b. The W-phase current is a current that flows from the common connection point T3 of the switching elements W1 and W2 to the W-phase coil 15c.

  The control circuit 70 is composed of a microcomputer, a memory, and the like, and controls the inverter circuit 30 based on a target rotational speed given from an electronic control unit (not shown), as well as a short-circuit failure of the stator core 14 to be described later. Processing for stopping the flow of current from the DC power supply 80 when a failure occurs is performed.

Specifically, the control circuit 70 includes a control input / output unit 71, a determination unit 72, an operation control unit 73, and a power cutoff control unit 74. The control input / output unit 71 converts the output signals of the control units 73 and 74 into inverters. It is an interface circuit that outputs to the circuit 30. The control input / output unit 71 outputs the output signal of the current sensor 50 to the determination unit 72 and outputs the output signal of the current sensor 60 to the operation control unit 73.

  First, the determination unit 72 will be described with reference to FIG. FIG. 4 is a flowchart showing the determination process.

  The determination unit 72 executes determination processing according to the flowchart of FIG.

  First, in step S100, the current value detected by the current sensor 50 is acquired. It is determined in step S110 whether or not the acquired current value (hereinafter referred to as an acquired current value) is equal to or greater than a current threshold value. The current threshold value is set to a value lower than the above-described fusing current value. Then, when the acquired current value is less than the current threshold value, it is determined as NO in step S110, assuming that a ground fault of the stator coil 15 and a short circuit failure of the switching element on the negative side bus 31 described later have not occurred. In connection with this, it progresses to step S120 and normal operation control is performed by the operation control part 73 as a switch control means. Hereinafter, normal operation control of the operation control unit 73 will be described.

  First, in order to bring the actual rotational speed of the motor 10b close to the target rotational speed from an electronic control device (not shown), the switching elements U1, U2, V1, V2, W1, W2 are set using a known triangular wave comparison PWM method. A control signal for switching operation is output.

  Accordingly, when switching elements U1, U2, V1, V2, W1, and W2 perform a switching operation, three-phase from common connection points T1, T2, and T3 based on the output voltage of capacitor 40 and the output voltage of DC power supply 80. An alternating current is output to the stator coil 15.

  At this time, when the switching element on the negative side bus 31 side, for example, the switching element U2 is turned on, a current flows from the neutral point 15x side to the negative side bus 31 through the U-phase coil 15a and the switching element U2. Along with this, energy is accumulated in the U-phase coil 15a.

  Thereafter, when switching element U2 is turned off, a current based on the energy of U-phase coil 15a flows to the positive-side bus 32 side through diode D1. That is, when switching element U2 is turned off, current flows from U-phase coil 15a to switching element U1 and flows to capacitor 40, and capacitor 40 is charged.

Also, the positive side bus bar 32 of the switching element, for example, when the switching element U1 is turned on, current flows through the U-phase coil 1 5a of the stator coil 15 through the switching element U 1 from the capacitor 4 0. That is, the capacitor 40 is discharged.

As described above, a three-phase alternating current is output to the stator coil 15 from the common connection points T1, T2, and T3 while charging and discharging the capacitor 40 are repeated.

  A rotating magnetic field based on the three-phase alternating current is generated in the stator coil 15. Therefore, the rotor 13 rotates in synchronization with the rotating magnetic field generated from the stator coil 15. As a result, the rotational speed of the rotary shaft 12 approaches the target rotational speed.

  Then, the compression mechanism 30 is driven by the rotating shaft 12 and turns to suck, compress, and discharge the refrigerant. Accordingly, the refrigerant from the outlet side of the evaporator is sucked into the suction port 11a of the housing 11, and the sucked refrigerant passes through the refrigerant flow paths 18a and 18b. Thereafter, the refrigerant that has passed through the refrigerant flow paths 18a and 18b flows to the compression mechanism 30 side as indicated by an arrow, and then the refrigerant is compressed by the compression mechanism 30 and discharged from the discharge port 11b to the condenser side.

  When the execution of the normal operation control is completed, the process returns to step S100 in FIG. 4, and then the current value flowing from the battery 81 through the current fuse 83 to the neutral point 15x of the stator coil 15 maintains a value less than the current threshold value. As long as it is the same as described above, the NO determination in step S110 and the processes in steps S120 and S100 are repeated.

  Thereafter, when a ground fault occurs in the stator coil 15, the value of the current flowing from the battery 81 through the current fuse 83 to the neutral point 15x of the stator coil 15 increases.

  The ground fault is a fault in which a short circuit occurs between the stator coil 15 and the ground and a current flows from the stator coil 15 to the ground. For example, the ground fault is a failure in which a short circuit occurs through the refrigerant between the insulation defect portion of the stator coil 15 and the housing 11. This occurs when the insulation deficient portion of the stator coil 15 is immersed in the refrigerant when the insulation resistance of the refrigerant is lowered due to erroneous mixing of lubricating oil or the like.

  Here, the decrease in the insulation resistance of the refrigerant occurs when R134 is used as the refrigerant and not the lubricating oil for the electric compressor but the lubricating oil for the engine driven compressor is mistakenly mixed into the refrigerant. The engine-driven compressor lubricating oil is, for example, a PAG oil. The lubricating oil for the electric compressor is, for example, a POE oil.

  The housing 11 is connected to the vehicle body of the automobile via the traveling engine 2 and has the same potential as the ground. The insulation defect portion is a portion of the stator coil 15 where a defect is generated in a part of the insulation coating covering the metal core material and the conductive member is exposed. The metal core material is a wire material through which a current from the DC power supply 80 or the capacitor 40 flows.

  Further, among the switching elements on the negative side bus 31 side, for example, when a short circuit failure occurs in the switching element U2, the current from the DC power supply 80 passes through the neutral point 15x of the stator coil 15, the U-phase coil 15c, and the switching element U2. It flows to the negative electrode side bus 31. Accordingly, the current flowing from the battery 81 to the neutral point 15x of the stator coil 15 through the current fuse 83 increases. The short circuit failure of the switching element is a short circuit between the emitter terminal and the collector terminal of the switching element due to a failure of the switching element due to static electricity or heat.

  Thus, although at least one of the short circuit failure of the switching element U2 on the negative side bus 31 side and the ground fault of the stator coil 15 has occurred, the current flowing from the battery 81 to the current fuse 83 is the fusing current value of the current fuse 83. When the current value is smaller than that, the current from the battery 81 flows to the neutral point 15x of the stator coil 15 through the current fuse 83.

  Then, when the current value flowing from the battery 81 through the current fuse 83 to the neutral point 15x of the stator coil 15 becomes equal to or greater than the current threshold, YES is determined in step S110. In connection with this, it transfers to step S130 and the power cutoff control part 74 performs power cutoff control. Hereinafter, the power shutdown control of the power shutdown controller 74 will be described with reference to FIG. FIG. 5 is a flowchart showing the power-off control.

  First, in step S200, the switching elements U1, V1, and W1 on the positive bus 32 side of the inverter 30 are turned off. As a result, the flow of current from the positive electrode side of the capacitor 40 to the stator coil 15 side is stopped.

  Next, in step S210, the switching elements U1, V2, and W2 on the negative side bus 31 side of the inverter 30 are turned on. Here, when a short circuit failure occurs in the switching element U2, the switching elements V2 and W2 other than the switching element U1 are turned on.

  Therefore, the current from the battery 81 flows to the negative side bus 31 side through the current fuse 83, the neutral point 15x of the stator coil 15, the V-phase coil 15b, and the switching element V2. In addition, the current flows through the neutral point 15x of the stator coil 15, the W-phase coil 15c, and the switching element W2 to the negative-side bus 31 side.

  As a result, the current value flowing from the battery 81 to the current fuse 83 becomes a value equal to or greater than the fusing current value, and the current fuse 83 is blown. Therefore, the neutral point 15x of the stator coil 15 and the battery 81 are disconnected.

  According to the present embodiment described above, a short circuit failure of the switching element on the negative side bus 31 side or a ground fault of the stator coil 15 occurs, and a current smaller than the fusing current value of the current fuse 83 is supplied from the battery 81 to the current fuse. Even when the current flows to 83, the current fuse 83 can be forcibly blown by turning on the switching elements U1, V2, and W2 on the negative side bus 31 side. As a result, the neutral point 15x of the stator coil 15 and the battery 81 are disconnected. Accordingly, it is possible to stop the current from flowing from the DC power supply 80 to the neutral point 15x side of the stator coil 15.

  Further, the electric compressor 1 is supported on the vehicle front wall of the traveling engine 2 as described above. For this reason, when using an electromagnetic relay in order to cut off between the neutral point 15x of the stator coil 15 and the battery 81, the movable contact of the electromagnetic relay vibrates due to the vibration of the traveling engine 2, and the drive device 20 May malfunction.

  On the other hand, in the present embodiment, as described above, the current fuse 83 is used to interrupt the neutral point 15x of the stator coil 15 and the battery 81. The current fuse 83 is not adversely affected by the vibration of the traveling engine 2. For this reason, it is possible to prevent the malfunction of the drive device 20 due to the vibration of the traveling engine 2.

  In the present embodiment, when a short circuit failure of the switching element on the negative electrode bus 31 side or a ground fault of the stator coil 15 occurs, the switching elements U1, V1, and W1 on the positive electrode bus 32 side of the inverter 30 are turned off. The current can be stopped from flowing from the positive electrode side of the capacitor 40 to the stator coil 15 side.

  In the above-described embodiment, the example in which the capacitor 40 is connected between the positive bus 32 and the neutral point 15x of the stator coil 15 is shown, but instead, the following may be used.

  (1) As shown in FIG. 6, the capacitor 40 may be connected between the negative electrode side bus 31 and the positive electrode bus 32. In FIG. 6, the same reference numerals as those in FIG.

  (2) As shown in FIG. 7, the capacitor 40 is connected between the negative electrode bus 31 and the neutral point 15x of the stator coil 15, and the DC power supply 80 is connected to the neutral point 15x of the positive electrode bus 32 and the stator coil 15. You may connect between. In FIG. 7, the same reference numerals as those in FIG.

(3) As shown in FIG. 8, a DC power source 80 is connected between the positive bus 32 and the neutral point 15x of the stator coil 15, and a capacitor 40 is connected between the positive bus 32 and the negative bus 31. You may connect.

  In the circuit configuration shown in FIG. 8, switching elements U 1, U 2, V 1, V 2, W 1, W 2 are generated with a negative potential generated at the negative electrode of capacitor 40 and a positive potential generated at the positive electrode of capacitor 40. Are switched, and a three-phase alternating current is output to the stator coil 15 from the common connection points T1, T2, and T3. In FIG. 8, the same reference numerals as those in FIG.

  In the above-described embodiment, the current fuse 83 is arranged between the plus electrode of the battery 81 of the DC power supply 80 and the plus electrode of the capacitor 82, and the current fuse 83 constitutes the DC power supply 80. However, instead of this, the current fuse 83 may be arranged on the drive device 20 side as follows.

  (1) As shown in FIG. 9, the current fuse 83 may be connected between the plus electrode of the capacitor 82 of the DC power supply 80 and the neutral point 15 x of the stator coil 15.

  In FIG. 9, the same reference numerals as those in FIG.

(2) As shown in FIG. 10, a DC power supply 80 is connected between the positive bus 32 and the neutral point 15x of the stator coil 15, and the capacitor 40 is connected between the negative bus 31 and the positive bus 32. In the connected configuration, the current fuse 83 may be connected between the positive electrode of the capacitor 82 of the DC power supply 80 and the positive-side bus 32. In FIG. 10, the same reference numerals as those in FIG. 3 denote the same elements, and the description thereof is omitted.

  In the circuit configuration shown in FIG. 10, when one of the ground fault of the stator coil 15 and the short-circuit fault of the switching element on the negative side bus 31 side occurs, the neutral point 15x of the stator coil 15 is connected to the negative electrode of the battery 81. The flowing current value becomes smaller.

  Therefore, the current sensor 50 detects the current flowing from the neutral point 15x of the stator coil 15 to the negative electrode of the battery 81.

  The determination unit 72 determines whether or not the current value detected by the current sensor 50 is less than the current threshold. When the current value detected by the current sensor 50 is equal to or greater than the current threshold, the ground fault of the stator coil 15 is determined. It is determined that the failure and the short circuit failure of the switching element on the negative electrode bus 31 side have not occurred. Further, when the current value detected by the current sensor 50 is less than the current threshold, the determination unit 72 determines at least one of the ground fault of the stator coil 15 and the short-circuit fault of the switching element on the negative side bus 31 side. Is determined to have occurred.

  Here, when a short-circuit occurs between the stator coil 15 and the positive electrode side of the battery 81, a so-called power fault occurs in the stator coil 15, the current value detected by the current sensor 50 becomes less than the current threshold value. Accordingly, the determination unit 72 performs the same determination as that in the case where at least one failure has occurred among the ground fault of the stator coil 15 and the short-circuit failure of the switching element on the negative-side bus 31 side. For this reason, the power cut-off control unit 74 turns on the switching elements U1, V1, and W1 to flow a fusing current through the current fuse 83 to blow the current fuse 83.

  When the DC power supply 80 is connected between the positive bus 32 and the neutral point 15x of the stator coil 15, the current sensor 50 detects the current flowing from the positive electrode of the battery 81 to the positive bus 32. It may be configured.

  In this case, as in the first embodiment described above, the determination unit 72 determines whether the current value detected by the current sensor 50 is equal to or greater than the current threshold value, thereby detecting a ground fault in the stator coil 15. It is determined whether any one of the short circuit faults of the switching element on the negative electrode bus 31 side has occurred.

  Further, as shown in FIG. 11, the DC power source 80 is connected between the positive electrode bus 32 and the neutral point 15 x of the stator coil 15, and the capacitor 40 is connected between the positive electrode bus 32 and the negative electrode side bus 31. In some cases, the current fuse 83 may be connected between the positive electrode of the capacitor 82 of the DC power supply 80 and the positive-side bus 32.

(Second Embodiment)
In the first embodiment described above, an example in which a sensor that detects a current flowing from the DC power source 80 to the neutral point 15x of the stator coil 15 is used as the current sensor 50 has been described. May be.

  FIG. 12 shows an electric circuit configuration of the drive device 20 of the present embodiment. 12, the same reference numerals as those in FIG. 3 denote the same elements, and the description thereof is omitted.

  The current sensor 50 according to the present embodiment detects a current flowing between the positive electrode of the capacitor 40 and the positive electrode bus 32.

  The determination unit 72 of the control circuit 70 of the present embodiment executes determination processing according to the flowchart of FIG. In FIG. 13, the same reference numerals as those in FIG.

  First, in step S100, the current value detected by the current sensor 50 is acquired. It is determined in step S111 whether or not the acquired current value is greater than or equal to the upper limit current value. The upper limit current value is set to a value lower than the fusing current value.

Here, in the case where, for example, the switching element U2 of the negative side bus 31 side switching elements has a short circuit failure, when the switching element U1 of the positive side bus 32 side switching elements is on, for example, the plus of the capacitor 40 A current equal to or higher than the upper limit current value flows from the electrode to the negative bus 31 through the switching element U 1 , the common connection point T 1, and the switching element U 2.

  Therefore, in step S111, it is determined that the acquired current value is equal to or greater than the upper limit current value, YES. That is, it is determined that a short circuit failure has occurred in the switching element on the negative side bus 31 side. Thereafter, the process proceeds to step S130.

  When the acquired current value is less than the upper limit current value, NO is determined in step S111, and the process proceeds to step S112 to determine whether or not the acquired current value is equal to or greater than the lower limit current value. The lower limit current value is a value less than the upper limit current value.

Here, when a ground fault has occurred in the stator coil 15, the current from the positive electrode of the capacitor 40 passes through the switching element U 1 , the switching element U 1 , the switching element U 1 , the switching element U 1 or the switching element U 1 , and This current flows to the coil 15 side, and this current flows from the stator coil 15 to the housing 11 through the refrigerant.

Therefore, when the ground fault of the stator coil 15 occurs, it reduces the amount of charge accumulated in the capacitor 4 0, the current value flowing from the positive electrode of the capacitor 4 0 to the positive side bus bar 32 side switching element side is reduced.

  Therefore, in step S112, it is determined that the acquired current value is less than the lower limit current value, YES. That is, it is determined that a ground fault has occurred in the stator coil 15. Thereafter, the process proceeds to step S130.

  Further, in step S112, when the acquired current value is equal to or greater than the lower limit current value, it is determined as NO because neither the short-circuit fault of the negative side bus 31 side switching element nor the ground fault of the stator coil 15 has occurred. The process proceeds to step S120.

  The operations of the control input / output unit 71, the operation control unit 73, and the power cutoff control unit 74 are the same as those in the first embodiment described above, and a description thereof will be omitted.

  According to the present embodiment described above, when a sensor that detects a current flowing between the positive electrode of the capacitor 40 and the positive electrode bus 32 is used as the current sensor 50, as in the first embodiment described above, It can be determined that any one of the short-circuit fault of the switching element on the negative-side bus 31 side and the ground fault of the stator coil 15 has occurred.

  In the second embodiment described above, an example in which a sensor that detects a current flowing between the positive electrode of the capacitor 40 and the positive electrode bus 32 is used as the current sensor 50 is described. As shown in FIG. 14, a sensor that detects a current flowing from the negative side bus 31 to the negative electrode of the battery 81 may be used. In this case, the determination unit 72 performs the determination process in the same manner as in the first embodiment described above.

(Third embodiment)
Next, using the voltage difference between the positive electrode and the negative electrode of the capacitor 40, one of the short circuit failure of the switching element on the negative side bus 31 side and the ground fault of the stator coil 15 occurs. The third embodiment in which it is determined that the

  FIG. 15 shows an electric circuit configuration of the driving device 20 of the present embodiment. In FIG. 15, the same reference numerals as those in FIG.

  In this embodiment, voltage sensors 90 and 91 are used instead of the current sensor 50 of FIG.

  The voltage sensor 90 detects a voltage difference (hereinafter referred to as a capacitor voltage) V1 between the plus electrode and the minus electrode of the capacitor 40. The voltage sensor 91 detects a voltage difference (hereinafter referred to as a power supply voltage) V2 between the plus electrode and the minus electrode of the battery 81.

  The determination unit 72 of the control circuit 70 of the present embodiment executes determination processing according to the flowchart of FIG. In FIG. 16, the same reference numerals as those in FIG.

First, in step S101, the detection value of the voltage sensor 91, that obtains the power supply voltage V 2, at the next step S102, the detection value of the voltage sensor 90, that obtains the capacitor voltage V 1.

Then, the process proceeds to step S113, the absolute value of the difference between the capacitor voltage V 1 and the power supply voltage V 2 ΔV (= V2-V1 ) | ΔV | look, the absolute value | [Delta] V | or is less than a predetermined value not Determine whether.

Here, when a short circuit failure has occurred in the switching element on the negative side bus 31 side, as described in the second embodiment, the switching element on the positive side bus 32 side from the positive electrode of the capacitor 40 , and A current flows through the negative-side bus 31 through the switching element on the negative-side bus 31 side.

  In addition to this, when a short-circuit failure occurs in the switching element on the negative side bus 31 side, for example, the switching element U2, the switching element U2 is not turned off, so that the capacitor 40 is charged when the switching element U2 is turned off. No longer done. For this reason, when a short circuit failure occurs in the switching element on the negative side bus 31 side, the charge stored in the capacitor 40 is reduced and the capacitor voltage V1 is reduced.

When the ground fault of the stator coil 15 has occurred, the current from the positive electrode of the capacitor 40 passes through the switching element on the positive side bus 32 side and the stator coil 15 side as described in the second embodiment. This current flows from the stator coil 15 to the housing 11 through the refrigerant. For this reason, if the ground fault of the stator coil 15 continues, the amount of charge stored in the capacitor 40 decreases, and the capacitor voltage V1 decreases.

As described above, when any one of the ground fault of the stator coil 15 and the short-circuit fault of the switching element on the negative-side bus 31 side has occurred, the capacitor voltage V1 becomes small. Accordingly, the absolute value | ΔV | becomes less than a certain value, and YES is determined in step S113. Thereafter, the process proceeds to step S130 .

If the absolute value | ΔV | is equal to or greater than a certain value, NO is determined in step S113 because no fault has occurred between the ground fault of the stator coil 15 and the ground fault of the stator coil 15. Thereafter, the process proceeds to step S120 .

  In the present embodiment described above, as in the first embodiment described above, either the ground fault of the stator coil 15 or the ground fault of the stator coil 15 is detected using the power supply voltage V1 and the capacitor voltage V2. Whether or not a failure has occurred can be determined.

In the third embodiment described above, it is determined whether one of the ground fault of the stator coil 15 and the ground fault of the stator coil 15 has occurred using the power supply voltage V 2 and the capacitor voltage V 1. an example is shown where it is determined, instead of this, by the capacitor voltages V 1 to determine whether it is less than a predetermined value by the judging unit 72, ground of the ground fault and the stator coil 15 of the stator coil 15 It may be determined whether one of the failures has occurred. This is because the capacitor voltage V1 becomes small when one of the ground fault of the stator coil 15 and the ground fault of the stator coil 15 occurs.

In the third embodiment described above, the DC power source 80 is connected between the negative side bus 31 and the neutral point 15x of the stator coil 15, and the capacitor 40 is connected between the positive side bus 32 and the neutral point 15x of the stator coil 15. determining in the structure connected between, using a power supply voltage V 2 and the capacitor voltage V 1, whether one of a failure or of ground fault of the ground fault and the stator coil 15 of the stator coil 15 has occurred Although an example is shown, the following may be used instead.

As shown in FIG. 17, a DC power supply 80 is connected between the positive bus 32 and the neutral point 15x of the stator coil 15, and the capacitor 40 is connected between the negative bus 31 and the neutral point 15x of the stator coil 15. In the configuration connected to, whether or not the determination unit 72 uses the power supply voltage V 2 and the capacitor voltage V 1 to cause either one of the ground fault of the stator coil 15 or the ground fault of the stator coil 15. Determine whether. Since the determination process of the determination unit 72 is the same as that in the third embodiment described above, description thereof is omitted.

In the configuration shown in FIG. 17, the determination unit 72 determines whether the capacitor voltage V 1 is less than a predetermined value, so that either the ground fault of the stator coil 15 or the ground fault of the stator coil 15 is detected. It may be determined whether one failure has occurred.

(Fourth embodiment)
Next, a fourth embodiment is described in which it is determined whether one of the ground fault of the stator coil 15 and the ground fault of the stator coil 15 has occurred based on the temperature of the stator coil 15.

  FIG. 18 shows an electric circuit configuration of the driving device 20 of the present embodiment. In FIG. 18, the same reference numerals as those in FIG.

  In the present embodiment, a temperature sensor 51 such as a thermistor for detecting the temperature of the stator coil 15 is used.

  The determination unit 72 of the control circuit 70 of the present embodiment executes determination processing according to the flowchart of FIG. In FIG. 19, the same reference numerals as those in FIG.

  First, in step S103, the temperature detected by the temperature sensor 51 is acquired. It is determined in step S114 whether or not the acquired (hereinafter referred to as acquired temperature) is equal to or higher than a predetermined temperature.

  Here, for example, when a short circuit failure occurs in the switching element U2 among the switching elements on the negative-side bus 31 side, the neutral point 15x of the stator coil 15 from the DC power source 80 through the U-phase coil 15a and the switching element U2 A current flows through the side bus 31. Since current flows through the stator coil 15 in this way, the temperature of the stator coil 15 rises.

  Further, when a ground fault has occurred in the stator coil 15, a current flows from the DC power source 80 to the housing 11 through the stator coil 15 and the refrigerant. Since current flows through the stator coil 15 in this way, the temperature of the stator coil 15 rises.

  As described above, when any one of the ground fault of the stator coil 15 and the ground fault of the stator coil 15 has occurred, the temperature of the stator coil 15 rises.

  Therefore, in step S103, when the acquired temperature is equal to or higher than the predetermined temperature, it is determined that one of the ground fault failure of the stator coil 15 and the ground fault failure of the stator coil 15 has occurred, and then determined as YES. Proceed to step S130.

  In step S103, when the acquired temperature is lower than the predetermined temperature, it is determined that the ground fault failure of the stator coil 15 and the ground fault failure of the stator coil 15 have not occurred, and NO is determined. Thereafter, the process proceeds to step S120.

  According to the embodiment described above, the determination unit 72 determines whether one of the ground fault of the stator coil 15 and the ground fault of the stator coil 15 has occurred based on the temperature of the stator coil 15. Can be determined.

  In the above-described fourth embodiment, the DC power source 80 is connected between the negative side bus 31 and the neutral point 15x of the stator coil 15, and the capacitor 40 is connected between the positive side bus 32 and the neutral point 15x of the stator coil 15. The example in which the failure is determined using the temperature of the stator coil 15 in the configuration connected in between has been described. Instead, the DC power supply 80 is connected between the positive bus 32 and the neutral point 15x of the stator coil 15. In the configuration in which the capacitor 40 is connected between the negative bus 31 and the neutral point 15x of the stator coil 15, the failure may be determined using the temperature of the stator coil 15.

  Further, in the configuration in which the DC power source 80 is connected between the positive electrode bus 32 and the neutral point 15x of the stator coil 15 and the capacitor 40 is connected between the negative electrode side bus 31 and the positive electrode bus 32, the stator coil 15 A failure may be determined using temperature.

(Fifth embodiment)
In the first embodiment described above, of the short-circuit fault of the switching element on the negative-side bus 31 side and the ground fault of the stator coil 15 based on the current value flowing from the DC power supply 80 to the neutral point 15x of the stator coil 15 Although an example in which it is determined whether or not one of the failures has occurred has been shown, the following may be used instead.

  FIG. 20 shows an electric circuit configuration of the drive device 20 of the present embodiment. 20, the same reference numerals as those in FIG. 3 denote the same elements, and the description thereof is omitted.

  In the present embodiment, current sensors 50a, 50b, and 50c are used instead of the current sensor 50 of FIG.

  The current sensor 50a is a sensor that detects a current value that flows from the neutral point 15x of the stator coil 15 through the switching element U2 and flows to the negative electrode bus 31b. The current sensor 50b is a sensor that detects a current value that flows from the neutral point 15x of the stator coil 15 through the switching element V2 and flows to the negative electrode bus 31b. The current sensor 50c is a sensor that detects a current value that flows from the neutral point 15x of the stator coil 15 through the switching element W2 to the negative bus 31b.

  The determination unit 72 of the control circuit 70 of the present embodiment executes determination processing according to the flowchart of FIG. 21, the same reference numerals as those in FIG. 4 indicate the same steps, and the description thereof is omitted. X in FIG. 21 indicates any of U, V, and W, and x indicates any of u, v, and w.

  The determination process of FIG. 21 determines whether or not a failure has occurred for each phase. First, the determination process for the U phase (X = U, x = u in the figure) will be described.

  First, in step S104, the current value Iu detected by the current sensor 50a is acquired. It is determined in step S115 whether or not the acquired current value Iu is greater than or equal to the upper limit current value. The upper limit current value is set to a value lower than the fusing current value.

  If it is determined in step S115 that the acquired current value Iu is equal to or greater than the upper limit current value, the process proceeds to step S117, where the control input / output unit 71 turns off the switching element U1 on the positive side bus 32 side. Is output, it is determined whether or not YES is determined in step S115. The off signal is a control signal output from the control input / output unit 71 to turn off the switching element U1 on the positive side bus 32 side.

  Here, when a short circuit failure occurs in the switching element U1 and the collector terminal and the emitter terminal of the switching element U1 are short-circuited, for example, when the switching element U2 is turned on among the switching elements on the negative side bus 31 side, the capacitor A current flows from 40 to the negative electrode bus 31 through the switching elements U1 and U2.

  For this reason, when the control input / output unit 71 outputs an OFF signal to the switching element U1, the acquired current value Iu becomes equal to or higher than the upper limit current value. For this reason, it determines with YES in step S117, progresses to step S118a, and sets a U-phase positive electrode short circuit flag. The U-phase positive electrode short-circuit flag corresponds to the X-phase positive electrode short-circuit flag in the drawing, and is a flag indicating that a short-circuit failure has occurred in the switching element U1 on the positive-side bus 32 side.

  Further, when a short circuit failure occurs in the switching element U2, when the switching element U1 is turned on, a current flows from the capacitor 40 to the negative electrode bus 31 through the switching elements U1 and U2.

  For this reason, when the control input / output unit 71 outputs an ON signal to the switching element U1, the acquired current value Iu becomes equal to or higher than the upper limit current value. For this reason, in step S117, it is determined that a short circuit failure has occurred in switching element U2, and it is determined NO, the process proceeds to step S118b, and the U-phase negative electrode short-circuit flag is set. The ON signal is a control signal output from the control input / output unit 71 to turn on the switching element U1 on the positive side bus 32 side. The U-phase negative electrode short-circuit flag corresponds to the X-phase negative electrode short-circuit flag in FIG. 21, and is a flag indicating that a short-circuit failure has occurred in the switching element U2.

  In step S115 described above, when the acquired current value Iu is less than the upper limit current value, it is determined as NO, and the process proceeds to step S116, where it is determined whether or not the acquired current value Iu is less than the lower limit current value. The lower limit current value is smaller than the upper limit current value.

Here, when a ground fault has occurred in the stator coil 15, the current from the positive electrode of the capacitor 40 passes through one of the switching elements U 1 , V1, and W1 on the positive side bus 32, This current flows to the stator coil 15 side, and this current flows from the stator coil 15 to the housing 11 through the refrigerant. In addition, a current from the DC power source 80 flows through the stator coil 15 and the refrigerant to the housing 11. For this reason, the value of the current flowing from the neutral point 15x of the stator coil 15 through the switching element U2 on the negative side bus 31 side to the negative side bus 31 becomes small.

  Therefore, when a ground fault has occurred in the stator coil 15, the acquired current value Iu becomes less than the lower limit current value, and YES is determined in step S116. Accordingly, the process proceeds to step S118c, and the U-phase ground fault flag is set. The U-phase ground fault fault flag corresponds to the X-phase ground fault fault flag in FIG. 21 and is a flag indicating that a ground fault has occurred in the stator coil 15.

  In step S116, when the acquired current value Iu is equal to or greater than the lower limit current value, it is determined as NO because the ground fault of the stator coil 15 and the short-circuit failure of the switching elements U1 and U2 have not occurred. Accordingly, the process proceeds to step S118d, and the U-phase normal flag is set. The U-phase normal flag corresponds to the X-phase normal flag in FIG. 21, and is a flag indicating that a ground fault in the stator coil 15 and a short-circuit fault in the switching elements U1 and U2 have not occurred.

  In this way, it is determined whether any one of the ground fault of the stator coil 15, the short circuit of the switching element U1, and the short circuit of the switching element U2 has occurred.

  Similarly, the determination process for the V phase is executed, and any one of the V phase positive short circuit flag, the V phase negative short circuit flag, the V phase ground fault flag, and the V phase normal flag is set. In addition, a determination process for the W phase is executed, and any one of the W phase positive short circuit flag, the W phase negative short circuit flag, the W phase ground fault flag, and the W phase normal flag is set.

  If all of the U-phase normal flag, the V-phase normal flag, and the W-phase normal flag are set, it is assumed that a ground fault failure of the stator coil 15 and a short-circuit failure of the switching element have not occurred. The normal operation control is executed by the operation control unit 73 as in the first embodiment.

Also, U phase positive short circuit flag, U phase negative short circuit flag, U phase ground fault flag, V phase positive short circuit flag, V phase negative short circuit flag, V phase ground fault flag, W phase positive short circuit flag, W phase negative short circuit flag, And if either of the W phase ground fault flags is set,
The power cutoff control unit 74 executes power cutoff control. Hereinafter, the power shutdown control of the power shutdown controller 74 will be described with reference to FIG. FIG. 22 is a flowchart showing the power shutdown control.

  First, in step S220, it is determined whether any of the U-phase positive electrode short-circuit flag, the V-phase positive electrode short-circuit flag, and the W-phase positive electrode short-circuit flag is set.

  Here, when any of the U-phase positive electrode short-circuit flag, the V-phase positive electrode short-circuit flag, and the W-phase positive electrode short-circuit flag is set, it is determined as YES. That is, it is determined that any one of the switching elements U1, V1, and W1 has a short circuit failure.

  Accordingly, the process proceeds to step S230 where the switching elements U2, V2, W2 are turned off, and in the next step S240, the switching elements U1, V1, W1 are turned on.

  At this time, since any one of the switching elements U1, V1, and W1 has a short circuit failure, a normal switching element other than the switching element that has caused the short circuit failure among the switching elements U1, V1, and W1 is turned on. become.

  Therefore, current flows from the positive electrode of the capacitor 40 to the stator coil 15 through the normal switching element until the potential of the positive electrode of the capacitor 40 and the potential of the positive electrode of the battery 81 become the same.

  Further, when any one of the U-phase negative short-circuit flag, the U-phase ground fault flag, the V-phase negative short-circuit flag, the V-phase ground fault flag, the W-phase negative short-circuit flag, and the W-phase ground fault flag is set, It determines with NO in step S220.

  That is, it is determined that any one of the ground faults of the switching element on the negative electrode bus 31 side and the stator coil 15 has occurred.

  Accordingly, the switching elements U1, V1, and W1 are turned off in step S200, and the switching elements U2, V2, and W2 are turned on in the next step S210.

  At this time, if any one of the switching elements U2, V2, and W2 has a short circuit fault, a normal switching element other than the switching element that has caused the short circuit fault is selected among the switching elements U2, V2, and W2. Will turn on.

  For this reason, the fusing current from the battery 81 flows to the negative side bus 31 side through the current fuse 83, the stator coil 15, and the normal switching element, so that the current fuse 83 is blown. Therefore, the neutral point 15x of the stator coil 15 and the battery 81 are disconnected.

  According to the embodiment described above, in addition to the determination of the ground fault of the stator coil 15 using the current sensors 50a, 50b, and 50c, the switching elements U1, V1, W1, U2, V2, and W2 are short-circuited. Whether or not has occurred can be determined for each switching element.

  When any one of the ground fault of the stator coil 15 and the short-circuit fault of the switching elements U2, V2, and W2 has occurred, the switching elements U2, V2, and W2 are turned on. For this reason, since the fusing current from the battery 81 flows to the current fuse 83, the current fuse 83 is blown. Therefore, the neutral point 15x of the stator coil 15 and the battery 81 can be shut off as in the first embodiment.

  In the present embodiment, when any of the switching elements U1, V1, and W1 has a short circuit failure, the switching elements U1, V1, and W1 are turned on, and the switching element on the positive side bus 32 side from the positive electrode of the capacitor 40 is turned on. Current is passed through the stator coil 15 side. Therefore, the energy stored in the capacitor 40 can be consumed by the stator coil 15. For this reason, it is possible to reduce the risk of leakage due to the energy stored in the capacitor 40.

  In the fifth embodiment described above, the DC power source 80 is connected between the negative side bus 31 and the neutral point 15x of the stator coil 15, and the capacitor 40 is connected to the positive side 32 and the neutral point 15x of the stator coil 15. In the configuration connected between the switching elements U1, V1, W1, U2, V2, and W2, the example in which the determination unit 72 determines whether or not a short-circuit failure has occurred has been described. Instead of this, the following may be used.

  (1) As shown in FIG. 23, a DC power source 80 is connected between the positive bus 32 and the neutral point 15x of the stator coil 15, and the capacitor 40 is neutral of the negative bus 31 and the stator coil 15. In the configuration connected to the point 15x, the determination unit 72 determines, for each switching element, whether or not a short circuit fault has occurred in the switching elements U1, V1, W1, U2, V2, and W2.

  In this case, it is necessary to use current sensors 51a, 51b, and 51c that detect currents passing through the switching elements U1, V1, and W1 on the positive bus side 32.

  Specifically, the current sensor 51a is a sensor that detects a current value that flows from the positive bus 32 side through the switching element U1 and flows to the neutral point 15x of the stator coil 15. The current sensor 51b is a sensor that detects a current value that flows from the positive bus 32 side through the switching element V1 to the neutral point 15x of the stator coil 15. The current sensor 51c is a sensor that detects a current value that flows from the positive bus 32 side through the switching element W1 and flows to the neutral point 15x of the stator coil 15.

  (2) In the configuration in which the DC power source 80 is connected between the positive side bus 32 and the neutral point 15x of the stator coil 15, and the capacitor 40 is connected between the negative side bus 31 and the positive side bus 32. The current sensors 51a, 51b, 51c are arranged in the same manner as in (1) above, and the determination unit 72 is based on the detection values of the current sensors 51a, 51b, 51c, and the switching elements U1, V1, W1, U2, V2, It is determined for each switching element whether or not a short circuit failure has occurred for W2.

(Sixth embodiment)
Next, a sixth embodiment will be described in which a current passing through a switching element is detected for each switching element, and it is determined for each switching element whether or not a short-circuit fault has occurred in the switching element based on the detected current.

  FIG. 24 shows an electric circuit configuration of the drive device 20 of the present embodiment. 24, the same reference numerals as those in FIG. 3 denote the same elements, and the description thereof is omitted.

  The drive device 20 of this embodiment is provided with current sensors 50a, 50b, and 50c in FIG. 20 and current sensors 51a, 51b, and 51c in FIG.

  The determination unit 72 of the control circuit 70 of the present embodiment executes determination processing according to the flowchart of FIG. 25, the same reference numerals as those in FIG. 4 denote the same steps, and the description thereof is omitted. In FIG. 25, X represents any one of U, V, and W, x represents any one of u, v, and w, and x represents any one of 1, 2.

  The determination process of FIG. 25 determines whether or not a failure has occurred for each switching element. First, the determination process for the switching element U1 (X = U, x = u, n = 1 in the figure). Will be explained.

  First, in step S104a, the current Iu1 passing through the switching element U1 is acquired by the current sensor 51a. It is determined in step S115a whether or not the acquired current Iu1 is greater than or equal to the upper limit current value. The upper limit current value is set to a value lower than the fusing current value.

  In the next step S115a, when it is determined YES that the acquired current value Iu1 is equal to or greater than the upper limit current value, the process proceeds to step S117a, and the control input / output unit 71 turns off the switching element U1 on the positive bus 32 side. Is output, it is determined whether or not YES is determined in step S115. The off signal is a control signal output from the control input / output unit 71 to turn off the switching element U1 on the positive side bus 32 side.

  Here, when a short circuit failure occurs in the switching element U1, for example, when the switching element U2 is turned on among the switching elements on the positive electrode bus 31 side, a current flows from the capacitor 40 to the negative electrode bus 31 through the switching elements U1 and U2. .

  For this reason, when the control input / output unit 71 outputs an off signal to the switching element U1, the acquired current value Iu1 becomes equal to or higher than the upper limit current value. For this reason, it determines with YES in step S117a supposing that the switching element U2 is normal and the short circuit failure has occurred in the switching element U1. Then, it progresses to step S119a and sets a U (1) phase short circuit flag. The U (1) phase positive electrode short circuit flag corresponds to the X (n) phase short circuit flag in the figure, and is a flag indicating that a short circuit failure has occurred in the switching element U1 on the positive side bus 32 side.

  In addition, when a short circuit failure occurs in the switching element U2, for example, when the switching element U1 is turned on among the switching elements on the positive electrode bus 31 side, a current flows from the capacitor 40 to the negative electrode side bus 31 through the switching elements U1 and U2.

  For this reason, when the control input / output unit 71 outputs an ON signal to the switching element U1, the acquired current value Iu1 becomes equal to or higher than the upper limit current value. For this reason, in step S117a, it is determined that the switching element U1 is normal and a short-circuit fault has occurred in the switching element U2. Then, it progresses to step S119b and sets a U (2) short circuit flag. The ON signal is a control signal output from the control input / output unit 71 to turn on the switching element U1 on the positive side bus 32 side. The U (2) short-circuit flag corresponds to the X (n + 1) short-circuit flag in FIG. 25, and is a flag indicating that a short-circuit failure has occurred in the switching element U2.

  In step S115a described above, when the acquired current value Iu1 is less than the upper limit current value, it is determined as NO, and the process proceeds to step S116a to determine whether or not the acquired current value Iu1 is less than the lower limit current value. The lower limit current value is smaller than the upper limit current value.

Here, when a ground fault occurs in the stator coil 15, the current from the positive electrode of the capacitor 40 passes through any one of the positive side bus 32 side switching elements U1, V1, and W1 and the stator coil 15 side. This current flows from the stator coil 15 to the housing 11 through the refrigerant. For this reason, when a ground fault occurs in the stator coil 15 and time elapses, the amount of charge stored in the capacitor 40 decreases, and flows from the positive bus 32 through the switching element U1 to the neutral point 15x of the stator coil 15. The current value becomes smaller.

  Therefore, when a ground fault has occurred in the stator coil 15, the acquired current value Iu1 becomes less than the lower limit current value, and NO is determined in step S116a. Accordingly, the process proceeds to step S119c, and the U (1) ground fault flag is set. The U (1) phase ground fault flag is equivalent to the X (n) ground fault flag in FIG. 25 and is a flag indicating that a ground fault has occurred in the stator coil 15.

  In step S116a, when the acquired current value Iu1 is equal to or greater than the lower limit current value, it is determined as NO because it is determined that the ground fault of the stator coil 15 and the short-circuit failure of the switching elements U1 and U2 have not occurred. Accordingly, the process proceeds to step S119d, and the U (1) normal flag is set. The U (1) normal flag corresponds to the X (n) normal flag in FIG.

  As described above, based on the detection value of the current sensor 51a, it is determined whether any one of the ground fault of the stator coil 15, the short circuit of the switching element U1, and the short circuit of the switching element U2 has occurred. Will do.

  Next, a determination process for the switching element U2 (X = U, x = u, n = 2 in the drawing) will be described.

  First, in step S104a, the current sensor 50a acquires the current Iu2 that passes through the switching element U2. It is determined in step S115a whether or not the acquired current Iu2 is greater than or equal to the upper limit current value.

  In the next step S115a, when it is determined YES that the acquired current value Iu2 is equal to or greater than the upper limit current value, the process proceeds to step S117a, and the control input / output unit 71 turns off the switching element U2 on the positive bus 32 side. Is output, it is determined whether or not YES is determined in step S115a. The off signal is a control signal output from the control input / output unit 71 to turn off the switching element U2 on the positive bus 32 side.

  Here, when a short circuit failure occurs in the switching element U2, for example, when the switching element U1 is turned on among the switching elements on the positive electrode bus 31 side, a current flows from the capacitor 40 to the negative electrode bus 31 through the switching elements U1 and U2. Flowing.

  For this reason, when the control input / output unit 71 outputs an OFF signal to the switching element U2, the acquired current value Iu2 becomes equal to or higher than the upper limit current value. For this reason, it is determined that the switching element U1 is normal and the switching element U2 has a short-circuit failure in step S117a. Then, it progresses to step S119a and sets a U (2) phase short circuit flag.

  The U (2) phase positive short-circuit flag corresponds to the X (n) phase short-circuit flag in the figure, and is a flag indicating that a short-circuit failure has occurred in the switching element U2 on the negative bus 31 side.

  Further, when a short circuit failure occurs in the switching element U1, for example, when the switching element U1 of the negative side bus 31 side switching elements is turned on, a current flows from the capacitor 40 to the negative side bus 31 through the switching elements U1 and U2. .

  For this reason, when the control input / output unit 71 outputs an ON signal to the switching element U2, the acquired current value Iu2 becomes equal to or higher than the upper limit current value. For this reason, in step S117a, it is determined that the switching element U2 is normal and a short-circuit fault has occurred in the switching element U1. Then, it progresses to step S118b and sets a U (1) short circuit flag. The ON signal is a control signal output from the control input / output unit 71 to turn on the switching element U1 on the positive side bus 32 side. The U (1) short-circuit flag corresponds to the X (n-1) short-circuit flag in FIG. 25, and is a flag indicating that a short-circuit failure has occurred in the switching element U1.

  Further, in step S115a described above, when the acquired current value Iu2 is less than the upper limit current value, it is determined as NO, and the process proceeds to step S116a, where it is determined whether or not the acquired current value Iu2 is less than the lower limit current value. The lower limit current value is smaller than the upper limit current value.

  Here, when a ground fault occurs in the stator coil 15, as described in the fifth embodiment, a current value that flows from the neutral point 15x of the stator coil 15 to the negative bus 31 through the switching element U1. Becomes smaller.

  Therefore, when a ground fault has occurred in the stator coil 15, the acquired current value Iu2 becomes less than the lower limit current value, and YES is determined in step S116a. Accordingly, the process proceeds to step S119c, and the U (2) ground fault flag is set. The U (2) phase ground fault flag is equivalent to the X (n) ground fault flag in FIG. 25 and is a flag indicating that a ground fault has occurred in the stator coil 15.

  In step S116a, when the acquired current value Iu2 is equal to or greater than the lower limit current value, it is determined as NO because it is determined that the ground fault of the stator coil 15 and the short-circuit failure of the switching elements U1 and U2 have not occurred. Accordingly, the process proceeds to step S119d, and the U (2) normal flag is set. The U (2) normal flag corresponds to the X (n) normal flag in FIG.

  In this way, it is determined whether any one of the ground fault of the stator coil 15, the short circuit of the switching element U1, and the short circuit of the switching element U2 has occurred.

  Similarly, determination processing is executed for each of the switching elements V1, V2, W1, and W2.

  Then, all of the U (1) normal flag, U (2) normal flag, V (1) normal flag, V (2) normal flag, W (1) normal flag, and W (2) normal flag are set. If there is a ground fault in the stator coil 15 and a short circuit failure in the switching element, normal operation control is executed by the operation control unit 73 as in the first embodiment.

  Also, U (1) short circuit flag, U (2) short circuit flag, U (1) ground fault flag, U (2) ground fault flag, V (1) short circuit flag, V (2) short circuit flag, V (1) Any of the ground fault flag, V (2) ground fault flag, W (1) short circuit flag, W (2) short circuit flag, W (1) ground fault flag, and W (2) ground fault flag is set. In such a case, the power cutoff control unit 74 executes the power cutoff control. Hereinafter, the power shutdown control of the power shutdown controller 74 will be described with reference to FIG. FIG. 26 is a flowchart showing the power-off control. 26, the same reference numerals as those in FIG. 21 denote the same steps, and a description thereof will be omitted.

  First, in step S221, it is determined whether or not a short circuit fault has occurred in at least one of the switching elements U1, U2, V1, V2, W1, and W2.

  One of the U (1) short circuit flag, U (2) short circuit flag, V (1) short circuit flag, V (2) short circuit flag, W (1) short circuit flag, and W (2) short circuit flag is set. If YES in step S221, it is determined as YES because at least one of the switching elements U1, U2, V1, V2, W1, and W2 has a short circuit fault. Accordingly, it is determined in step S222 whether or not the switching element in which the short circuit failure has occurred is a switching element of the positive bus 32.

  At this time, if the set flag is any one of the U (1) short circuit flag, the V (1) short circuit flag, and the W (1) short circuit flag, YES is determined in step S222.

  Accordingly, the process proceeds to step S230 where the switching elements U2, V2, W2 are turned off, and in the next step S240, the switching elements U1, V1, W1 are turned on.

At this time, a current flows from the positive electrode of the capacitor 40 to the stator coil 15 side through a normal switching element among the switching elements U1, V1, and W1. Therefore, the energy stored in the capacitor 40 can be consumed by the stator coil 15.

  In step S221 described above, U (1) ground fault flag, U (2) ground fault flag, V (1) ground fault flag, V (2) ground fault flag, W (1) ground fault flag, and W (2) If any one of the ground fault flags is set, it is determined that no short-circuit failure has occurred in the switching elements U1, U2, V1, V2, W1, and W2, and NO is determined. Migrate to

  In step S222 described above, when any one of the U (2) short-circuit flag, the V (2) short-circuit flag, and the W (2) short-circuit flag is set, it is determined as NO. That is, it is determined that the switching element causing the short-circuit failure is the switching element of the negative side bus 31. Accordingly, the process proceeds to step S200.

  In this way, the process proceeds to step S200, where the switching elements U1, V1, W1 are turned off, and in the next step S210, the switching elements U2, V2, W2 are turned on. For this reason, since the fusing current from the battery 81 flows to the current fuse 83, the current fuse 83 is blown. Therefore, the neutral point 15x of the stator coil 15 and the battery 81 are disconnected.

  According to the present embodiment described above, when one of the ground fault of the stator coil 15 and the short-circuit fault of the switching elements U2, V2, and W2 has occurred, the fusing current from the battery 81 is The current fuse 83 is blown by flowing through the current fuse 83. Therefore, the neutral point 15x of the stator coil 15 and the battery 81 can be shut off as in the first embodiment.

  In the present embodiment, when any of the switching elements U1, V1, and W1 has a short circuit failure, the stator passes through the switching element on the positive side bus 32 side from the positive electrode of the capacitor 40, as in the first embodiment described above. Since the current flows through the coil 15, the energy stored in the capacitor 40 can be consumed by the stator coil 15.

  In the above-described sixth embodiment, an example in which all of the positive side bus 32 side switching elements U2, V2, and W2 are turned on in step S240 is shown, but not limited thereto, the positive side bus 32 side switching elements U2, V2, Of W2, only normal switching elements that are not short-circuited may be turned on.

  Here, the determination as to whether or not the positive side bus 32 side switching element is normal is made as follows.

  First, determination of the switching element U1 on the positive electrode bus 32 side will be described with reference to FIG.

  When the control circuit 70 outputs an off signal for stopping the energization of the switching element U1 to the switching element U1, if the detected value of the current sensor 51a is less than a predetermined value, the control circuit 70 determines the positive-side short circuit failure. As a means, it is determined that a short circuit failure has not occurred in the switching element U1. Similarly, the switching elements V1 and W1 are determined for each switching element based on the detection values of the current sensors 51b and 51c when the off signal is output to the switching elements V1 and W1.

  From the above, it is possible to determine for each switching element whether or not the positive-side bus-side switching element is normal.

  In the above-described sixth embodiment, an example in which all of the negative-side bus-side switching elements U1, V1, and W1 are turned on in step S210 has been shown. However, the present invention is not limited thereto, and the negative-side bus-side switching elements U1, V1, and W1 Of these, only normal switching elements that are not short-circuited may be turned on.

  Here, the determination as to whether or not the negative side bus side switching element is normal is made as follows.

  For example, the determination of the switching element U2 on the negative bus 31 side will be described with reference to FIG.

  When the control circuit 70 outputs an off signal for stopping energization of the switching element U2 to the switching element U2, if the detected value of the current sensor 50a is less than a predetermined value, the control circuit 70 determines the negative-side short circuit fault As a means, it is determined that a short circuit failure has not occurred in the switching element U2. Similarly, the negative-side bus 32 side switching elements V2 and W2 are also determined for each switching element based on the detection values of the current sensors 50b and 50c when the OFF signal is output to the switching elements V2 and W2.

  From the above, it is possible to determine for each switching element whether or not the positive-side bus-side switching element is normal.

  In the above-described sixth embodiment, an example in which the capacitor 40 is disposed between the positive side bus 32 and the neutral point 15x of the stator coil 15 has been described, but instead, the capacitor 40 is connected to the positive side bus 32 and the negative electrode. You may arrange | position between the side bus-bars 31. FIG.

  In the above-described sixth embodiment, the DC power supply 80 is connected between the negative side bus 31 and the neutral point 15x of the stator coil 15, and the capacitor 40 is connected to the neutral point 15x of the positive side bus 32 and the stator coil 15. However, instead of this, as shown in FIG. 27, a DC power supply 80 is connected between the positive bus 32 and the stator coil 15. The determination processing may be executed for each switching element with a configuration in which the capacitor 40 is connected between the negative point bus 31 and the neutral point 15x of the stator coil 15.

For example, when at least one of the short-circuit fault of the positive-side bus-side switching element and the ground fault of the stator coil 15 occurs, all the positive-side bus-side switching elements U1, V1, and W1 are energized. The fusing current from the battery 81 may be passed through the fuse 83.
Alternatively, when at least one of the short-circuit fault of the positive-side bus-side switching element and the ground fault of the stator coil 15 has occurred, the positive-side bus-side switching element determined that no short-circuit fault has occurred. May be energized to cause a fusing current from the battery 81 to flow through the fuse 83.

  Further, when at least one of the short-circuit fault of the positive-side bus-side switching element and the ground fault of the stator coil 15 occurs, all of the negative-side bus-side switching elements (U2, V2, W2 are stopped) It may be operated.

  Here, the capacitor 40 may be connected between the positive side bus 32 and the negative side bus 31 instead of between the negative side bus 31 and the neutral point 15x of the stator coil 15.

(Seventh embodiment)
Next, a seventh embodiment in which a current fuse is added in the driving device in addition to the current fuse in the DC power supply will be described.

  FIG. 28 shows the configuration of the drive device 20 of the present embodiment. 28, the same reference numerals as those in FIG. 3 denote the same components, and the description thereof is omitted.

  The drive device 20 of FIG. 28 is obtained by adding a current fuse 85 to the configuration of FIG.

The current fuse 85 is connected in series with the current fuse 83 between the plus electrode of the capacitor 82 and the plus electrode of the battery 81. Fusing current value of the current fuse 85, it is smaller than the fusing current value of a current fuse 8 3 are set. Therefore, the fusing current from the switching element U2, V2, W2 is turned on the battery 81 flows in the current fuse 85,8 3, only the current fuse 85 comes to fusing.

  In the present embodiment, the current fuse 85 and the capacitor 82 are disposed on the drive device 20 side, with the current fuse 85 and the capacitor 82 removed from the DC power supply 80.

According to the embodiment described above, it is possible to blow the only current fuse 85 by fusing current from the battery 81, without using a current fuse 8 3 of the DC power supply 80, the neutral point of the stator coil 15 It is possible to block between 15x and the battery 81.

In the seventh embodiment described above, an example is shown in which the current fuse 85 is connected between the plus electrode of the capacitor 82 and the plus electrode of the battery 81. Instead, as shown in FIG. May be connected between the positive electrode of the capacitor 82 and the neutral point 15x of the stator coil 15.
(Eighth embodiment)
In the seventh embodiment, the current fuses 81 and 85 are connected in series between the positive electrode of the capacitor 82 and the positive electrode of the battery 81. Instead, in the eighth embodiment, A current fuse is arranged as shown in FIG.

  FIG. 30 shows the configuration of the drive device 20 of the present embodiment. In FIG. 30, the same reference numerals as those in FIG.

  The drive device 20 of FIG. 30 is obtained by adding current fuses 87a and 87b to the configuration of FIG.

  The current fuse 87a is connected between the positive electrode of the capacitor 40 and the positive side bus 32. The current fuse 87b is connected as a fourth fuse between the negative electrode of the battery 81 and the negative side bus 31.

Flow In the thus configured present embodiment, when a ground fault occurs in the stator coil 15, the current from the positive electrode current fuse 8 3 and stator coils 15 of the battery 81, and the housing 11 through the refrigerant This current flows to the negative electrode of the battery 81 through the current fuse 87b.

Here, the fusing current value of the current fuse 87b is small than fusing current value of a current fuse 8 3 are set. Therefore, when a ground fault occurs in the stator coil 15 can be blown by a current fuse 87 b.

For example, when a short circuit failure occurs in the switching element U2 among the negative-side bus 31 side switching elements, for example, when the switching element U1 is turned on among the positive-side bus 32 side switching elements, the current is supplied from the capacitor 40 to the switching element U1, It flows to the current fuse 87b through U2 and the negative side bus 31.

Here, the fusing current value of the current fuse 87b is small than fusing current value of a current fuse 8 3 are set. For this reason, when a short circuit failure occurs in the switching element on the negative side bus 31 side, only the current fuse 87b can be blown.

  In addition, when a ground fault occurs in the stator coil 15, the current from the positive electrode of the capacitor 40 flows into the housing 11 through the stator coil 15 through the positive side bus 32 side switching elements U 1, V 1, W 1 and through the refrigerant. This current may flow to the negative electrode of the battery 81, bypassing the current fuse 87b, as indicated by the arrow Ya. At this time, if a current equal to or greater than the fusing current value of the current fuse 87a flows, the current fuse 87a can be blown.

  In the present embodiment described above, when one of the short circuit failure of the switching element on the negative side bus 31 side and the ground fault of the stator coil 15 occurs, only the current fuse 87b is blown, and the battery 81 and the stator coil 15 Can be blocked.

Further, when a ground fault occurs in the stator coil 15, the current fuse 87a is blown even when the current from the positive electrode of the capacitor 40 bypasses the current fuse 87b and flows to the negative electrode of the battery 81. be able to. Therefore, the capacitor 40 and the stator coil 15 can be interrupted. Electric leakage from the capacitor 40 can be suppressed.
(Ninth embodiment)
In the seventh embodiment described above, an example is shown in which the DC power source 80 is connected between the neutral point 15x of the stator coil 15 and the negative-side bus 31 and a current fuse is added. A ninth embodiment in which a power source 80 is connected between the neutral point 15x of the stator coil 15 and the positive bus 32 and a current fuse is added will be described.

  FIG. 31 shows the configuration of the drive device 20 of the present embodiment. In FIG. 31, the same reference numerals as those in FIG.

  The drive device 20 of FIG. 31 is obtained by adding a current fuse 85 to the configuration of FIG.

Current fuse 85 is connected to a current fuse 8 3 series between the positive electrode and the positive electrode bus 32 of the battery 81. Fusing current value of the current fuse 85, it is smaller than the fusing current value of a current fuse 8 3 are set. Therefore, the switching elements U1, V1, W1 are turned on fusing current from the battery 8 3 flows a current fuse 85,8 3, only the current fuse 85 comes to fusing. In the present embodiment, the current fuse 85 constitutes the driving device 20.

According to the present embodiment described above, in the configuration in which the DC power supply 80 is connected between the neutral point 15x of the stator coil 15 and the negative side bus 31, only the current fuse 85 is blown by the blowing current from the battery 81. it is possible, even without using a current fuse 8 3 of the DC power supply 80, can be cut off and between the neutral point 15x and the battery 8 3 of the stator coil 15.
(10th Embodiment)
Next, the tenth embodiment in which a current fuse is arranged for each switching element on the negative electrode bus 31 side will be described.

  FIG. 32 shows the configuration of the drive device 20 of the present embodiment. 32, the same reference numerals as those in FIG. 3 denote the same components, and the description thereof is omitted.

  32 is obtained by adding current fuses 86a, 86b, and 87c to the configuration of FIG.

  The current fuse 86a is connected between the switching element U2 and the negative side bus 31. The current fuse 86b is connected between the switching element V2 and the negative side bus 31. The current fuse 86c is connected between the switching element W2 and the negative electrode bus 31.

Here, the fusing current value of the current fuse 86a is small than fusing current value of a current fuse 8 3 are set. Fusing current value of the current fuse 86b is small than fusing current value of a current fuse 8 3 are set. The fusing current value is the minimum current value at which the fuse element of the current fuse blows. Fusing current value of the current fuse 86c is small than fusing current value of a current fuse 8 3 are set.

  In the present embodiment configured as described above, when the power cutoff control unit 74 turns on the switching elements U2, V2, and W2, the current from the battery 81 is changed to the current fuse 83, the U-phase coil 15a of the stator coil 15, It flows to the negative electrode side bus 31 through the switching element U2 and the current fuse 86a. As a result, the current fuse 83 is not blown, and the current fuse 86a is blown.

  Furthermore, the current from the battery 81 flows to the negative bus 31 through the current fuse 83, the V-phase coil 15b of the stator coil 15, the switching element V2, and the current fuse 86b. Accordingly, the current fuse 83 is not blown, and the current fuse 86b is blown.

  Further, the current from the battery 81 flows to the negative bus 31 through the current fuse 83, the W-phase coil 15c of the stator coil 15, the switching element W2, and the current fuse 86c. As a result, the current fuse 83 is not blown, and the current fuse 86c is blown.

  Therefore, when a short circuit failure occurs in the switching elements U2, V2, W2 on the negative side bus 31 side, the negative side is passed from the battery 81 through the switching element on the negative side bus 31 side without using the current fuse 83 of the DC power supply 80. It is possible to stop the current from flowing through the bus 31.

  In the tenth embodiment described above, an example in which the DC power source 80 is connected between the neutral point 15x of the stator coil 15 and the negative side bus 31 and a current fuse is arranged for each switching element on the negative side bus 31 side. Instead of this, as shown in FIG. 33, a DC power source 80 is connected between the neutral point 15x of the stator coil 15 and the positive side bus 32, and for each switching element on the positive side bus 32 side. Current fuses 86a, 86b, 86c may be arranged.

  The current fuse 86a is connected between the switching element U1 and the positive electrode bus 32. The current fuse 86b is connected between the switching element V2 and the positive electrode bus 32. The current fuse 86c is connected between the switching element W2 and the positive electrode bus 32.

Current fuse 86a, 86b, fusing current value of 86c, respectively, is smaller than the fusing current value of a current fuse 8 3 are set. For this reason, when the power cutoff control unit 74 turns on the switching elements U1, V1, and W1 on the positive bus 32 side, the current fuse 83 of the DC power supply 80 is not blown, and the current fuses 86a, 86b, and 86c are blown. it can. Therefore, it is possible to stop the current from the battery 81 from flowing through the switching element U1 to the negative bus 31 without using the current fuse 83 of the DC power supply 80.

  In the above-described first to tenth embodiments, the example in which the current fuse 83 is used as the first fuse has been described, but instead, the thermal fuse 83 may be used as the first fuse.

  In this case, it is necessary to use a thermal fuse 85 instead of the current fuse 85 as the second fuse of FIGS. 28, 29, and 31.

  Here, when a current flows through the thermal fuse 83 and the temperature of the fuse element of the thermal fuse 83 becomes equal to or higher than the first fusing temperature, the fuse element of the thermal fuse 83 is set to blow. The fusing temperature of the thermal fuse 83 is the lowest temperature at which the fuse element blows.

  When the current flows through the thermal fuse 85 and the temperature of the fuse element of the thermal fuse 85 becomes equal to or higher than the second melting temperature, the thermal fuse 85 fuse element is set to blow.

  Here, the first and second threshold values are set to different values. For this reason, when a short circuit occurs in the switching element U2 on the negative side bus 31 side, the current from the battery 81 flows into the fuses 83 and 85, and only one of the fuses 83 and 85 is blown. For example, if the second threshold value is set to a value smaller than the first threshold value and only the thermal fuse 85 is blown, a current is supplied from the battery 81 to the negative bus 31 without using the thermal fuse 83 of the DC power supply 80. Can stop flowing.

  Further, it is necessary to use thermal fuses 86a, 86b, 86c instead of the current fuses 86a, 86b, 86c as the third fuses in FIG.

  Here, the fusing current value of each of the thermal fuses 86 a, 86 b, 86 c is set to a temperature different from the fusing temperature of the fuse 83. For example, when the negative-side bus-side switching elements U2, V2, and W2 are turned on, the fusing temperature of the fuses 86a, 86b, and 86c is such that the fuse 83 is not blown and the fuses 86a, 86b, and 86c are blown. It is set to a temperature lower than the fusing temperature.

  In practicing the present invention, the above first to tenth embodiments may be implemented by combining any two or more embodiments.

  In the first to tenth embodiments described above, the example in which the synchronous motor drive device is applied to an electric compressor for a vehicle air conditioner has been shown. However, the present invention is not limited thereto, and the synchronous motor drive device is applied to various devices. Also good.

  In the first to tenth embodiments described above, an example in which a three-phase AC synchronous motor is used as a synchronous motor has been described. Good.

It is a mounting view of the electric compressor in the first embodiment of the present invention. It is a figure which shows the internal structure of the electric compressor of FIG. It is a figure which shows the circuit structure of the drive device of FIG. It is a flowchart which shows the process of the determination part of FIG. It is a flowchart which shows the process of the power cutoff control part of FIG. It is a figure which shows the circuit structure of the drive device which is a modification of 1st Embodiment. It is a figure which shows the circuit structure of the drive device which is a modification of 1st Embodiment. It is a figure which shows the circuit structure of the drive device which is a modification of 1st this embodiment. It is a figure which shows the circuit structure of the drive device which is a modification of 1st Embodiment. It is a figure which shows the circuit structure of the drive device which is a modification of 1st Embodiment. It is a figure which shows the circuit structure of the drive device which is a modification of 1st Embodiment. It is a figure which shows the circuit structure of the drive device in 2nd Embodiment of this invention. It is a flowchart which shows the process of the determination part in 2nd Embodiment. It is a figure which shows the circuit structure of the drive device which is a modification of 2nd Embodiment. It is a figure which shows the circuit structure of the drive device in 3rd Embodiment of this invention. It is a flowchart which shows the process of the determination part in 3rd Embodiment. It is a figure which shows the circuit structure of the drive device in the modification of 3rd Embodiment. It is a figure which shows the circuit structure of the drive device in 4th Embodiment of this invention. It is a flowchart which shows the process of the determination part in 4th Embodiment. It is a figure which shows the circuit structure of the drive device in 5th Embodiment of this invention. It is a flowchart which shows the process of the determination part in 5th Embodiment. It is a flowchart which shows the process of the power cutoff control part in 5th Embodiment. It is a figure which shows the circuit structure of the drive device in the modification of 5th Embodiment. It is a figure which shows the circuit structure of the drive device in 6th Embodiment of this invention. It is a flowchart which shows the process of the determination part in 6th Embodiment. It is a flowchart which shows the process of the power cutoff control part in 6th Embodiment. It is a figure which shows the circuit structure of the drive device in the modification of 6th Embodiment. It is a figure which shows the circuit structure of the drive device in 7th Embodiment of this invention. It is a figure which shows the circuit structure of the drive device in the modification of 7th Embodiment. It is a figure which shows the circuit structure of the drive device in 8th Embodiment of this invention. It is a figure which shows the circuit structure of the drive device in 9th Embodiment of this invention. It is a figure which shows the circuit structure of the drive device in 10th Embodiment of this invention. It is a figure which shows the circuit structure of the drive device in the modification of 10th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric compressor 10 Motor 11 Housing 12 Rotating shaft 13 Rotor 14 Stator core 15 Stator coil 20 Drive device 30 Inverter circuit 40 Capacitor 50 Current sensor 50a Current sensor 50b Current sensor 50c Current sensor 51a Current sensor 51b Current sensor 51c Current sensor 60 Current sensor 70 Control circuit 81 Battery 82 Capacitor 83 Current fuse U1 Switching element U2 Switching element V1 Switching element V2 Switching element W1 Switching element W2 Switching element

Claims (41)

A synchronous motor driving device comprising a stator coil (15) star-connected and having a neutral point (15x) and a rotor (13) rotated by a rotating magnetic field generated from the stator coil (15),
An inverter circuit (30) having a large number of pairs of switching elements connected in series and a large number of the pair of switching elements being connected in parallel between the positive side bus (32) and the negative side bus (31) When,
A capacitor (40);
By switching the plurality of switching elements (U1, V1, W1, U2, V2, W2) constituting the inverter circuit (30), the output voltage of the capacitor (40) and the DC power supply means (81) An inverter circuit control means (73) for outputting an alternating current to the stator coil (15) based on the output voltage of the stator coil to generate the rotating magnetic field from the stator coil (15),
The DC power source means (81) is provided between any one of the positive side bus (32) and the negative side bus (31) and a neutral point (15x) of the stator coil (15). Connected,
The output voltage of the DC power supply means (81) is applied to the stator coil (15) through a first fuse (83),
Among the plurality of switching elements, at least one of the short-circuit fault of one bus side switching element connected to the DC power source means (81) and the ground fault of the stator coil (15) occurs. Failure determination means (S110, S111, S112, S113, S114, S115, S116, S117, S115a, S117a) for determining whether or not
When the failure determination means determines that one of the failures, the first fuse is operated by energizing one bus side switching element connected to the DC power supply means (81) among the plurality of switching elements. Fusing current control means (S210) for flowing a fusing current for fusing (83) from the DC power supply means (81) to the first fuse (83);
A drive device for a synchronous motor, comprising: The DC power source means (81) is disposed between the negative side bus (31) and the neutral point (15x) of the stator coil (15),
The synchronous motor according to claim 1, wherein the capacitor (40) is disposed between the positive-side bus (32) and a neutral point (15x) of the stator coil (15). Drive device. The DC power source means (81) is disposed between the negative side bus (31) and the neutral point (15x) of the stator coil (15),
2. The synchronous motor drive device according to claim 1, wherein the capacitor is disposed between the positive-side bus and the negative-side bus.   The said 1st fuse (83) is arrange | positioned between the said DC power supply means (81) and the neutral point (15x) of the said stator coil (15), The Claim 2 or 3 characterized by the above-mentioned. The drive apparatus of the synchronous motor of description. A second fuse (85) connected in series with the first fuse (83) is provided between the DC power supply means (81) and a neutral point (15x) of the stator coil (15). ,
The first fuse (83) is set so that the first fuse (83) is blown when a current greater than or equal to a first threshold flows through the first fuse (83).
The second fuse (85) is set so that the second fuse (85) is blown when a current of a second threshold value or more flows through the second fuse (85);
Of the first and second fuses (83, 85), when one of the bus-side switching elements connected to the DC power source means (81) is energized by the fusing current control means (S210). 5. The synchronous motor drive device according to claim 4, wherein the first and second threshold values are set so that only one fuse is blown.   When the one bus side switching element connected to the DC power source means (81) is energized by the fusing current control means (S210), only the second fuse (85) as the one fuse is used. The synchronous motor drive device according to claim 5, wherein the second threshold value is set to a value smaller than the first threshold value so as to melt. A second fuse (85) connected in series with the first fuse (83) is provided between the DC power supply means (81) and a neutral point (15x) of the stator coil (15). ,
The first fuse (83) is set to blow when a current flows through the first fuse (83) to reach a first melting temperature or higher,
The second fuse (85) is set so that the second fuse (85) is blown when a current flows through the second fuse (85) and becomes equal to or higher than a second blowing temperature,
When one of the bus-side switching elements connected to the DC power supply means (81) is energized by the fuse control means (S210), one fuse of the first and second fuses (85). 5. The synchronous motor drive device according to claim 4, wherein the first and second fusing temperatures are set so that only the fusing is performed.   When the one bus side switching element connected to the DC power source means (81) is energized by the fusing current control means (S210), only the second fuse (85) as the one fuse is used. The synchronous motor drive device according to claim 7, wherein the second fusing temperature is set to a temperature lower than the first fusing temperature so as to melt. The short circuit fault of one bus side switching element connected to the DC power source means (81) is a short circuit fault of the negative side bus side switching element (U2, V2, W2), and the DC power source means (81) A current detection means (50) for detecting a current flowing through a neutral point (15x) of the stator coil (15);
The failure determination means determines whether or not the detection value of the current detection means (50) is equal to or greater than a predetermined value, whereby a short-circuit failure of the negative-side bus-side switching element (U2, V2, W2) and the The synchronous motor drive device according to any one of claims 2 to 8, wherein it is determined whether at least one of the ground faults of the stator coil (15) has occurred. The short circuit failure of one bus side switching element connected to the DC power source means (81) is a short circuit failure of the negative side bus side switching element (U2, V2, W2),
Current detection means (50) for detecting a current flowing from the capacitor (40) to the positive-side bus (32);
When the detection value of the current detection means (50) is not less than the upper limit value and when the detection value of the current detection means (50) is less than the lower limit value, the failure determination means is either It is determined that at least one of the short-circuit failure of the negative-side bus-side switching element (U2, V2, W2) and the ground fault of the stator coil (15) has occurred. The drive device for a synchronous motor according to any one of 2 to 8. The short circuit failure of one bus side switching element connected to the DC power source means (81) is a short circuit failure of the negative side bus side switching element (U2, V2, W2),
Current detection means (50) for detecting a current flowing from the negative electrode bus (31) to the DC power supply means (81);
The failure determination means determines whether or not the detection value of the current detection means (50) is equal to or greater than a predetermined value, whereby a short-circuit failure of the negative-side bus-side switching element (U2, V2, W2) and the The synchronous motor drive device according to any one of claims 2 to 8, wherein it is determined whether at least one of the ground faults of the stator coil (15) has occurred.   The fusing current control means (S210) indicates that at least one of the short-circuit fault of the negative-side bus-side switching element (U2, V2, W2) and the ground fault of the stator coil (15) has occurred. When the failure determination means determines, all of the negative-side bus-side switching elements (U2, V2, W2) among the plurality of switching elements (U1, V1, W1, U2, V2, W2) are energized. The synchronous motor driving device according to any one of claims 2 to 11, wherein the synchronous motor driving device according to any one of claims 2 to 11, characterized in that the fusing current is caused to flow from the DC power supply means (81) to the first fuse (83). A negative-side short-circuit fault determination that determines whether or not a short-circuit fault has occurred in the negative-side bus-side switching elements (U2, V2, W2) connected to the negative-side bus (31) among the plurality of switching elements. With means,
When the failure determination means determines that at least one of the short-circuit failure of the negative-side bus-side switching element (U2, V2, W2) and the ground fault of the stator coil (15) has occurred, The fusing current control means (S210) energizes the negative-side bus-side switching elements (U2, V2, W2) determined by the negative-side short-circuit fault judging means that the short-circuit fault has not occurred, thereby causing the DC power source to operate. The synchronous motor driving device according to any one of claims 2 to 11, wherein the fusing current flows from the means (81) to the first fuse (83).   When the failure determination means determines that at least one of the short-circuit failure of the negative-side bus-side switching element (U2, V2, W2) and the ground fault of the stator coil (15) has occurred, Switching control means (S200) is provided for stopping all the positive-side bus-side switching elements (U1, V1, W1) among the plurality of switching elements (U1, V1, W1, U2, V2, W2). The synchronous motor drive device according to any one of claims 2 to 13, wherein the drive device is a synchronous motor. Positive-side short-circuit fault determination means (S117a) for determining whether or not a short-circuit fault has occurred in the positive-side bus-side switching element (U1, V1, W1) connected to the positive-side bus (32);
When the positive-side short-circuit fault determination means (S117a) determines that a short-circuit fault has occurred in the positive-side bus-side switching element (U1, V1, W1), the negative-side bus-side switching element (U2, V2, A switching control means (S210) for energizing all of the positive-side bus-side switching elements (U1, V1, W1) after stopping all of W2);
The drive device for a synchronous motor according to any one of claims 2 to 11, further comprising: Positive-side short-circuit fault determination for determining whether a short-circuit fault has occurred in the positive-side bus-side switching elements (U1, V1, W1) connected to the positive-side bus (32) among the plurality of switching elements. Means (S117a);
When the positive-side short-circuit fault determination means (S117a) determines that a short-circuit fault has occurred in the positive-side bus-side switching element (U1, V1, W1), the negative-side bus-side switching element (U2, V2, Switching control for energizing the positive-side bus-side switching elements (U1, V1, W1) determined by the positive-side short-circuit failure determination means (S117a) that the short-circuit failure has not occurred after stopping all of W2) Means (S240);
The drive device for a synchronous motor according to any one of claims 2 to 11, further comprising: The DC power source means (81) is disposed between the positive side bus (32) and the neutral point (15x) of the stator coil (15),
2. The synchronous motor drive device according to claim 1, wherein the capacitor is disposed between the positive-side bus and the negative-side bus. The DC power source means (81) is disposed between the positive side bus (32) and the neutral point (15x) of the stator coil (15),
The synchronous motor according to claim 1, wherein the capacitor (40) is disposed between the negative bus (31) and a neutral point (15x) of the stator coil (15). Drive device.   The synchronous motor drive according to claim 17 or 18, wherein the first fuse (83) is arranged between the DC power supply means (81) and the positive-side bus (32). apparatus. A second fuse (85) connected in series with the first fuse (83) is provided between the DC power source means (81) and the positive-side bus (32).
The second fuse (85) is set so that the second fuse (85) is blown when a current of a second threshold value or more flows through the second fuse (85);
The first fuse (83) is set so that the first fuse (83) is blown when a current greater than or equal to a first threshold flows through the first fuse (83).
Of the first and second fuses (83, 85), when one of the bus-side switching elements connected to the DC power source means (81) is energized by the fusing current control means (S210). 20. The synchronous motor drive device according to claim 19, wherein the first and second threshold values are set so that only one fuse is blown.   When the one bus side switching element connected to the DC power source means (81) is energized by the fusing current control means (S210), only the second fuse (85) as the one fuse is used. 21. The synchronous motor drive device according to claim 20, wherein the second threshold value is set to a value smaller than the first threshold value so as to melt. A second fuse (85) connected in series with the first fuse (83) is provided between the DC power source means (81) and the positive-side bus (32).
The first fuse (83) is set to blow when a current flows through the first fuse (83) to reach a first melting temperature or higher,
The second fuse (85) is set so that the second fuse (85) is blown when a current flows through the second fuse (85) and becomes equal to or higher than a second blowing temperature,
When one bus-side switching element connected to the DC power supply means (81) is energized by the fusing current control means (S210), one of the first and second fuses (85) is operated. The synchronous motor driving device according to claim 19, wherein the first and second fusing temperatures are set so that only the fuse is blown.   When the one bus side switching element connected to the DC power source means (81) is energized by the fusing current control means (S210), only the second fuse (85) as the one fuse is used. 23. The synchronous motor drive device according to claim 22, wherein the second fusing temperature is set to a temperature lower than the first fusing temperature so as to melt. The short circuit failure of one bus side switching element connected to the DC power source means (81) is a short circuit fault of the positive side bus side switching element (U1, V1, W1),
Current detection means (50) for detecting current flowing from the DC power supply means (81) to the positive-side bus (32);
The failure determination means determines whether the detected value of the current detection means (50) is equal to or greater than a predetermined value, thereby causing a short-circuit failure of the positive-side bus-side switching element (U1, V1, W1) and the 24. The drive device for a synchronous motor according to claim 17, wherein it is determined whether or not at least one of the ground faults of the stator coil (15) has occurred. The short circuit failure of one bus side switching element connected to the DC power source means (81) is a short circuit fault of the positive side bus side switching element (U1, V1, W1),
Current detection means (50) for detecting current flowing from the neutral point (15x) of the stator coil (15) to the DC power supply means (81);
The failure determination means determines whether or not a ground fault has occurred in the stator coil (15) by determining whether or not the detection value of the current detection means (50) is less than a predetermined value, By determining whether or not the detection value of the current detection means (50) is greater than or equal to a predetermined value, it is determined whether or not a short-circuit fault has occurred in the positive-side bus-side switching element (U1, V1, W1). 24. The synchronous motor drive device according to claim 17, wherein the drive device is a synchronous motor.   When the failure determination means determines that at least one of the short-circuit failure of the positive-side bus-side switching element (U1, V1, W1) and the ground fault of the stator coil (15) has occurred, The fusing current control means (S210) energizes all of the positive side bus side switching elements (U1, V1, W1) among the plurality of switching elements (U1, V1, W1, U2, V2, W2). 26. The synchronous motor driving device according to claim 17, wherein the driving device is operated so that the fusing current flows from the DC power supply means (81) to the first fuse (83). A positive-side short-circuit fault determining means for determining whether a short-circuit fault has occurred in the positive-side bus-side switching element (U1, V1, W1);
The positive-side short-circuit fault determination means determines that at least one of the short-circuit fault of the positive-side bus-side switching element (U1, V1, W1) and the ground fault of the stator coil (15) has occurred. The fusing current control means (S210) energizes the positive-side bus-side switching elements (U1, V1, W1) determined by the positive-side short-circuit fault determination means that the short-circuit fault has not occurred. 26. The driving apparatus for a synchronous motor according to claim 17, wherein the fusing current is passed from the DC power supply means (81) to the first fuse (83).   When the failure determination means determines that at least one of the short-circuit failure of the positive-side bus-side switching element (U1, V1, W1) and the ground fault of the stator coil (15) has occurred, Switching control means for stopping all of the negative-side bus-side switching elements (U2, V2, W2) among the plurality of the switching elements (U1, V1, W1, U2, V2, W2) is provided. 26. The driving device for a synchronous motor according to claim 17, wherein: A negative-side short-circuit fault determination that determines whether or not a short-circuit fault has occurred in the negative-side bus-side switching elements (U2, V2, W2) connected to the negative-side bus (31) among the plurality of switching elements. Means (S117a);
When the negative-side short-circuit fault determination means (S117a) determines that a short-circuit fault has occurred in the negative-side bus-side switching element (U2, V2, W2), the positive-side bus-side switching element (U1, V1, Switching control means (S210) for energizing all of the negative-side bus-side switching elements (U2, V2, W2) after turning off all of W1);
The drive device for a synchronous motor according to any one of claims 17 to 25, comprising: Of the plurality of switching elements, a negative-side short-circuit fault determination is performed to determine whether or not a short-circuit fault has occurred in the negative-side bus-side switching elements (U2, V2, W2) connected to the negative-side bus (31). Means,
When the negative-side short-circuit fault determining means determines that a short-circuit fault has occurred in the negative-side bus-side switching element (U2, V2, W2), the positive-side bus-side switching element (U1, V1, W1) Switching control means (S210) for energizing only the negative-side bus-side switching elements (U2, V2, W2) determined by the negative-side short-circuit fault determination means that the short-circuit fault has not occurred after all of them are turned off; ,
The drive device for a synchronous motor according to any one of claims 17 to 25, comprising: The inverter circuit control means (73) outputs a control signal to the plurality of switching elements (U1, V1, W1, U2, V2, W2) and outputs the plurality of switching elements (U1, V1, W1, U2). , V2, W2) for switching operation,
For each switching element, a current flowing between the neutral point (15x) of the stator coil (15) and the negative-side bus-side switching element (U2, V2, W2) and flowing to the negative-side bus (31) is supplied to each switching element. Comprising first current detecting means (50a, 50b, 50c) for detecting,
The inverter circuit control means (73) outputs the control signal for stopping energization of the negative side bus side switching elements (U2, V2, W2) to the negative side bus side switching elements (U2, V2, W2). Sometimes, when the detected value of the first current detecting means (50a, 50b, 50c) is less than a predetermined value, the short circuit failure occurs in the negative side bus side switching element (U2, V2, W2). The synchronous motor drive device according to claim 13 or 30, wherein the negative-side short-circuit fault determination means determines that the negative-side short-circuit failure is not present. A current flowing through the neutral point (15x) of the stator coil (15) through the positive side bus (32) and the positive side bus switching element (U1, V1, W1) is detected for each switching element. Second current detection means (51a, 51b, 51c),
The inverter circuit control means (73) outputs the control signal for stopping energization of the positive-side bus-side switching elements (U1, V1, W1) to the positive-side bus-side switching elements (U1, V1, W1). Sometimes, when the detection value of the second current detection means (51a, 51b, 51c) is less than a predetermined value, the short-circuit failure occurs in the positive-side bus-side switching element (U1, V1, W1). The synchronous motor drive device according to claim 16 or 27, wherein the positive-side short-circuit fault judging means judges that the motor is not present. Between one of the positive side bus (32) and the negative side bus (31) to which the DC power supply means (81) is connected and the neutral point (15x) of the stator coil (15). A third fuse (86a, 86b, 86c) connected in series to the one bus-side switching element,
The third fuse (86a, 86b, 86c) is set to be blown when a current of a third threshold value or more flows through the third fuse,
The first fuse (83) is set so that the first fuse (83) is blown when a current greater than or equal to a first threshold flows through the first fuse (83).
When the one bus-side switching element connected to the DC power supply means (81) is energized by the fusing current control means (S210), the first and third fuses (83, 86a, 86b, The drive device for a synchronous motor according to claim 4 or 19, wherein the first and third threshold values are set so that only one fuse of 86c) is blown.   When the one bus-side switching element connected to the DC power supply means (81) is energized by the fusing current control means (S210), the third fuse (86a, 86b) as the one fuse is operated. 34. The synchronous motor drive device according to claim 33, wherein the third threshold value is set to be smaller than the first threshold value so that only 86c) is fused. Between one of the positive side bus (32) and the negative side bus (31) to which the DC power supply means (81) is connected and the neutral point (15x) of the stator coil (15). A third fuse (86a, 86b, 86c) connected in series to the one bus-side switching element,
The third fuse (86a, 86b, 86c) is set to be blown when a current flows through the third fuse and exceeds a third blowing temperature,
The first fuse (83) is set to blow when a current flows through the first fuse (83) to reach a first melting temperature or higher,
When the one bus-side switching element connected to the DC power supply means (81) is energized by the fusing current control means (S210), the first and third fuses (83, 86a, 86b, The driving apparatus for a synchronous motor according to claim 4 or 19, wherein the first and third fusing temperatures are set so that only one fuse of 86c) is blown.   When the one bus-side switching element connected to the DC power supply means (81) is energized by the fusing current control means (S210), the third fuse (86a, 86b) as the one fuse is operated. 36. The synchronous motor drive device according to claim 35, wherein the third fusing temperature is set to a temperature lower than the first fusing temperature so that only 86c) is fused. A fourth fuse (87b) connected to the negative side bus (31),
The fourth fuse (87b) is set such that the fourth fuse is blown when a current of a fourth threshold value or more flows.
The first fuse (83) is set so that the first fuse (83) is blown when a current greater than or equal to a first threshold flows through the first fuse (83).
Of the first and fourth fuses (83, 87b), when the fusing current control means (S210) energizes one bus side switching element connected to the DC power supply means (81). The synchronous motor drive device according to claim 4 or 19, wherein the first and fourth threshold values are set so that only one fuse is blown.   When the one bus side switching element connected to the DC power source means (81) is energized by the fusing current control means (S210), only the fourth fuse (87b) as the one fuse is operated. 38. The synchronous motor drive device according to claim 37, wherein the fourth threshold value is set to a threshold value smaller than the first fusing temperature so as to melt. First voltage detecting means (90) for detecting a voltage between the positive electrode and the negative electrode of the capacitor (40);
The failure determination means (S113) determines whether or not the detection value of the first voltage detection means is less than a predetermined value, whereby a short-circuit failure of the one bus-side switching element and the stator coil (15 39) The synchronous motor drive device according to any one of claims 1 to 38, wherein it is determined whether or not at least one of the ground faults has occurred. First voltage detection means (90) for detecting a voltage between the positive electrode and the negative electrode of the capacitor (40);
Second voltage detection means (91) for detecting a voltage between the positive electrode and the negative electrode of the DC power supply means (81),
The failure determination means determines whether the absolute value of the difference between the detection value of the first voltage detection means (90) and the detection value of the second voltage detection means (91) is less than a predetermined value. Determining whether or not at least one of the short-circuit failure of the one bus-side switching element and the ground fault of the stator coil (15) has occurred. The drive device for a synchronous motor according to any one of 1 to 38. Temperature detecting means (51) for detecting the temperature of the stator coil (15);
The failure determination means (S114) determines whether the detected value of the temperature detection means (51) is equal to or higher than a predetermined temperature, whereby a short-circuit failure of the one bus side switching element and the stator coil (15 39) The synchronous motor drive device according to any one of claims 1 to 38, wherein it is determined whether or not at least one of the ground faults has occurred.

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