JP3734122B2 - Three-phase inverter circuit module - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a three-phase inverter circuit module for controlling a traveling motor of an electric vehicle, for example, and more particularly to a three-phase inverter circuit module for driving and controlling a traveling motor of a hybrid electric vehicle.
[0002]
[Prior art]
Since the three-phase inverter device can recover the rotational energy of the load as electric power to the DC power source side by regenerative operation during braking, it is widely used for motor drive control for driving a traveling motor of an electric vehicle.
A conventional three-phase inverter device used for driving motor control of a hybrid electric vehicle will be described with reference to FIG.
[0003]
Reference numeral 1 is a main battery, 3 is a current detection circuit module, 4 is a three-phase inverter circuit module, and 5 is a running motor.
In the three-phase inverter circuit module 4, 19 to 24 are IGBTs, 19, 21, and 23 are high-side switches, and 20, 22, and 24 are low-side switches. The high-side switch 19 and the low-side switch 20 connected in series constitute the first phase switch circuit 4a, and the high-side switch 21 and the low-side switch 22 connected in series constitute the second phase switch circuit 4b. The high-side switch 23 and the low-side switch 24 connected in series to each other constitute a third phase switch circuit 4c, and each phase switch circuit 4a to 4c is supplied with power from the main battery 1. Reference numerals 25 to 30 denote flywheel diodes individually connected in parallel with the IGBTs 19 to 24, for supplying a return current to the traveling motor 5 which is a three-phase AC motor which is an inductive load.
[0004]
An output end of the first phase switch circuit 4a which is a connection point of the high side switch 19 and the low side switch 20, an output end 4b of the second phase switch circuit which is a connection point of the high side switch 21 and the low side switch 22, and The output terminal of the third phase switch circuit 4c, which is a connection point between the high side switch 23 and the low side switch 24, is connected to each phase terminal of the traveling motor 5 through the bus bars 41 to 43 and the insulation coating cables 44 to 46. Connected individually.
[0005]
Reference numeral 40 denotes a microcomputer-structured control circuit built in the three-phase inverter circuit module 4, which is based on a detected motor current from a current detection circuit module 3 described later, a command signal from an external controller, or the like. The IGBTs 19 to 24 are intermittently controlled to generate a three-phase AC voltage. Since the operation of the controller 40 is well known, description thereof is omitted.
[0006]
The current detection circuit module 3 includes a current detection unit 31 that detects a U-phase current, a current detection unit 32 that detects a W-phase current, and a current detected by the current detection units 31 and 32, It comprises a peripheral circuit unit 33 that feeds power to the detection units 31 and 32.
Reactor 34 and smoothing capacitor 35 constitute a well-known smoothing circuit, and average the power supply current from main battery 1 to three-phase inverter circuit module 4 to suppress the shortening of the life of the main battery.
[0007]
[Problems to be solved by the invention]
However, it has been found that the conventional three-phase inverter device for driving the above-described traveling motor of the hybrid electric vehicle has the following problems requiring improvement.
That is, in a hybrid electric vehicle, a large electromagnetic noise source such as an engine or a star motor exists in the vicinity of the three-phase inverter device. Therefore, the reliability of driving motor control is attributed to external noise such as electromagnetic noise. There was a possibility that the performance would decrease. Since the operation of the traveling motor is more than the basis of vehicle operation, it is necessary to sufficiently secure the anti-electromagnetic noise performance of the three-phase inverter device that drives and controls the traveling motor. In particular, the hybrid electric vehicle needs to be able to exhibit excellent driving motor control performance even in a high electromagnetic noise environment.
[0008]
Based on the above recognition, the present inventors have analyzed the malfunction and cause of a three-phase inverter device for driving motor drive control in a high electromagnetic noise environment such as a hybrid electric vehicle. The following problems exist. I understood it.
That is, in the conventional three-phase inverter device, the output current is detected by a Hall element capable of detecting with high accuracy, but the voltage change of the Hall element is extremely small. Therefore, the weak output voltage output from the Hall element is greatly amplified by the bridge circuit configuration or the like and transmitted to the controller 40.
[0009]
For this reason, electromagnetic wave noise is superimposed on the output signal line 47 that sends the signal voltage from the Hall element to the peripheral circuit unit 33 for amplification, and the output signal line 48 that sends the signal voltage from the peripheral circuit unit 33 to the controller 40. It has been found that there is a problem that the SN ratio of the detected output current value is lowered and the control accuracy of the traveling motor 5 is lowered.
The present invention has been made in view of the above problems, and an object thereof is to realize a three-phase inverter circuit module capable of high-precision motor control even in a high electromagnetic noise environment.
[0010]
[Means for Solving the Problems]
The three-phase inverter circuit module according to claim 1 is a three-phase inverter circuit in which three sets of phase inverter circuits each configured by connecting a high-side switch and a low-side switch in series are parallel to each other to supply power to the motor; A control circuit for intermittently controlling the three-phase inverter circuit based on an output current of the phase inverter circuit, an output conductor extending from a connection point of the high-side switch and the low-side switch, and fitted to the output conductor to Magnetic core for inducing magnetic field due to current of output conductor, semiconductor current detection element for detecting current of output conductor by magnetic field of said magnetic core, and sensor signal amplification circuit for amplifying output signal voltage of said semiconductor current detection element And an inverter circuit board on which the three-phase inverter circuit is mounted, the control circuit, a magnetic core, And a control circuit board on which the current detecting element and a sensor signal amplifier circuit is mounted.
[0011]
Particularly in the present invention, the output conductor extends in parallel with the control circuit board from the inverter circuit board through the vicinity of the semiconductor current detection element of the control circuit board.
In this way, the magnetic field of the magnetic core with a gap due to the current of the output conductor immediately above is detected by the semiconductor current detection element mounted on the core control circuit board, and the signal voltage output from the semiconductor current detection element is the same for control. An analog voltage is amplified by a sensor signal amplifier circuit mounted on a circuit board, and this amplified signal voltage is A / D converted by a control circuit and sent to the control circuit.
[0012]
In this way, the signal line such as an analog signal line from the semiconductor current detecting element to the control circuit, for example, the A / D converter can be significantly shortened, so that the electromagnetic wave noise superimposed thereon can be reduced. The motor can be driven and controlled stably even in a highly accurate high electromagnetic noise environment .
[0013]
According to the second aspect of the present invention, in the three-phase inverter circuit module according to the first aspect, the control circuit board and the inverter circuit board are arranged in parallel with a predetermined gap in parallel to the main surface, and the output conductor Is drawn to the outside in parallel with the control circuit board through this gap, the magnetic core is fixed to one of the boards, and the semiconductor current detection element is erected from the control circuit board into the gap of the magnetic core.
[0014]
In this way, the module can be made compact without hindering the high electromagnetic noise performance described above.
According to the third aspect of the present invention, the three-phase inverter circuit module according to the first or second aspect is used to drive and control a traveling motor of a hybrid electric vehicle. That is, it is mounted on a hybrid electric vehicle together with an engine (ignition internal combustion engine).
[0015]
In this way, it is possible to prevent the traveling motor from malfunctioning due to electromagnetic noise generated from the ignition type internal combustion engine, and to further stabilize the traveling control of the noise source vehicle without adding an electromagnetic shielding that is complicated and increases the weight of the vehicle body. Can be
In particular, a traveling motor of a hybrid electric vehicle is operated at a much higher frequency than a conventional commercial frequency motor when traveling at a high speed. For this reason, the three-phase inverter circuit needs to be controlled intermittently at a very high speed. The relatively high frequency component of the signal voltage output from the detection element must also be used as the signal component. For this reason, the band of the signal voltage output from the semiconductor current detection element is wide, and the noise power is correspondingly increased. Furthermore, since electromagnetic noise becomes stronger as the frequency becomes higher, the influence is further increased.
[0016]
According to the configuration of claim 4, in the three-phase inverter circuit module according to claim 2 or 3, the outer surface side of the inverter circuit board on which the three-phase inverter circuit is mounted is a metal cooling block. To be electrically insulated. That is, the three-phase inverter circuit is cooled by joining to a metal cooling block for heat dissipation and heat sinking.
[0017]
In this case, as a result, the wiring from the semiconductor current detection element on the control circuit board to the control circuit is shielded by the cooling block via the inverter circuit board. Electromagnetic noise performance can be improved.
According to the fifth aspect of the present invention, in the three-phase inverter circuit module according to the fourth aspect, the pair of inverter circuit boards and control circuit boards facing each other are provided in the cooling block and the metal tank. Sandwiched by a smoothing capacitor.
[0018]
As a result, the wiring from the semiconductor current detection element on the control circuit board to the control circuit is shielded by electromagnetic waves by both the cooling block and the smoothing capacitor circuit. Can be improved.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
As the high-side switch and low-side switch of the three-phase inverter circuit, MOS, bipolar, SIT, IGBT or the like can be adopted.
The three-phase inverter circuit may have a fourth phase inverter circuit for controlling the neutral current of the star connection motor.
[0020]
【Example】
A circuit of a hybrid electric vehicle using the three-phase inverter circuit module of the present invention is shown in FIG. However, for the sake of easy understanding, the same reference numerals are assigned to components having the same main functions as those of the conventional three-phase inverter device shown in FIG.
Since this three-phase inverter circuit module is a slight modification of the conventional three-phase inverter device shown in FIG. 8, only the changes will be described below.
[0021]
In this embodiment, the current detection circuit module 3 shown in FIG. 8 is omitted, and a current detection circuit 300 is mounted in the three-phase inverter circuit module 4 instead. Reference numerals 41 to 43 denote bus bars constituting the output conductors in the present invention.
The current detection circuit 300 is detected by a current detection unit 301 that detects a U-phase current flowing through the bus bar 41, a current detection unit 302 that detects a W-phase current flowing through the bus bar 43, and current detection units 301 and 302. The peripheral circuit section 303 (including the sensor signal amplifier circuit referred to in the present invention) 303 amplifies the received current and supplies power to the current detection sections 301 and 302. The peripheral circuit section 303 is described later together with the control circuit 40. Mounted on a control circuit board.
[0022]
The principle configuration of the current detection circuit 300 will be described with reference to FIG.
A magnetic core 3011 having a gap is fitted to the bus bar 41, and a Hall element (semiconductor current detecting element in the present invention) 3012 is interposed in the gap of the magnetic core 3011. The output end is amplified by an amplifier 3030 that forms part of the peripheral circuit unit 303. That is, the magnetic core 3011 and the Hall element 3012 constitute a current detection unit 301. Since the configuration of the current detection unit 302 is the same as that of the current detection unit 301, description thereof is omitted.
[0023]
A schematic perspective view of the three-phase inverter circuit module is shown in FIG. The aluminum cooling block 6 has a substantially rectangular shape with an open top and a shallow bottom box, and an inverter circuit board, which will be described later, is disposed on the bottom plate portion so as to be electrically insulated. Three windows 62 to 64 are opened in the side wall 61 in front of the cooling block 6, and bus bars 41 to 43 that form output conductors project individually and parallel to the bottom plate portion from these windows 62 to 64. Three magnetic cores 3011 made of ferrite are individually fitted and bonded to the windows 62 to 64, and the bus bars 41 to 43 individually penetrate the magnetic cores 3011 and project horizontally, and their tips are formed in the three windows. The AC output terminal of the phase inverter circuit module is configured.
[0024]
The upper end opening of the cooling block 6 is sealed with a control circuit board 7 parallel to the bottom plate portion of the cooling block 6, and both are fixed with screws, and necessary elements and ICs are mounted on both sides of the control circuit board 7. Wired.
Reference numeral 8 denotes a total of three positive DC input terminals for supplying power to each phase inverter circuit, and is connected to the + terminal of the main battery 1 through a bus bar (not shown). Reference numeral 9 denotes a total of three negative DC input terminals for supplying power to each phase inverter circuit, and is connected to the terminal of the main battery 1 through a bus bar (not shown). Reference numeral 10 denotes a connector for connection with an external ECU (not shown). Reference numeral 3016 denotes a protective resin member covering the Hall element 3012.
[0025]
A longitudinal sectional view of this three-phase inverter circuit module is shown in FIG. The inverter circuit board 1 is joined to the bottom surface of the aluminum cooling block 6 so as to be electrically insulated. The inverter circuit board 11 is connected to the three-phase inverter circuit 4, that is, the IGBTs 19 to 24 and the diodes 25 to 25. 30 is mounted and wired, and bus bars 41 to 43 are provided along the gap between the inverter circuit board 11 and the control circuit board 7 from the output ends of the respective inverter circuits 4a to 4c. It extends in parallel with both.
[0026]
An overall perspective view of the three-phase inverter circuit module is shown in FIG. A smoothing capacitor 35 is fixed on the upper surface of the side wall of the cooling block 6 with a sleeve 12 for securing a gap interposed therebetween.
The smoothing capacitor 35 is made of an aluminum case that houses three or more small cylindrical capacitors (not shown) arranged in a row. The smoothing capacitor 35 shields the control circuit board 7 and protects the control circuit board. The electromagnetic shielding is performed.
[0027]
Therefore, in this embodiment, the traveling motor 5 from the Hall element 3012 and the Hall element 3012 to the control circuit 40 is constituted by the cooling block 6 for cooling the three-phase inverter circuit 4 and the flat smoothing capacitor 35 for protecting the main battery. Since the surroundings of the detection current signal voltage transmission wiring are electromagnetically shielded, accurate driving motor control can be realized even in a high electromagnetic noise environment such as close to an ignition engine.
[0028]
Although the three-phase inverter circuit module shown in FIG. 4 is finally housed in a resin case and fastened and fixed to a vehicle, it is not related to the gist of the present invention, and therefore the illustration and description thereof will be omitted.
In FIG. 1, the pair of current detection units 301 and 302 is used. However, if each phase current is detected by three current detection units as shown in FIG. 4, there is an advantage that a leak current can be detected.
(Modification)
A modification of this embodiment will be described with reference to FIGS.
[0029]
In this modification, the configuration of the current detection units 301 to 303 is changed, and a magnetic flux canceling type (magnetic balance type) current sensor is used.
The principle of the magnetic flux canceling type current sensor 300a is shown in FIG.
A magnetic core 3011 having a gap is fitted to the bus bar 41, and a Hall element (semiconductor current detection element in the present invention) 3012 is interposed in the gap of the magnetic core 3011. The compensation coil 3016 is wound around its entire circumference.
[0030]
A magnetic flux generated in the magnetic core 3011 is detected by the Hall element 3012, a canceling current is generated by the magnetic balance circuit 3031 included in the peripheral circuit unit 303, and this canceling current is passed through the compensation coil 3016 to cause the Hall element 3012. The detected magnetic field is detected with the canceling current value at this time.
According to this modification, since the wiring between the Hall element 3012 and the compensation coil 3016 and the peripheral circuit unit 303 is increased, the problem due to the superposition of electromagnetic wave noise becomes more important. The effect of improving the noise-resistant environment due to the structure of the circuit module becomes more effective.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing an embodiment of a travel motor control device for a hybrid electric vehicle employing a three-phase inverter circuit module of the present invention.
FIG. 2 is a schematic perspective view of the three-phase inverter circuit module shown in FIG.
FIG. 3 is a longitudinal sectional view of the three-phase inverter module 1 shown in FIG. 2;
4 is a schematic perspective view with a smoothing capacitor of the three-phase inverter circuit module shown in FIG. 1; FIG.
FIG. 5 is a schematic perspective view showing a modification of the three-phase inverter circuit module shown in FIG.
6 is a schematic circuit diagram of a current detection unit 301. FIG.
7 is a schematic circuit diagram showing a modification of the current detection unit 301. FIG.
FIG. 8 is a circuit diagram showing a traveling motor control device of a hybrid electric vehicle employing a conventional three-phase inverter circuit module.
[Explanation of symbols]
19, 21 and 23 are high side switches,
20, 22 and 24 are low side switches,
4a, 4b, 4c are phase inverter circuits,
4 is a three-phase inverter circuit,
5 is a running motor (motor),
40 is a control circuit,
40 to 43 are bus bars (output conductors),
3011 is a magnetic core,
Reference numeral 3012 denotes a Hall element (semiconductor current detection element),
303 is a sensor signal amplifier circuit;
7 is a control circuit board,
11 is an inverter circuit board;
6 is a metal cooling block,
35 is a smoothing capacitor.

Claims (5)

A three-phase inverter circuit in which a high-side switch and a low-side switch are connected in series and each of three sets of phase inverter circuits configured in parallel with each other supplies power to the motor;
A control circuit for intermittently controlling the three-phase inverter circuit based on an output current of the three-phase inverter circuit;
An output conductor extending from a connection point of the high-side switch and the low-side switch;
A magnetic core that is fitted to the output conductor to induce a magnetic field due to the current of the output conductor;
A semiconductor current detecting element for detecting a current of the output conductor by a magnetic field of the magnetic core;
A sensor signal amplification circuit for amplifying an output signal voltage of the semiconductor current detection element;
An inverter circuit board on which the three-phase inverter circuit is mounted;
A control circuit board on which the control circuit, magnetic core, semiconductor current detection element and sensor signal amplification circuit are mounted;
In a three-phase inverter circuit module comprising:
The three-phase inverter circuit, wherein the output conductor extends from the inverter circuit board through the vicinity of the semiconductor current detection element of the control circuit board in parallel with the control circuit board. module. The control circuit board and the inverter circuit board are coupled to each other in a state where the main surfaces are parallel to each other with a predetermined gap therebetween,
The output conductor is drawn out from the inverter circuit board to the outside in parallel with the board through the gap.
The magnetic core has a U-shape with a gap and is directly or indirectly held on the control circuit board or the inverter circuit board in a state of being fitted to the output conductor,
It said semiconductor current detecting element, the three-phase inverter circuit module according to claim 1 Symbol mounting, characterized in that it is erected from said control circuit board is located in the gap of the magnetic core.   3. The three-phase inverter circuit module according to claim 1, wherein the driving motor of the hybrid electric vehicle is driven and controlled.   4. The three-phase inverter according to claim 2, wherein an outer surface side of the inverter circuit board on which the three-phase inverter circuit is mounted is joined to a metal cooling block so as to be electrically insulated. Circuit module.   A smoothing capacitor connected between a pair of DC input terminals of the three-phase inverter circuit, and the smoothing capacitor is directly or indirectly supported by the board in the vicinity of the outer surface side of the control circuit board; The three-phase inverter circuit module according to claim 4.

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