JP4703018B2 - Power output apparatus and control method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power output apparatus and a control method thereof.
[0002]
[Prior art]
Conventional power output devices include a capacitor connected to the positive and negative buses of the inverter circuit that supplies three-phase alternating current to the motor, and a positive or negative bus of the inverter circuit and the neutral point of the motor. There have been proposed ones having a direct current power source (for example, Japanese Patent Laid-Open Nos. 10-337047 and 11-178114). In this apparatus, a circuit composed of a three-phase coil of an electric motor and a switching element of an inverter circuit is caused to function as a boost chopper circuit that boosts a voltage from a DC power source and stores it in a capacitor, and the stored capacitor functions as a DC power source. Drive the motor. At this time, the storage control to the capacitor is performed by switching control of the switching element of the inverter circuit.
[0003]
In such a power output device, the voltage between the terminals of the capacitor, that is, the potential difference acting between the positive and negative buses of the inverter circuit decreases with the power consumption by the motor, so that stable drive control of the motor can be achieved. Therefore, it is necessary to control the voltage between the terminals of the capacitor. As a method for controlling the voltage between the terminals of the capacitor, a method of performing feedback control based on a difference between the voltage between the terminals of the capacitor detected by the voltage sensor and the voltage between the target terminals of the capacitor can be considered.
[0004]
[Problems to be solved by the invention]
However, in a power output device that adjusts the voltage between terminals of a capacitor by feedback control, depending on the processing capacity of the control device provided in the device, the power output device diverges without being able to follow the change in the voltage between terminals of the capacitor due to a sudden change in load. In some cases, the potential difference acting between the positive and negative buses of the inverter circuit cannot be maintained in a stable state.
[0005]
An object of the power output apparatus and the control method thereof of the present invention is to stably maintain a potential difference acting between a positive electrode bus and a negative electrode bus of an inverter circuit even when a load fluctuates rapidly.
[0006]
[Means for solving the problems and their functions and effects]
The power output apparatus and the control method thereof according to the present invention employ the following means in order to achieve the above-described object.
[0007]
  A first power output device of the present invention includes an electric motor that is rotationally driven by polyphase AC, an inverter circuit that can supply polyphase AC power to the electric motor by switching of a plurality of switching elements, and a positive bus of the inverter circuit, A first power source capable of storing electricity connected to a negative electrode bus; a second power source connected to one of the positive and negative buses of the inverter circuit and a neutral point of the motor; and Power according to the required outputAnd offset the polyphase AC power based on the difference between the neutral point current command value obtained from the terminal voltage of the second power supply and the read neutral point current, and from the second power supply, the While supplying to the electric motorSupply to the first power sourceDoLike,And a control means for switching control of the switching element of the inverter circuit.
[0008]
In the first power output device of the present invention, the control means performs switching control of the switching element of the inverter circuit so that the electric power according to the output required for the electric motor is supplied from the second power source to the first power source. The voltage between the terminals of the first power source, that is, the potential difference between the positive and negative buses of the inverter circuit can be stably maintained without being diverged even when the load fluctuates rapidly. Here, the “output required for the electric motor” includes both a positive output and a negative output.
[0009]
  A second power output device of the present invention includes an electric motor that is rotationally driven by polyphase AC, an inverter circuit that can supply polyphase AC power to the electric motor by switching of a plurality of switching elements, a positive bus of the inverter circuit, and A first power source connected to one of the negative buses and a neutral point of the motor; a second power source different from the first bus of the inverter circuit; and a neutral point of the motor A second power source connected to the power source and electric power corresponding to the output required for the motorAnd offset the polyphase AC power based on the difference between the neutral point current command value obtained from the terminal voltage of the second power supply and the read neutral point current, and from the second power supply, the While supplying to the electric motorSupply to the first power sourceDoLike,And a control means for switching control of the switching element of the inverter circuit.
[0010]
In the second power output device of the present invention, the control means performs switching control of the switching element of the inverter circuit so that the electric power according to the output required for the electric motor is supplied from the second power source to the first power source. The voltage between the terminals of the first power source, that is, the potential difference between the positive and negative buses of the inverter circuit can be stably maintained without being diverged even when the load fluctuates rapidly. Here, the “output required for the electric motor” includes both a positive output and a negative output.
[0011]
  In the first and second power output apparatuses of the present invention, the control means includes power corresponding to the output required for the electric motor and the voltage of the second power source.The multiphase AC power is offset based on the difference between the neutral point current command value obtained from the above and the read neutral point current, and supplied from the second power source to the motor.It may be a means for adjusting a current flowing through a neutral point of the electric motor.
[0012]
In the first and second power output apparatuses of the present invention, the output required for the electric motor may be a value obtained by multiplying the torque command of the electric motor by the rotational speed.
[0013]
Furthermore, the first and second power output devices of the present invention further include an electric device that is driven in accordance with charging / discharging of the first power source, and the control means further receives electric power according to a required output of the electric device. Means may be included for controlling the switching element of the inverter circuit to be supplied from the second power source to the first power source.
[0014]
  A third power output device of the present invention includes an electric motor that is rotationally driven by polyphase AC, an inverter circuit that can supply polyphase AC power to the electric motor by switching of a plurality of switching elements, and a positive bus of the inverter circuit; A first power source capable of storing electricity connected to a negative electrode bus; a second power source connected to one of the positive and negative buses of the inverter circuit and a neutral point of the motor;A voltage of the second power source and half of a target voltage of the first power source;The multiphase AC power is offset based on the difference between the second power supply and the electric power from the second power supply to the electric motor, and the first power supply voltage is held at the target voltage by being supplied to the first power supply. And a control means for controlling the switching of the switching element of the inverter circuit.
[0015]
  In the third power output apparatus of the present invention, the control means switches the inverter circuit so that the voltage of the first power supply is held at the target voltage based on the target voltage of the first power supply and the voltage of the second power supply. Since the switching control of the element is performed, it can be generated even when the load fluctuates rapidly compared to the feedback control based on the deviation between the voltage of the first power supply and the target voltage.ScatteredCan be stably maintained at the target voltage.
[0016]
  A fourth power output device of the present invention includes an electric motor that is rotationally driven by polyphase alternating current, an inverter circuit that can supply polyphase alternating current power to the electric motor by switching of a plurality of switching elements, a positive bus of the inverter circuit, and A first power source connected to one of the negative buses and a neutral point of the motor; a second power source different from the first bus of the inverter circuit; and a neutral point of the motor A second power source connected toA voltage of the second power source and half of a target voltage of the first power source;The multiphase AC power is offset based on the difference between the second power supply and the electric power from the second power supply to the electric motor, and the first power supply voltage is held at the target voltage by being supplied to the first power supply. The gist of the invention is that the inverter circuit is provided with a control means for switching control of the switching element.
[0017]
  In the fourth power output apparatus of the present invention, the control means switches the inverter circuit so that the voltage of the first power supply is held at the target voltage based on the target voltage of the first power supply and the voltage of the second power supply. Since the switching control of the element is performed, it can be generated even when the load fluctuates rapidly compared to the feedback control based on the deviation between the voltage of the first power supply and the target voltage.ScatteredCan be stably maintained at the target voltage.
[0018]
  A control method for a first power output apparatus of the present invention includes an electric motor that is rotationally driven by polyphase AC, an inverter circuit that can supply polyphase AC power to the electric motor by switching of a plurality of switching elements, and an inverter circuit A first power source capable of storing electricity connected to the positive and negative buses; a second power source connected to one of the positive and negative buses of the inverter circuit and a neutral point of the motor; A method for controlling a power output device comprising: electric power corresponding to an output required for the electric motorAnd offset the polyphase AC power based on the difference between the neutral point current command value obtained from the terminal voltage of the second power supply and the read neutral point current, and from the second power supply, the While supplying to the electric motorSupply to the first power sourceDoLike,The gist is to perform switching control of the switching element of the inverter circuit.
  Further, in the first and second power output apparatuses of the present invention, the control means further includes the neutral point based on a target voltage of the first power supply and a detected voltage of the first power supply. Means for correcting the current command value may be included. In this way, the voltage between the terminals of the first power source, that is, the potential between the positive and negative buses of the inverter circuit can be held more stably.
[0019]
In the control method for the first power output device of the present invention, the switching element of the inverter circuit is switching-controlled so that the electric power corresponding to the output required for the electric motor is supplied from the second power source to the first power source. It is possible to stably hold the voltage between the terminals of the first power supply, that is, the potential difference between the positive and negative buses of the inverter circuit without divergence even when the fluctuations of the power supply are sudden. Here, the “output required for the electric motor” includes both a positive output and a negative output.
[0020]
The control method of the second power output device of the present invention is:
An electric motor that is rotationally driven by polyphase alternating current;
An inverter circuit capable of supplying multiphase AC power to the electric motor by switching of a plurality of switching elements;
A first power source capable of storing electricity connected to either a positive bus or a negative bus of the inverter circuit and a neutral point of the motor;
A second power source connected to the other bus bar of the inverter circuit different from the one bus bar and to the neutral point of the motor;
A method for controlling a power output device comprising:
The gist of the invention is to perform switching control of the switching element of the inverter circuit so that electric power corresponding to the output required for the electric motor is supplied from the second power source to the first power source.
[0021]
In the control method for the second power output apparatus of the present invention, the switching element of the inverter circuit is switching-controlled so that the electric power corresponding to the output required for the electric motor is supplied from the second power source to the first power source. It is possible to stably hold the voltage between the terminals of the first power supply, that is, the potential difference between the positive and negative buses of the inverter circuit without divergence even when the fluctuations of the power supply are sudden. Here, the “output required for the electric motor” includes both a positive output and a negative output.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described using examples. FIG. 1 is a configuration diagram showing an outline of the configuration of a power output apparatus 20 according to an embodiment of the present invention. As shown in the figure, the power output device 20 of the embodiment includes a motor 22 that is rotationally driven by three-phase AC, an inverter circuit 24 that can convert DC power to three-phase AC power and supply the motor 22, and an inverter circuit 24. A capacitor 30 connected to the positive electrode bus 26 and the negative electrode bus 28, a DC power source 32 connected to the negative electrode bus 28 of the inverter circuit 24 and the neutral point of the motor 22, and an electronic control unit 40 for controlling the entire apparatus. With.
[0023]
The motor 22 is configured, for example, as a PM type synchronous motor generator capable of generating power, which includes a rotor having a permanent magnet attached to an outer surface and a stator around which a three-phase coil is wound. The rotating shaft of the motor 22 is an output shaft of the power output device 20 of the embodiment, and power is output from this rotating shaft. Since the motor 22 is configured as a generator motor, the motor 22 can generate power when power is input to the rotating shaft of the motor 22.
[0024]
The inverter circuit 24 is composed of six transistors T1 to T6 and six diodes D1 to D6. Two transistors T1 to T6 are arranged in pairs so as to be on the source side and the sink side with respect to the positive electrode bus 26 and the negative electrode bus 28 of the inverter circuit 24, and the three-phase coils (u, Each of v, w) is connected.
[0025]
The DC power supply 32 is configured as a chargeable / dischargeable secondary battery such as a nickel metal hydride system or a lithium ion system.
[0026]
The electronic control unit 40 is configured as a microprocessor centered on a CPU 42, and includes a ROM 44 that stores a processing program, a RAM 46 that temporarily stores data, and an input / output port (not shown). The electronic control unit 40 includes the phase currents Iu, Iv, Iw from the current sensors 52 to 56 attached to the respective phases of the three-phase coils (u, v, w) of the motor 22 and the neutral point of the motor 22. The neutral point current Io from the current sensor 58 attached to the motor 30, the rotational angle θ from the rotational angle sensor 60 attached to the rotational shaft of the motor 22, and the terminals of the capacitor 30 from the voltage sensor 62 attached to the capacitor 30. The voltage Vc, the voltage Vb between the terminals of the DC power supply 32 from the voltage sensor 64 attached to the DC power supply 32, the command value related to the operation of the motor 22, and the like are input via the input port. Further, a control signal for performing switching control of the transistors T1 to T6 of the inverter circuit 24 is output from the electronic control unit 40 through an output port.
[0027]
The operation of the power output apparatus 20 of the embodiment thus configured will be described. First, an operation when power is exchanged between the DC power supply 32 and the capacitor 30 by switching the transistors T1 to T6 of the inverter circuit 24 will be described.
[0028]
FIG. 2 is a circuit diagram of the power output apparatus 20 of the embodiment focusing on the u-phase of the three-phase coil of the motor 22. Considering a state where the u-phase transistor T2 of the inverter circuit 24 is turned on, in this state, a short circuit indicated by a wavy arrow in the figure is formed, and the u-phase of the three-phase coil of the motor 22 functions as a reactor. When the transistor T2 is turned off from this state, the energy stored in the u-phase of the three-phase coil functioning as the reactor is stored in the capacitor 30 by the circuit indicated by the solid line arrow in the figure. The voltage at this time can be higher than the supply voltage of the DC power supply 32. On the other hand, the DC power source 32 can be charged using the potential of the capacitor 30 in this circuit. Therefore, this circuit can be regarded as a step-up / down chopper circuit capable of boosting the energy of the DC power supply 32 and storing it in the capacitor 30 and charging the DC power supply 32 using the potential of the capacitor 30. Similarly to the u phase, the vw phase of the three-phase coil of the motor 22 can be regarded as a step-up / step-down chopper circuit. Therefore, the capacitor 30 is charged or stored in the capacitor 30 by turning on and off the transistors T2, T4, and T6. The DC power source 32 can be charged using the electric charge.
[0029]
Since the potential difference generated by charging the capacitor 30 fluctuates in accordance with the amount of charge stored in the capacitor 30, that is, the current flowing through the reactor, the switching control of the transistors T2, T4, and T6 of the inverter circuit 24 is performed and the potential difference flows. The voltage between the terminals of the capacitor 30 can be adjusted by adjusting the current. The drive control of the motor 22 by such a circuit is performed by supplying pseudo three-phase alternating current to the three-phase coil of the motor 22 by switching control of the transistors T1 to T6 of the inverter circuit 24. At this time, if a direct current component is added to the three-phase alternating current, that is, the three-phase alternating current is offset and supplied to the motor 22, the motor 22 can be rotationally driven with the alternating current component and can be stored in the capacitor 30 with the direct current component. . At this time, if the three-phase alternating current is offset and the three-phase alternating current potential (average potential), that is, the neutral point potential V0 of the motor 22 is set to be higher than the potential of the DC power supply 32, the neutral point of the motor 22 is obtained. Then, it is possible to charge the DC power supply 32 using the energy stored in the capacitor 30 when a current flows in the direction of charging the DC power supply 32. On the other hand, if the neutral point potential V0 of the motor 22 in the three-phase alternating current is set to be lower than the potential of the DC power source 32, a current flows in the direction in which the DC power source 32 is discharged at the neutral point of the motor 22, and the DC power source The capacitor 30 can be charged using 32 discharge energies. Note that the neutral point potential V0 of the motor 22 and the potential of the DC power source 32 have the potential of the negative bus 28 of the inverter circuit 24 as a reference potential. Therefore, the current flowing to the neutral point of the motor 22 can be adjusted by switching the transistors T1 to T6 of the inverter circuit 24 to adjust the neutral point potential V0 of the motor 22, and the capacitor 30 is driven while the motor 22 is driven. The terminal voltage Vc can be adjusted.
[0030]
Next, an operation when adjusting the inter-terminal voltage Vc of the capacitor 30 while driving the motor 22 will be described. FIG. 3 is a flowchart showing an example of a capacitor voltage control routine executed by the CPU 42 of the electronic control unit 40. This routine is repeatedly executed every predetermined time.
[0031]
When the capacitor voltage control routine is executed, the CPU 42 of the electronic control unit 40 firstly, the torque command value T * of the motor 22, the rotation angle θ of the rotor of the motor 22 from the rotation angle sensor 60, and the direct current from the voltage sensor 64. The inter-terminal voltage Vb of the power source 32, the phase currents Iu, Iv, Iw from the current sensors 52 to 56, and the neutral point current Io from the current sensor 58 are read (step S100).
[0032]
When each data is read, a process for setting a three-phase alternating current for driving the motor 22 based on the read torque command value T *, each phase current Iu, Iv, Iw, and the rotation angle θ is executed (step). S102). Here, the process of setting the three-phase alternating current is the same process as in the case of the normal motor 22 drive control. For example, the motor 22 is calculated based on the torque command value T * or the rotor rotation angle θ. Voltage commands to be applied to each phase of the motor 22 by proportional-integral control (PI control) based on deviations between the current commands Iu *, Iv *, Iw * of each phase and the read phase currents Iu, Iv, Iw * (three This can be done by setting the amplitude of the phase alternating current).
[0033]
Then, the process which sets the offset amount O for offsetting the set three-phase alternating current is performed (step S104). Here, the offset amount O is an intermediate potential between terminals of the capacitor 30, that is, a neutral point potential V0 (average potential of three-phase alternating current) of the motor 22 with respect to an intermediate potential between the positive bus 26 and the negative bus 28 of the inverter circuit 24. The operation amount is set, and the offset amount O is set by an offset amount setting processing routine illustrated in FIG. Hereinafter, the offset amount O setting process will be described, and then the process after the capacitor voltage control routine will be described.
[0034]
When the offset amount setting process routine is executed, the CPU 42 of the electronic control unit 40 calculates an output required for the motor 22 (step S202). The output P required for the motor 22 is calculated by, for example, multiplying the read torque command value T * by the rotation speed N (θ) of the motor 22 calculated based on the rotation angle θ. Of course, it can be derived from the torque command value T * and the rotational speed N by a map. It should be noted that a negative output (negative torque command value T *), that is, a braking output is similarly calculated as an output required for the motor 22. When the output required for the motor 22 is calculated, a neutral point current command value (flowing from the DC power source 32 to the neutral point of the motor 22 so that electric power corresponding to the output request is stored in the capacitor 30 ( Hereinafter, the neutral point current command Io * is calculated (step S204). The neutral point current command Io * is calculated, for example, by converting the output P required for the motor 22 into power and dividing the inter-terminal voltage Vb of the DC power supply 32 from the output P after power conversion. Thus, when the neutral point current command Io * is calculated, the offset amount O is set based on the difference between the calculated neutral point current command Io * and the read neutral point current Io (step S206). ) End this routine. The offset amount O is, for example, a neutral point current command using the neutral point potential V0 of the motor 22 with respect to the intermediate potential between the terminals of the capacitor 30 (intermediate potential between the positive bus 26 and the negative bus 28 of the inverter circuit 24) as an operation amount. Adjustment can be made by performing proportional integral control (PI control) based on the difference between Io * and neutral point current Io. Note that the reading process of the torque command value T *, the rotation angle θ, the DC power supply terminal voltage Vb, and the neutral point current Io in step S200 has already been read in the process of step S100 of the routine of FIG. Although it is unnecessary in the routine of No. 4, it is described for easy understanding.
[0035]
Returning to the motor drive control routine of FIG. 3, a PWM control signal is set by adding an offset amount O to the three-phase AC applied to the motor 22 (step S106), and the set PWM control signal is output to the inverter circuit 24. (Step S108), and this routine is finished. The setting of the PWM control signal is performed, for example, by offsetting the three-phase alternating current set in step S102 by an offset amount O with respect to the carrier wave (such as a triangular wave).
[0036]
According to the power output apparatus 20 of the embodiment described above, the neutral point potential V0 is manipulated so that power corresponding to the output required for the motor 22 is supplied to the capacitor 30, that is, the three-phase alternating current is offset. Since the inter-terminal voltage Vc of the capacitor 30 is adjusted, the inter-terminal voltage Vc of the capacitor 30, that is, the positive bus of the inverter circuit 24 can be obtained by performing simple arithmetic processing without causing a sudden load fluctuation. 26 and the negative electrode bus 28 can stably hold the potential difference.
[0037]
In the power output apparatus 20 of the embodiment, a value obtained by dividing the output required for the motor 22 by the voltage Vb between the terminals of the DC power supply 32 is set as the neutral point current command Io *. An inter-terminal voltage Vc * is input, and a neutral point current command Io * is added by adding a value calculated by PI control based on the difference between the target inter-terminal voltage Vc * and the capacitor voltage Vc detected by the voltage sensor 62. It is good also as what corrects. In this way, the inter-terminal voltage Vc of the capacitor 30, that is, the potential of the positive electrode bus 26 and the negative electrode bus 28 of the inverter circuit 24 can be held more stably. Here, the target terminal voltage Vc * of the capacitor 30 is set based on the torque command value T * of the motor 22 and the rotation angle θ.
[0038]
In the power output apparatus 20 of the embodiment, the voltage Vc between the terminals of the capacitor 30 is held by supplying power corresponding to the output required for the motor 22 to the capacitor 30. When other electric devices such as other auxiliary machines driven by the electric power of the capacitor 30 and other motors attached via an inverter are provided, the electric power corresponding to the output required for these drivings is also added and the capacitor 30 may be supplied.
[0039]
In the power output apparatus 20 of the embodiment, the current flowing to the neutral point of the motor 22 is adjusted based on the electric power according to the output required for the motor 22 and the voltage Vb between the terminals of the DC power supply 32, that is, three-phase AC. However, the inter-terminal voltage Vc of the capacitor 30 is held at the target inter-terminal voltage Vc * based on the target inter-terminal voltage Vc * of the capacitor 30 and the inter-terminal voltage Vb of the DC power supply 32. As described above, the offset amount O may be set. In this case, the offset amount setting process routine of FIG. 5 is executed instead of the routine of FIG. In the offset amount O setting process, the offset amount O is calculated using the following equation based on the read target terminal voltage Vc * of the capacitor 30 and the terminal voltage Vb of the DC power supply 32 (steps S210 and S212). It is done by.
[0040]
O = Vb−Vc * / 2 (1)
[0041]
FIG. 6 is an explanatory diagram showing the relationship among the potential Vc of the capacitor 30, the potential Vb of the DC power supply 32, and the offset amount O. Note that the potential Vc of the capacitor 30 and the potential Vb of the DC power source 32 are set to the negative potential bus 28 of the inverter circuit 24 as a reference potential. Now, the state in which the average potential Voutave of the voltage command Vout for one phase of the three-phase AC applied to the three-phase coil of the motor 22 matches the potential Vb of the DC power supply 32 (this state is referred to as a steady state). ), That is, when the motor 22 is driven without power transfer to the capacitor 30, the average potential Voutave of the three-phase alternating current is given by the capacitor 30 as shown in FIG. The potential Vc can be expressed by an offset amount O with respect to the intermediate potential Vc / 2 (formula (2)).
[0042]
Voutave = Vb = Vc / 2 + O (2)
[0043]
Therefore, the offset amount O with respect to the three-phase AC when the motor 22 is driven in a steady state can be expressed by the following equation.
[0044]
O = Vb−Vc / 2 (3)
[0045]
Thus, if the motor 22 is driven in a state where the three-phase alternating current is offset using the offset amount O calculated from the equation (3), the power supply to the capacitor 30 is stopped in a steady state. It can be seen that the potential of the capacitor 30 is held at the potential Vc. Therefore, the value calculated by the equation (1) is used as the offset amount O with respect to the intermediate potential Vc / 2 between the positive bus 26 and the negative bus 28 of the inverter circuit 24 when the target terminal voltage Vc * of the capacitor 30 is input. As a result, the voltage between the terminals of the capacitor 30 can be held at the target terminal voltage Vc * when the steady state is reached. The target inter-terminal voltage Vc * of the capacitor 30 is set based on the torque command value T *, the rotation angle θ, or the like, but includes other motors or auxiliary devices that are driven as the capacitor 30 is charged / discharged. Is set in consideration of these output requests.
[0046]
Here, the inter-terminal voltage Vb of the DC power supply 32 is not directly detected using the voltage sensor 64 but based on the inter-terminal voltage Vc of the capacitor 30 detected by the voltage sensor 62. May be estimated. In this case, the inter-terminal voltage Vb of the DC power supply 32 can be calculated from the equation (2) by the offset amount O and the inter-terminal voltage Vc of the capacitor 30, and therefore the value set in the previous routine as the offset amount O. Can be estimated by using. Further, the inter-terminal voltage Vb of the DC power supply 32 may be estimated based on the storage state (SOC) of the DC power supply 32 or the like.
[0047]
In the power output apparatus 20 of the embodiment and its modification, the DC power source 32 is connected to the neutral point of the motor 22 and the negative bus 28 of the inverter circuit 24. However, the DC power source 32 is connected to the neutral point of the motor 22 and the inverter circuit. It may be connected to 24 positive buses 26.
[0048]
In the power output device 20 of the embodiment and its modification, the capacitor 30 is connected to the positive bus 26 and the negative bus 28 of the inverter circuit 24. However, as shown in the power output device 20B illustrated in FIG. 30B may be connected to the neutral point of the motor 22 and the positive bus 26 of the inverter circuit 24. In the power output device 20B of this modification, a DC power source having a sum of a voltage between terminals of the capacitor 30B and a voltage between terminals of the DC power source 32 is connected to the positive bus 26 and the negative bus 28 of the inverter circuit 24. In other words, the capacitor 30 of the power output apparatus 20 according to the embodiment can be regarded as the same configuration as the configuration in which the positive bus 26 and the negative bus 28 of the inverter circuit 24 are connected.
[0049]
FIG. 8 is a circuit diagram of a power output apparatus 20B of a modified example that focuses on the u-phase of the three-phase coil of the motor 22. Considering a state where the transistor T2 is turned on, a short circuit indicated by a wavy arrow in the figure is formed, and the u-phase of the three-phase coil of the motor 22 functions as a reactor. When the transistor T2 is turned off from this state, the energy stored in the u-phase of the three-phase coil functioning as the reactor is stored in the capacitor 30B by the circuit indicated by the solid line arrow in the figure. On the other hand, by turning off the circuit transistor T1 from the on state, the DC power source 32 can be similarly charged using the charge of the capacitor 30B. Therefore, this circuit can be regarded as a chopper circuit capable of storing the energy of the DC power supply 32 in the capacitor 30B and charging the DC power supply 32 using the potential of the capacitor 30B. Similarly to the u phase, the vw phase of the motor 22 can be regarded as a chopper circuit. Therefore, the capacitor 30B is charged by turning on and off the transistors T1 to T6, or the DC power source 32 is used using the charge stored in the capacitor 30B. Can be charged.
[0050]
Since the potential difference generated by charging the capacitor 30B varies depending on the amount of charge stored in the capacitor 30B, that is, the current flowing through the reactor, the switching control of the transistors T1 to T6 of the inverter circuit 24 is performed, and the current flowing through the reactor is changed. By adjusting, the voltage between terminals of the capacitor 30B can be adjusted. The drive control of the motor 22 by such a circuit is performed by supplying pseudo three-phase alternating current to the three-phase coil of the motor 22 by switching control of the transistors T1 to T6 of the inverter circuit 24. At this time, if a direct current component is added to the three-phase alternating current, that is, the three-phase alternating current is offset and supplied to the motor 22, the motor 22 can be rotationally driven with the alternating current component and can be stored in the capacitor 30B with the direct current component. . Therefore, in the power output device 20B of the modified example, the neutral point potential V0 of the motor 22 is adjusted by switching control of the transistors T1 to T6 of the inverter circuit 24 as in the power output device 20 of the embodiment and the modified example. Thus, the current flowing to the neutral point of the motor 22 can be adjusted, and the voltage across the terminals of the capacitor 30 can be adjusted while driving the motor 22.
[0051]
Therefore, the power output device 20B of the modified example can also execute the above-described capacitor voltage control routine of FIG. 3 and the offset amount setting processing routine of FIG. 4 or FIG. Similar effects can be obtained. In the modified power output apparatus 20B, the capacitor 30B is connected to the neutral point of the motor 22 and the positive bus 26 of the inverter circuit 24, and the DC power source 32 is connected to the neutral point of the motor 22 and the negative bus of the inverter circuit 24. However, the capacitor 30B and the DC power supply 32 may be replaced with each other.
[0052]
In the power output device 20 and the power output device 20B according to the embodiment and the modification thereof, the synchronous generator motor driven by the three-phase AC is used as the motor 22. However, any type of motor driven by the multiphase AC may be used. Good.
[0053]
The embodiments of the present invention have been described using the embodiments. However, the present invention is not limited to these embodiments and can be implemented in various forms without departing from the gist of the present invention. Of course you get.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an outline of a configuration of a power output apparatus 20 according to an embodiment of the present invention.
FIG. 2 is a circuit diagram focusing on the u phase of a motor 22 in the power output apparatus 20 of the embodiment.
FIG. 3 is a flowchart illustrating an example of a capacitor voltage control routine executed by the electronic control unit 40 of the power output apparatus 20 according to the embodiment.
FIG. 4 is a flowchart illustrating an example of an offset amount setting process routine executed by the electronic control unit 40 of the power output apparatus 20 according to the embodiment.
FIG. 5 is a flowchart showing another example of an offset amount setting processing routine.
6 is an explanatory diagram showing a relationship among a voltage Vc between terminals of a capacitor 30, a voltage Vb between terminals of a DC power supply 32, and an offset amount O. FIG.
FIG. 7 is a configuration diagram showing an outline of a configuration of a power output apparatus 20B according to a modification.
FIG. 8 is a circuit diagram focusing on the u phase of a motor 22 in a power output apparatus 20B according to a modification.
[Explanation of symbols]
20, 20B power output device, 22 motor, 24 inverter circuit, 26 positive bus, 28 negative bus, 30, 30B capacitor, 32 DC power supply, 40 electronic control unit, 42 CPU, 44 ROM, 46 RAM, 52-58 current sensor , 60 rotation angle sensor, 62, 64 voltage sensor.

Claims (10)

An electric motor that is rotationally driven by polyphase alternating current;
An inverter circuit capable of supplying multiphase AC power to the electric motor by switching of a plurality of switching elements;
A first power source capable of storing electricity connected to the positive and negative buses of the inverter circuit;
A second power source connected to one of the positive and negative buses of the inverter circuit and a neutral point of the motor;
The multi-phase AC power based on the difference between the neutral point current command value obtained from the power corresponding to the output required for the motor and the voltage between the terminals of the second power source and the read neutral point current And a control means for performing switching control of the switching element of the inverter circuit so that the second power supply supplies the electric motor and the first power supply. An electric motor that is rotationally driven by polyphase alternating current;
An inverter circuit capable of supplying multiphase AC power to the electric motor by switching of a plurality of switching elements;
A first power source capable of storing electricity connected to one of the positive and negative buses of the inverter circuit and a neutral point of the motor;
A second power source connected to the other bus bar different from the one bus bar of the inverter circuit and a neutral point of the motor;
The multi-phase AC power based on the difference between the neutral point current command value obtained from the power corresponding to the output required for the motor and the voltage between the terminals of the second power source and the read neutral point current And a control means for performing switching control of the switching element of the inverter circuit so that the second power supply supplies the electric motor and the first power supply.   The control means is based on the difference between the neutral point current command value obtained from the electric power corresponding to the output required for the electric motor and the voltage of the second power source and the read neutral point current. 3. The power output apparatus according to claim 1, wherein the power output device is means for adjusting a current flowing to a neutral point of the electric motor by offsetting phase AC power and supplying the electric power from the second power source to the electric motor.   The power output apparatus according to any one of claims 1 to 3, wherein the output required for the electric motor is a value obtained by multiplying a torque command of the electric motor by a rotation speed. A power output device according to any one of claims 1 to 4,
An electric device that is driven in accordance with charging and discharging of the first power source;
The power output device further includes a means for switching control of the switching element of the inverter circuit so that the electric power according to the required output of the electric device is supplied from the second power source to the first power source. An electric motor that is rotationally driven by polyphase alternating current;
An inverter circuit capable of supplying multiphase AC power to the electric motor by switching of a plurality of switching elements;
A first power source capable of storing electricity connected to the positive and negative buses of the inverter circuit;
A second power source connected to one of the positive and negative buses of the inverter circuit and a neutral point of the motor;
Based on the difference between the voltage of the second power supply and half of the target voltage of the first power supply, the multiphase AC power is offset and supplied from the second power supply to the electric motor, and to the first power supply. And a control means for switching-controlling the switching element of the inverter circuit so that the voltage of the first power supply is maintained at the target voltage by supplying the power. An electric motor that is rotationally driven by polyphase alternating current;
An inverter circuit capable of supplying multiphase AC power to the electric motor by switching of a plurality of switching elements;
A first power source capable of storing electricity connected to one of the positive and negative buses of the inverter circuit and a neutral point of the motor;
A second power source connected to the other bus bar different from the one bus bar of the inverter circuit and a neutral point of the motor;
Based on the difference between the voltage of the second power supply and half of the target voltage of the first power supply, the multiphase AC power is offset and supplied from the second power supply to the electric motor, and to the first power supply. And a control means for switching-controlling the switching element of the inverter circuit so that the voltage of the first power supply is maintained at the target voltage by supplying the power. An electric motor that is rotationally driven by polyphase alternating current;
An inverter circuit capable of supplying multiphase AC power to the electric motor by switching of a plurality of switching elements;
A first power source capable of storing electricity connected to the positive and negative buses of the inverter circuit;
A second power source connected to one of the positive and negative buses of the inverter circuit and a neutral point of the motor;
A method for controlling a power output device comprising:
The multi-phase AC power based on the difference between the neutral point current command value obtained from the power corresponding to the output required for the motor and the voltage between the terminals of the second power source and the read neutral point current A control method for a power output device that performs switching control of a switching element of the inverter circuit so that the second power supply supplies the electric motor and the first power supply. An electric motor that is rotationally driven by polyphase alternating current;
An inverter circuit capable of supplying multiphase AC power to the electric motor by switching of a plurality of switching elements;
A first power source capable of storing electricity connected to either a positive bus or a negative bus of the inverter circuit and a neutral point of the motor;
A control method of a power output device comprising: a second power source connected to the other bus bar different from the one bus bar of the inverter circuit and a neutral point of the motor,
The multi-phase AC power based on the difference between the neutral point current command value obtained from the power corresponding to the output required for the motor and the voltage between the terminals of the second power source and the read neutral point current A control method for a power output device that performs switching control of a switching element of the inverter circuit so that the second power supply supplies the electric motor and the first power supply. The power output device according to any one of claims 1 to 5,
The control means further includes means for correcting the neutral point current command value based on the target voltage of the first power supply and the detected voltage of the first power supply.

Images