JP2009027811A - Power control device and vehicle equipped with the same - Google Patents

Abstract

A power control device capable of reducing a high-frequency current appearing in a plug connectable to a power supply or an electric load outside the vehicle and suppressing an increase in the size of the device, and a vehicle including the same.
In hybrid vehicle 100, a load 90 outside the vehicle can be electrically connected to neutral points N1 and N2 of motor generators MG1 and MG2, and power is transferred between power storage device B and load 90. Is possible. When power is transferred between power storage device B and load 90, relay RY1 is turned on, and capacitor C5 is electrically connected between the motor cable connecting motor generator MG2 to inverter 20 and vehicle ground 80. The
[Selection] Figure 1

Description

  The present invention relates to a power control device and a vehicle including the power control device, and more particularly to a power control device capable of transferring power between a power storage device mounted on the vehicle and a power source or an electric load outside the vehicle, and a vehicle including the power control device. About.

  Japanese Laid-Open Patent Publication No. 4-295202 discloses an electric motor drive and power processing apparatus capable of transferring power between an AC power supply outside the vehicle and an in-vehicle DC power supply. This apparatus comprises a DC power supply, two inverters, two induction motors, a control unit, an input / output port, and an EMI filter. Each induction motor includes a Y-connected winding, and an input / output port is connected to the neutral point of each winding.

  In this device, in the recharging mode, the DC power can be charged by converting the AC power applied to the neutral point of each winding from the single-phase power connected to the input / output port into DC power. Further, it is possible to generate sine wave-adjusted AC power between the neutral points of each winding and output the generated AC power to an external device connected to the input / output port.

The EMI filter is provided between the neutral point of each winding and the input / output port, and reduces common-mode high-frequency current appearing at the input / output port (see Patent Document 1).
JP-A-4-295202 JP 2006-101632 A JP 2005-237133 A

  However, in the device disclosed in Japanese Patent Laid-Open No. 4-295202, since the EMI filter is provided to reduce the high frequency current appearing at the input / output port in the recharge mode, the size of the device increases. .

  Therefore, the present invention has been made in order to solve such a problem, and an object of the present invention is to transfer power between a power storage device mounted on a vehicle and a power source or an electric load outside the vehicle, An object of the present invention is to provide a power control device capable of reducing a high-frequency current appearing in a plug connectable to a power source or an electric load outside the vehicle, and suppressing an increase in the size of the device, and a vehicle including the same.

  According to this invention, the power control device converts the AC power supplied from the power supply outside the vehicle to DC power to charge the in-vehicle power storage device, or converts the DC power from the power storage device to AC power. A power control apparatus that can output to an electric load outside the vehicle, and includes a plurality of AC rotating electric machines, a plurality of inverters, a plug, a power line pair, a control unit, and a compensation circuit. Each AC rotating electric machine includes a star-connected multiphase winding as a stator winding. The plurality of inverters are provided corresponding to the plurality of AC rotating electric machines. The plug can be connected to a power source or an electric load outside the vehicle. The power line pair connects a plug to a neutral point of a multiphase winding of two AC rotating electric machines among a plurality of AC rotating electric machines. The control unit controls the inverter corresponding to one of the two AC rotating electric machines using the pulse width modulation method, and supplies the AC power to the upper arm and the lower arm of the inverter corresponding to the other of the two AC rotating electric machines. By alternately turning on according to the direction, power is exchanged between the power storage device and a power supply or electric load outside the vehicle. The compensation circuit includes a current flowing through the stray capacitance between the one AC rotating electric machine and the vehicle ground, a current flowing through the stray capacitance between the other AC rotating electric machine and the vehicle ground, and a plurality of inverters. And a sum of currents flowing through the stray capacitance between the vehicle and the vehicle ground can be compensated.

  Preferably, the compensation circuit includes a first capacitor. The first capacitor is connected between a motor power line connecting one AC rotating electric machine to a corresponding inverter and the vehicle ground.

  More preferably, the compensation circuit further includes a cutoff circuit. The interruption circuit can interrupt an electric circuit formed between the motor power line and the vehicle ground via the first capacitor.

  Preferably, the compensation circuit includes a coil. The coil is disposed on a power line that connects a plug to the neutral point of the multiphase winding of one AC rotating electric machine.

  More preferably, the compensation circuit further includes a second capacitor. The second capacitor is connected between the power line disposed between the neutral point of the multiphase winding of one AC rotating electrical machine and the coil and the vehicle ground.

  Preferably, the compensation circuit includes a capacitor. The capacitor is connected between a power line disposed between the plurality of inverters and the power storage device and the vehicle ground.

  More preferably, the compensation circuit further includes a cutoff circuit. The interruption circuit can interrupt an electric circuit formed between the power line and the vehicle ground via a capacitor.

  Preferably, the compensation circuit includes a first capacitor. The first capacitor is connected between the motor power line connecting the other AC rotating electric machine to the corresponding inverter and the vehicle ground.

  More preferably, the compensation circuit further includes a cutoff circuit. The interruption circuit can interrupt an electric circuit formed between the motor power line and the vehicle ground via the first capacitor.

  Preferably, the compensation circuit includes a coil. The coil is disposed on a power line that connects the plug to the neutral point of the multiphase winding of the other AC rotating electric machine.

  More preferably, the compensation circuit further includes a second capacitor. The second capacitor is connected between the power line arranged between the neutral point of the multiphase winding of the other AC rotating electric machine and the coil and the vehicle ground.

  According to the invention, the vehicle includes a wheel that receives a driving torque from at least one of the plurality of AC rotating electric machines, and any one of the power control devices described above.

  In the present invention, between the power storage device and a power source or an electric load outside the vehicle via a power line pair disposed between a neutral point of two AC rotating electric machines and a plug among a plurality of AC rotating electric machines. Electric power can be exchanged. When power is transferred between the power storage device and a power source or an electric load outside the vehicle, the inverter corresponding to one of the two AC rotating electric machines is controlled using the pulse width modulation method, and the two AC rotating electric machines In the inverter corresponding to the other, the upper arm and the lower arm are alternately turned on according to the energization direction of the AC power. At this time, the compensation circuit includes a current flowing through the stray capacitance between the one AC rotating electric machine and the vehicle ground, a current flowing through the stray capacitance between the other AC rotating electric machine and the vehicle ground, and Since the difference between the total current flowing through the stray capacitance between the plurality of inverters and the vehicle ground is compensated, the current flowing through the vehicle ground is recirculated without flowing out of the vehicle.

  Therefore, according to the present invention, the power line pair disposed between the neutral point of the two AC rotating electric machines and the plug does not have a filter, and appears in a plug that can be connected to a power source or an electric load outside the vehicle. High frequency current can be reduced. That is, it is possible to reduce the high-frequency current that appears in the plug while suppressing an increase in the size of the device.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
1 is an overall block diagram of a hybrid vehicle shown as an example of a vehicle according to Embodiment 1 of the present invention. Referring to FIG. 1, hybrid vehicle 100 includes an engine 2, motor generators MG <b> 1 and MG <b> 2, a power split mechanism 4, and wheels 6. Hybrid vehicle 100 includes power storage device B, inverters 10 and 20, electronic control unit (hereinafter referred to as "ECU") 30, smoothing capacitor C1, positive electrode line PL, and negative electrode line NL. And a vehicle ground 80, a capacitor C5, and a relay RY1. Hybrid vehicle 100 further includes power lines ACL1 and ACL2, a smoothing capacitor C2, an AC port 60, and a plug 70.

  Power split device 4 is coupled to engine 2 and motor generators MG1, MG2 to distribute power between them. For example, the power split mechanism 4 can be a planetary gear having three rotation shafts: a sun gear, a planetary carrier, and a ring gear. These three rotary shafts are connected to the rotary shafts of engine 2 and motor generators MG1, MG2, respectively. For example, engine 2 and motor generators MG1, MG2 can be mechanically connected to power split mechanism 4 by making the rotor of motor generator MG1 hollow and passing the crankshaft of engine 2 through its center.

  The power generated by the engine 2 is distributed by the power split mechanism 4 to the wheels 6 and the motor generator MG1. In other words, engine 2 is incorporated into hybrid vehicle 100 as a power source that drives wheels 6 and motor generator MG1. Motor generator MG1 operates as a generator driven by engine 2 and is incorporated in hybrid vehicle 100 as an electric motor that can start engine 2, and motor generator MG2 is a driving power for driving wheels 6. It is incorporated in the hybrid vehicle 100 as a source.

  Further, as will be described later, hybrid vehicle 100 transmits and receives electric power between power storage device B and load 90 by connecting plug 70 to load 90 that generally indicates a power source or an electric load outside the vehicle. can do.

  A positive electrode terminal of power storage device B is connected to positive electrode line PL, and a negative electrode terminal of power storage device B is connected to negative electrode line NL. Smoothing capacitor C1 is connected between positive electrode line PL and negative electrode line NL. Inverter 10 includes a U-phase arm 12, a V-phase arm 14, and a W-phase arm 16. U-phase arm 12, V-phase arm 14 and W-phase arm 16 are connected in parallel between positive electrode line PL and negative electrode line NL. The U-phase arm 12 includes switching elements Q11 and Q12 connected in series, the V-phase arm 14 includes switching elements Q13 and Q14 connected in series, and the W-phase arm 16 includes switching elements connected in series. It consists of elements Q15 and Q16. Diodes D11-D16 are connected in antiparallel to switching elements Q11-Q16, respectively. Inverter 20 includes a U-phase arm 22, a V-phase arm 24 and a W-phase arm 26. The configuration of the inverter 20 is the same as that of the inverter 10.

  In addition, as said switching element, IGBT (Insulated Gate Bipolar Transistor), power MOSFET (Metal Oxide Semiconductor Field-Effect Transistor) etc. can be used, for example.

  Motor generator MG1 includes a Y-connected three-phase coil, and one end of each coil is connected to each other to form neutral point N1. Motor generator MG2 also includes a Y-connected three-phase coil, and one end of each coil is connected to each other to form neutral point N2. Power lines ACL1 and ACL2 are connected to neutral points N1 and N2, respectively. Smoothing capacitor C2 is connected between power lines ACL1 and ACL2. The power lines ACL1 and ACL2 are connected to the AC port 60, and the plug 70 is connected to the AC port 60.

  The power storage device B is a chargeable / dischargeable DC power source, and is composed of, for example, a secondary battery such as nickel metal hydride or lithium ion. The power storage device B supplies electric power to the inverters 10 and 20 and is charged by receiving regenerative power output from at least one of the inverters 10 and 20. Note that a large-capacity capacitor may be used as the power storage device B.

  Smoothing capacitor C1 smoothes the voltage between positive electrode line PL and negative electrode line NL. The capacitance C3 indicates a stray capacitance between the positive electrode line PL and the vehicle ground 80 (hereinafter, the capacitance C3 is also referred to as “stray capacitance C3”). Capacitance C4 indicates a stray capacitance between negative electrode line NL and vehicle ground 80 (hereinafter, capacitance C4 is also referred to as “floating capacitance C4”). For example, a vehicle frame or a vehicle body is used as the vehicle ground 80.

  Based on signal PWM1 from ECU 30, inverter 10 converts the DC voltage from power storage device B into a three-phase AC voltage and outputs the same to motor generator MG1. Inverter 10 also converts the three-phase AC voltage generated by motor generator MG1 using the power of engine 2 into a DC voltage and outputs the DC voltage to positive line PL and negative line NL.

  Inverter 20 converts the DC voltage from power storage device B into a three-phase AC voltage based on signal PWM2 from ECU 30, and outputs the converted three-phase AC voltage to motor generator MG2. Inverter 20 also converts the three-phase AC voltage generated by motor generator MG2 into the DC voltage using the rotational force of wheel 6 during braking of the vehicle, and outputs the DC voltage to positive line PL and negative line NL.

  Here, when charging of power storage device B is requested from a load 90 as a power source (for example, a system power source) outside the vehicle, inverters 10 and 20 are connected to load 90 via plug 70, AC port 60, and power lines ACL1 and ACL2. AC power applied to neutral points N1 and N2 is converted into DC power and output to positive line PL and negative line NL to charge power storage device B. When power supply to load 90 as an AC electric load (for example, home appliance) is required, inverters 10 and 20 apply an AC voltage having a predetermined frequency (for example, a commercial power supply frequency) between neutral points N1 and N2. AC power is output from the plug 70 to the load 90.

  Each of motor generators MG1 and MG2 is a three-phase AC rotating electric machine, and includes, for example, a three-phase permanent magnet synchronous motor having a permanent magnet in a rotor. Motor generator MG <b> 1 is regeneratively driven by inverter 10, and outputs three-phase AC power generated using the power of engine 2 to inverter 10. Motor generator MG1 is driven by power by inverter 10 when engine 2 is started, and cranks engine 2. Motor generator MG <b> 2 is driven by power by inverter 20, and generates a driving force for driving wheels 6. Motor generator MG <b> 2 is regeneratively driven by inverter 20 during braking of the vehicle, and outputs three-phase AC power generated using the rotational force of wheel 6 to inverter 20.

  Capacitor C5 and relay RY1 are connected in series between at least one line of a three-phase motor cable connecting motor generator MG2 to inverter 20 and vehicle ground 80. In FIG. 1, the capacitor C5 is connected to the W-phase motor cable, but the capacitor C5 may be connected to a motor cable of another phase.

  As will be described in detail later, capacitor C5 is a high current flowing through stray capacitances C3 and C4 due to high-frequency switching of the inverter when power is transferred between power storage device B and load 90 outside the vehicle. Difference between the sum of the frequency current and the high frequency current flowing through the stray capacitance between motor generator MG1 and vehicle ground 80 and the high frequency current flowing through the stray capacitance between motor generator MG2 and vehicle ground 80 It functions as a compensation circuit that compensates for.

  Relay RY1 is turned on in response to a signal from ECU 30 when power is transferred between power storage device B and load 90, and capacitor C5 is interposed between the motor cable of motor generator MG2 and vehicle ground 80. Forming an electric circuit. On the other hand, when power is not exchanged between power storage device B and load 90, relay RY1 is turned off in response to a signal from ECU 30 and between motor cable of motor generator MG2 and vehicle ground 80. The electric circuit formed via the capacitor C5 is interrupted.

  ECU 30 generates a PWM signal for driving inverter 10 and outputs the generated PWM signal to inverter 10 as signal PWM1. ECU 30 also generates a PWM signal for driving inverter 20, and outputs the generated PWM signal to inverter 20 as signal PWM2.

  Here, when charging of power storage device B is requested from load 90 as an external power source, ECU 30 converts AC power from load 90 applied to neutral points N1 and N2 to DC power to power storage device B. The inverters 10 and 20 are controlled to output. When power supply to the load 90 as an AC electric load is required, the ECU 30 controls the inverters 10 and 20 to generate an AC voltage between the neutral points N1 and N2 and output the AC voltage to the load 90. Control of inverters 10 and 20 when power is transferred to and from load 90 will be described later.

  In addition, when power is exchanged between power storage device B and load 90, ECU 30 generates a signal instructing ON of relay RY1 and outputs the signal to relay RY1. On the other hand, when power is not exchanged between power storage device B and load 90, ECU 30 generates a signal instructing to turn off relay RY1, and outputs the signal to relay RY1.

  Smoothing capacitor C2 smoothes the voltage between power lines ACL1 and ACL2. That is, smoothing capacitor C <b> 2 suppresses normal mode noise generated due to high frequency switching of inverter 10 or 20 when power is transferred between the vehicle and load 90.

  AC port 60 includes a relay for connecting / disconnecting power lines ACL1, ACL2 and plug 70, a voltage sensor for detecting voltage VAC between power lines ACL1, ACL2, and a current sensor for detecting current IAC flowing through power line ACL1 or ACL2. (Both not shown). When power is exchanged between the vehicle and load 90, AC port 60 turns on a relay in response to a command from ECU 30, and electrically connects plug 70 connected to load 90 with power lines ACL1 and ACL2. Connecting. Further, AC port 60 outputs detected values of voltage VAC and current IAC to ECU 30.

  Plug 70 is a connection terminal for electrically connecting hybrid vehicle 100 to load 90. Load 90 collectively indicates an external AC power supply for charging power storage device B or an AC electrical load that receives power supplied from hybrid vehicle 100, and is grounded to ground node 95.

  In hybrid vehicle 100, when power is transferred between the vehicle and load 90, neutral points N1, N2 and load 90 are electrically connected via power lines ACL1, ACL2. Here, when the inverter performs a high-frequency switching operation, the common mode voltage for the vehicle ground 80 fluctuates at a high frequency, and a high-frequency current flows to the vehicle ground 80 via the stray capacitance. Then, a circuit is formed between the vehicle and load 90 via the contact resistance between vehicle ground 80 and ground node 95, and a current can flow between vehicle ground 80 and ground node 95.

  Therefore, in the first embodiment, when power is exchanged between the vehicle and the load 90, a capacitor is provided between the motor cable disposed between the inverter 20 and the motor generator MG2 and the vehicle ground 80. C5 is connected, and a high frequency current flowing out from the vehicle ground 80 and a high frequency current flowing back from the vehicle ground 80 are balanced. Thereby, it is possible to prevent a current from flowing between vehicle ground 80 and ground node 95.

  FIG. 2 is an equivalent circuit diagram of the system shown in FIG. 1 when electric power is transferred between the vehicle and the load 90. Although FIG. 2 shows the case where the load 90 is an AC power supply, a similar equivalent circuit is obtained when the load 90 is an AC electric load.

  Referring to FIG. 2, when power storage device B is charged from load 90, each of inverters 10 and 20 is subjected to switching control at the same time for three phases. Therefore, in FIG. 2, in each of the inverters 10 and 20, the three switching elements of the upper arm are collectively shown, and the three switching elements of the lower arm are also collectively shown.

  Inductances L1 and L2 indicate leakage inductances of motor generators MG1 and MG2, respectively (hereinafter, inductances L1 and L2 are also referred to as “leakage inductance L1” and “leakage inductance L2”, respectively). Capacitances C6 and C7 indicate stray capacitances between motor generators MG1 and MG2 and vehicle ground 80 (hereinafter, capacities C6 and C7 are also referred to as “floating capacitance C6” and “floating capacitance C7”, respectively). Resistance Rh indicates a contact resistance between vehicle ground 80 and ground node 95.

  As described later, when power is transferred between the vehicle and the load 90, the inverter 20 performs a switching operation at a high frequency. A high-frequency common mode voltage is generated due to the high-frequency switching, and a high-frequency current flows to the vehicle ground 80 via the stray capacitances C3, C4, C6, and C7. The direction of the current flowing through each of the stray capacitances C3, C4, C6, and C7 varies depending on the switching state of the inverters 10 and 20. When the difference between the current flowing out to vehicle ground 80 and the current flowing back from vehicle ground 80 is large, a high-frequency current can flow between vehicle ground 80 and ground node 95 outside the vehicle via contact resistance Rh. Therefore, in this hybrid vehicle 100, a capacitor C5 is provided for the purpose of balancing the current flowing out to the vehicle ground 80 and the current flowing back from the vehicle ground 80.

  Next, the control of the ECU 30 when electric power is exchanged between the vehicle and the load 90 will be described.

  FIG. 3 is a functional block diagram of ECU 30 shown in FIG. Referring to FIG. 3, ECU 30 includes first and second inverter control units 32 and 34 and a charge / discharge control unit 36. When the signal CTL from the charge / discharge control unit 36 is inactivated, the first inverter control unit 32 detects the detected value of the voltage VDC between the positive line PL and the negative line NL, and the torque command value TR1 of the motor generator MG1. Based on the detected values of motor current I1 and rotation angle θ1 of motor generator MG1, a PWM signal for driving motor generator MG1 is generated, and the generated PWM signal is output to inverter 10 as signal PWM1.

  When the signal CTL from the charge / discharge control unit 36 is inactivated, the second inverter control unit 34 detects the detected value of the voltage VDC, the torque command value TR2 of the motor generator MG2, and the motor current I2 of the motor generator MG2. Based on the detected values of the rotation angle θ2, the PWM signal for driving the motor generator MG2 is generated, and the generated PWM signal is output to the inverter 20 as the signal PWM2.

  On the other hand, when the signal CTL from the charge / discharge control unit 36 is activated, the first and second inverter control units 32, 34 are neutral based on the commands AC1, AC2 from the charge / discharge control unit 36. Signals PWM1 and PWM2 are generated for transferring power between the vehicle and a load 90 outside the vehicle via points N1 and N2, respectively, and the generated signals PWM1 and PWM2 are output to inverters 10 and 20, respectively. .

  Charging / discharging control unit 36 activates signal CTL output to first and second inverter control units 32 and 34 when signal CG instructing charging of power storage device B from load 90 is activated. . Based on voltage VAC and current IAC detected at AC port 60, charge / discharge control unit 36 converts AC power from load 90 applied to neutral points N1 and N2 to DC power to store power storage device B. The commands AC1 and AC2 for controlling the inverters 10 and 20 are generated so as to be output to the first and second inverter control units 32 and 34, respectively.

  Specifically, charge / discharge control unit 36 performs commands for PWM control of inverter 20 based on voltage VAC and current IAC, and generates commands AC1 and AC2 so that inverter 10 is in an energized state. More specifically, when the voltage VAC is positive (when the voltage of the power line ACL1 is higher than the voltage of the power line ACL2), the charge / discharge control unit 36 outputs a command AC2 for PWM control of the inverter 20. Generated based on voltage VAC and current IAC, and for inverter 10, generates a command AC1 for always turning on the upper arm. On the other hand, when voltage VAC is negative, charge / discharge control unit 36 generates command AC2 for PWM control of inverter 20, and generates command AC1 for turning on the lower arm for inverter 10 at all times. . That is, the charge / discharge control unit 36 performs PWM control of the inverter 20 based on the voltage VAC and the current IAC, and always turns on the inverter 10 by alternately turning on the upper arm and the lower arm of the inverter 10 according to the sign of the voltage VAC. Control to energized state.

  Note that the frequency of AC power from the load 90 is sufficiently lower than the carrier frequency in PWM control. In other words, the on / off switching frequency of the upper and lower arms of the inverter 10 is sufficiently lower than the switching frequency of the inverter 20 that is PWM controlled. For example, the frequency of AC power from the load 90 is a commercial power supply frequency, and the carrier frequency of PWM control is about several kHz to 10 kHz.

  The charge / discharge control unit 36 is output to the first and second inverter control units 32 and 34 when the signal DCG instructing power supply from the neutral points N1 and N2 to the load 90 is activated. Activate the signal CTL. Then, the charge / discharge control unit 36 performs the PWM control of the inverter 20 so that a voltage difference having a predetermined frequency is generated between the neutral points N1 and N2, and the command AC1 so that the inverter 10 is energized. , AC2 is generated.

  More specifically, when the voltage difference generated between the neutral points N1 and N2 is positive (when the voltage generated at the neutral point N1 is higher than the voltage generated at the neutral point N2, positive). The discharge control unit 36 generates a command AC2 for PWM control of the inverter 20, and generates a command AC1 for turning on the upper arm for the inverter 10 at all times. On the other hand, when the voltage difference generated between the neutral points N1 and N2 is negative, the charge / discharge control unit 36 generates a command AC2 for PWM control of the inverter 20, and for the inverter 10, the lower arm is always on. A command AC1 for setting the state is generated. In other words, the charge / discharge control unit 36 performs PWM control of the inverter 20 based on the voltage difference generated between the neutral points N1 and N2, and the inverter according to the sign of the voltage difference generated between the neutral points N1 and N2. By alternately turning on the upper arm and the lower arm of the inverter 10, the inverter 10 is controlled to be always energized.

  Signal CG is activated when charging is instructed by the user when plug 70 is connected to load 90, for example, and signal DCG is connected to load 90, for example. It is activated when the user instructs the start of power supply.

  FIG. 4 is a waveform diagram showing the switching state of the inverters 10 and 20 and the variation of the common mode voltage. In FIG. 4, a waveform diagram when power storage device B is charged from load 90 is shown, but a similar waveform diagram can also be obtained when power is supplied from vehicle to load 90.

  Referring to FIG. 4, at times t1 to t2 and t3 to t4 when voltage VAC is positive, inverter 10 is controlled so that the upper arm is always on (energized state), and inverter is based on voltage VAC and current IAC. 20 is PWM controlled. On the other hand, after times t2 to t3 and t4 when voltage VAC becomes negative, inverter 10 is controlled so that the lower arm is always on (energized), and inverter 20 is PWM-controlled.

  Therefore, the command value of the voltage difference (VN1−VN2) between the neutral points N1 and N2 is as shown in the figure, and a charging current synchronized with the voltage VAC can be obtained from the load 90.

  At times t1 to t2 and t3 to t4, since the upper arm of inverter 10 is on, the common mode voltage varies between VDC / 2 and VDC. That is, the common mode voltage does not swing to near zero. This is because the lower arm of the inverters 10 and 20 is never turned on because the upper arm of the inverter 10 is always on (energized).

  On the other hand, after time t2 to t3 and t4, since the lower arm of inverter 10 is in the ON state, the common mode voltage varies between 0 and VDC / 2. That is, the common mode voltage does not swing to near VDC. This is because since the lower arm of the inverter 10 is always on (energized state), neither of the upper arms of the inverters 10 and 20 is turned on.

  Next, a description will be given of the return mechanism of the high-frequency current flowing in the vehicle ground 80 due to the fluctuation of the common mode voltage when the inverter control as described above is performed.

  FIG. 5 is an equivalent circuit diagram when the upper arm of inverter 10 is on (voltage VAC> 0) and the lower arm of inverter 20 is on in the circuit shown in FIG. Referring to FIG. 5, current (1) flows from positive line PL to vehicle ground 80 via stray capacitance C3, and current (2) flows from negative line NL to vehicle ground 80 via stray capacitance C4. Since the upper arm of inverter 10 is on, current (3) flows from positive line PL to vehicle ground 80 through leakage inductance L1 of motor generator MG1 and stray capacitance C6.

  On the other hand, since the lower arm of inverter 20 is on, currents (1) to (3) flowing out to vehicle ground 80 are returned to negative electrode line NL via stray capacitance C7 of motor generator MG2 and leakage inductance L2. (Current (4)).

  Here, when the currents (1) to (3) cannot be recirculated by the stray capacitance C7 and the leakage inductance L2, the surplus current can flow to the ground node 95 outside the vehicle via the contact resistance Rh.

  Therefore, in the first embodiment, a capacitor C5 is connected between the motor cable of motor generator MG2 and vehicle ground 80, and the current is circulated through capacitor C5 (and the motor cable of motor generator MG2). The difference between the currents (1) to (3) and the current (4) is compensated. In other words, by providing the capacitor C5, a balance between the currents (1) to (3) and the current (4) can be achieved. Thereby, it is possible to prevent a current from flowing from vehicle ground 80 to ground node 95 via contact resistance Rh.

  FIG. 6 is an equivalent circuit diagram when the upper arm of the inverter 10 is on (voltage VAC> 0) and the upper arm of the inverter 20 is on in the circuit shown in FIG. Referring to FIG. 6, since the upper arm of inverter 20 is on, current (1) flows from positive line PL to vehicle ground 80 via leakage inductance L2, stray capacitance C7 and capacitor C5.

  On the other hand, the current (1) flowing out to the vehicle ground 80 is returned via the stray capacitances C3 and C4, the stray capacitance C6 and the leakage inductance L1 (currents (2) to (4)).

  That is, even when the upper arm of the inverter 20 is on, the difference between the currents (2) to (4) and the current (1) is compensated by the capacitor C5. In other words, by providing the capacitor C5, a balance between the currents (1) and (2) to (4) can be achieved. As a result, current can be prevented from flowing from ground node 95 to vehicle ground 80 via contact resistance Rh.

  As described above, in the first embodiment, when electric power is transferred between the vehicle and the load 90, by providing the capacitor C5, the current flowing out to the vehicle ground 80 and the current flowing back from the vehicle ground 80 And balance is achieved. Therefore, according to the first embodiment, the high frequency current that can flow between vehicle ground 80 and ground node 95 can be reduced without providing noise filters on power lines ACL1 and ACL2. Since the noise filters are not provided on the power lines ACL1 and ACL2, an increase in the size of the apparatus can be suppressed.

[Embodiment 2]
FIG. 7 is an overall block diagram of a hybrid vehicle shown as an example of a vehicle according to the second embodiment. Referring to FIG. 7, hybrid vehicle 100A includes a coil L3 in place of capacitor C5 and relay RY1 in the configuration of hybrid vehicle 100 according to the first embodiment shown in FIG.

  Coil L3 is arranged on power line ACL2. More specifically, motor generator MG2 is arranged between neutral point N2 and smoothing capacitor C2 at a node connected to power line ACL2.

  The other configuration of hybrid vehicle 100A is the same as that of hybrid vehicle 100 according to the first embodiment.

  FIG. 8 is an equivalent circuit diagram of the system shown in FIG. 7 when electric power is transferred between the vehicle and the load 90. Although FIG. 8 also shows the case where the load 90 is an AC power supply, a similar equivalent circuit is obtained when the load 90 is an AC electric load.

  Referring to FIG. 8, the control of each inverter is the same as that of hybrid vehicle 100 according to the first embodiment. Also in FIG. 8, the arms of each inverter are shown together. A coil L3 is disposed on the power line ACL2. In FIG. 8, the smoothing capacitor C2 is not shown.

  As described above, if the difference between the current flowing out to the vehicle ground 80 via the stray capacitance and the current flowing back from the vehicle ground 80 is large, the contact resistance Rh is interposed between the vehicle ground 80 and the ground node 95 outside the vehicle. High frequency current can flow. Therefore, in the second embodiment, by providing the coil L3, the voltage applied to the stray capacitance C7 of the motor generator MG2 is increased, and the current flowing to the vehicle ground 80 is increased by increasing the amount of current flowing through the stray capacitance C7. And the current flowing back from the vehicle ground 80 are balanced.

  FIG. 9 is an equivalent circuit diagram when the upper arm of the inverter 10 is on (voltage VAC> 0) and the lower arm of the inverter 20 is on in the circuit shown in FIG. FIG. 9 corresponds to FIG. 5 shown in the first embodiment. Referring to FIG. 9, coil L 3 is electrically connected between leakage inductance L 2 of motor generator MG 2 and ground node 95.

  The coil L3 functions as a compensation circuit that compensates for the difference between the currents (1) to (3) and the current (4). That is, by providing the coil L3, the voltage applied to the stray capacitance C7 increases by the amount applied to the coil L3. Therefore, the current (4) increases, and the difference between the currents (1) to (3) and the current (4) is compensated. In other words, the balance between the currents (1) to (3) and the current (4) is achieved by providing the coil L3. Thereby, it is possible to prevent a current from flowing from vehicle ground 80 to ground node 95 via contact resistance Rh.

  FIG. 10 is an equivalent circuit diagram when the upper arm of inverter 10 is on (voltage VAC> 0) and the upper arm of inverter 20 is on in the circuit shown in FIG. FIG. 10 corresponds to FIG. 6 shown in the first embodiment. Referring to FIG. 10, similarly to FIG. 9, coil L <b> 3 is electrically connected between leakage inductance L <b> 2 and ground node 95.

  The coil L3 functions as a compensation circuit that compensates for the difference between the current (1) and the currents (2) to (4). That is, by providing the coil L3, the voltage applied to the stray capacitance C7 increases by the amount applied to the coil L3. Therefore, the current (1) increases, and the difference between the current (1) and the currents (2) to (4) is compensated. In other words, by providing the coil L3, the balance between the current (1) and the currents (2) to (4) can be achieved. As a result, current can be prevented from flowing from ground node 95 to vehicle ground 80 via contact resistance Rh.

  As described above, in the second embodiment, by providing coil L3 on power line ACL2, a balance between the current flowing out from vehicle ground 80 and the current recirculated from vehicle ground 80 is achieved. Therefore, according to the second embodiment, the same effect as in the first embodiment can be obtained without connecting a capacitor to the motor cable.

[Embodiment 3]
FIG. 11 is an overall block diagram of a hybrid vehicle shown as an example of a vehicle according to the third embodiment. Referring to FIG. 11, hybrid vehicle 100B further includes a capacitor C8 and a relay RY2 in the configuration of hybrid vehicle 100A according to the second embodiment shown in FIG. Capacitor C8 and relay RY2 are connected in series between power line ACL2 and vehicle ground 80 between neutral point N2 of motor generator MG2 and coil L3.

  Relay RY2 is turned on in response to a signal from ECU 30 when power is transferred between power storage device B and load 90 outside the vehicle. On the other hand, when power is not transferred between power storage device B and load 90 outside the vehicle, relay RY2 is turned off in response to a signal from ECU 30, and a capacitor is connected between power line ACL2 and vehicle ground 80. The electric circuit formed via C8 is interrupted.

  Other configurations of hybrid vehicle 100B are the same as hybrid vehicle 100A according to the second embodiment.

  FIG. 12 is an equivalent circuit diagram of the system shown in FIG. 11 when electric power is transferred between the vehicle and the load 90. 12 also shows the case where the load 90 is an AC power supply, the same equivalent circuit is obtained when the load 90 is an AC electric load.

  Referring to FIG. 12, the control of each inverter is the same as that of hybrid vehicle 100 according to the first embodiment. Also in FIG. 12, the arms of each inverter are shown together. A coil L3 is disposed on the power line ACL2, and a capacitor C8 is connected between the leakage inductance L2 and the coil L3.

  In the second embodiment, the voltage applied to the stray capacitance C7 of the motor generator MG2 is increased by providing the coil L3, and the amount of current flowing through the stray capacitance C7 is increased. However, the coil L3 can be enlarged. There is sex. Therefore, in the third embodiment, by providing the capacitor C8 between the leakage inductance L2 and the coil L3, while obtaining the same effect as increasing the amount of current flowing through the stray capacitance C7, Miniaturization is achieved.

  13 is an equivalent circuit diagram when the upper arm of inverter 10 is on (voltage VAC> 0) and the lower arm of inverter 20 is on in the circuit shown in FIG. FIG. 13 corresponds to FIG. 5 shown in the first embodiment. Referring to FIG. 13, capacitor C8 is electrically connected between a connection node between leakage inductance L2 and coil L3 and vehicle ground 80.

  The coil L3 and the capacitor C8 function as a compensation circuit that compensates for the difference between the currents (1) to (3) and the current (4). That is, by providing the coil L3, a voltage is applied to the capacitor C8, and a reflux current also flows through the capacitor C8. Therefore, the current (4) increases, and the difference between the currents (1) to (3) and the current (4) is compensated. In other words, the balance between the currents (1) to (3) and the current (4) is achieved by providing the coil L3 and the capacitor C8. Thereby, it is possible to prevent a current from flowing from vehicle ground 80 to ground node 95 via contact resistance Rh.

  FIG. 14 is an equivalent circuit diagram when the upper arm of inverter 10 is on (voltage VAC> 0) and the upper arm of inverter 20 is on in the circuit shown in FIG. FIG. 14 corresponds to FIG. 6 shown in the first embodiment. Referring to FIG. 14, similarly to FIG. 13, capacitor C <b> 8 is electrically connected between a connection node between leakage inductance L <b> 2 and coil L <b> 3 and vehicle ground 80.

  The coil L3 and the capacitor C8 function as a compensation circuit that compensates for the difference between the current (1) and the currents (2) to (4). That is, by providing the coil L3, a voltage is applied to the capacitor C8, and a current in the same direction as the stray capacitance C7 flows through the capacitor C8. Therefore, the current (1) increases, and the difference between the current (1) and the currents (2) to (4) is compensated. In other words, the balance between the current (1) and the currents (2) to (4) is achieved by providing the coil L3 and the capacitor C8. As a result, current can be prevented from flowing from ground node 95 to vehicle ground 80 via contact resistance Rh.

  As described above, according to the third embodiment, since the coil L3 is provided on the power line ACL2 and the capacitor C8 is provided, the same effect as that of the second embodiment is obtained and the coil is compared with the second embodiment. L3 can be reduced in size.

[Embodiment 4]
In the above first to third embodiments, the current flowing through stray capacitance C7 of motor generator MG2 is smaller than the current flowing through stray capacitances C3 and C4 on the inverter side and stray capacitance C6 of motor generator MG1. The configuration of the compensation circuit has been described.

  However, there may be a case where the current flowing through the stray capacitance C7 is larger than the current flowing through the stray capacitance C3, C4, C6. Therefore, in the following embodiments, the configuration of the compensation circuit in such a case will be described.

  FIG. 15 is an overall block diagram of a hybrid vehicle shown as an example of a vehicle according to the fourth embodiment. Referring to FIG. 15, hybrid vehicle 100C includes a capacitor C9 and relay RY3 in place of capacitor C5 and relay RY1 in the configuration of hybrid vehicle 100 according to the first embodiment shown in FIG. Capacitor C9 and relay RY3 are connected in series between negative electrode line NL and vehicle ground 80.

  Relay RY3 is turned on in response to a signal from ECU 30 when power is transferred between power storage device B and load 90 outside the vehicle. On the other hand, when power is not exchanged between power storage device B and load 90 outside the vehicle, relay RY3 is turned off in response to a signal from ECU 30 and between negative electrode line NL and vehicle ground 80. The electric circuit formed via the capacitor C9 is interrupted.

  The other configuration of hybrid vehicle 100C is the same as that of hybrid vehicle 100 according to the first embodiment.

  FIG. 16 is an equivalent circuit diagram of the system shown in FIG. 15 when electric power is transferred between the vehicle and the load 90. FIG. 16 also shows the case where the load 90 is an AC power supply, but a similar equivalent circuit is obtained when the load 90 is an AC electric load.

  Referring to FIG. 16, the control of each inverter is the same as that of hybrid vehicle 100 according to the first embodiment. Also in this FIG. 16, the arms of each inverter are shown together. A capacitor C9 is connected between negative electrode line NL and vehicle ground 80.

  In the fourth embodiment, the current flowing through the stray capacitance C7 is larger than the current flowing through the stray capacitance C3, C4, C6. Therefore, in the hybrid vehicle 100C, a capacitor C9 is provided on the inverter side in order to compensate for the current difference.

  FIG. 17 is an equivalent circuit diagram when the upper arm of inverter 10 is on (voltage VAC> 0) and the lower arm of inverter 20 is on in the circuit shown in FIG. FIG. 17 corresponds to FIG. 5 shown in the first embodiment. Referring to FIG. 17, capacitor C9 is connected in parallel with stray capacitance C4 between negative electrode line NL and vehicle ground 80.

  The capacitor C9 functions as a compensation circuit that compensates for the difference between the currents (1) to (3) and the current (4). That is, by providing the capacitor C9 in parallel with the stray capacitance C4, the current (2) increases, and the difference between the currents (1) to (3) and the current (4) is compensated. In other words, by providing the capacitor C9, a balance between the currents (1) to (3) and the current (4) can be achieved. Thereby, it is possible to prevent a current from flowing from vehicle ground 80 to ground node 95 via contact resistance Rh.

  18 is an equivalent circuit diagram when the upper arm of inverter 10 is on (voltage VAC> 0) and the upper arm of inverter 20 is on in the circuit shown in FIG. FIG. 18 corresponds to FIG. 6 shown in the first embodiment. Referring to FIG. 18, similarly to FIG. 17, capacitor C <b> 9 is connected in parallel to stray capacitance C <b> 4 between negative electrode line NL and vehicle ground 80.

  The capacitor C9 functions as a compensation circuit that compensates for the difference between the current (1) and the currents (2) to (4). That is, by providing the capacitor C9 in parallel with the stray capacitance C4, the current (3) increases, and the difference between the current (1) and the currents (2) to (4) is compensated. In other words, by providing the capacitor C9, the balance between the current (1) and the currents (2) to (4) can be achieved. As a result, current can be prevented from flowing from ground node 95 to vehicle ground 80 via contact resistance Rh.

  As described above, in the fourth embodiment, the current flowing through the stray capacitance C7 is larger than the current flowing through the stray capacitances C3, C4, C6. The current flowing out to 80 and the current returned from vehicle ground 80 are balanced. Therefore, the effect similar to that of the first embodiment can be obtained also by the fourth embodiment.

[Embodiment 5]
The fifth embodiment also shows a configuration example of the compensation circuit in the case where the current flowing through the stray capacitance C7 is larger than the current flowing through the stray capacitances C3, C4, C6.

  FIG. 19 is an overall block diagram of a hybrid vehicle shown as an example of a vehicle according to the fifth embodiment. Referring to FIG. 19, hybrid vehicle 100D includes a capacitor C10 and relay RY4 in place of capacitor C9 and relay RY3 in the configuration of hybrid vehicle 100C according to the fourth embodiment shown in FIG. Capacitor C10 and relay RY4 are connected in series between positive line PL and vehicle ground 80.

  Relay RY4 is turned on in response to a signal from ECU 30 when power is transferred between power storage device B and load 90 outside the vehicle. On the other hand, when power is not transferred between power storage device B and load 90 outside the vehicle, relay RY4 is turned off in response to a signal from ECU 30, and between positive line PL and vehicle ground 80. The electric circuit formed via the capacitor C10 is interrupted.

  The other configuration of hybrid vehicle 100D is the same as that of hybrid vehicle 100C according to the fourth embodiment.

  Also in the fifth embodiment, by providing the capacitor C10 in parallel with the stray capacitance C3, a balance between the current flowing out to the vehicle ground 80 and the current flowing back from the vehicle ground 80 can be achieved. Therefore, the effect similar to that of the first embodiment can be obtained also by the fifth embodiment.

[Embodiment 6]
In the sixth embodiment, when the current flowing through the stray capacitance C7 is larger than the current flowing through the stray capacitances C3, C4, C6, a configuration example of the compensation circuit corresponding to the first embodiment is shown. It is.

  FIG. 20 is an overall block diagram of a hybrid vehicle shown as an example of a vehicle according to the sixth embodiment. Referring to FIG. 20, hybrid vehicle 100E includes a capacitor C11 and a relay RY5 in place of capacitor C5 and relay RY1 in the configuration of hybrid vehicle 100 according to the first embodiment shown in FIG.

  Capacitor C11 and relay RY5 are connected in series between at least one line of a three-phase motor cable connecting motor generator MG1 to inverter 10 and vehicle ground 80. In FIG. 20, the capacitor C11 is connected to the W-phase motor cable, but the capacitor C11 may be connected to a motor cable of other phases.

  Relay RY5 is turned on in response to a signal from ECU 30 when power is transferred between power storage device B and load 90 outside the vehicle. On the other hand, when power is not transferred between power storage device B and load 90 outside the vehicle, relay RY5 is turned off in response to a signal from ECU 30, and motor cable of motor generator MG1 and vehicle ground 80 are connected to each other. The electric circuit formed via the capacitor C11 is cut off during

  The other configuration of hybrid vehicle 100E is the same as that of hybrid vehicle 100 according to the first embodiment.

  In the sixth embodiment, the current flowing through the stray capacitance C7 is larger than the current flowing through the stray capacitances C3, C4, C6. By providing C11, a balance between the current flowing out from the vehicle ground 80 and the current flowing back from the vehicle ground 80 is achieved. Therefore, the effect similar to that of the first embodiment can be obtained by the sixth embodiment.

[Embodiment 7]
In the seventh embodiment, when the current flowing through the stray capacitance C7 is larger than the current flowing through the stray capacitances C3, C4, C6, a configuration example of a compensation circuit corresponding to the second embodiment is shown. It is.

  FIG. 21 is an overall block diagram of a hybrid vehicle shown as an example of a vehicle according to the seventh embodiment. Referring to FIG. 21, hybrid vehicle 100F includes a coil L4 instead of coil L3 in the configuration of hybrid vehicle 100A according to the second embodiment shown in FIG.

  Coil L4 is arranged on power line ACL1. More specifically, motor generator MG1 is arranged between neutral point N1 and smoothing capacitor C2 at a node connected to power line ACL1.

  The other configuration of hybrid vehicle 100F is the same as that of hybrid vehicle 100 according to the first embodiment.

  Also in the seventh embodiment, the current flowing through the stray capacitance C7 is larger than the current flowing through the stray capacitances C3, C4, C6. By providing L4, a balance between the current flowing out from the vehicle ground 80 and the current flowing back from the vehicle ground 80 is achieved. Therefore, according to the seventh embodiment, the same effect as in the first embodiment can be obtained.

[Embodiment 8]
In the eighth embodiment, when the current flowing through the stray capacitance C7 is larger than the current flowing through the stray capacitances C3, C4, C6, a configuration example of a compensation circuit corresponding to the third embodiment is shown. It is.

  FIG. 22 is an overall block diagram of a hybrid vehicle shown as an example of a vehicle according to the eighth embodiment. Referring to FIG. 22, hybrid vehicle 100G further includes a capacitor C12 and a relay RY6 in the configuration of hybrid vehicle 100F according to the seventh embodiment shown in FIG. Capacitor C12 and relay RY6 are connected in series between power line ACL1 and vehicle ground 80 between neutral point N1 of motor generator MG1 and coil L4.

  Relay RY6 is turned on in response to a signal from ECU 30 when power is transferred between power storage device B and load 90 outside the vehicle. On the other hand, when power is not transferred between power storage device B and load 90 outside the vehicle, relay RY6 is turned off in response to a signal from ECU 30, and a capacitor is connected between power line ACL1 and vehicle ground 80. The electric circuit formed via C12 is interrupted.

  The other configuration of hybrid vehicle 100G is the same as that of hybrid vehicle 100F according to the seventh embodiment.

  According to the eighth embodiment, since the coil L4 is provided on the power line ACL1 and the capacitor C12 is provided, the coil L4 can be downsized as compared with the seventh embodiment.

  In each of the above embodiments, each vehicle is equipped with two motor generators. However, the present invention can also be applied to a vehicle equipped with three or more motor generators.

  FIG. 23 is an overall block diagram of a hybrid vehicle on which three motor generators are mounted. Referring to FIG. 23, hybrid vehicle 100H further includes a motor generator MGR, wheels 8, and an inverter 25 in the configuration of hybrid vehicle 100 according to the first embodiment shown in FIG. 1, and replaces power line ACL1. Power line ACL3.

  Motor generator MGR is incorporated in hybrid vehicle 100H as a power source for driving wheels 8 (for example, wheels 6 are front wheels while wheels 8 are rear wheels). Motor generator MGR includes Y-connected three-phase coils, and one end of each coil is connected to each other to form neutral point N3. A power line ACL3 is disposed between the neutral point N3 and the AC port 60.

  Inverter 25 is provided corresponding to motor generator MGR, and is connected in parallel to inverters 10 and 20 to positive line PL and negative line NL. The configuration of the inverter 25 is the same as that of the inverter 10.

  In hybrid vehicle 100H, power is transferred between the vehicle and load 90 using motor generators MG2, MGR among motor generators MG1, MG2, MGR. That is, power lines ACL2 and ACL3 are connected to neutral point N2 of motor generator MG2 and neutral point N3 of motor generator MGR, respectively, and power is exchanged between the vehicle and load 90 via power lines ACL2 and ACL3. .

  Capacitor C5 and relay RY1 are connected in series between at least one of the three-phase motor cables connecting motor generator MGR to inverter 25 and vehicle ground 80. In FIG. 23, the capacitor C5 is connected to the W-phase motor cable, but the capacitor C5 may be connected to a motor cable of another phase.

  The control of inverters 20 and 25 when power is exchanged between the vehicle and load 90 is the same as the control of inverters 10 and 20 described in the first embodiment.

  In the above description, power is exchanged between the vehicle and load 90 using inverters 20 and 25 and motor generators MG2 and MGR. However, any two of motor generators MG1, MG2 and MGR are used. You can choose.

  Further, in the above, the configuration example in which the compensation circuit in the first embodiment is applied to a vehicle on which three motor generators are mounted is shown. However, the other embodiments described above in a vehicle on which three or more motor generators are mounted. It is also possible to apply.

  In each of the above embodiments, the hybrid vehicle is a series / parallel type in which the power of the engine 2 can be divided and transmitted to the axle and the motor generator MG1 by the power split mechanism 4. However, the present invention uses the engine 2 only for driving the motor generator MG1 and generates the driving force of the vehicle only by the motor generator MG2, or a so-called series type hybrid vehicle or the engine as the main power as required. The present invention can also be applied to a motor-assisted hybrid vehicle that is assisted by a motor.

  Further, the present invention can also be applied to an electric vehicle that does not include the engine 2 and runs only by electric power, and a fuel cell vehicle that further includes a fuel cell as a power source in addition to a power storage device. In other words, the present invention can be applied to a general system including at least two AC motors including Y-connected motor coils.

  In each of the above embodiments, a converter that performs voltage conversion between power storage device B and inverters 10 and 20 may be provided between power storage device B and inverters 10 and 20. As such a converter, for example, a known chopper circuit can be used.

  In the above description, load 90 corresponds to one embodiment of “power source outside the vehicle” or “electric load outside the vehicle” in the present invention, and motor generators MG1, MG2, and MGR correspond to “a plurality of alternating currents” in the present invention. This corresponds to an example of “rotary electric machine”. Power lines ACL1 and ACL2 correspond to an example of “power line pair” in the present invention, and ECU 30 corresponds to an example of “control unit” in the present invention.

  Further, motor generators MG1 and MG2 correspond to one embodiment of "the other AC rotating electric machine" and "one AC rotating electric machine" in the present invention, respectively, and capacitors C5, C8 to C12 and coils L3 and L4 are respectively This corresponds to one embodiment of the “compensation circuit” in the present invention. Further, each of relays RY1, RY3 to RY5 corresponds to an embodiment of “cutoff circuit” in the present invention.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

1 is an overall block diagram of a hybrid vehicle shown as an example of a vehicle according to Embodiment 1 of the present invention. FIG. 2 is an equivalent circuit diagram of the system shown in FIG. 1 when electric power is transferred between a vehicle and a load. It is a functional block diagram of ECU shown in FIG. It is the wave form diagram which showed the switching state of the inverter, and the fluctuation | variation of the common mode voltage. 3 is an equivalent circuit diagram when the upper arm of the inverter 10 is turned on (voltage VAC> 0) and the lower arm of the inverter 20 is turned on in the circuit shown in FIG. 3 is an equivalent circuit diagram when the upper arm of the inverter 10 is on (voltage VAC> 0) and the upper arm of the inverter 20 is on in the circuit shown in FIG. FIG. 10 is an overall block diagram of a hybrid vehicle shown as an example of a vehicle according to a second embodiment. FIG. 8 is an equivalent circuit diagram of the system shown in FIG. 7 when power is transferred between the vehicle and a load. FIG. 9 is an equivalent circuit diagram when the upper arm of the inverter 10 is on (voltage VAC> 0) and the lower arm of the inverter 20 is on in the circuit shown in FIG. 9 is an equivalent circuit diagram when the upper arm of the inverter 10 is on (voltage VAC> 0) and the upper arm of the inverter 20 is on in the circuit shown in FIG. FIG. 10 is an overall block diagram of a hybrid vehicle shown as an example of a vehicle according to a third embodiment. FIG. 12 is an equivalent circuit diagram of the system shown in FIG. 11 when power is transferred between the vehicle and a load. 13 is an equivalent circuit diagram when the upper arm of the inverter 10 is turned on (voltage VAC> 0) and the lower arm of the inverter 20 is turned on in the circuit shown in FIG. 13 is an equivalent circuit diagram when the upper arm of the inverter 10 is on (voltage VAC> 0) and the upper arm of the inverter 20 is on in the circuit shown in FIG. FIG. 10 is an overall block diagram of a hybrid vehicle shown as an example of a vehicle according to a fourth embodiment. FIG. 16 is an equivalent circuit diagram of the system shown in FIG. 15 when power is transferred between the vehicle and a load. 17 is an equivalent circuit diagram when the upper arm of the inverter 10 is turned on (voltage VAC> 0) and the lower arm of the inverter 20 is turned on in the circuit shown in FIG. FIG. 17 is an equivalent circuit diagram when the upper arm of the inverter 10 is turned on (voltage VAC> 0) and the upper arm of the inverter 20 is turned on in the circuit shown in FIG. 16. FIG. 10 is an overall block diagram of a hybrid vehicle shown as an example of a vehicle according to a fifth embodiment. FIG. 10 is an overall block diagram of a hybrid vehicle shown as an example of a vehicle according to a sixth embodiment. FIG. 16 is an overall block diagram of a hybrid vehicle shown as an example of a vehicle according to a seventh embodiment. FIG. 20 is an overall block diagram of a hybrid vehicle shown as an example of a vehicle according to an eighth embodiment. 1 is an overall block diagram of a hybrid vehicle equipped with three motor generators.

Explanation of symbols

  2 engine, 4 power split mechanism, 6, 8 wheels, 10, 20, 25 inverter, 12, 22 U-phase arm, 14, 24 V-phase arm, 16, 26 W-phase arm, 30 ECU, 32 first inverter control 34, second inverter control unit, 36 charge / discharge control unit, 60 AC port, 70 plug, 80 vehicle ground, 90 load, 95 ground node, 100, 100A to 100H hybrid vehicle, B power storage device, C1, C2 smooth Capacitor, C3, C4, C6, C7 stray capacitance, C5, C8 to C12 capacitor, RY1 to RY6 relay, PL positive line, NL negative line, MG1, MG2, MGR motor generator, N1 to N3 neutral point, ACL1 to ACL3 Power line, L1, L2 leakage inductance, L3, L4 coil, Rh contact resistance

Claims (12)

Electric power that can be converted to DC power by converting AC power supplied from a power source outside the vehicle to DC power, or can be output to an electric load outside the vehicle by converting DC power from the power storage device to AC power A control device,
A plurality of AC rotating machines each including a star-connected multiphase winding as a stator winding; and
A plurality of inverters provided corresponding to the plurality of AC rotating electric machines;
A plug connectable to the power source or the electrical load;
A pair of power lines connecting the plug to a neutral point of a multiphase winding of two AC rotating machines among the plurality of AC rotating machines;
The inverter corresponding to one of the two AC rotating electric machines is controlled using a pulse width modulation method, and the upper arm and the lower arm of the inverter corresponding to the other of the two AC rotating electric machines are set to the energization direction of the AC power. A control unit configured to exchange power between the power storage device and the power source or the electric load by alternately turning on according to
A current flowing through a stray capacitance between the one AC rotating electric machine and the vehicle ground; a current flowing through a stray capacitance between the other AC rotating electric machine and the vehicle ground; and the plurality of inverters; A power control apparatus comprising: a compensation circuit configured to be able to compensate for a difference from a sum of currents flowing through a stray capacitance with respect to a vehicle ground.   2. The power control device according to claim 1, wherein the compensation circuit includes a first capacitor connected between a motor power line connecting the one AC rotating electric machine to a corresponding inverter and the vehicle ground.   The power control apparatus according to claim 2, wherein the compensation circuit further includes a cut-off circuit capable of cutting off an electric circuit formed between the motor power line and the vehicle ground via the first capacitor.   4. The compensation circuit according to claim 1, wherein the compensation circuit includes a coil disposed on a power line that connects the plug to a neutral point of the multiphase winding of the one AC rotating electric machine. 5. Power control device.   The compensation circuit further includes a second capacitor connected between a power line disposed between a neutral point of the multiphase winding of the one AC rotating electric machine and the coil and the vehicle ground. The power control apparatus according to claim 4.   The power control apparatus according to claim 1, wherein the compensation circuit includes a capacitor connected between a power line disposed between the plurality of inverters and the power storage device and the vehicle ground.   The power control apparatus according to claim 6, wherein the compensation circuit further includes a cut-off circuit capable of cutting off an electric circuit formed between the power line and the vehicle ground via the capacitor.   2. The power control device according to claim 1, wherein the compensation circuit includes a first capacitor connected between a motor power line connecting the other AC rotating electric machine to a corresponding inverter and the vehicle ground.   9. The power control apparatus according to claim 8, wherein the compensation circuit further includes a cutoff circuit capable of cutting off an electric circuit formed between the motor power line and the vehicle ground via the first capacitor.   The said compensation circuit contains the coil arrange | positioned by the power line which connects the said plug to the neutral point of the multiphase winding of said other alternating current rotating electrical machine. The power control apparatus according to item 1.   The compensation circuit further includes a second capacitor connected between a power line disposed between a neutral point of the multiphase winding of the other AC rotating electric machine and the coil and the vehicle ground. The power control apparatus according to claim 10. A wheel that receives a driving torque from at least one of the plurality of AC rotating electric machines;
A vehicle comprising the power control device according to any one of claims 1 to 11.

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