JP5292186B2 - Electric vehicle power supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve efficiency during external charging by constructing a power supply system so that a power supply destination when an on-board energy storage device is externally charged is properly set. <P>SOLUTION: A main battery 10 is externally charged by an output voltage of a charger 110 with power from an external power supply 400 as a source by turning on relays RL1 and RL2. The output voltages of the main battery 10 and the charger 110 are not applied to a PCU 20 by turning off system main relays SMR1 and SMR2. Thus, a protection function of the PCU 20 can be made in a non-operation state. Consequently, power supply voltage Vi from a DC/DC converter 60 where power from the external power supply 400 is set to be the source is not transmitted to the PCU 20 by turning off a relay RL4. Then, efficiency of external charging can be improved by stopping a control power supply of the PCU 20. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a power supply system for an electric vehicle, and more particularly to a power supply system for an electric vehicle equipped with a power storage device that can be charged by a power supply external to the vehicle.

  An electric vehicle, a hybrid vehicle, or a fuel cell vehicle is known as an electric vehicle configured to be able to drive a vehicle driving motor using electric power from an in-vehicle power storage device typified by a secondary battery. In an electric vehicle, a configuration has been proposed in which an in-vehicle power storage device is charged by a power source outside the vehicle (hereinafter also simply referred to as “external power source”). Hereinafter, charging of the power storage device by the external power supply is also simply referred to as “external charging”.

  For example, Japanese Patent Application Laid-Open No. 2000-59919 discloses a battery charging device for an electric vehicle that can be externally charged. A rectifier of a charging circuit at the time of external charging is connected to an external charging target via an air conditioner relay for controlling an air conditioner motor. A configuration for connecting to the main battery is described. In this configuration, when the fuse is blown, the voltage between the terminals of the rectifier rises and an overvoltage is applied to the main battery, so that the relay drive signal is output from the relay drive circuit, thereby cutting off the charging circuit. The

  Thereby, in the structure of patent document 1, external charging which protects a motor drive circuit by cut | disconnecting a connection of a battery and a charging circuit reliably at the time of an overvoltage is realizable, without adding a new relay etc.

JP 2000-59919 A

  In the configuration of the battery charging device described in Patent Literature 1, when the main battery (power storage device) is externally charged, the charging power of the main battery is also applied to a power conversion circuit (such as an inverter) for driving the motor. Become.

  On the other hand, since it is not necessary to operate the drive motor during external charging, it is preferable to completely stop the control system circuit of the power conversion circuit in order to increase the efficiency of external charging.

  However, in the configuration of Patent Document 1, the charging voltage of the main battery is commonly applied to the drive inverter (power conversion circuit) even during external charging. For this reason, if the control system circuit is stopped, the inverter protection control function in case of malfunction does not operate normally, and there is a risk of equipment failure due to overvoltage or overcurrent due to power fluctuation or noise effects. .

  Therefore, in the configuration of Patent Document 1, it is necessary to continue power supply to the control system circuit of the drive inverter (power conversion circuit) even during external charging. For this reason, the efficiency of external charging is reduced.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power supply destination for externally charging an in-vehicle power storage device for an electric vehicle that can be charged by an external power source. Is to increase the efficiency during external charging by configuring the power supply system to be set appropriately.

  An electric vehicle power supply system according to the present invention is an electric vehicle power supply system configured to be rechargeable by an external power supply outside the vehicle, and includes a rechargeable power storage device, a charger, a power control unit, and connection means. And a disconnecting means, a voltage supply means, and a voltage cutoff means. The charger is configured to convert power supplied from the external power source into charging power for the power storage device during external charging in which the power storage device is charged by the front external power source. The power control unit is connected between the power storage device and the electric motor for generating vehicle driving force, and is configured to drive and control the electric motor. The connecting means electrically connects the charger and the power storage device during external charging. The disconnecting means electrically disconnects the charger, the power storage device, and the power control unit during external charging. The voltage supply means supplies the power supply voltage of the auxiliary system lower than the output voltage of the power storage device using the power supplied from the external power supply as a source during external charging. The voltage cut-off means cuts off the supply of the power supply voltage from the voltage supply means to the control power supply of the power control unit during external charging.

  According to the power supply system for an electric vehicle, when the power storage device is externally charged, the power control unit can be generated from the power storage device and the charger while the power supply voltage of the auxiliary system can be generated from the power from the external power source. Can be separated. As a result, the operation of the low voltage system (auxiliary system) circuit / equipment can be ensured, and the efficiency of external charging can be increased by stopping the control power supply of the power control unit. That is, it is to increase the efficiency at the time of external charging by configuring the power supply system so that the power supply destination is appropriately set when externally charging the in-vehicle power storage device.

  Preferably, the power control unit is supplied with power from the first power supply wiring and the first ground wiring, and the charger outputs charging power between the second power supply wiring and the second ground wiring. The disconnecting means includes a first main switch connected between the first power supply wiring and the positive terminal of the power storage device. The connecting means includes a second main switch connected between the first ground wiring and the negative terminal of the power storage device, and a first main switch connected between the second power supply wiring and the positive terminal of the power storage device. And a second switch connected between the second ground wiring and the first ground wiring. The voltage supply means connects the converter configured to output the power supply voltage by converting the DC voltage on the input side, and the positive terminal and the input side of the converter without going through the first main switch. 3 power wiring, a low voltage power wiring for transmitting a power voltage inside the electric vehicle, and a first auxiliary switch connected between the output side of the converter and the low voltage power wiring. The voltage interruption means includes a second auxiliary switch connected between the low voltage power supply wiring and the control power supply of the power control unit. During external charging, the first main switch and the second auxiliary switch are turned off, while the second main switch, the first and second switches, and the first auxiliary switch are Turn on. On the other hand, when the electric vehicle is traveling, the first and second switches are turned off, while the first and second main switches and the first and second auxiliary switches are turned on.

  In this way, by turning off the first and second main switches, the power storage device can be externally charged in a state where no voltage is applied to the power control unit. That is, it is possible to realize a configuration of a power supply system that can stop the control power supply of the power control unit during external charging. Further, when the vehicle is traveling, the electric vehicle is driven using the electric power of the power storage device, and the charger for external charging can be protected by turning off the first and second switches.

  Preferably, the power control unit is supplied with power from the first power supply wiring and the first ground wiring, and the charger outputs charging power between the second power supply wiring and the second ground wiring. Further, the first ground wiring is directly electrically connected to the second ground wiring. The disconnecting means includes a first main switch connected between the first power supply wiring and the positive terminal of the power storage device. The connecting means includes a second main switch connected between the first ground wiring and the negative terminal of the power storage device, and a first main switch connected between the second power supply wiring and the positive terminal of the power storage device. Switchgear. The voltage supply means includes a converter configured to output a power supply voltage by converting a DC voltage on the input side, and a third power supply wiring that electrically connects the second power supply wiring and the input side of the converter. And a low voltage power supply line for transmitting a power supply voltage inside the electric vehicle, and a first auxiliary switch connected between the output side of the converter and the low voltage power supply line. The voltage cut-off means includes a second auxiliary switch connected between the low-voltage power supply wiring and the control power supply of the power control unit. During external charging, the first main switch and the second auxiliary switch are turned off, while the second main switch, the first switch, and the first auxiliary switch are turned on. On the other hand, when the electric vehicle travels, the first and second main switches, the first switch, and the first and second auxiliary switches are turned on.

  In this case, the second main switch is also used as a switch on the negative electrode output side of the charger, and the first main switch is turned off to store power in a state where no voltage is applied to the power control unit. The device can be externally charged. Therefore, it is possible to realize a configuration of a power supply system capable of stopping the control power supply of the power control unit during external charging while reducing the number of switches disposed. Further, when the vehicle is traveling, the electric vehicle can be driven using the electric power of the power storage device.

  Alternatively, preferably, the power control unit is supplied with power from the first power supply wiring and the first ground wiring, and the charger outputs charging power between the second power supply wiring and the second ground wiring. Further, the disconnecting means is connected between the first main switch connected between the first power supply wiring and the positive terminal of the power storage device, and between the first ground wiring and the negative terminal of the power storage device. And a second main switch. The connecting means includes a first switch connected between the second power supply line and the positive terminal of the power storage device, and a second switch connected between the second ground wiring and the negative terminal of the power storage device. Including a switch. The voltage supply means includes a converter configured to output a power supply voltage by converting a DC voltage on the input side, and a second power supply with a direction from the second power supply wiring toward the input side of the converter as a forward direction. The first rectifier element connected between the wiring and the input side of the converter, the low voltage power wiring for transmitting the power voltage inside the electric vehicle, and connected between the output side of the converter and the low voltage power wiring. And a first auxiliary switch. The voltage interruption means includes a second auxiliary switch connected between the low voltage power supply wiring and the control power supply of the power control unit. Further, the power supply system further includes a second rectifying element connected between the first power supply wiring and the input side of the converter, with a direction from the first power supply wiring toward the input side of the converter as a forward direction. During external charging, the first and second main switches and the second auxiliary switch are turned off, while the first and second switches and the first auxiliary switch are turned on. On the other hand, when the electric vehicle is traveling, the first and second switches are turned off, while the first and second main switches and the first and second auxiliary switches are turned on.

  Thus, by turning off the first and second main switches, the power storage device can be externally charged in a state where no voltage is applied to the power control unit. For this reason, the structure of the power supply system which can stop the control power supply of a power control unit at the time of external charging is realizable. In addition, when the vehicle is traveling, the electric vehicle can be driven using the electric power of the power storage device, and the first rectifying element is reverse-biased, so that a charger for external charging is connected to a high voltage (output of the power storage device). Voltage).

  Preferably, the power control unit is supplied with power from the first power supply wiring and the first ground wiring, and the charger outputs charging power between the second power supply wiring and the second ground wiring. The first ground wiring is directly electrically connected to the second ground wiring. Further, the disconnecting means includes a first main switch connected between the first power supply wiring and the positive terminal of the power storage device. The connecting means includes a second main switch connected between the first ground wiring and the negative terminal of the power storage device, and a first main switch connected between the second power supply wiring and the positive terminal of the power storage device. Switchgear. The voltage supply means includes a converter configured to output a power supply voltage by converting a DC voltage on the input side, and a first power supply with a direction from the second power supply wiring toward the input side of the converter as a forward direction. The first rectifier element connected between the wiring and the input side of the converter, the low voltage power wiring for transmitting the power voltage inside the electric vehicle, and connected between the output side of the converter and the low voltage power wiring. And a first auxiliary switch. The voltage interruption means includes a second auxiliary switch connected between the low voltage power supply wiring and the control power supply of the power control unit. Furthermore, the power supply system includes a second rectifying element. The second rectifying element is connected between the first power supply wiring and the input side of the converter with the direction from the first power supply wiring toward the input side of the converter as a forward direction. During external charging, the first main switch and the second auxiliary switch are turned off, while the second main switch, the first switch, and the first auxiliary switch are turned on. On the other hand, when the electric vehicle travels, the first switch is turned off, while the first and second main switches and the first and second auxiliary switches are turned on.

  In this case, the second main switch is also used as a switch on the negative electrode output side of the charger, and the first main switch is turned off to store power in a state where no voltage is applied to the power control unit. The device can be externally charged. Therefore, it is possible to realize a configuration of a power supply system capable of stopping the control power supply of the power control unit during external charging while reducing the number of switches disposed. Further, when the vehicle is running, the electric vehicle is driven using the electric power of the power storage device, and the first rectifying element is reverse-biased, so that the charger for external charging has a high voltage (output voltage of the power storage device). Can be protected from application.

  Preferably, the power control unit is supplied with power from the first power supply wiring and the first ground wiring, and the charger outputs charging power between the second power supply wiring and the second ground wiring. Further, the disconnecting means is connected between the first main switch connected between the first power supply wiring and the positive terminal of the power storage device, and between the first ground wiring and the negative terminal of the power storage device. And a second main switch. The connecting means includes a first switch connected between the second power supply line and the positive terminal of the power storage device, and a second switch connected between the second ground wiring and the negative terminal of the power storage device. Including a switch. The voltage supply means includes a converter configured to output a power supply voltage by converting a DC voltage on the input side, and a third for electrically connecting the positive terminal of the power storage device and the input side of the converter. Power supply wiring, low voltage power supply wiring for transmitting a power supply voltage inside the electric vehicle, and a first auxiliary switch connected between the output side of the converter and the low voltage power supply wiring are included. The voltage interruption means includes a second auxiliary switch connected between the low voltage power supply wiring and the control power supply of the power control unit. The voltage supply means further includes a third auxiliary switch interposed and connected to the third power supply wiring. During external charging, the first and second main switches and the second auxiliary switch are turned off, while the first and second switches and the first auxiliary switch are turned on. On the other hand, when the electric vehicle is traveling, the first and second switches are turned off, while the first and second main switches and the first and second auxiliary switches are turned on. Further, in each of external charging and traveling, the third auxiliary switch is controlled to be turned on / off based on the supply state of the power supply voltage.

  Thus, by turning off the first and second main switches, the power storage device can be externally charged in a state where no voltage is applied to the power control unit. For this reason, the structure of the power supply system which can stop the control power supply of a power control unit at the time of external charging is realizable. In addition, when the vehicle is running, the electric vehicle can be driven using the electric power of the power storage device, and the first and second switches are turned off, so that the charger for external charging has a high voltage (the power storage device It can be protected from the application of the output voltage. Furthermore, since the third auxiliary switch can be turned off according to the supply state of the power supply voltage during external charging and when the vehicle is running, the power consumption of the auxiliary system (low voltage system) can be reduced. That is, it is possible to improve the efficiency of external charging and improve the fuel efficiency during vehicle travel.

  Alternatively, preferably, the power control unit is supplied with power from the first power supply wiring and the first ground wiring, and the charger outputs charging power between the second power supply wiring and the second ground wiring. Further, the disconnecting means is connected between the first main switch connected between the first power supply wiring and the positive terminal of the power storage device, and between the first ground wiring and the negative terminal of the power storage device. And a second main switch. The connecting means includes a first switch connected between the second power supply line and the positive terminal of the power storage device, and a second switch connected between the second ground wiring and the negative terminal of the power storage device. Including a switch. The voltage supply means includes an auxiliary converter for converting power supplied from an external power source to a power supply voltage, a low-voltage power wiring for transmitting the power voltage inside the electric vehicle, and an output voltage of the auxiliary converter to the low-voltage power wiring. Transmission means (195) for transmission. The power supply system includes a converter configured to output a power supply voltage by converting a DC voltage on the input side, and a third power supply for electrically connecting the positive terminal of the power storage device and the input side of the converter Wiring and a first auxiliary switch connected between the output side of the converter and the low voltage power supply wiring. The voltage interruption means includes a second auxiliary switch connected between the low voltage power supply wiring and the control power supply of the power control unit. During external charging, the first and second main switches and the first and second auxiliary switches are turned off, while the first and second switches are turned on and the converter is stopped. The auxiliary converter operates in On the other hand, when the electric vehicle is traveling, the first and second switches are turned off, while the first and second main switches and the first and second auxiliary switches are turned on, and the auxiliary converter is turned on. The converter operates while stopping. The converter has a larger power capacity and power consumption than the auxiliary converter.

  Thus, by turning off the first and second main switches, the power storage device can be externally charged in a state where no voltage is applied to the power control unit. For this reason, the structure of the power supply system which can stop the control power supply of a power control unit at the time of external charging is realizable. In addition, when the vehicle is running, the electric vehicle can be driven using the electric power of the power storage device, and the first and second switches are turned off, so that the charger for external charging has a high voltage (the power storage device It can be protected from the application of the output voltage. Furthermore, since the auxiliary system (low voltage system) power supply voltage can be supplied by the auxiliary converter during external charging, the converter having relatively large power capacity and power consumption can be stopped. For this reason, the efficiency of external charging can be further increased.

  More preferably, the transmission means includes a rectifying element connected between the output side of the auxiliary converter and the low-voltage power supply line with the direction from the output side of the auxiliary converter toward the low-voltage power supply line as the forward direction.

  In this way, since the rectifying element is reverse-biased during vehicle travel when the auxiliary converter is stopped, it is possible to prevent voltage application to the auxiliary converter and to protect the circuit.

  According to the present invention, for an electric vehicle that can be charged by an external power supply, by configuring the power supply system so that the power supply destination in the external charging of the in-vehicle power storage device is appropriately set, the efficiency at the time of external charging can be improved. Can be increased.

It is a block diagram explaining the structure of the power supply system of the electric vehicle by the comparative example of embodiment of this invention. It is a chart explaining ON / OFF of each switch in the power supply system shown in FIG. It is a block diagram explaining the structure of the power supply system of the electric vehicle by Embodiment 1 of this invention. FIG. 4 is a chart for explaining on / off of each switch in the power supply system shown in FIG. 3. FIG. It is a block diagram explaining the modification of a structure of the power supply system shown in FIG. It is a block diagram explaining the structure of the power supply system of the electric vehicle by Embodiment 2 of this invention. 7 is a chart for explaining on / off of each switch in the power supply system shown in FIG. 6. It is a block diagram explaining the modification of a structure of the power supply system shown in FIG. It is a block diagram explaining the structure of the power supply system of the electric vehicle by Embodiment 3 of this invention. 10 is a chart for explaining on / off of each switch in the power supply system shown in FIG. 9. FIG. 10 is a block diagram illustrating a modified example of the configuration of the power supply system illustrated in FIG. 9. It is a block diagram explaining the structure of the power supply system of the electric vehicle by Embodiment 4 of this invention. 13 is a chart for explaining on / off of each switch in the power supply system shown in FIG. 12. It is a block diagram explaining the modification of a structure of the power supply system shown in FIG. It is a block diagram explaining the structure of the power supply system of the electric vehicle by Embodiment 5 of this invention. 16 is a chart for explaining on / off of each switch in the power supply system shown in FIG. 15. It is a block diagram explaining the modification of a structure of the power supply system shown in FIG. It is a block diagram explaining the structure of the power supply system of the electric vehicle by Embodiment 6 of this invention. It is a chart explaining on-off of each switch in the power supply system shown in FIG. It is a block diagram explaining the modification of a structure of the power supply system shown in FIG.

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

[Description of Comparative Example]
First, the configuration of a power supply system as a comparative example for the power supply system of an electric vehicle according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a block diagram showing a power system configuration of an electric vehicle according to a comparative example of the embodiment of the present invention.

  Referring to FIG. 1, an electric vehicle 100 includes a main battery 10, a power control unit (PCU) 20, an overall ECU (Electronic Control Unit) 21, a motor generator 30, a power transmission gear 40, and drive wheels 50. With.

  The main battery 10 is shown as a representative example of the “power storage device”, and typically includes a secondary battery such as a lithium ion battery or a nickel metal hydride battery. For example, the output voltage of the main battery 10 is about 200V. Alternatively, the “power storage device” may be configured by a capacitor for an electric vehicle or a combination of a secondary battery and a capacitor.

  The PCU 20 converts the stored power of the main battery 10 into power for driving and controlling the motor generator 30. For example, motor generator 30 is configured with a permanent magnet type three-phase synchronous motor, and PCU 20 is configured to include inverter 26.

  The output torque of motor generator 30 is transmitted to the drive wheels via power transmission gear 40 constituted by a speed reducer and a power split mechanism, and causes electric vehicle 100 to travel. The motor generator 30 can generate electric power by the rotational force of the drive wheels 50 during the regenerative braking operation of the electric vehicle 100. The generated power is converted into charging power for the main battery 10 by the PCU 20.

  Further, in a hybrid vehicle equipped with an engine (not shown) in addition to motor generator 30, the necessary vehicle driving force of electric vehicle 100 is generated by operating this engine and motor generator 30 in a coordinated manner. . At this time, it is also possible to charge the main battery 10 using the power generated by the rotation of the engine.

  That is, the electric vehicle 100 indicates a vehicle on which an electric motor for generating vehicle driving force is mounted, and includes a hybrid vehicle that generates vehicle driving force by an engine and an electric motor, an electric vehicle that does not have an engine, a fuel cell vehicle, and the like. .

  From the configuration of the electric vehicle 100 shown in the figure, a portion excluding the motor generator 30, the power transmission gear 40, and the drive wheels 50 constitutes an “electric vehicle power supply system”. Hereinafter, the configuration of the power supply system will be described in detail.

  Power control unit (PCU) 20 includes a converter CNV, a smoothing capacitor C0, an inverter 26, an internal power supply circuit 22, and an MG (Motor Generator) -ECU 25.

  Converter CNV is configured to perform DC voltage conversion between DC voltage VL of power supply wiring 153p and DC voltage VH of power supply wiring 154p. DC voltages VL and VH are detected by voltage sensors 163 and 164, respectively.

  Power supply wiring 153p and ground wiring 153g are electrically connected to the positive terminal and the negative terminal of main battery 10 through system main relays SMR1 and SMR2, respectively. The smoothing capacitor C0 is connected to the power supply wiring 154p and smoothes the DC voltage. Similarly, the smoothing capacitor C1 is connected to the power supply wiring 153p and smoothes the DC voltage VL.

  As shown in FIG. 1, converter CNV is configured as a chopper circuit including power semiconductor switching elements (hereinafter also simply referred to as “switching”) Q1, Q2, a reactor L1, and a smoothing capacitor C1. Since antiparallel diodes are connected to switching elements Q1 and Q2, converter CNV can perform bidirectional voltage conversion between power supply line 153p and power supply line 154p. Alternatively, the switching element Q1, which is the upper arm element, is fixed on, while the switching element Q2, which is the lower arm element, is fixed off, so that the voltages of the power supply lines 154p and 153p are the same (VH = VL). The converter CNV can also be operated.

  Since the inverter 26 is a general three-phase inverter, the detailed circuit configuration is not shown. For example, the inverter 26 is arranged so that the upper arm element and the lower arm element are arranged in each phase, and the connection point of the upper and lower arm elements in each phase is connected to the stator coil winding of the corresponding phase of the motor generator 30. Composed.

  When electric powered vehicle 100 is traveling, inverter 26 is turned on and off by MG-ECU 25 to convert the DC voltage of power supply wiring 154p into a three-phase AC voltage and supply it to motor generator 30. Alternatively, during regenerative braking operation of electrically powered vehicle 100, inverter 26 is controlled to be turned on and off by MG-ECU 25 so that inverter 26 converts the AC voltage from motor generator 30 into a DC voltage and outputs it to power supply wiring 154p. The

  The entire ECU 21 is comprehensively described as a block having a function of supervising control of the electric vehicle 100 during traveling of the vehicle and during external charging. The entire ECU 21 operates by being supplied with the power supply voltage Vi from the power supply wiring 156p.

  On the other hand, the MG-ECU 25 separately describes functional portions for realizing the control functions related to the PCU 20 among the control functions of the entire vehicle. Unlike the overall ECU 21, the MG-ECU 25 is configured such that operating power is supplied from an internal power supply circuit 22 in the PCU 20.

  Note that the overall ECU 21 and the MG-ECU 25 achieve a desired control function through predetermined arithmetic processing by execution of a program stored in advance in a built-in memory (not shown) or predetermined arithmetic processing by hardware such as an electronic circuit. Composed.

  MG-ECU 25 generates control instructions for converter CNV and inverter 26 so as to drive motor generator 30 in accordance with an operation command from overall ECU 21. The internal power supply circuit 22 is configured to supply operating power of various devices including a control system circuit in the PCU 20 using a power supply voltage Vi corresponding to the output voltage of the auxiliary battery 70 as a source. The MG-ECU 25 is also supplied with operating power from the internal power supply circuit 22. That is, the internal power supply circuit 22 corresponds to a control power supply for the PCU 20.

  The MG-ECU 25 further has a protection function such as forcibly turning off the switching element when an overcurrent is generated in the PCU 20. Therefore, when the MG-ECU 25 is operating by being supplied with operating power, even if the switching element malfunctions due to noise or the like, failure of the switching element can be avoided by the operation of the protection function. Alternatively, the protection function (hereinafter also referred to as “PCU protection function”) may be realized by a protection circuit (not shown) that operates by supplying power from the internal power supply circuit 22.

  On the other hand, when the internal power supply circuit 22 is stopped, that is, when the control power supply of the PCU 20 is stopped, the PCU protection function does not operate. If the PCU 20 is electrically connected to the main battery 10 in such a state, the PCU protection function cannot appropriately prevent the occurrence of overvoltage or overcurrent in the PCU 20 due to malfunction or voltage fluctuation due to noise. There is a possibility that a failure may occur in the switching element or the like.

  The power supply system of electrically powered vehicle 100 further includes a DC / DC converter 60, an auxiliary battery 70, power supply wirings 155p and 156p, and relay RL3 as a low voltage system (auxiliary system) configuration. Auxiliary battery 70 is connected to power supply wiring 155p and ground wiring 155g. Auxiliary battery 70 is typically formed of a lead storage battery. The output voltage of the auxiliary battery 70 corresponds to the low-voltage power supply voltage Vi. The power supply voltage Vi is lower than the output voltage of the main battery 10 and is, for example, about 12V.

  The DC / DC converter 60 outputs the power supply voltage Vi by stepping down the DC voltage VL corresponding to the output voltage of the main battery 10. The output side of the DC / DC converter 60 is connected to the power supply wiring 155p.

  Relay RL3 is electrically connected between power supply lines 155p and 156p. The power supply wiring 156p is arranged to supply the operating power supply voltage Vi to the low voltage system circuit of the electric vehicle 100. That is, in addition to the entire ECU 21, a low voltage system (auxiliary system) circuit / device group (not shown) that is operated by the power supply voltage Vi is connected.

  Furthermore, the power supply system of electrically powered vehicle 100 includes a charging connector 105, a charger 110, and relays RL1 and RL2 as a configuration for external charging of main battery 10 (power storage device).

  The charging connector 105 is electrically connected to the external power source 400 by being connected to the charging plug 410 of the charging cable that is connected to the external power source 400. It is assumed that the charging cable incorporates a relay 405 for cutting off the charging path of the external power source 400. In general, the external power source 400 is a commercial AC power source.

  Instead of the configuration shown in FIG. 1, the external power source 400 and the electric vehicle 100 are electromagnetically coupled in a non-contact manner to supply electric power, specifically, a primary coil is provided on the external power source side, A secondary coil may be provided on the vehicle side, and electric power may be supplied from the external power supply 400 to the electric vehicle 100 using the mutual inductance between the primary coil and the secondary coil. Even when such external charging is performed, the configuration after the charger 110 that converts the power supplied from the external power source 400 can be shared.

  Power supply wiring 151 electrically connects between charging connector 105 and charger 110. A voltage sensor 161 is provided in the power supply wiring 151. The charger 110 converts the AC voltage from the external power supply 400 transmitted to the power supply wiring 151 into a DC voltage for charging the main battery 10. The converted DC voltage is output between the power supply wiring 152p and the ground wiring 152g. A voltage sensor 162 for detecting the output voltage of the charger 110 is connected between the power supply wiring 152p and the ground wiring 152g.

  The output of charger 110 is transmitted to power supply wiring 152p via diode 155. That is, the inflow current from the power supply wiring 152p to the charger 110 is blocked by the diode 155.

  Relay RL1 is electrically connected between power supply wiring 152p and power supply wiring 153p. Relay RL2 is electrically connected between ground wiring 152g and ground wiring 153g.

  Each of relays RL1 to RL3 and system main relays SMR1 and SMR2 are typically turned on (turned on) when an exciting current is supplied by an exciting circuit (not shown), and opened (turned off) when no exciting current is supplied. Consists of electromagnetic relays. However, any circuit element can be used as the relay or the system main relay as long as it is a switch that can control conduction (ON) / interruption (OFF) of the energization path. Therefore, in the following, these relays and the system main relay are also collectively referred to as “switches”.

  FIG. 2 shows on / off of each switch during external charging and when the vehicle travels after completion of normal external charging.

  Referring to FIGS. 2 and 1, relays RL1 and RL2 are turned on during external charging. Therefore, a DC voltage obtained by converting AC power from the external power supply 400 by the charger 110 is transmitted to the power supply wiring 153p. Further, by turning on system main relays SMR1 and SMR2, the DC voltage from charger 110 transmitted to power supply wiring 153p is used for charging main battery 10.

  Note that the DC voltage of the power supply wiring 153 p is also transmitted to the DC / DC converter 60. Therefore, the DC / DC converter 60 can generate the power supply voltage Vi by the power supplied from the external power supply 400. Further, since relay RL3 is turned on, power supply voltage Vi generated using power supplied from external power supply 400 is supplied from power supply wiring 156p to a circuit group and a device group of a low voltage system (auxiliary system). The

  On the other hand, when the vehicle travels, system main relays SMR1, SMR2 are turned on, while relays RL1, RL2 are turned off.

  As a result, the charger 110 is disconnected from the power supply wiring 153p and the ground wiring 153g by the relays RL1 and RL2, and the output voltage from the main battery 10 is supplied to the power supply wiring 153p and the ground wiring 153g via the system main relays SMR1 and SMR2. Is transmitted to. That is, the electric power on the power supply wiring 153p electrically connected to the main battery 10 is used for driving control of the motor generator 30 by the PCU 20, and used for supplying the low-voltage power supply voltage Vi by the DC / DC converter 60. In this state, the electric vehicle 100 travels.

  When relay RL3 is turned on, power supply voltage Vi from DC / DC converter 60 and / or auxiliary battery 70 is supplied from power supply wiring 156p to the low voltage circuit system including internal power supply circuit 22 of PCU 20.

  However, in the configuration of the comparative example shown in FIG. 1, the system main relays SMR1 and SMR2 are turned on even during external charging, so that power is supplied from the power supply wiring 153p to the PCU 20. As a result, the output voltage of the main battery 10 is applied to the power supply wirings 153p and 154p. If the operation of the control circuit system of the PCU 20 including the MG-ECU 25 is stopped in such a state, the PCU protection function is activated when malfunctions or voltage fluctuations occur in the converter CNV and the switching elements of the inverter 26. I can't.

  Therefore, in the configuration of the comparative example shown in FIG. 1, it is necessary to supply the control power of the PCU 20 even during external charging where it is not necessary to operate the motor generator 30 as in the case of Patent Document 1. As a result, the efficiency of external charging is reduced due to the power consumption of the control power supply.

  In the power supply system according to the present embodiment described below, the efficiency of external charging is improved by appropriately setting the energization path during external charging of the main battery 10 in order to solve the problems in the comparative example.

[Embodiment 1]
FIG. 3 is a circuit diagram illustrating the configuration of the power supply system for the electric vehicle according to the first embodiment of the present invention.

  As understood from the comparison between FIG. 3 and FIG. 1, the power supply system for the electric vehicle according to the first embodiment is different from the power supply system of the comparative example between the charger 110, the power supply wiring 153p, and the ground wiring 153g. The connection and the connection between the power supply wiring 153p and the DC / DC converter 60 are different. Further, relay RL4 is further provided between power supply wiring 156p and internal power supply circuit 22.

  Relay RL1 is electrically connected between power supply line 152p and the positive terminal of main battery 10. That is, when relay RL1 is turned on, power supply line 152p is electrically connected to the positive terminal of main battery 10 without passing through power supply line 153p. Relay RL2 is electrically connected between ground wires 152g and 153g. The positive terminal of the main battery 10 is electrically connected to the power supply wiring 153p via the system main relay SMR1 as in FIG.

  The input side of the DC / DC converter 60 is electrically connected to the positive terminal of the main battery 10 and the ground wiring 153g by the power supply wiring 158p and the ground wiring 158g, respectively. That is, the DC / DC converter 60 is electrically connected to the positive terminal of the main battery 10 without passing through the system main relay SMR1. Since the configuration of other parts of electrically powered vehicle 100 is the same as that of the comparative example shown in FIG. 1, detailed description will not be repeated.

  FIG. 4 is a chart for explaining on / off of each switch in the power supply system shown in FIG.

  Referring to FIG. 4, in the power supply system for the electric vehicle according to the first embodiment, relays RL1, RL2, RL3 and system main relay SMR2 are turned on during external charging, while system main relay SMR1 and relay RL4 are turned off. Is done.

  Therefore, at the time of external charging, the output voltage of charger 110 is directly applied to main battery 10 via relays RL1 and RL2. Thereby, the main battery 10 can be charged with the power supplied from the external power source 400.

  Furthermore, since the input side of the DC / DC converter 60 is connected to the positive terminal of the main battery 10 by the power supply wiring 158p, the power supply voltage is derived from the output voltage of the charger 110 that uses the power supplied from the external power supply 400 as a source. Vi can be generated. When the relay RL3 is turned on, the power supply voltage Vi is supplied from the power supply wiring 156p to a circuit / device group of a low voltage system (auxiliary system).

  On the other hand, since system main relay SMR1 is turned off, power supply wiring 153p is electrically disconnected from charger 110 and main battery 10. Thereby, external charging can be performed in a state where the voltage from the main battery 10 is not applied to the PCU 20. As a result, unlike the comparative example (FIG. 1), it is possible to prevent the PCU 20 from failing even if the PCU protection function is deactivated. Therefore, by turning off relay RL4, the supply of power supply voltage Vi to internal power supply circuit 22 is interrupted, whereby the control power supply of PCU 20 is stopped. As a result, since power consumption is reduced, the efficiency of external charging is increased.

  That is, in the power supply system according to the first embodiment, relays RL1 and RL2 and system main relay SMR2 constitute “connection means” and system main relay SMR1 constitutes “disconnection means”. The power supply wirings 156p, 158p, the DC / DC converter 60, and the relay RL3 constitute a “voltage supply means”, and the relay RL4 constitutes a “voltage cutoff means”.

  When the vehicle travels, the main battery 10 and the PCU 20 are electrically connected by turning on the system main relays SMR1, SMR2. Thereby, the electric power of main battery 10 can be used for running electric vehicle 100. Furthermore, since the DC / DC converter 60 is connected to the positive terminal of the main battery 10 by the power supply wiring 158p, the low-voltage power supply voltage Vi can be generated using the power of the main battery 10. Further, the control power of the PCU 20 is supplied by the internal power supply circuit 22 by turning on the relay RL4. Thereby, PCU 20 can control converter CNV and inverter 26 such that motor generator 30 operates in accordance with an operation command from overall ECU 21.

  As described above, in the power supply system for an electric vehicle according to the first embodiment, when the main battery 10 is externally charged, the power supply voltage Vi can be generated using the power from the external power supply 400 as a source, and then the PCU 20 is connected to the main battery. 10 and charger 110 can be electrically disconnected. As a result, the operation of the low-voltage system (auxiliary system) circuit / device can be ensured, and the efficiency of external charging can be increased by stopping the control power supply of the PCU 20.

  Further, when the vehicle travels, it is possible to prevent the output voltage of the main battery 10 from being applied to the charger 110 by turning off the relays RL1 and RL2. As a result, it is possible to protect the circuit group for external charging including the charger 110 while using the electric power of the main battery 10 for traveling of the electric vehicle 100.

  In addition, about PCU20 shown in FIG. 3, it is also possible to set it as the structure which abbreviate | omits arrangement | positioning of the converter CNV.

FIG. 5 is a block diagram for explaining a modification of the configuration of the power supply system shown in FIG.
The modification of the power supply system shown in FIG. 5 differs from the power supply system according to the first embodiment shown in FIG. 3 only in that PCU 20 # is arranged instead of PCU 20.

  Referring to FIG. 5, PCU 20 # has a configuration in which converter CNV and voltage sensor 164 are removed from the configuration of PCU 20 shown in FIG. In other words, in PCU 20 #, DC voltage VL corresponding to the output voltage from main battery 10 is directly input to inverter 26, and motor generator 30 is driven and supplied by a pseudo AC voltage whose amplitude is DC voltage VL. .

  Also in the power supply system according to the modification of the first embodiment shown in FIG. 5, each switch is turned on and off at the time of external charging and when the vehicle travels according to FIG. 4, so that it is the same as the power supply system according to the first embodiment. You can enjoy the effects of

[Embodiment 2]
FIG. 6 is a block diagram illustrating a configuration of a power supply system for an electric vehicle according to the second embodiment of the present invention.

  FIG. 6 is different from FIG. 3 in that the power supply system for an electric vehicle according to the second embodiment is different from the power supply system according to the first embodiment shown in FIG. 3 in that the arrangement of relay RL2 is omitted. . That is, the ground wiring 153g is electrically connected to the ground wiring 152g without a relay. Further, the power supply wiring 158p on the input side of the DC / DC converter 60 is electrically connected to the power supply wiring 152p. That is, DC / DC converter 60 is electrically connected to the positive terminal of main battery 10 via relay RL1.

  The configuration of the parts other than the above shown in FIG. 6 is the same as the configuration according to the first embodiment shown in FIG. 3, and therefore detailed description will not be repeated.

  FIG. 7 is a table for explaining on / off of each switch in the power supply system shown in FIG.

  Referring to FIG. 7, in the electric vehicle power supply system according to the second embodiment, relays RL1 and RL3 and system main relay SMR2 are turned on during external charging, while system main relay SMR1 and relay RL4 are turned off. .

  During external charging, the output voltage of charger 110 is transmitted to main battery 10 via relay RL1 and system relay SMR2. Thereby, the main battery 10 can be charged with the power supplied from the external power source 400.

  Furthermore, since the input side of the DC / DC converter 60 is connected to the power supply wiring 152p, the power supply voltage Vi can be generated from the output voltage of the charger 110 using the power supplied from the external power supply 400 as a source. . When the relay RL3 is turned on, the power supply voltage Vi is supplied from the power supply wiring 156p to a circuit / device group of a low voltage system (auxiliary system).

  On the other hand, as in the first embodiment (FIGS. 3 and 4), power supply wiring 153p is electrically disconnected from main battery 10 and charger 110 by turning off system main relay SMR1. Therefore, as in the first embodiment, the PCU protection function can be deactivated during external charging, so that relay RL4 can be turned off. As a result, the efficiency of external charging is increased by stopping the control power supply of the PCU 20.

  That is, in the power supply system according to the first embodiment, “connection means” is configured by relay RL1 and system main relay SMR2, and “disconnection means” is configured by system main relay SMR1. The power supply wirings 156p, 158p, the DC / DC converter 60, and the relay RL3 constitute a “voltage supply means”, and the relay RL4 constitutes a “voltage cutoff means”.

  Further, when the vehicle travels, the main battery 10 is electrically connected to the PCU 20 by turning on the system main relays SMR1 and SMR2. Further, by turning on relay RL1, the output voltage of main battery 10 can be transmitted to DC / DC converter 60 via power supply wiring 158p. The output voltage of the DC / DC converter 60 is supplied from the power supply wiring 156p to the low voltage system (auxiliary system) circuit / device group including the control system circuit in the PCU 20 by turning on the relays RL3, RL4. As described above, the electric power of the main battery 10 can be used for traveling the electric vehicle 100.

  As described above, in the power supply system for an electric vehicle according to the second embodiment, the arrangement of relay RL2 is omitted, and the control power supply of PCU 20 is stopped during external charging of main battery 10 as in the first embodiment. Thus, the efficiency of external charging can be increased. That is, in addition to the effects of the first embodiment, the cost can be reduced by reducing the number of switches.

  On the other hand, when the vehicle is traveling, relay RL1 needs to be turned on in order to supply power from main battery 10 to DC / DC converter 60. For this reason, the output voltage of the main battery 10 is applied to the charger 110 when the vehicle travels, together with the disposition of the relay RL2. Therefore, the protection of the circuit group for external charging including the charger 110 is more disadvantageous than the power supply system according to the first embodiment.

FIG. 8 is a block diagram illustrating a modification of the configuration of the power supply system shown in FIG.
The modification of the power supply system shown in FIG. 8 differs from the power supply system according to the second embodiment shown in FIG. 6 only in that PCU 20 # is arranged instead of PCU 20. PCU 20 # has the same configuration as that shown in FIG. 5, and thus detailed description thereof will not be repeated.

  In the power supply system shown in FIG. 8, the same effect as that of the power supply system according to the second embodiment can be obtained by turning on / off each switch according to FIG. 7 during external charging and during vehicle travel.

[Embodiment 3]
FIG. 9 is a block diagram illustrating a configuration of a power supply system for an electric vehicle according to Embodiment 3 of the present invention.

  Compared with FIG. 3, in the power supply system for an electric vehicle according to the third embodiment, the relay RL <b> 2 is connected to the negative terminal of the main battery 10, as compared with the power supply system according to the first embodiment shown in FIG. 3. It differs in that it is electrically connected to the ground wiring 152g.

  Further, the connection on the input side of the DC / DC converter 60 is different from that of the first embodiment. Specifically, the power supply wiring 158p is electrically connected to the power supply wirings 153p and 152p via the diodes 191 and 192, respectively. Similarly, the ground wiring 158g is electrically connected to the ground wirings 152g and 153g via the diodes 193 and 194, respectively. The diodes 191 to 194 are connected in a direction to block current inflow from the DC / DC converter 60 to the power supply wirings 152p and 153p.

  9 is the same as the configuration according to the first embodiment shown in FIG. 3, and therefore detailed description will not be repeated.

  FIG. 10 is a chart for explaining on / off of each switch in the power supply system shown in FIG.

  Referring to FIG. 10, in the power supply system for an electric vehicle according to the third embodiment, relays RL1-RL3 are turned on during external charging, while system main relays SMR1, SMR2 and relay RL4 are turned off.

  At the time of external charging, the output voltage of the charger 110 is transmitted to the main battery 10 via the relays RL1 and RL2, so that the main battery 10 can be charged with the power supplied from the external power source 400.

  Further, the output voltage of charger 110 is transmitted to the input side of DC / DC converter 60 via diodes 192 and 193. Therefore, the power supply voltage Vi can be generated from the output voltage of the charger 110 using the power supplied from the external power supply 400 as a source. When the relay RL3 is turned on, the power supply voltage Vi is supplied from the power supply wiring 156p to a circuit / device group of a low voltage system (auxiliary system).

  On the other hand, when system main relays SMR1 and SMR2 are turned off, power supply wiring 153p is electrically disconnected from charger 110 and main battery 10 as in the first and second embodiments. Therefore, similar to Embodiments 1 and 2, relay RL4 can be turned off during external charging. Thereby, the efficiency of external charging is improved by stopping the control power supply of the PCU 20.

  That is, in the power supply system according to the first embodiment, “connection unit” is configured by relays RL1 and RL2, and “disconnection unit” is configured by system main relays SMR1 and SMR2. The power supply wirings 156p, 158p, the diode 192, the DC / DC converter 60, and the relay RL3 constitute a “voltage supply means”, and the relay RL4 constitutes a “voltage cutoff means”.

  Further, when the vehicle travels, the main battery 10 is electrically connected to the PCU 20 by turning on the system main relays SMR1 and SMR2. Further, when the diodes 191 and 194 are turned on, the output voltage of the main battery 10 is transmitted from the power supply wiring 153p and the ground wiring 153g to the input side of the DC / DC converter 60.

  The output voltage of the DC / DC converter 60 is supplied from the power supply wiring 156p to the low voltage system (auxiliary system) circuit / device group including the circuit in the PCU 20 when the relays RL3, RL4 are turned on. As a result, the electric power of the main battery 10 can be used for running the electric vehicle 100.

  Furthermore, since relays RL1 and RL2 are turned off, charger 110 can be electrically disconnected from main battery 10 during vehicle travel. Further, since the diodes 192 and 193 are reverse-biased, the charger 110 is also electrically disconnected from the DC / DC converter 60.

  As described above, in the power system for an electric vehicle according to the third embodiment, the PCU 20 is electrically disconnected from the main battery 10 and the charger 110 when the main battery 10 is externally charged, as in the first and second embodiments. Therefore, the efficiency of external charging can be increased by stopping the control power supply of the PCU 20. That is, in addition to the effects of the first embodiment, cost reduction can be achieved by reducing the number of switches.

  Further, when the vehicle is running, the relay RL1 and RL2 can prevent the output voltage of the main battery 10 from being applied to the charger 110, and the arrangement of the diodes 192 and 193 can prevent the voltage from being applied to the power supply wiring 152p. It can be surely prevented. As a result, it is possible to protect the circuit group for external charging including the charger 110 while using the electric power of the main battery 10 for traveling of the electric vehicle 100.

FIG. 11 is a block diagram illustrating a modification of the configuration of the power supply system illustrated in FIG.
The modification of the power supply system shown in FIG. 11 differs from the power supply system according to the third embodiment shown in FIG. 9 only in that PCU 20 # is arranged instead of PCU 20. PCU 20 # has the same configuration as that shown in FIG. 5, and thus detailed description thereof will not be repeated.

  In the power supply system shown in FIG. 11 as well, the same effect as that of the power supply system according to Embodiment 3 can be obtained by turning on and off each switch according to FIG. 10 during external charging and during vehicle travel.

[Embodiment 4]
FIG. 12 is a block diagram illustrating a configuration of a power system for an electric vehicle according to the fourth embodiment of the present invention.

  Compared with FIG. 6 in FIG. 6, in the power supply system of the electric vehicle according to the fourth embodiment, the connection on the input side of the DC / DC converter 60 is different from that in the second embodiment shown in FIG. Specifically, the power supply wiring 158p is electrically connected to the power supply wirings 153p and 152p via the diodes 191 and 192, respectively. On the other hand, the ground wiring 158g is directly electrically connected to the ground wiring 152g.

  The configuration of the parts other than the above in FIG. 12 is the same as the configuration according to the second embodiment shown in FIG. 6, and therefore detailed description will not be repeated.

  FIG. 13 is a table for explaining on / off of each switch in the power supply system shown in FIG.

  Referring to FIG. 13, in the power supply system for an electric vehicle according to the fourth embodiment, each switch is controlled in the same manner as in the second embodiment (FIG. 7) during external charging. Specifically, the output voltage of charger 110 is transmitted to main battery 10 when relay RL1 and system relay SMR2 are turned on. Thereby, the main battery 10 can be charged with the power supplied from the external power source 400.

  Further, the output voltage of charger 110 is transmitted from power supply wiring 152 p to the input side of DC / DC converter 60 via diode 192. Therefore, the power supply voltage Vi can be generated from the output voltage of the charger 110 using the power supplied from the external power supply 400 as a source. When the relay RL3 is turned on, the power supply voltage Vi is supplied from the power supply wiring 156p to a circuit / device group of a low voltage system (auxiliary system).

  On the other hand, as in the second embodiment (FIGS. 6 and 7), system main relay SMR1 is turned off, so that main battery 10 and power supply wiring 153p are electrically disconnected. Therefore, similarly to Embodiments 1 to 3, the control power supply of PCU 20 can be stopped during external charging, and therefore relay RL4 can be turned off. That is, the efficiency of external charging is increased by stopping the control power supply of the PCU 20.

  In the power supply system according to the fourth embodiment, “connection means” is configured by relay RL1 and system main relay SMR2, and “disconnection means” is configured by system main relay SMR1. The power supply wirings 156p, 158p, the diode 192, the DC / DC converter 60, and the relay RL3 constitute a “voltage supply means”, and the relay RL4 constitutes a “voltage cutoff means”.

  When the vehicle travels, the main battery 10 is electrically connected to the PCU 20 by turning on the system main relays SMR1 and SMR2. Furthermore, unlike Embodiment 2 (FIG. 7), even when relay RL1 is turned off, the output voltage of main battery 10 can be transmitted from power supply wiring 153p to power supply wiring 158p by diode 191. The output voltage of the DC / DC converter 60 is supplied from the power supply wiring 156p to the low voltage system (auxiliary system) circuit / equipment group including the circuit in the PCU 20 when the relays RL3, RL4 are turned on. As a result, the electric power of the main battery 10 can be used for running the electric vehicle 100.

  Furthermore, since relay RL1 is turned off, charger 110 can be electrically disconnected from main battery 10 during vehicle travel. In addition, since the diode 192 is reverse-biased, the charger 110 is also electrically disconnected from the DC / DC converter 60.

  As described above, in the power supply system for an electric vehicle according to the fourth embodiment, the PCU 20 is electrically disconnected from the main battery 10 and the charger 110 when the main battery 10 is externally charged, as in the first to third embodiments. Therefore, the efficiency of external charging can be increased by stopping the control power supply of the PCU 20. Furthermore, since the arrangement of relay RL2 can be omitted as in the second embodiment, the cost can be reduced.

  Further, when the vehicle travels, the relay RL1 that is turned off and the diode 192 that is reversely biased can disconnect the main battery 10 from the charger 110 and reliably prevent voltage from being applied to the power supply wiring 152p. As a result, it is possible to protect the circuit group for external charging including the charger 110 while using the electric power of the main battery 10 for traveling of the electric vehicle 100.

FIG. 14 is a block diagram for explaining a modification of the configuration of the power supply system shown in FIG.
The modification of the power supply system shown in FIG. 14 differs from the power supply system according to the fourth embodiment shown in FIG. 12 only in that PCU 20 # is arranged instead of PCU 20. PCU 20 # has the same configuration as that shown in FIG. 5 and the like, and detailed description thereof will not be repeated.

  In the power supply system shown in FIG. 14 as well, the same effect as that of the power supply system according to the fourth embodiment can be obtained by turning on / off each switch according to FIG. 13 during external charging and during vehicle travel.

[Embodiment 5]
FIG. 15 is a block diagram showing a configuration of a power supply system for an electric vehicle according to the fifth embodiment.

  15 is compared with FIG. 9, the power supply system of the electric vehicle according to the fifth embodiment has a connection on the input side of the DC / DC converter 60 as compared with the power supply system according to the third embodiment shown in FIG. 9. Different. Specifically, the arrangement of the diodes 191 to 194 is omitted, and the power supply wiring 158p is electrically connected to the positive terminal of the main battery 10 via the relay RL5. The ground wiring 158g. It is electrically connected to the negative terminal of main battery 10.

  The configuration of the portion other than the above in FIG. 15 is the same as the configuration according to the third embodiment shown in FIG. 9, and therefore detailed description will not be repeated.

  FIG. 16 is a chart for explaining on / off of each switch in the power supply system shown in FIG.

  Referring to FIG. 16, in the power supply system for an electric vehicle according to the fifth embodiment, as in the third embodiment (FIG. 10), relays RL1-RL3 are turned on during external charging, while system main relay SMR1, SMR2 and relay RL4 are turned off. Relay RL5 is basically turned on.

  As a result, the output voltage of charger 110 is transmitted to main battery 10 via relays RL1 and RL2, so that main battery 10 can be charged with the power supplied from external power supply 400.

  Further, by turning on relay RL5, the output voltage of charger 110 is transmitted to the input side of DC / DC converter 60. Therefore, the power supply voltage Vi can be generated from the output voltage of the charger 110 using the power supplied from the external power supply 400 as a source. When the relay RL3 is turned on, the power supply voltage Vi is supplied from the power supply wiring 156p to a circuit / device group of a low voltage system (auxiliary system).

  On the other hand, main battery 10 and power supply wiring 153p can be electrically disconnected by turning off system main relays SMR1 and SMR2. Therefore, as in the first to fourth embodiments, relay RL4 can be turned off during external charging, so that the efficiency of external charging is increased by stopping the control power supply of PCU 20.

  That is, in the power supply system according to the fifth embodiment, “connection means” is configured by relays RL1 and RL2, and “disconnection means” is configured by system main relays SMR1 and SMR2. The power supply wirings 156p and 158p, the diode 192, the DC / DC converter 60, and the relays RL3 and RL5 constitute a “voltage supply means”, and the relay RL4 constitutes a “voltage cutoff means”.

  Note that the relay RL5 can be arranged to turn off the relay RL5 and stop the DC / DC converter 60 according to the supply state of the power supply voltage Vi during external charging. For example, when the remaining capacity of the auxiliary battery 70 is sufficient (SOC is equal to or greater than a predetermined value), the operating power of the low voltage system (auxiliary system) can be supplied even if the DC / DC converter 60 is stopped. The efficiency of external charging can be further improved by turning off relay RL5.

  On the other hand, when the vehicle travels, main battery 10 is electrically connected to PCU 20 by turning on system main relays SMR1 and SMR2. Further, the output voltage of main battery 10 is transmitted from power supply wiring 153p to the input side of DC / DC converter 60 by relay RL5. Therefore, the power supply voltage Vi generated using the power of the main battery 10 is switched from the power supply wiring 156p to the low voltage system (auxiliary system) circuit / equipment including the circuit in the PCU 20 when the relays RL3, RL4 are turned on. Supplied to the group. As a result, the electric power of the main battery 10 can be used for running the electric vehicle 100.

  Furthermore, since relays RL1 and RL2 are turned off, charger 110 can be electrically disconnected from main battery 10 during vehicle travel.

  Further, the ON / OFF of the relay RL5 can be controlled according to the supply state of the power supply voltage Vi, even when the vehicle is running, as in the case of external charging. That is, since the operation of the DC / DC converter 60 can be stopped within a range that does not hinder the supply of the power supply voltage Vi, the energy efficiency (fuel consumption) of the electric vehicle can be improved.

  As described above, in the power supply system for an electric vehicle according to the fifth embodiment, the PCU 20 is electrically disconnected from the main battery 10 and the charger 110 when the main battery 10 is externally charged, as in the first to fourth embodiments. Therefore, the efficiency of external charging can be increased by stopping the control power supply of the PCU 20.

  Further, when the vehicle travels, the output voltage of the main battery 10 can be prevented from being applied to the charger 110 by the relays RL1 and RL2. Therefore, while the electric power of the main battery 10 is used for running of the electric vehicle 100, the circuit group for external charging including the charger 110 can be protected.

  Furthermore, the arrangement of relay RL5 makes it possible to stop the operation of DC / DC converter 60 within a range that does not hinder the supply of power supply voltage Vi both during external charging and during vehicle travel. As a result, it is possible to improve the efficiency of external charging and improve the fuel efficiency when the vehicle is traveling.

FIG. 17 is a block diagram for explaining a modification of the configuration of the power supply system shown in FIG.
The modification of the power supply system shown in FIG. 17 differs from the power supply system according to the fifth embodiment shown in FIG. 15 only in that PCU 20 # is arranged instead of PCU 20. PCU 20 # has the same configuration as that shown in FIG. 5 and the like, and detailed description thereof will not be repeated.

  In the power supply system shown in FIG. 17 as well, the same effects as those of the power supply system according to the fifth embodiment can be obtained by turning on and off each switch according to FIG. 16 during external charging and during vehicle travel.

[Embodiment 6]
FIG. 18 is a circuit diagram showing a configuration of a power supply system for an electric vehicle according to the sixth embodiment.

  18 is compared with FIG. 15, the power supply system for an electric vehicle according to the sixth embodiment is external to DC / DC converter 60 separately from the power supply system according to the fifth embodiment shown in FIG. 15. The difference is that a DC / DC converter 115 used for charging is arranged. The DC / DC converter 115 is configured to generate a DC voltage corresponding to the power supply voltage Vi using power supplied from the external power supply 400 as a source. For example, the DC / DC converter 115 is built in the charger 110.

  The DC / DC converter 115 is configured by a small converter having a smaller power capacity than the DC / DC converter 60. That is, the power consumption of the DC / DC converter 115 is lower than the power consumption of the DC / DC converter 60.

  The output terminal of the DC / DC converter 115 is electrically connected to the power supply wiring 156p through the diode 195. Since the DC / DC converter 60 is not used during external charging, the power supply wiring 158p and the ground wiring 158g are connected to the input terminal of the power supply wiring 156p with the power supply wiring 153p and the ground wiring 153g, as in the comparative example of FIG. Connecting.

  18 is the same as that according to the fifth embodiment shown in FIG. 15, and therefore detailed description thereof will not be repeated.

  FIG. 19 is a table for explaining on / off of each switch in the power supply system shown in FIG.

  Referring to FIG. 19, in the power supply system for an electric vehicle according to the sixth embodiment, as in the fifth embodiment (FIG. 16), relays RL1, RL2 are turned on during external charging, while system main relay SMR1, SMR2 is turned off.

  Thus, the output voltage of charger 110 is transmitted to main battery 10 via relays RL1 and RL2, while system main relays SMR1 and SMR2 are turned off, so that power supply wiring 153p is connected to charger 110 and It is electrically disconnected from the main battery 10.

  Therefore, as in the first to fifth embodiments, main battery 10 can be charged with the power supplied from external power supply 400, while relay RL4 can be turned off during external charging. As a result, the efficiency of external charging is increased by stopping the control power supply of the PCU 20.

  At the time of external charging, the DC / DC converter 115 converts the AC voltage from the external power source 400 into a DC voltage, or reduces the output voltage of the charger 110, thereby reducing the DC voltage corresponding to the power source voltage Vi. Occur. The DC voltage from the DC / DC converter 115 is supplied to the power supply wiring 156p by the diode 195 whose forward direction is from the DC / DC converter 115 to the power supply wiring 156p. The power supply voltage Vi is supplied from the power supply wiring 156p to a circuit / device group of a low voltage system (auxiliary system).

  Accordingly, during external charging, the operation of DC / DC converter 60 can be stopped and relay RL3 can be turned off. As described above, since the DC / DC converter 115 is dedicated for external charging, the power capacity and power consumption are smaller than those of the DC / DC converter 60 used during vehicle travel.

  As a result, in the configuration of the power supply system according to the sixth embodiment, the power supply voltage Vi is generated by the output voltage of the DC / DC converter 115 using the power supplied from the external power supply 400 as a source, and the power consumption of the low voltage system is reduced. The efficiency during external charging can be improved by the reduction.

  That is, in the power supply system according to the sixth embodiment, “connection means” is configured by relays RL1 and RL2, and “disconnection means” is configured by system main relays SMR1 and SMR2. The power supply wirings 156p and 158p, the diode 195 (transmission means), the DC / DC converter 115, and the relay RL3 constitute a “voltage supply means”, and the relay RL4 constitutes a “voltage cutoff means”.

  On the other hand, when the vehicle travels, main battery 10 is electrically connected to PCU 20 by turning on system main relays SMR1 and SMR2. Further, the DC / DC converter 60 operates to convert the output voltage of the main battery 10 transmitted through the power supply wirings 153p and 158p into a low-voltage power supply voltage Vi. Since the relays RL3 and RL4 are turned on, the power supply voltage Vi from the DC / DC converter 60 is supplied from the power supply wiring 156p to the low voltage system (auxiliary system) circuit / device group including the circuit in the PCU 20. Is done. As a result, the electric power of the main battery 10 can be used for running the electric vehicle 100.

  Furthermore, since relays RL1 and RL2 are turned off, charger 110 can be electrically disconnected from main battery 10 and charger 110 when the vehicle is traveling. Further, since the diode 195 is reverse-biased, the power supply voltage Vi is not applied to the DC / DC converter 115.

  As described above, in the power supply system for an electric vehicle according to the sixth embodiment, the PCU 20 is electrically disconnected from the main battery 10 and the charger 110 when the main battery 10 is externally charged, as in the first to fifth embodiments. Therefore, the efficiency of external charging can be increased by stopping the control power supply of the PCU 20. Furthermore, by separately disposing a small capacity DC / DC converter 115 dedicated to external charging, the efficiency of external charging can be further improved.

  In addition, when the vehicle is traveling, the electric battery 100 is allowed to travel using the electric power of the main battery 10, while the circuit group for external charging including the charger 110 can be protected.

FIG. 20 is a block diagram for explaining a modification of the configuration of the power supply system shown in FIG.
The modification of the power supply system shown in FIG. 20 differs from the power supply system according to the fifth embodiment shown in FIG. 18 only in that PCU 20 # is arranged instead of PCU 20. PCU 20 # has the same configuration as that shown in FIG. 5 and the like, and detailed description thereof will not be repeated.

  Also in the power supply system shown in FIG. 20, the same effects as those of the power supply system according to the sixth embodiment can be obtained by turning on and off each switch according to FIG. 19 during external charging and when the vehicle is running.

  As described above, in the power supply system for electric vehicles according to the first to sixth embodiments, PCU 20 can be electrically disconnected from main battery 10 and charger 110 when external charging of main battery 10 is performed. The control power can be stopped. That is, the efficiency at the time of external charging can be increased by configuring the power supply system so that the power supply destination is appropriately set when externally charging the main battery 10 that is the in-vehicle power storage device.

In the first to sixth embodiments, the system main relays SMR1 and SMR2 correspond to the “first main switch” and the “second main switch”, respectively, and the relays RL1 and RL2 correspond to the “first main switch”. It corresponds to “switch” and “second switch”, respectively. Further, the relays RL3, RL4, and RL5 correspond to the “first auxiliary switch”, the “second auxiliary switch”, and the “third auxiliary switch”, respectively. The DC / DC converter 60 corresponds to a “converter”, and the DC / DC converter 115 corresponds to an “auxiliary converter”.

  Furthermore, power supply wiring 153p and ground wiring 153g connected to power control unit 20 correspond to “first power supply wiring” and “first ground wiring”, respectively, and power supply wiring 152p on the output side of charger 10 and The ground wiring 152g corresponds to the “second power supply wiring” and the “second ground wiring”, respectively. The power supply wiring 158p on the input side of the DC / DC converter 60 corresponds to the “third power supply wiring”, and the low-voltage power supply wiring 156p corresponds to the “low-voltage power supply wiring”.

  Further, in the present embodiment, the configuration after power supply wiring 153p (load side) is not limited to the illustrated configuration, and may be any configuration including a configuration that generates vehicle driving force. . That is, the present invention includes an electric vehicle and a fuel cell vehicle that are not equipped with an engine, and a hybrid vehicle that is equipped with an engine, a power storage device that can be externally charged, and a wheel that is configured to be driven by the power of the power storage device. The present invention can be commonly applied to an electric vehicle equipped with an electric motor for generating a driving force.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention can be applied to an electric vehicle equipped with a power storage device that can be charged by a power source external to the vehicle.

  DESCRIPTION OF SYMBOLS 10 Main battery, 21 Overall ECU, 22 Internal power supply circuit, 25 MG-ECU, 26 Inverter, 30 Motor generator, 40 Power transmission gear, 50 Drive wheel, 60 DC / DC converter, 70 Auxiliary battery, 100 Electric vehicle, 105 Charging connector, 110 charger (external charging), 115 DC / DC converter (external charging only), 151 power wiring (AC), 152g, 153g, 155g, 158g ground wiring, 152p, 153p power wiring (VL system), 155p, 156p power supply wiring (low voltage system), 154p power supply wiring (VH system), 155 diode (charger output side block diode), 158p power supply wiring (DC / DC converter), 161-164 voltage sensor, 190-195 diode 400 External power supply, 05 relay, 410 charging plug, C0, C1 smoothing capacitor, CNV converter, L1 reactor, Q1, Q2 power semiconductor switching element, RL1-RL5, SMR1, SMR2 switch (relay, system main relay), VH DC voltage, Vi Power supply voltage (low voltage system), VL DC voltage (main battery output voltage).

Claims (8)

An electric vehicle power supply system configured to be rechargeable by an external power supply outside the vehicle,
A rechargeable power storage device;
A charger that converts power supplied from the external power source into charging power for the power storage device during external charging for charging the power storage device with a front external power supply;
A power control unit connected between the power storage device and a motor for generating vehicle driving force and configured to drive and control the motor;
Connection means for electrically connecting the charger and the power storage device during the external charging;
A disconnecting means for electrically disconnecting the charger and the power storage device and the power control unit during the external charging;
Voltage supply means for supplying a power supply voltage of the auxiliary system lower than the output voltage of the power storage device, using the power supplied from the external power supply as a source during the external charging;
A power supply system for an electric vehicle, comprising: a voltage cut-off means for cutting off the supply of the power supply voltage from the voltage supply means to the control power supply of the power control unit during the external charging. The power control unit is fed from a first power supply wiring and a first ground wiring,
The charger outputs the charging power between a second power supply wiring and a second ground wiring,
The disconnecting means includes a first main switch connected between the first power supply wiring and a positive electrode terminal of the power storage device,
The connecting means includes
A second main switch connected between the first ground wiring and the negative terminal of the power storage device;
A first switch connected between the second power supply wiring and a positive terminal of the power storage device;
A second switch connected between the second ground wiring and the first ground wiring;
The voltage supply means includes
A converter configured to output the power supply voltage by converting a DC voltage on the input side;
A third power supply wiring for connecting the positive terminal and the input side of the converter without going through the first main switch;
Low-voltage power supply wiring for transmitting the power supply voltage inside the electric vehicle;
A first auxiliary switch connected between the output side of the converter and the low-voltage power supply wiring;
The voltage cutoff means includes a second auxiliary switch connected between the low-voltage power supply wiring and the control power supply of the power control unit,
During the external charging, the first main switch and the second auxiliary switch are turned off, while the second main switch, the first and second switches, and the first switch The auxiliary switch of the
When the electric vehicle is traveling, the first and second switches are turned off, while the first and second main switches and the first and second auxiliary switches are turned on. Item 2. A power supply system for an electric vehicle according to Item 1. The power control unit is fed from a first power supply wiring and a first ground wiring,
The charger outputs the charging power between a second power supply wiring and a second ground wiring,
The first ground wiring is directly electrically connected to the second ground wiring;
The disconnecting means includes a first main switch connected between the first power supply wiring and a positive electrode terminal of the power storage device,
The connecting means includes
A second main switch connected between the first ground wiring and the negative terminal of the power storage device;
A first switch connected between the second power supply wiring and a positive terminal of the power storage device;
The voltage supply means includes
A converter configured to output the power supply voltage by converting a DC voltage on the input side;
A third power supply wiring for electrically connecting the second power supply wiring and the input side of the converter;
Low-voltage power supply wiring for transmitting the power supply voltage inside the electric vehicle;
A first auxiliary switch connected between the output side of the converter and the low-voltage power supply wiring;
The voltage cutoff means includes a second auxiliary switch connected between the low-voltage power supply wiring and the control power supply of the power control unit,
During the external charging, the first main switch and the second auxiliary switch are turned off, while the second main switch, the first switch, and the first auxiliary switch are Turn on
2. The electric vehicle power source according to claim 1, wherein when the electric vehicle is running, the first and second main switches, the first switch, and the first and second auxiliary switches are turned on. system. The power control unit is fed from a first power supply wiring and a first ground wiring,
The charger outputs the charging power between a second power supply wiring and a second ground wiring,
The separating means includes
A first main switch connected between the first power supply wiring and a positive terminal of the power storage device;
A second main switch connected between the first ground wiring and the negative terminal of the power storage device;
The connecting means includes
A first switch connected between the second power supply wiring and a positive terminal of the power storage device;
A second switch connected between the second ground wiring and the negative terminal of the power storage device,
The voltage supply means includes
A converter configured to output the power supply voltage by converting a DC voltage on the input side;
A first rectifying element connected between the second power supply wiring and the input side of the converter, with a direction from the second power supply wiring toward the input side of the converter as a forward direction;
Low-voltage power supply wiring for transmitting the power supply voltage inside the electric vehicle;
A first auxiliary switch connected between the output side of the converter and the low-voltage power supply wiring;
The voltage cutoff means includes a second auxiliary switch connected between the low-voltage power supply wiring and the control power supply of the power control unit,
The power supply system includes:
A second rectifying element connected between the first power supply wiring and the input side of the converter, with the direction from the first power supply wiring toward the input side of the converter as a forward direction;
During the external charging, the first and second main switches and the second auxiliary switch are turned off, while the first and second switches and the first auxiliary switch are turned on. And
When the electric vehicle is running, the first and second switches are turned off, while the first and second main switches and the first and second auxiliary switches are turned on. The power supply system for an electric vehicle according to claim 1. The power control unit is fed from a first power supply wiring and a first ground wiring,
The charger outputs the charging power between a second power supply wiring and a second ground wiring,
The first ground wiring is directly electrically connected to the second ground wiring;
The disconnecting means includes a first main switch connected between the first power supply wiring and a positive electrode terminal of the power storage device,
The connecting means includes
A second main switch connected between the first ground wiring and the negative terminal of the power storage device;
A first switch connected between the second power supply wiring and a positive terminal of the power storage device;
The voltage supply means includes
A converter configured to output the power supply voltage by converting a DC voltage on the input side;
A first rectifying element connected between the first power supply wiring and the input side of the converter, with a direction from the second power supply wiring toward the input side of the converter as a forward direction;
Low-voltage power supply wiring for transmitting the power supply voltage inside the electric vehicle;
A first auxiliary switch connected between the output side of the converter and the low-voltage power supply wiring;
The voltage cutoff means includes a second auxiliary switch connected between the low-voltage power supply wiring and the control power supply of the power control unit,
The power supply system includes:
A second rectifying element connected between the first power supply wiring and the input side of the converter, with the direction from the first power supply wiring toward the input side of the converter as a forward direction;
During the external charging, the first main switch and the second auxiliary switch are turned off, while the second main switch, the first switch, and the first auxiliary switch are Turn on
The first and second main switches and the first and second auxiliary switches are turned on while the first switch is turned off when the electric vehicle is traveling. Electric vehicle power system. The power control unit is fed from a first power supply wiring and a first ground wiring,
The charger outputs the charging power between a second power supply wiring and a second ground wiring,
The separating means includes
A first main switch connected between the first power supply wiring and a positive terminal of the power storage device;
A second main switch connected between the first ground wiring and the negative terminal of the power storage device;
The connecting means includes
A first switch connected between the second power supply wiring and a positive terminal of the power storage device;
A second switch connected between the second ground wiring and the negative terminal of the power storage device,
The voltage supply means includes
A converter configured to output the power supply voltage by converting a DC voltage on the input side;
A third power supply wiring for electrically connecting the positive terminal of the power storage device and the input side of the converter;
Low-voltage power supply wiring for transmitting the power supply voltage inside the electric vehicle;
A first auxiliary switch connected between the output side of the converter and the low-voltage power supply wiring;
The voltage cutoff means includes a second auxiliary switch connected between the low-voltage power supply wiring and the control power supply of the power control unit,
The voltage supply means further includes a third auxiliary switch inserted and connected to the third power supply wiring,
During the external charging, the first and second main switches and the second auxiliary switch are turned off, while the first and second switches and the first auxiliary switch are turned on. And
During travel of the electric vehicle, the first and second switches are turned off, while the first and second main switches and the first and second auxiliary switches are turned on,
2. The power supply system for an electric vehicle according to claim 1, wherein on / off of the third auxiliary switch is controlled based on a supply state of the power supply voltage at each of the external charging and the traveling. The power control unit is fed from a first power supply wiring and a first ground wiring,
The charger outputs the charging power between a second power supply wiring and a second ground wiring,
The separating means includes
A first main switch connected between the first power supply wiring and a positive terminal of the power storage device;
A second main switch connected between the first ground wiring and the negative terminal of the power storage device;
The connecting means includes
A first switch connected between the second power supply wiring and a positive terminal of the power storage device;
A second switch connected between the second ground wiring and the negative terminal of the power storage device,
The voltage supply means includes
An auxiliary converter for converting power supplied from the external power source to the power source voltage;
Low-voltage power supply wiring for transmitting the power supply voltage inside the electric vehicle;
Transmission means for transmitting the output voltage of the auxiliary converter to the low-voltage power supply wiring,
The power supply system includes:
A converter configured to output the power supply voltage by converting a DC voltage on the input side, and having a larger power capacity and power consumption than the auxiliary converter;
A third power supply wiring for electrically connecting the positive terminal of the power storage device and the input side of the converter;
A first auxiliary switch connected between the output side of the converter and the low-voltage power supply wiring;
The voltage cutoff means includes a second auxiliary switch connected between the low-voltage power supply wiring and the control power supply of the power control unit,
During the external charging, the first and second main switches and the first and second auxiliary switches are turned off, while the first and second switches are turned on, and The auxiliary converter operates while the converter stops,
When the electric vehicle is traveling, the first and second switches are turned off, while the first and second main switches and the first and second auxiliary switches are turned on, and The power supply system for an electric vehicle according to claim 1, wherein the converter is operated while the auxiliary converter is stopped.   The transmission means includes a rectifying element connected between the output side of the auxiliary converter and the low-voltage power supply wiring with the direction from the output side of the auxiliary converter toward the low-voltage power supply wiring as a forward direction. The electric vehicle power supply system described.

Images