Power supply system

Abstract

To provide a power supply system that is configured to be able to perform short circuit control and that enables charging from an external power source.SOLUTION: A power supply system 10 includes a motor 20, an inverter 30, a gate driver 52, a switching power supply 54 that supplies power to the gate driver 52, and a support power supply 56 that supplies power to the gate driver 52 when short circuit control is performed. The switching power supply 54 supplies power at a voltage higher than a first threshold in a normal state, and supplies power at a lower voltage during external charging. When the switching power supply 54 fails, the gate driver 52 performs short circuit control using power supplied from the support power supply 56. On the other hand, during external charging, the gate driver 52 drives and controls the inverter 30 using power supplied from either the switching power supply 54 or the support power supply 56, whichever has a higher output voltage, or using power supplied from the support power supply 56.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a power supply system. [Background technology]

[0002] When an external power supply provided outside the power supply system charges an electric storage device, the voltage of the external power supply may be applied to the load driving device as well as the electric storage device. In this case, parasitic capacitance may be generated in the load driving device, which may cause the load driving device to operate unintentionally. To avoid such a situation, a switching element that cuts off the power supply to the load driving device during external charging may be controlled to an off state.

[0003] In this case, a power supply is required to supply power for operating the switching element during external charging. If this power supply is configured as a switching power supply, noise will be generated from the switching power supply during external charging. It is preferable to reduce such noise during external charging.

[0004] Therefore, in Patent Document 1, the noise is reduced by intermittently operating the switching power supply during external charging. It is also possible to reduce the noise by lowering the output voltage of the switching power supply, for example.

[0005] In recent electric vehicles, a rotating electric machine and an inverter are generally used in the power unit. In a vehicle using a rotating electric machine and an inverter, when the rotation speed of the rotating electric machine increases, the back electromotive force generated in the coil by the magnetic flux of the permanent magnet of the rotating electric machine may become larger than the voltage of the storage battery. In this situation, if the inverter driving power supply for driving the inverter fails due to an accident or the like, the inverter cannot be operated, all phases are shut down, and a back electromotive force is generated. As a result, even if, for example, the upper and lower arm switches are all turned off, a high-voltage back electromotive force may be applied from the coil to the storage battery or the electric load through the diodes connected in parallel to the upper and lower arm switches. In this case, the high-voltage back electromotive force may cause problems such as the failure of the storage battery or the like. In addition, the back electromotive force may generate an unintended torque to the drive wheels.

[0006] Therefore, in recent electric vehicles, as described in Patent Document 2, ASC (Active Short Circuit) control (also called short circuit control) is implemented in the event of an abnormality. The ASC control is a control in which one of the upper and lower arm switches of all phases constituting the inverter is turned on and the other is turned off. This makes it possible to prevent various problems caused by back electromotive force. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2022-118417 [Patent Document 2] Patent Publication No. 2022-28347 Summary of the Invention [Problem to be solved by the invention]

[0008] Incidentally, in Patent Document 1, the switching element that cuts off the current supply to the load driving device during external charging constitutes an inverter, and the switching power supply corresponds to an inverter driving power supply.

[0009] For this reason, when attempting to employ the ASC control described in Patent Document 2 in a configuration in which the switching power supply is operated intermittently during external charging as in Patent Document 1 described above, the following problem occurs. That is, when the output voltage from the switching power supply (inverter driving power supply) is reduced or operated intermittently during charging by an external power supply, it may be erroneously determined that the switching power supply (inverter driving power supply) has failed, and ASC control may be implemented. In this case, as described above, one of the upper and lower arm switches of all phases is turned on, making it impossible to operate the inverter and making it impossible to charge by the external power supply.

[0010] The present invention has been made to solve the above-mentioned problems, and a main object of the present invention is to provide a power supply system that is configured to be able to perform short-circuit control and that allows charging from an external power supply. [Means for solving the problem]

[0011] A power supply system for solving the above problems includes: A power supply system capable of performing external charging in which an electric storage device is charged by an external power supply provided externally, a rotating electric machine having an armature winding; an inverter including a series connection of upper arm switches and lower arm switches, the inverter performing power conversion between the power storage device and the rotating electric machine; A drive control unit that drives and controls the upper arm switch and the lower arm switch; A first power source that supplies power to the drive control unit; a second power source that supplies power to the drive control unit when short-circuit control is performed to turn on one of the upper arm switch and the lower arm switch and turn off the other arm switch, the first power source is configured to supply power at a voltage higher than a first threshold in a normal state, and to supply power intermittently, supply power at a reduced voltage, or stop supplying power during external charging; The drive control unit is configured to perform the short-circuit control using power supplied from the second power source when the first power source fails, and to drive and control the upper arm switch and the lower arm switch using power supplied from the first power source or the second power source, whichever has the higher output voltage, or using power supplied from the second power source during external charging.

[0012] When the first power source fails, the drive control unit can suppress the influence of the back electromotive force by performing short circuit control. At this time, the short circuit control is performed using the power from the second power source, so that the short circuit control is performed reliably.

[0013] On the other hand, during external charging, in order to reduce noise from the first power supply, the first power supply is operated intermittently. In this case, the upper arm switch and the lower arm switch may not be driven and controlled stably with the power supplied from the first power supply. Therefore, the device is configured so that power can also be supplied from the second power supply used in short circuit control during external charging. This makes it possible to reliably perform drive control during external charging. [Brief description of the drawings]

[0014] [Figure 1] A diagram of the power supply system. [Diagram 2] FIG. [Diagram 3] 4 is a flowchart showing a control flow during external charging. [Figure 4] 4 is a flowchart showing a procedure for abnormality diagnosis. [Diagram 5] FIG. 13 is a configuration diagram of a control device according to a modified example. [Figure 6] FIG. 13 is a configuration diagram of a control device according to a modified example. [Figure 7] FIG. 13 is a configuration diagram of a control device according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, with reference to the drawings, a description will be given of one embodiment in which the "power supply system" according to the present disclosure is applied to a vehicle (e.g., a mobile body such as a hybrid vehicle or an electric vehicle) in several embodiments and their modified examples. In the several embodiments and their modified examples, functionally and / or structurally corresponding and / or associated parts may be given the same reference numerals or reference numerals with different digits in the hundreds or more places. For corresponding and / or associated parts, the descriptions of other embodiments may be referred to.

[0016] First Embodiment As shown in FIG. 1, the power supply system 10 includes a motor 20 as a rotating electric machine, an inverter 30 as a power converter that supplies a three-phase current to the motor 20, a battery pack 40 as a charging device that can be charged and discharged, and a control device 50 that controls the inverter 30.

[0017] The motor 20 (motor generator) is an in-vehicle main engine capable of transmitting power to driving wheels (not shown). In this embodiment, a three-phase permanent magnet synchronous motor is used as the motor 20.

[0018] The inverter 30 is configured with a full-bridge circuit having upper and lower arms in the same number as the number of phases of the phase windings, and the current flowing in each phase winding is adjusted by turning on and off a switch provided in each arm.

[0019] Specifically, the inverter 30 includes three phases of series-connected upper-arm switches SWH and lower-arm switches SWL. In each phase, a first end of the armature winding 21 of the motor 20 is connected to a connection point between the upper-arm switch SWH and the lower-arm switch SWL. A second end of the armature winding 21 of each phase is connected at a neutral point. The armature windings 21 of each phase are arranged to be shifted from each other by 120° in electrical angle. Incidentally, in this embodiment, a voltage-controlled semiconductor switching element is used as the upper-arm switch SWH and the lower-arm switch SWL, and more specifically, an IGBT (Insulated Gate Bipolar Transistor) is used. In addition, an upper-arm diode DH, which is a freewheel diode, is connected in inverse parallel to the upper-arm switch SWH. Similarly, a lower-arm diode DL, which is a freewheel diode, is connected in inverse parallel to the lower-arm switch SWL.

[0020] The collector, which is a high potential side terminal of each upper arm switch SWH, is connected to the positive terminal of the battery pack 40 via a high potential side electrical path 31H. The emitter, which is a low potential side terminal of each lower arm switch SWL, is connected to the negative terminal of the battery pack 40 via a low potential side electrical path 31L.

[0021] A relay switch SMR (system main relay switch) is provided in each of the high potential side electric path 31H and the low potential side electric path 31L, and configured to be able to switch between energization and de-energization by the relay switch SMR. Each relay switch SMR may be driven by the control device 50, or may be driven by a host ECU 100 serving as a host control device with respect to the control device 50.

[0022] The inverter 30 includes a smoothing capacitor 32. One end of the smoothing capacitor 32 is connected to the high potential side electrical path 31H between the relay switch SMR and the inverter 30. The other end of the smoothing capacitor 32 is connected to the low potential side electrical path 31L between the relay switch SMR and the inverter 30. That is, the smoothing capacitor 32 is provided between the high potential side electrical path 31H and the low potential side electrical path 31L so as to be in parallel with the series connection of the upper arm switch SWH and the lower arm switch SWL of each phase. The smoothing capacitor 32 may be provided inside or outside the inverter 30.

[0023] The battery pack 40 is electrically connected to the motor 20 via the inverter 30. The battery pack 40 has an inter-terminal voltage of, for example, 100 V or more, and is configured by connecting a plurality of battery cells 41 in series. As the battery cells 41 (secondary batteries), for example, lithium iron phosphate batteries (LFP batteries), lithium ion batteries, or nickel-metal hydride batteries can be used. Each battery cell 41 is a storage battery having an electrolytic solution (a solution consisting of an electrolyte and a solvent) and a plurality of electrodes.

[0024] The power supply system 10 also includes an external charging mechanism 60. The external charging mechanism 60 includes an inlet 62 and a relay 61. The inlet 62 is connected to the electric paths 31H, 31L between the battery pack 40 and the inverter 30 via the relay 61. The inlet 62 is configured to supply power from the external power source 210 of the charging equipment 200 to the battery pack 40 during external charging in which the relay switch SMR and the relay 61 are in the on state (closed state, energized state). Note that, as shown in FIG. 1, the inlet 62 may be connected to a neutral point to enable neutral point charging.

[0025] External charging is performed when a vehicle is connected to charging equipment 200. Charging equipment 200 includes an external power supply 210 and a connector 220. Connector 220 is configured to be connectable to an inlet 62 of the vehicle. External power supply 210 is, for example, a DC power supply, but may also be an AC power supply. In this case, an AC / DC converter is required.

[0026] The power supply system 10 also includes a phase current sensor 11 and an angle sensor 12. The phase current sensor 11 detects at least two of the U-, V-, and W-phase currents flowing through the armature winding 21 of the motor 20, and outputs a current signal. The angle sensor 12 outputs an angle signal corresponding to the electrical angle of the motor 20. The angle sensor 12 is, for example, a resolver, an encoder, or an MR sensor having a magnetoresistance effect element, and is a resolver in this embodiment. The power supply system 10 also includes a voltage sensor 13 that detects the voltage between the terminals of the smoothing capacitor 32 and outputs a detected voltage VS.

[0027] The configuration of the control device 50 will be described with reference to Fig. 2. The control device 50 includes a microcomputer 51 provided in a low-voltage area. The microcomputer 51 includes a CPU, RAM, ROM, etc. The microcomputer 51 (its CPU) realizes various functions by executing programs stored in the ROM.

[0028] The microcomputer 51 receives a current signal from the phase current sensor 11. The microcomputer 51 calculates a phase current Ir based on the input current signal. The microcomputer 51 also receives an angle signal from the angle sensor 12. The microcomputer 51 obtains an electrical angle θe of the motor 20 based on the input angle signal.

[0029] A command value is input to the microcomputer 51 from the host ECU 100. The microcomputer 51 generates switching commands to turn on and off the upper arm switches SWH and the lower arm switches SWL of each phase constituting the inverter 30 based on the phase current Ir and the electrical angle θe in order to control the control amount of the motor 20 to the command value. The control amount is, for example, torque.

[0030] The control device 50 includes a gate driver 52 as a drive control unit. The gate driver 52 normally turns on and off the upper arm switch SWH and the lower arm switch SWL of each phase based on a switching command (on command or off command) from the microcomputer 51.

[0031] Specifically, the gate drivers 52 are provided individually corresponding to the upper arm switches SWH and the lower arm switches SWL of each phase. Therefore, six gate drivers 52 are provided in total. Note that illustration is omitted in FIG. 2. When an ON command is input, each gate driver 52 supplies a charging current to the gate of the corresponding switch SWH, SWL. As a result, the gate voltage of the switch SWH, SWL becomes equal to or higher than the threshold voltage Vth, and the switch SWH, SWL is turned on. On the other hand, when an OFF command is input, each gate driver 52 flows a discharging current from the gate of the corresponding switch SWH, SWL to the emitter side. As a result, the gate voltage of the switch SWH, SWL becomes less than the threshold voltage Vth, and the switch SWH, SWL is turned off. Note that in this embodiment, the gate driver 52 is provided in a high voltage region.

[0032] The gate driver 52 is configured to be able to perform abnormality control, which is performed to deal with the occurrence of an abnormality such as an overvoltage abnormality, in addition to the above-mentioned normal drive control. In this embodiment, the abnormality control is a short-circuit control that turns off the upper arm switch SWH and turns on the lower arm switch SWL. Note that, prior to the short-circuit control, a shutdown control may be performed that forcibly turns off the upper arm switch SWH and the lower arm switch SWL of each phase.

[0033] Furthermore, the gate driver 52 is configured to be able to perform external charging control for maintaining the upper arm switch SWH and the lower arm switch SWL of each phase in the off state during external charging, separately from the normal driving control and abnormality control described above. The external charging control is performed when the host ECU 100 notifies the vehicle via the microcomputer 51 that the charging facility 200 has been connected to the vehicle.

[0034] The control device 50 includes an abnormality determination unit 53. The detected voltage VS, the phase current Ir (or a current signal), and the electrical angle θe (or an angle signal) are input to the abnormality determination unit 53. If any one of these has an abnormal value, the abnormality determination unit 53 determines that an abnormality has occurred in at least one of the components used for normal drive control. The components used for normal drive control include, for example, the phase current sensor 11, the angle sensor 12, the voltage sensor 13, the microcomputer 51, the gate driver 52, the upper arm switch SWH of each phase, and the lower arm switch SWL of each phase.

[0035] When the abnormality determination unit 53 determines that an abnormality has occurred, it notifies the gate driver 52 of that fact (outputs an abnormality detection signal). This causes the gate driver 52 to carry out abnormality control (short circuit control in this embodiment). Note that the abnormality control is carried out with priority over other controls (normal control, etc.). This abnormality determination unit 53 may be provided in the microcomputer 51 or in the gate driver 52. Furthermore, the abnormality determination unit 53 may be provided in both the microcomputer 51 and the gate driver 52. Furthermore, the abnormality determination unit 53 may be realized by software or by hardware.

[0036] The control device 50 also includes a switching power supply 54 as a first power supply used when normal control is performed. The switching power supply 54 is, for example, an insulated DC / DC switching power supply. In this embodiment, the switching power supply 54 is connected to a low-voltage battery 55, such as a lead storage battery, whose output voltage is lower than that of the assembled battery 40, and boosts the voltage of the low-voltage battery 55 and supplies it to each gate driver 52. That is, the switching power supply 54 is connected to the low-voltage battery 55 in the low-voltage region, and is connected to the gate driver 52 via a diode 54a in the high-voltage region. In the switching power supply 54, the low-voltage region and the high-voltage region are insulated from each other. Although not shown, power is supplied from the switching power supply 54 to the microcomputer 51.

[0037] When performing normal control, each gate driver 52 operates using power supplied from the switching power supply 54. Specifically, when performing normal control, each gate driver 52 uses power supplied from the switching power supply 54 to pass current through the gates of each switch SWH, SWL, turning each switch SWH, SWL on and off.

[0038] 2, a power supply failure determination unit 57 is provided which inputs an output voltage from an electric path between the switching power supply 54 and the diode 54a, and compares the output voltage with a first threshold value to determine whether the switching power supply 54 has failed. When the power supply failure determination unit 57 determines that the switching power supply 54 has failed, it outputs a failure signal to the gate driver 52. When the gate driver 52 receives a notification (failure signal) from the power supply failure determination unit 57 that the switching power supply 54 has failed, it performs abnormality control as described above. Note that the power supply failure determination unit 57 is disposed in the high voltage region.

[0039] The control device 50 also includes a support power supply 56 as a second power supply used when abnormality control (short circuit control) is performed. The support power supply 56 is, for example, a linear power supply (also called a series power supply) such as a dropper power supply. The support power supply 56 made up of these power supplies generally has lower noise than the switching power supply 54, but has a large heat loss. However, the support power supply 56 is an emergency power supply used for abnormality control and the like, and the period of use is limited, so the heat loss is acceptable.

[0040] The support power supply 56 is disposed in the high-voltage region, and is connected to the battery pack 40, which has a higher voltage than the low-voltage battery 55 in the high-voltage region. The support power supply 56 is also connected to the gate driver 52 via a diode 56a in the high-voltage region. In this embodiment, the support power supply 56 adjusts the input voltage of the battery pack 40 and supplies it to each gate driver 52. Each gate driver 52 operates using power supplied from the support power supply 56 when performing abnormality control. Specifically, each gate driver 52 uses power supplied from the support power supply 56 to pass a current through the gate of each switch SWH, SWL and turn on and off each switch SWH, SWL when performing abnormality control.

[0041] Incidentally, the switching power supply 54 is connected to the microcomputer 51 in the low voltage region, and is configured so that the output voltage and the like can be adjusted by the microcomputer 51. Specifically, the microcomputer 51 is configured to change the output voltage when normal drive control is performed and when external charging control is performed. For example, the microcomputer 51 outputs a voltage higher than the second threshold when normal drive control is performed, whereas when external charging control is performed, the microcomputer 51 outputs a voltage higher than the first threshold and equal to or lower than the second threshold. This makes it possible to reduce noise of the switching power supply 54 when external charging control is performed, compared to when normal drive control is performed.

[0042] However, as described above, when the output voltage of the switching power supply 54 is reduced during external charging, the margin between the first threshold value at which a failure is determined becomes smaller. This makes the switching power supply 54 more susceptible to the effects of noise and a drop in the output of the low-voltage battery 55, increasing the possibility that the power supply failure determination unit 57 will erroneously determine that the switching power supply 54 has failed. In this case, the gate driver 52 prioritizes abnormality control (short-circuit control) and is therefore unable to perform external charging control.

[0043] Therefore, in this embodiment, during external charging, power can also be supplied from the support power supply 56 to the gate driver 52. Specifically, in this embodiment, each gate driver 52 is configured to receive power from either the switching power supply 54 or the support power supply 56, whichever has the higher output voltage, during external charging.

[0044] 2, the switching power supply 54 is connected to the gate driver 52 via a diode 54a in the high voltage region, and the support power supply 56 is connected to an electrical path between the diode 54a and the gate driver 52 via a diode 56a in the high voltage region. This allows each gate driver 52 to receive power from either the switching power supply 54 or the support power supply 56, whichever has the higher output voltage.

[0045] Furthermore, the switching power supply 54 supplies power at a voltage higher than the second threshold during normal operation, while supplying power at a voltage lower than the second threshold and higher than the first threshold during external charging. During external charging, the support power supply 56 is also operated as described above to supply power. The output voltage of the support power supply 56 may be any voltage that can properly operate the gate driver 52, but in this embodiment, the output voltage is set to be higher than the second threshold in consideration of the effects of noise, etc.

[0046] Next, a control flow during external charging will be described with reference to Fig. 3. The microcomputer 51 determines whether the vehicle state is external charging or not (step S101). Specifically, when the host ECU 100 has connected the connector 220 of the charging equipment 200 to the inlet 62 of the vehicle and inputs a notification that power supply is possible, the microcomputer 51 makes a positive determination. Note that when the determination result of step S101 is negative, the microcomputer 51 performs normal control (step S102).

[0047] When the determination result in step S101 is positive (when external charging is in progress), the microcomputer 51 reduces the output voltage of the switching power supply 54 (step S103). Specifically, the microcomputer 51 causes the output voltage to be greater than the first threshold and equal to or less than the second threshold.

[0048] Then, the microcomputer 51 activates the support power supply 56 to supply power from the support power supply 56 to the gate driver 52 (step S104). After that, the microcomputer 51 performs control related to external charging (step S105). At this time, for example, the microcomputer 51 outputs an OFF command to the upper arm switch SWH and the lower arm switch SWL of each phase to cause the gate driver 52 to perform control during external charging.

[0049] The configuration of the first embodiment provides the following effects.

[0050] The gate driver 52 (drive control section) can suppress the influence of the back electromotive force by performing short circuit control in the event of an abnormality such as a failure of the switching power supply 54 (first power supply). At this time, the gate driver 52 performs the short circuit control using power from the support power supply 56 (second power supply), thereby ensuring that the short circuit control is performed reliably.

[0051] On the other hand, during external charging, in order to reduce noise from the switching power supply 54, the output voltage of the switching power supply 54 is lowered. In this case, there is a possibility that the upper arm switch SWH and the lower arm switch SWL cannot be stably driven and controlled with the power supplied from the switching power supply 54. Therefore, a configuration is provided in which power can also be supplied to the gate driver 52 from the support power supply 56 used in short-circuit control during external charging. This makes it possible to reliably perform drive control during external charging.

[0052] Insulation is required in the circuit design in which the switching power supply 54 is placed in a low-voltage region and the gate driver 52 is placed in a high-voltage region. This results in a circuit configuration in which the switching power supply 54 generates high noise. On the other hand, because the switching power supply 54 is placed in a low-voltage region, there is an advantage in that heat loss is small and power consumption can be reduced even when used for a long period of time under normal conditions.

[0053] The gate driver 52 and the support power supply 56 are arranged in the same high voltage area, so there is no need to consider insulation. Also, because it is an emergency power supply, there is no need to consider heat loss or power loss. This makes it possible to adopt a linear power supply and achieve low noise. Therefore, even if it is used during external charging, the impact of noise can be reduced.

[0054] Incidentally, because support power supply 56 is arranged in the high voltage area, heat loss is large and power consumption is likely to become large; however, since support power supply 56 is used only when switching power supply 54 fails or for a limited period of time such as when external charging is performed, that is, since support power supply 56 is an emergency power supply, this disadvantage can be tolerated.

[0055] During external charging, the switching power supply 54 supplies power at a voltage lower than the supply voltage (second threshold) in the normal state and higher than the first threshold at which it is determined that an abnormality exists. Therefore, during normal control, power can be stably supplied from the switching power supply 54 to the gate driver 52, while noise can be reduced during external charging. Also, it is possible to easily determine whether the switching power supply 54 is abnormal.

[0056] Second embodiment The configuration of the first embodiment may be partially modified. A second embodiment in which the configuration of the first embodiment is partially modified will be described below.

[0057] In the second embodiment, during external charging, the microcomputer 51 stops the switching power supply 54, but operates the support power supply 56, and supplies power from the support power supply 56 to the gate driver 52.

[0058] In addition, when the gate driver 52 receives a switching command (on command or off command) from the microcontroller 51 and a failure signal of the switching power supply 54 from the power supply failure determination unit 57, the gate driver 52 is configured to process the failure signal as invalid (mask the failure signal).

[0059] As a result, even if the switching power supply 54 is intentionally stopped by instruction from the microcontroller 51 during external charging, causing the power supply failure determination unit 57 to output a failure signal, the gate driver 52 can perform external charging control without performing abnormality control.

[0060] If the switching power supply 54 actually fails, the power supply from the switching power supply 54 to the microcomputer 51 is also cut off, and therefore no switching command is output from the microcomputer 51. In other words, if the switching power supply 54 actually fails, the gate driver 52 performs abnormality control in response to the input of a failure signal.

[0061] According to the configuration of the second embodiment, it is possible to simplify the control of the switching power supply 54 during external charging.

[0062] Third embodiment The configuration of the first embodiment may be partially modified. Hereinafter, a third embodiment in which the configuration of the first embodiment is partially modified will be described.

[0063] The power supply system 10 of the third embodiment has a diagnostic function for diagnosing whether the support power supply 56 can operate normally or not. This will be described in detail below.

[0064] The gate driver 52 is configured to output a FAIL signal to the microcomputer 51 when the power supply voltage input from the switching power supply 54 or the support power supply 56 falls below the operable lower limit voltage. Therefore, the microcomputer 51 performs the diagnostic process shown in FIG. 4 at a predetermined timing (for example, when the vehicle is started) and intentionally stops the operation of the switching power supply 54 (step S201). As a result, a FAIL signal is input from the gate driver 52 to the microcomputer 51.

[0065] Next, the microcomputer 51 operates the support power supply 56 (step S202), and determines whether or not the output of the FAIL signal is stopped by supplying power from the support power supply 56 to the gate driver 52 (step S203).

[0066] If the result of this determination is positive, i.e., if the output of the FAIL signal has been stopped, microcomputer 51 determines that support power supply 56 is operating normally, and transitions to normal control (step S204). On the other hand, if the result of the determination in step S202 is negative, i.e., if the output of the FAIL signal has not been stopped, microcomputer 51 determines that support power supply 56 is not operating normally, and transitions to abnormal control (step S205).

[0067] According to the configuration of the third embodiment, the operation of the support power supply 56 can be easily checked, and the gate driver 52 can be made to reliably perform the external charging control and the abnormality control (short-circuit control).

[0068] (Modification) A modification in which a part of the configuration of the above embodiment is changed will be described.

[0069] In the second embodiment described above, when the gate driver 52 receives a switching command (ON command or OFF command) from the microcomputer 51 and also receives a failure signal of the switching power supply 54 from the power supply failure determination unit 57, the gate driver 52 processes the failure signal as invalid. As a modification of this, as shown in Fig. 5, during external charging, the microcomputer 51 may input an external charging instruction signal notifying the gate driver 52 that external charging is in progress via a dedicated line provided separately from the signal line that outputs the switching command. This allows the gate driver 52 to reliably recognize that external charging is in progress even if the switching command is not correctly input due to the influence of noise or the like.

[0070] In the above embodiment, the support power supply 56 is connected to the gate driver 52 in the high voltage region, but as shown in Fig. 6, it may be connected to the electrical path between the switching power supply 54 and the diode 54a in the low voltage region. In this case, the power supply failure determination unit 57 receives the output voltage of the switching power supply 54 from the electrical path between the switching power supply 54 and the diode 54a in the low voltage region.

[0071] In the above embodiment, when the external charging control is performed, the microcomputer 51 controls the switching power supply 54 to output a voltage that is greater than the first threshold and equal to or less than the second threshold. As a variation of this, when the external charging control is performed, the microcomputer 51 may cause the switching power supply 54 to output a voltage intermittently.

[0072] In the above embodiment, the power supply failure determination unit 57 may be configured to determine that the switching power supply 54 has failed when the output voltage of the switching power supply 54 is equal to or lower than the second threshold during normal operation, and to determine that the switching power supply 54 has failed when the output voltage of the switching power supply 54 is equal to or lower than the first threshold during external charging. In other words, the threshold may be changed between the normal operation and during external charging.

[0073] In the above embodiment, the power failure determination unit 57 may be provided inside the gate driver 52. The power supply system 10 of the above embodiment may be configured to enable neutral point charging.

[0074] In the above embodiment, as shown in FIG. 7, the gate driver 52 may be connected to the switching power supply 54 and the support power supply 56 via a wired-OR circuit 300 using transistors or the like.

[0075] In the above embodiment, an insulated power supply is used as the switching power supply 54, but a non-insulated power supply may also be used. In this case, it is necessary to provide an insulation circuit between the switching power supply 54 and the gate driver 52.

[0076] Characteristic configurations extracted from each of the above-described embodiments will be described below. [Configuration 1] A power supply system (10) capable of performing external charging for charging an electricity storage device (40) by an external power supply (210) provided externally, A rotating electric machine (20) having an armature winding (21); an inverter (30) having a series connection of an upper arm switch (SWH) and a lower arm switch (SWL) and performing power conversion between the power storage device and the rotating electric machine; a drive control unit (52) that drives and controls the upper arm switch and the lower arm switch; a first power source (54) that supplies power to the drive control unit; a second power source (56) that supplies power to the drive control unit when short-circuit control is performed to turn on one of the upper arm switch and the lower arm switch and turn off the other arm switch, the first power source is configured to supply power at a voltage higher than a first threshold in a normal state, and to supply power intermittently, supply power at a reduced voltage, or stop supplying power during external charging; The drive control unit is configured to perform the short-circuit control using power supplied from the second power source when the first power source fails, and to drive and control the upper arm switch and the lower arm switch using power supplied from the first power source or the second power source, whichever has a higher output voltage, or using power supplied from the second power source during external charging. [Configuration 2] 2. The power supply system according to configuration 1, wherein at least the drive control unit and the second power supply are arranged in a high voltage region, while the first power supply is arranged in a low voltage region. [Configuration 3] the first power source is configured to supply power at a voltage higher than a second threshold during a normal state, and to supply power at a voltage equal to or lower than the second threshold and higher than the first threshold during external charging; The power supply system of configuration 1 or 2, wherein the drive control unit, when the output voltage of the first power supply is equal to or lower than the first threshold value, determines that the first power supply has failed and performs the short circuit control using power supplied from the second power supply. [Configuration 4] a voltage control unit (51) that instructs an output voltage of the first power source; the voltage control unit instructs the first power source to output power at a voltage equal to or lower than the first threshold during external charging, and notifies the drive control unit of the instruction; The power supply system of configuration 1 or 2, wherein when the notification is received from the voltage control unit, the drive control unit drives and controls the upper arm switch and the lower arm switch using the power supplied from the second power source without performing the short circuit control, even if the power supplied from the first power source is below the first threshold value. [Configuration 5] a switch control unit (51) for instructing the on / off states of the upper arm switch and the lower arm switch, the switch control unit is operated by power from the first power source, The power supply system of configuration 1 or 2, wherein the drive control unit, when instructed by the switch control unit, drives and controls the upper arm switch and the lower arm switch in accordance with the instruction from the switch control unit without performing the short circuit control, even if the output voltage of the first power supply is below the first threshold. [Configuration 6] a voltage control unit (51) that instructs an output voltage of the first power source; The voltage control unit is configured to be able to execute an abnormality diagnosis process, The power supply system of any of configurations 1 to 5, wherein, in the abnormality diagnosis process, the voltage control unit instructs the first power supply to output power at a voltage lower than the first threshold, and if the short-circuit control is then performed by the drive control unit using power supplied from the second power supply, the voltage control unit diagnoses that the second power supply is operating normally, whereas if the short-circuit control is not performed, the voltage control unit diagnoses that an abnormality has occurred. [Explanation of symbols]

[0077] 10...power supply system, 20...motor, 21...armature winding, 30...inverter, 40...battery pack, 50...control device, 51...microcomputer, 52...gate driver, 53...abnormality determination unit, 54...switching power supply, 56...support power supply, 57...power supply failure determination unit.

Claims

1. A power supply system (10) capable of performing external charging for charging a power storage device (40) by an external power supply (210) provided externally, A rotating electric machine (20) having an armature winding (21); an inverter (30) having a series connection of an upper arm switch (SWH) and a lower arm switch (SWL) and performing power conversion between the storage device and the rotating electric machine; A drive control unit (52) that drives and controls the upper arm switch and the lower arm switch; A first power source (54) for supplying power to the drive control unit; a second power source (56) that supplies power to the drive control unit when short-circuit control is performed to turn on one of the upper arm switch and the lower arm switch and turn off the other arm switch; A voltage control unit (51) that instructs an output voltage of the first power source, The first power supply is configured to supply power at a voltage higher than a first threshold in a normal state, and to supply power intermittently, supply power at a reduced voltage, or stop supplying power during external charging; the drive control unit is configured to perform the short circuit control using power supplied from the second power source when the first power source fails, and to drive and control the upper arm switch and the lower arm switch using power supplied from one of the first power source and the second power source, which has a higher output voltage, or using power supplied from the second power source during external charging; the voltage control unit instructs the first power source to output power at a voltage equal to or lower than the first threshold during external charging, and notifies the drive control unit of the instruction; When the notification is received from the voltage control unit, the drive control unit drives and controls the upper arm switch and the lower arm switch using the power supplied from the second power source without performing the short circuit control, even if the power supplied from the first power source is below the first threshold value.

2. 2. The power supply system according to claim 1, wherein at least the drive control unit and the second power supply are arranged in a high voltage region, while the first power supply is arranged in a low voltage region.

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