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 Art

[0002] When external charging is performed to charge a power storage device by an external power supply provided outside the power supply system, the voltage of the external power supply may be applied to the load driving device together with the power storage device. In this case, a parasitic capacitance is generated in the load driving device, and the load driving device may operate unintentionally. In order to avoid such a situation, a switching element that interrupts power supply to the load driving device during external charging may be controlled to be in an off state.

[0003] In this case, a power supply for supplying power for operating the switching element during external charging is required. When this power supply is constituted by a switching power supply, noise is generated from the switching power supply during external charging. It is preferable that such noise be reduced during external charging.

[0004] Therefore, in Patent Document 1, the switching power supply is intermittently operated during external charging to reduce noise. Also, for example, it is conceivable to reduce noise by lowering the output voltage of the switching power supply.

[0005] Furthermore, in recent electric vehicles, rotating electric motors and inverters are generally used as power units. In vehicles employing rotating electric motors and inverters, when the rotational speed of the rotating electric motor increases, the back electromotive force generated in the coil by the magnetic flux of the permanent magnets of the rotating electric motor can become greater than the voltage of the storage battery. Under these circumstances, if the inverter drive power supply that drives the inverter is lost due to an accident or other reason, the inverter cannot be operated, resulting in a full-phase shutdown and the generation of back electromotive force. As a result, even if, for example, both the upper and lower arm switches are turned off, a high-voltage back electromotive force can be applied from the coil to the storage battery or electrical load via diodes connected in parallel to the upper and lower arm switches. In this case, problems such as failure of the storage battery or other components may occur due to the high-voltage back electromotive force. In addition, there is a possibility that unintended torque will be generated on the drive wheels due to the back electromotive force.

[0006] Therefore, in recent electric vehicles, as described in Patent Document No. 2, Active Short Circuit (ASC) control (also called short-circuit control) is implemented in the event of an abnormality. ASC control is a control that turns on one of the upper or lower arm switches of all phases that make up the inverter, while turning off the other. This prevents various problems caused by back electromotive force. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2022-118417 [Patent Document 2] Japanese Patent Publication No. 2022-28347 [Overview of the project] [Problems that the invention aims to solve]

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

[0009] Therefore, when attempting to adopt the ASC control described in Patent Document 2 in a configuration that intermittently operates the switching power supply during external charging, as described in Patent Document 1 above, the following problems arise. Specifically, when the output voltage from the switching power supply (inverter-driven power supply) is reduced or operated intermittently during charging by an external power supply, it may be mistakenly determined that the switching power supply (inverter-driven power supply) has failed, and the ASC control may be implemented. In this case, as described above, one of the upper or lower arm switches of all phases will be turned on, preventing the inverter from operating and making it impossible to charge by the external power supply.

[0010] The present invention was made to solve the above problems, and its main objective is to provide a power supply system that enables short-circuit control and charging by an external power supply. [Means for solving the problem]

[0011] The power supply system for solving the above problem is as follows: A power supply system capable of external charging, which charges a power storage device using an external power source located outside, A rotating electric machine having an armature winding, An inverter having a series connection of an upper arm switch and a lower arm switch, which performs power conversion between the energy storage device and the rotating electric machine, A drive control unit that controls the operation of the upper arm switch and the lower arm switch, A first power supply that supplies power to the drive control unit, The system includes a second power supply 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 supply is configured to supply power at a voltage higher than a first threshold under normal conditions, while intermittently supplying power, lowering the voltage to supply power, or stopping the power supply during external charging. The drive control unit is configured to perform the short-circuit control using power supplied from the second power supply when the first power supply fails, and to drive the upper arm switch and the lower arm switch using power supplied from the power supply with the higher output voltage of the first power supply and the second power supply, or using power supplied from the second power supply, while external charging is in progress.

[0012] The drive control unit can suppress the effects of back electromotive force by performing short-circuit control when the first power supply fails. At this time, the short-circuit control is performed using power from the second power supply to ensure reliable operation.

[0013] On the other hand, during external charging, the first power supply is operated intermittently to reduce noise from the first power supply. In this case, the power supplied from the first power supply may not be sufficient to stably drive and control the upper and lower arm switches. Therefore, the system is configured to also supply power from the second power supply used for short-circuit control during external charging. This ensures reliable drive control during external charging. [Brief explanation of the drawing]

[0014] [Figure 1] Power supply system configuration diagram. [Figure 2] Configuration diagram of the control device. [Figure 3] A flowchart showing the control flow during external charging. [Figure 4] A flowchart illustrating the process for diagnosing abnormalities. [Figure 5] Configuration diagram of the control device in a modified example. [Figure 6] Configuration diagram of the control device in a modified example. [Figure 7] Configuration diagram of the control device in a modified example.

Best Mode for Carrying Out the Invention

[0015] Hereinafter, an embodiment in which the "power supply system" according to the present disclosure is applied to a vehicle (for example, a moving body such as a hybrid vehicle or an electric vehicle) will be described with reference to the drawings, together with a plurality of embodiments and their modifications. In the plurality of embodiments and their modifications, parts that functionally and / or structurally correspond and / or are associated may be assigned the same reference numerals, or reference numerals that differ in the hundreds or more digits. For corresponding parts and / or associated parts, reference may be made to the description of other embodiments.

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

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

[0018] The inverter 30 is composed of a full-bridge circuit having upper and lower arms equal in number to the number of phases of the phase windings, and the energizing current in each phase winding is adjusted by turning on and off the switches provided in each arm.

[0019] Specifically, the inverter 30 is equipped with three series connections of upper arm switches SWH and lower arm switches SWL for each phase. In each phase, the first end of the armature winding 21 of the motor 20 is connected to the connection point between the upper arm switch SWH and the lower arm switch SWL. The second end of the armature winding 21 for each phase is connected at the neutral point. The armature windings 21 for each phase are arranged with an electrical angle offset of 120° from each other. Incidentally, in this embodiment, voltage-controlled semiconductor switching elements are used as the upper arm switch SWH and the lower arm switch SWL, and more specifically, IGBTs (Insulated Gate Bipolar Transistors) are used. In addition, an upper arm diode DH, which is a freewheeling diode, is connected in antiparallel to the upper arm switch SWH. Similarly, a lower arm diode DL, which is a freewheeling diode, is connected in antiparallel to the lower arm switch SWL.

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

[0021] The high-potential electrical path 31H and the low-potential electrical path 31L are each provided with a relay switch SMR (system main relay switch), and the relay switch SMR is configured to switch between energizing and disconnecting the power. Each relay switch SMR may be driven by the control device 50, or it may be driven by a higher-level ECU 100 which is a higher-level control device than the control device 50.

[0022] The inverter 30 is equipped with 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. In other words, the smoothing capacitor 32 is provided in parallel with the series connection between the upper arm switch SWH and the lower arm switch SWL of each phase, between the high-potential side electrical path 31H and the low-potential side electrical path 31L. 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 a terminal voltage of, for example, 100 [V] or more, and is composed of multiple battery cells 41 connected in series. As the battery cells 41 (secondary batteries), for example, lithium iron phosphate batteries (LFP batteries), lithium-ion batteries, and nickel-metal hydride batteries can be used. Each battery cell 41 is a battery having an electrolyte (a solution consisting of an electrolyte and a solvent) and multiple electrodes.

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

[0025] External charging is performed when the vehicle is connected to the charging equipment 200. The charging equipment 200 comprises an external power supply 210 and a connector 220. The connector 220 is configured to be connectable to the vehicle's inlet 62. The external power supply 210 is, for example, a DC power supply, but it 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 the currents of 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 magnetoresistive element, and in this embodiment it is a resolver. The power supply system 10 also includes a voltage sensor 13 that detects the terminal voltage of the smoothing capacitor 32 and outputs a detected voltage VS.

[0027] The configuration of the control device 50 will be explained using Figure 2. The control device 50 is equipped with a microcontroller 51 located in the low-voltage region. The microcontroller 51 consists of a CPU, RAM, ROM, etc. The microcontroller 51 (its CPU) realizes various functions by executing programs stored in ROM.

[0028] The microcontroller 51 receives the current signal from the phase current sensor 11. Based on the input current signal, the microcontroller 51 calculates the phase current Ir. The microcontroller 51 also receives the angle signal from the angle sensor 12. Based on the input angle signal, the microcontroller 51 obtains the electrical angle θe of the motor 20.

[0029] The microcontroller 51 receives command values ​​from the higher-level ECU 100. The microcontroller 51 generates switching commands to turn on and off the upper arm switch SWH and lower arm switch 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. Under normal circumstances, the gate driver 52 turns the upper arm switch SWH and lower arm switch SWL of each phase on and off based on switching commands (on commands or off commands) from the microcontroller 51.

[0031] More specifically, each gate driver 52 is individually provided corresponding to the upper arm switch SWH and lower arm switch SWL of each phase. Therefore, a total of six gate drivers 52 are provided. Note that they are not shown in Figure 2. When an ON command is input, each gate driver 52 supplies a charging current to the gate of the corresponding switch SWH or SWL. This causes the gate voltage of the switch SWH or SWL to become equal to or greater than the threshold voltage Vth, and the switch SWH or SWL is turned ON. On the other hand, when an OFF command is input, each gate driver 52 flows a discharge current from the gate to the emitter side of the corresponding switch SWH or SWL. This causes the gate voltage of the switch SWH or SWL to become less than the threshold voltage Vth, and the switch SWH or SWL is turned OFF. Note that in this embodiment, the gate drivers 52 are provided in the high-voltage region.

[0032] The gate driver 52 is configured to perform abnormal control in addition to the normal drive control described above, in order to deal with abnormalities such as overvoltage abnormalities. In this embodiment, the abnormal control is a short-circuit control that turns off the upper arm switch SWH and turns on the lower arm switch SWL. Prior to the implementation of the short-circuit control, a shutdown control may be performed to forcibly turn off the upper arm switch SWH and lower arm switch SWL for each phase.

[0033] Furthermore, the gate driver 52 is configured to perform external charging control, which keeps the upper arm switch SWH and lower arm switch SWL of each phase in the OFF state, in addition to the normal drive control and abnormality control described above. External charging control is performed when the higher-level ECU 100 notifies the vehicle via the microcontroller 51 that the charging equipment 200 has been connected.

[0034] The control device 50 includes an abnormality detection unit 53. The abnormality detection unit 53 receives the detected voltage VS, phase current Ir (or current signal), and electrical angle θe (or angle signal) as inputs. If any one of these values ​​becomes abnormal, the abnormality detection unit 53 determines that an abnormality has occurred in at least one of the components used for normal drive control. Components used for normal drive control include, for example, a phase current sensor 11, an angle sensor 12, a voltage sensor 13, a microcontroller 51, a gate driver 52, upper arm switches SWH for each phase, and lower arm switches SWL for each phase.

[0035] If the abnormality detection unit 53 determines that an abnormality has occurred, it notifies the gate driver 52 of this fact (by outputting an abnormality detection signal). As a result, the gate driver 52 performs abnormality control (short-circuit control in this embodiment). Note that abnormality control is performed preferentially over other controls (such as normal control). The abnormality detection unit 53 may be provided in the microcontroller 51 or in the gate driver 52. Furthermore, the abnormality detection unit 53 may be provided in both the microcontroller 51 and the gate driver 52, respectively. In addition, the abnormality detection unit 53 may be implemented in software or in hardware.

[0036] Furthermore, the control device 50 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 isolated 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-acid battery, which has a lower output voltage compared to the battery pack 40, and boosts the voltage of the low-voltage battery 55 and supplies it to each gate driver 52. In other words, the switching power supply 54 is connected to the low-voltage battery 55 in the low-voltage region and to the gate driver 52 via a diode 54a in the high-voltage region. Note that the switching power supply 54 is isolated between the low-voltage region and the high-voltage region. Although not shown in the figures, power is also supplied from the switching power supply 54 to the microcontroller 51.

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

[0038] Furthermore, as shown in Figure 2, the system includes a power supply failure detection unit 57 that receives an output voltage from the electrical path between the switching power supply 54 and the diode 54a, compares the output voltage with a first threshold value, and determines whether or not the switching power supply 54 has failed. If the power supply failure detection 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 detection unit 57 indicating that the switching power supply 54 has failed, it performs abnormal control as described above. The power supply failure detection unit 57 is located in the high-voltage region.

[0039] Furthermore, the control device 50 includes a support power supply 56 as a second power supply used when abnormal 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. Although the support power supply 56, which consists of these power supplies, generally has lower noise than the switching power supply 54, it has a large heat loss. However, since the support power supply 56 is an emergency power supply used for abnormal control and the period of use is limited, the heat loss is acceptable.

[0040] This support power supply 56 is located in the high-voltage region and is connected to the battery pack 40, which is high-voltage in the high-voltage region compared to the low-voltage battery 55. 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 the power supplied from the support power supply 56 when performing abnormal control. Specifically, when performing abnormal control, each gate driver 52 uses the power supplied from the support power supply 56 to supply current to the gates of each switch SWH, SWL, thereby turning each switch SWH, SWL on and off.

[0041] Incidentally, the switching power supply 54 is connected to the microcontroller 51 in the low-voltage region, and the output voltage and other parameters are adjustable by the microcontroller 51. Specifically, the microcontroller 51 is configured to change the output voltage depending on whether normal operation control is performed or external charging control is performed. For example, when normal operation control is performed, the microcontroller 51 outputs a voltage higher than the second threshold, while when external charging control is performed, it outputs a voltage higher than the first threshold but lower than or equal to the second threshold. As a result, when external charging control is performed, the noise of the switching power supply 54 can be reduced compared to when normal operation control is performed.

[0042] However, as mentioned above, if the output voltage of the switching power supply 54 is reduced during external charging, the margin between the reduced output voltage and the first threshold value at which failure is determined becomes smaller. As a result, it becomes more susceptible to the effects of noise and the decrease in output voltage of the low-voltage battery 55, and the power failure determination unit 57 is more likely to mistakenly determine that the switching power supply 54 has failed. In this case, the gate driver 52 prioritizes abnormal control (short circuit control) and is unable to perform external charging control.

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

[0044] For example, as shown in Figure 2, the switching power supply 54 is connected to the gate driver 52 via diode 54a in the high-voltage region, and the support power supply 56 is connected to the electrical path between diode 54a and the gate driver 52 via diode 56a in the high-voltage region. This allows each gate driver 52 to receive power from 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 but higher than the first threshold during external charging. During external charging, the support power supply 56 is also operated to supply power as described above. The output voltage of the support power supply 56 can be any voltage that can properly operate the gate driver 52, but in this embodiment, it is set to be higher than the second threshold to take into account the effects of noise and other factors.

[0046] Next, with reference to Figure 3, the control flow when external charging is performed will be explained. The microcontroller 51 determines whether or not the vehicle is undergoing external charging (step S101). Specifically, if the higher-level ECU 100 has notified the microcontroller 51 that the connector 220 of the charging equipment 200 is connected to the vehicle's inlet 62 and that power supply is possible, the microcontroller 51 determines this to be positive. If the result of the determination in step S101 is negative, the microcontroller 51 performs normal control (step S102).

[0047] If the result of step S101 is positive (indicating external charging), the microcontroller 51 reduces the output voltage of the switching power supply 54 (step S103). Specifically, the microcontroller 51 outputs a voltage that is greater than the first threshold but less than or equal to the second threshold.

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

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

[0050] The gate driver 52 (drive control unit) can suppress the effects of back electromotive force by performing short-circuit control in abnormal situations such as when the switching power supply 54 (first power supply) fails. At this time, the gate driver 52 performs short-circuit control using power from the support power supply 56 (second power supply) to ensure that short-circuit control is reliably performed.

[0051] On the other hand, during external charging, the output voltage of the switching power supply 54 is reduced to reduce noise from the switching power supply 54. In this case, there is a possibility that the power supplied from the switching power supply 54 may not be sufficient to stably drive and control the upper arm switch SWH and the lower arm switch SWL. Therefore, during external charging, the system is configured to also supply power to the gate driver 52 from the support power supply 56 used in short-circuit control. This ensures that drive control can be reliably performed during external charging.

[0052] Due to the circuit design, the switching power supply 54 is located in the low-voltage region and the gate driver 52 is located in the high-voltage region, requiring isolation. As a result, the switching power supply 54 has a circuit configuration that generates high noise. On the other hand, because the switching power supply 54 is located in the low-voltage region, it has the advantage of reducing heat loss and power consumption even when used for long periods under normal conditions.

[0053] The gate driver 52 and the support power supply 56 are located in the same high-voltage region, eliminating the need for isolation considerations. Furthermore, as they are emergency power supplies, there is no need to consider heat loss or power loss. Therefore, it is possible to employ a linear power supply to achieve low noise. Consequently, even when used during external charging, the impact of noise can be minimized.

[0054] Furthermore, because the support power supply 56 is located in the high-voltage region, it experiences significant heat loss and tends to consume a large amount of power. However, since it is used only for a limited period, such as when the switching power supply 54 fails or when it is externally charged, in other words, it is an emergency power supply, and therefore this disadvantage can be tolerated.

[0055] During external charging, the switching power supply 54 supplies power at a voltage lower than the supply voltage under normal conditions (second threshold) but higher than the first threshold voltage at which an abnormality is detected. 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. Furthermore, abnormality detection of the switching power supply 54 can be easily performed.

[0056] (Second Embodiment) The configuration of the first embodiment described above 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, the microcontroller 51 stops the switching power supply 54 while the support power supply 56 is activated and supplies power to the gate driver 52 from the support power supply 56 during external charging.

[0058] Furthermore, the gate driver 52 is configured to process a switching command (on command or off command) from the microcontroller 51 and a power failure detection unit 57 that detects a power failure signal from the switching power supply 54, by invalidating the failure signal (masking the failure signal).

[0059] As a result, even if the switching power supply 54 is intentionally stopped by the microcontroller 51 during external charging, and the power failure detection unit 57 outputs a failure signal as a result, the gate driver 52 can perform external charging control without performing abnormal control.

[0060] Furthermore, if the switching power supply 54 actually fails, the power supply from the switching power supply 54 to the microcontroller 51 will also be interrupted, and therefore no switching command will be output from the microcontroller 51. In other words, if the switching power supply 54 actually fails, the gate driver 52 will perform abnormal control in response to the input of the failure signal.

[0061] According to the configuration of the second embodiment described above, control of the switching power supply 54 can be simplified during external charging.

[0062] (Third embodiment) The configuration of the first embodiment described above may be partially modified. A third embodiment, in which the configuration of the first embodiment is partially modified, will be described below.

[0063] The power supply system 10 of the third embodiment includes a diagnostic function for diagnosing whether the support power supply 56 is able to operate normally. This will be explained in detail below.

[0064] The gate driver 52 is configured to output a FAIL signal to the microcontroller 51 if the power supply voltage input from the switching power supply 54 or the support power supply 56 falls below the lower limit of the operating voltage. Therefore, at a predetermined timing (for example, when the vehicle starts up), the microcontroller 51 performs the diagnostic process shown in Figure 4 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 microcontroller 51.

[0065] Next, the microcontroller 51 activates the support power supply 56 (step S202) and supplies power from the support power supply 56 to the gate driver 52 to determine whether or not the output of the FAIL signal is stopped (step S203).

[0066] If the result of this determination is positive, that is, if the output of the FAIL signal is stopped, the microcontroller 51 determines that the support power supply 56 is operating normally and switches to normal control (step S204). On the other hand, if the determination in step S202 is negative, that is, if the output of the FAIL signal is not stopped, the microcontroller 51 determines that the support power supply 56 is not operating normally and switches 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 reliably controlled during external charging and during abnormal conditions (short circuit control).

[0068] (modified version) A modified example in which some parts of the configuration of the above embodiment are changed will be described.

[0069] In the second embodiment described above, the gate driver 52 receives a switching command (on command or off command) from the microcontroller 51, and also receives a power failure detection unit 57 that detects a power failure of the switching power supply 54. In this embodiment, the gate driver 52 is configured to invalidate the power failure signal. As a modified example, as shown in Figure 5, during external charging, the microcontroller 51 may input an external charging instruction signal to the gate driver 52 via a dedicated line separate from the signal line that outputs the switching command. This ensures that the gate driver 52 is reliably aware that external charging is in progress, even if the switching command is not input correctly due to noise or other reasons.

[0070] In the above embodiment, the support power supply 56 was connected to the gate driver 52 in the high-voltage region, but as shown in Figure 6, it may also 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 failure detection unit 57 will receive 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 external charging control is performed, the microcontroller 51 controls the switching power supply 54 to output a voltage greater than the first threshold and less than or equal to the second threshold. As a variation, when external charging control is performed, the microcontroller 51 may cause the switching power supply 54 to output voltage intermittently.

[0072] In the above embodiment, the power failure determination unit 57 may determine that the switching power supply 54 has failed if the output voltage of the switching power supply 54 is below the second threshold during normal operation, while it may also determine that the switching power supply 54 has failed if the output voltage of the switching power supply 54 is below the first threshold during external charging. In other words, the thresholds may be changed between normal operation and external charging.

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

[0074] In the above embodiment, as shown in Figure 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 a transistor or the like.

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

[0076] The following describes the characteristic configurations extracted from each of the embodiments described above. [Configuration 1] In a power supply system (10) capable of external charging, which charges a power storage device (40) using 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), which performs power conversion between the energy storage device and the rotating electric machine, A drive control unit (52) that controls the operation of the upper arm switch and the lower arm switch, A first power supply (54) that supplies power to the drive control unit, The system includes a second power supply (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 supply is configured to supply power at a voltage higher than a first threshold under normal conditions, while intermittently supplying power, lowering the voltage to supply power, or stopping the power supply during external charging. The drive control unit is configured to perform the short-circuit control using power supplied from the second power supply when the first power supply fails, and to drive and control the upper arm switch and the lower arm switch using power supplied from the power supply with the higher output voltage of the first power supply and the second power supply, or using power supplied from the second power supply, while external charging is in progress. [Configuration 2] The power supply system according to Configuration 1, wherein at least the drive control unit and the second power supply are located in the high-voltage region, while the first power supply is located in the low-voltage region. [Configuration 3] The first power supply is configured to supply power at a voltage higher than the second threshold during normal operation, and at a voltage below the second threshold but higher than the first threshold during external charging. The power supply system according to configuration 1 or 2, wherein the drive control unit, when the output voltage of the first power supply is below the first threshold, assumes that the first power supply has failed and performs the short-circuit control using power supplied from the second power supply. [Structure 4] The system includes a voltage control unit (51) that indicates the output voltage of the first power supply, The voltage control unit, during external charging, instructs the first power supply to output power at a voltage below the first threshold, and notifies the drive control unit of this fact. The power supply system according to configuration 1 or 2, wherein the drive control unit, when notified by the voltage control unit, drives and controls the upper arm switch and the lower arm switch using the power supplied from the second power supply without performing the short-circuit control, even if the power supplied from the first power supply is below the first threshold. [Composition 5] The system includes a switch control unit (51) that indicates the on / off state of the upper arm switch and the lower arm switch, The switch control unit is operated by power from the first power supply, The power supply system according to 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 instructions 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. [Composition 6] The system includes a voltage control unit (51) that indicates the output voltage of the first power supply, The voltage control unit is configured to perform abnormality diagnosis processing, The power supply system according to any one of configurations 1 to 5, wherein the voltage control unit instructs the first power supply to output power at a voltage lower than the first threshold during the abnormality diagnosis process, and thereafter diagnoses that the second power supply is operating normally if the short-circuit control is performed by the drive control unit using power supplied from the second power supply, while diagnosing that an abnormality has occurred if the short-circuit control is not performed. [Explanation of symbols]

[0077] 10...Power supply system, 20...Motor, 21...Armature winding, 30...Inverter, 40...Battery pack, 50...Control device, 51...Microcontroller, 52...Gate driver, 53...Anomaly detection unit, 54...Switching power supply, 56...Support power supply, 57...Power failure detection unit.

Claims

1. In a power supply system (10) capable of external charging, which charges a power storage device (40) using an external power supply (210) provided outside, 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), which performs power conversion between the energy storage device and the rotating electric machine, A drive control unit (52) that controls the driving of the upper arm switch and the lower arm switch, A first power supply (54) 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 second power supply (56) supplies power to the drive control unit, The system includes a voltage control unit (51) that indicates the output voltage of the first power supply, The first power supply is configured to supply power at a voltage higher than a first threshold under normal conditions, while intermittently supplying power, lowering the voltage to supply power, or stopping the power supply during external charging. The drive control unit is configured to perform the short-circuit control using power supplied from the second power supply when the first power supply fails, and to drive the upper arm switch and the lower arm switch using power supplied from the power supply with the higher output voltage of the first power supply and the second power supply, or using power supplied from the second power supply, while external charging is in progress. The voltage control unit instructs the first power supply to output power at a voltage below the first threshold during external charging, and notifies the drive control unit of this fact. The drive control unit is a power supply system that, when notified by the voltage control unit, drives and controls the upper arm switch and the lower arm switch using the power supplied from the second power supply without performing the short-circuit control, even if the power supplied from the first power supply is below the first threshold.

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

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