Power supply system

Abstract

A power supply system (10) includes a rotating electrical machine (20), an inverter (30), a drive control unit (52), a first power supply (54) that supplies power to the drive control unit, and a second power supply (56) that supplies power to the drive control unit when short circuit control is performed. The first power supply supplies power at a voltage higher than a first threshold value in a normal state, and supplies power intermittently, or supplies power by reducing the voltage, or stops power supply during external charging. When the first power supply fails, the drive control unit performs the short-circuit control by means of the supply power from the second power supply, and when external charging is performed, the drive control unit performs the short-circuit control by means of the supply power from one of the first power supply and the second power supply having a higher output voltage. Alternatively, the inverter is driven and controlled by power supplied from the second power source.

Description

Citation of related applications

[0001] This application is based on Japanese Patent Application No. 2023-010699 filed on January 27, 2023, and the contents thereof are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to a power supply system. Background Art

[0003] During external charging, where the power storage device is charged by an external power source located outside the power supply system, the voltage of the external power source may also be applied to the load driving device along with the power storage device. In this case, parasitic capacitance may be generated in the load driving device, causing it to operate unintentionally. To prevent this, a switching element that shuts off power to the load driving device during external charging is sometimes controlled to the off state.

[0004] In this case, a power source is required to supply the power required to operate the switching element during external charging. If this power source is a switching power supply, noise is generated from the switching power supply during external charging. It is desirable to reduce this noise during external charging.

[0005] Therefore, in Patent Document 1, noise is reduced by operating the switching power supply intermittently during external charging. Another possible approach is to reduce noise by, for example, lowering the output voltage of the switching power supply.

[0006] Furthermore, recent electric vehicles often incorporate a rotating electrical machine and an inverter in their power units. In vehicles employing these devices, when the rotating electrical machine's rotational speed increases, the back EMF generated in the coils by the magnetic flux of the permanent magnets in the rotating electrical machine can become greater than the battery voltage. In this situation, if the inverter drive power supply used to drive the inverter fails due to an accident or other cause, the inverter cannot operate, becoming fully disconnected and generating back EMF. As a result, even when both the upper and lower arm switches are completely disconnected, a high-voltage back EMF is applied from the coils to the battery or electrical loads via the diodes connected in parallel with the upper and lower arm switches. In this case, the high-voltage back EMF can cause problems such as battery failure. Furthermore, the back EMF can generate undesirable torque on the drive wheels.

[0007] Therefore, in recent electric vehicles, as described in Patent Document 2, ASC (Active Short Circuit) control (also known as short-circuit control) is implemented during abnormal conditions. ASC control switches on one of the upper and lower arm switches of all phases of the inverter while turning off the other. This prevents various problems caused by back electromotive force. Prior art literature Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2022-118417 Patent Document 2: Japanese Patent Application Laid-Open No. 2022-28347 Summary of the Invention

[0009] In Patent Document 1, a switching element that cuts off power to a load driving device during external charging constitutes an inverter, and a switching power supply corresponds to an inverter driving power supply.

[0010] Therefore, in a configuration such as Patent Document 1 that intermittently operates the switching power supply during external charging, employing the ASC control described in Patent Document 2 presents the following problem. Specifically, during charging with an external power source, if the output voltage from the switching power supply (inverter drive power supply) is reduced or intermittent, there is a risk of erroneously determining that the switching power supply (inverter drive power supply) has failed, leading to the implementation of ASC control. In this case, as described above, turning on either the upper arm switch or the lower arm switch for all phases disables the inverter operation, rendering charging with the external power source impossible.

[0011] The present disclosure is made to solve the above-mentioned technical problems, and its main purpose is to provide a power supply system that can implement short-circuit control and can be charged using an external power supply.

[0012] The power supply system for solving the above-mentioned technical problem is capable of performing external charging for charging a power storage device by an external power supply provided outside. The above power supply system includes: a rotating electrical machine having an armature winding; an inverter including an upper arm switch and a lower arm switch connected in series and performing power conversion between the power storage device and the rotating electric machine; a drive control unit configured to drive and control the upper arm switch and the lower arm switch; a first power supply configured to supply power to the drive control unit; and a second power supply for supplying power to the drive control unit when short-circuiting control is performed to turn on one of the upper arm switch and the lower arm switch and to turn off the other arm switch; The first power supply is configured to supply power at a voltage higher than a first threshold value 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 implement the short-circuit control by supplying power from the second power supply when the first power supply fails. On the other hand, during external charging, the upper arm switch and the lower arm switch are driven and controlled by supplying power from the first power supply and the second power supply with a higher output voltage, or by supplying power from the second power supply.

[0013] The drive control unit can suppress the influence of the back electromotive force by performing short-circuit control when the first power supply fails. In this case, the short-circuit control can be performed reliably by using the power from the second power supply.

[0014] During external charging, on the other hand, to reduce noise from the first power supply, the first power supply is operated intermittently. In this case, the upper and lower arm switches may not be stably driven and controlled using power supplied from the first power supply. Therefore, power is supplied from the second power supply used for short-circuit control during external charging. This ensures reliable drive control during external charging. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above objects, other objects, features and advantages of the present disclosure will become more apparent with reference to the accompanying drawings and the following detailed description. Figure 1 It is a structural diagram of the power supply system. Figure 2 It is a structural diagram of the control device. Figure 3 This is a flowchart showing the control flow during external charging. Figure 4 is a flowchart showing the abnormality diagnosis flow. Figure 5 It is a structural diagram of a control device in a modified example. Figure 6 It is a structural diagram of a control device in a modified example. Figure 7 It is a structural diagram of a control device in a modified example. DETAILED DESCRIPTION

[0016] Hereinafter, with reference to the accompanying drawings, multiple embodiments and variations thereof are described with respect to one embodiment of the "power supply system" disclosed herein applied to a vehicle (e.g., a hybrid vehicle, an electric vehicle, or other mobile object). In the various embodiments and variations thereof, functionally and / or structurally corresponding and / or associated parts are sometimes labeled with the same reference numerals or with reference numerals that differ by more than one digit. For corresponding and / or associated parts, reference can be made to the descriptions of other embodiments.

[0017] <First embodiment> like Figure 1 As shown, the power supply system 10 includes: a motor 20 as a rotating electrical machine; an inverter 30 as a power converter for passing a three-phase current through the motor 20; a battery pack 40 as a chargeable and dischargeable charging device; and a control device 50 for controlling the inverter 30.

[0018] The electric motor 20 (motor generator) is a vehicle-mounted main unit capable of transmitting power to drive wheels (not shown). In this embodiment, a three-phase permanent magnet synchronous motor is used as the electric motor 20 .

[0019] The inverter 30 is configured as a full-bridge circuit having upper and lower arms whose number is equal to the number of phases of the phase windings, and the current flowing through each phase winding is adjusted by turning on and off switches provided in each arm.

[0020] Specifically, the inverter 30 includes a series connection body of three corresponding upper arm switches SWH and lower arm switches SWL. In each phase, the first end of the armature winding 21 of the motor 20 is connected to the connection point of the upper arm switch SWH and the lower arm switch SWL. The second end of the armature winding 21 of each phase is connected at the neutral point. The armature winding 21 of each phase is arranged in such a way that the electrical angle is staggered by 120° from each other. Incidentally, in this embodiment, as the upper arm switch SWH and the lower arm switch SWL, a voltage-controlled semiconductor switching element is used, more specifically, an IGBT (Insulated Gate Bipolar Transistor). In addition, an upper arm diode DH serving as a freewheeling diode is connected in reverse parallel to the upper arm switch SWH. Similarly, a lower arm diode DL serving as a freewheeling diode is connected in reverse parallel to the lower arm switch SWL.

[0021] The positive terminal of the battery pack 40 is connected to the collector of each upper arm switch SWH as the high potential terminal via the high potential side electrical path 31H, and the negative terminal of the battery pack 40 is connected to the emitter of each lower arm switch SWL as the low potential side terminal via the low potential side electrical path 31L.

[0022] A relay switch SMR (system main relay switch) is provided on each of the high-potential-side electrical path 31H and the low-potential-side electrical path 31L. The relay switches SMR are configured to switch between energizing and de-energizing. Each relay switch SMR can be driven by the control device 50 or by the host ECU 100, acting as a host control device, for the control device 50.

[0023] The inverter 30 includes a smoothing capacitor 32. One end of the smoothing capacitor 32 is connected to a high-potential-side electrical path 31H between the relay switch SMR and the inverter 30. Furthermore, the other end of the smoothing capacitor 32 is connected to a low-potential-side electrical path 31L between the relay switch SMR and the inverter 30. Specifically, the smoothing capacitor 32 is provided between the high-potential-side electrical path 31H and the low-potential-side electrical path 31L, 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 can be provided inside or outside the inverter 30.

[0024] 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 higher and is composed of a plurality of battery cells 41 connected in series. Examples of battery cells 41 (secondary batteries) include lithium iron phosphate batteries (LFP batteries), lithium-ion batteries, and nickel-metal hydride batteries. Each battery cell 41 is a battery having an electrolyte (a solution composed of an electrolyte and a solvent) and a plurality of electrodes.

[0025] In addition, the power supply system 10 has an external charging mechanism 60. The external charging mechanism 60 includes a socket 62 and a relay 61. The socket 62 is connected to the electrical paths 31H and 31L between the battery pack 40 and the inverter 30 via the relay 61. The socket 62 is configured to supply power from the external power supply 210 of the charging device 200 to the battery pack 40 during external charging when the relay switch SMR and the relay 61 are in the on state (closed state, energized state). In addition, as Figure 1 As shown, it is also possible to connect to a neutral point and perform neutral point charging.

[0026] External charging is performed when the vehicle is connected to charging equipment 200. Charging equipment 200 includes an external power source 210 and a connector 220. Connector 220 is configured to connect to the vehicle's power outlet 62. External power source 210 is, for example, a DC power source, but may also be an AC power source. In this case, an AC / DC converter is required.

[0027] In addition, the power supply system 10 includes a phase current sensor 11 and an angle sensor 12. The phase current sensor 11 detects the current of at least two phases of the U-phase current, V-phase current, and W-phase current 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, an MR sensor having a resolver, an encoder, or a magnetoresistive element, and in this embodiment, is a resolver. In addition, the power supply system 10 includes a voltage sensor 13 that detects the voltage between the terminals of the smoothing capacitor 32 and outputs a detection voltage VS.

[0028] use Figure 2 Next, the structure of the control device 50 will be described. The control device 50 includes a microcomputer 51 installed in a low-voltage area. The microcomputer 51 is composed of a CPU, RAM, ROM, etc. The microcomputer 51 (CPU) realizes various functions by executing the programs stored in the ROM.

[0029] The microcomputer 51 receives a current signal from the phase current sensor 11. The microcomputer 51 calculates the phase current Ir based on the received current signal. The microcomputer 51 also receives an angle signal from the angle sensor 12. The microcomputer 51 obtains the electrical angle θe of the motor 20 based on the received angle signal.

[0030] The host ECU 100 inputs a command value to the microcomputer 51. Based on the phase current Ir and the electrical angle θe, the microcomputer 51 generates switching commands for turning on and off the upper arm switches SWH and lower arm switches SWL of each phase of the inverter 30 to control the controlled variable of the motor 20 to the command value. For example, the controlled variable is torque.

[0031] As a drive control unit, the control device 50 includes a gate driver 52. 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.

[0032] Specifically, the gate driver 52 is provided separately corresponding to the upper arm switch SWH and the lower arm switch SWL of each phase. Therefore, a total of six gate drivers 52 are provided. Figure 2Illustration omitted. 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 switches SWH or SWL to exceed the threshold voltage Vth, turning switches SWH or SWL on. On the other hand, when an off command is input, each gate driver 52 causes a discharge current to flow from the gate of the corresponding switch SWH or SWL to the emitter side. This causes the gate voltage of switches SWH or SWL to fall below the threshold voltage Vth, turning switches SWH or SWL off. In this embodiment, the gate driver 52 is located in the high-voltage region.

[0033] The gate driver 52 is configured to implement, in addition to the normal drive control described above, abnormal control to address abnormal situations such as overvoltage. In this embodiment, the abnormal control is short-circuit control, which disconnects the upper arm switch SWH and connects the lower arm switch SWL. Furthermore, before short-circuit control is implemented, disconnection control can be implemented to forcibly disconnect the upper arm switch SWH and lower arm switch SWL of each phase.

[0034] In addition to the normal driving control and abnormal control described above, gate driver 52 can also implement external charging control, which maintains the upper arm switch SWH and lower arm switch SWL of each phase in the OFF state during external charging. This external charging control is implemented when the host ECU 100 notifies the microcomputer 51 that the charging facility 200 is connected to the vehicle.

[0035] The control device 50 includes an abnormality determination unit 53. The abnormality determination unit 53 receives inputs of the detected voltage VS, the phase current Ir (or current signal), and the electrical angle θe (or angle signal). If any of these parameters reaches 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. Examples of the components used for normal drive control include 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 for each phase, and the lower arm switch SWL for each phase.

[0036] When the abnormality determination unit 53 determines that an abnormality has occurred, it notifies the gate driver 52 of this information (outputs an abnormality detection signal). As a result, the gate driver 52 implements abnormality control (short-circuit control in this embodiment). Furthermore, abnormality control takes priority over other controls (such as normal control). The abnormality determination unit 53 can be provided in the microcomputer 51 or in the gate driver 52. Furthermore, the abnormality determination unit 53 can be provided in both the microcomputer 51 and the gate driver 52. Furthermore, the abnormality determination unit 53 can be implemented by software or hardware.

[0037] In addition, the control device 50 includes a switching power supply 54 as a first power supply used when performing normal control. The switching power supply 54 is, for example, an insulated DC / DC switching power supply. In the present embodiment, the switching power supply 54 is connected to a low-voltage battery 55 such as a lead-acid battery, whose output voltage is lower than that of the battery pack 40, and the voltage of the low-voltage battery 55 is boosted and supplied to each gate driver 52 respectively. 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 addition, in the switching power supply 54, the low-voltage region and the high-voltage region are insulated. In addition, although not shown in the figure, power is supplied from the switching power supply 54 to the microcomputer 51.

[0038] When performing normal control, each gate driver 52 operates using the power supplied from the switching power supply 54. Specifically, when performing normal control, each gate driver 52 uses the power supplied from the switching power supply 54 to flow current through the gate of each switch SWH, SWL and to turn each switch SWH, SWL on and off.

[0039] In addition, if Figure 2 As shown, the power supply 54 includes a power failure determination unit 57. The power failure determination unit 57 receives an output voltage from the electrical 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. If the power failure determination unit 57 determines that the switching power supply 54 has failed, it outputs a failure signal to the gate driver 52. Upon receiving a notification (failure signal) indicating that the switching power supply 54 has failed from the power failure determination unit 57, the gate driver 52 implements abnormal control in the same manner as described above. The power failure determination unit 57 is located in the high voltage region.

[0040] The control device 50 also includes a backup power supply 56, which serves as a second power source for use during abnormality control (short-circuit control). For example, the backup power supply 56 is a linear power supply (also known as a series power supply) such as a step-down power supply (step-down power supply). This type of power supply generally produces lower noise than the switching power supply 54, but generates greater heat loss. However, since the backup power supply 56 is an emergency power supply used for abnormality control and other purposes, its lifetime is limited, so heat loss is tolerated.

[0041] The support power supply 56 is located in the high-voltage region and is connected to the battery pack 40, which has a higher voltage than the low-voltage battery 55. Furthermore, the support power supply 56 is connected to the gate driver 52 in the high-voltage region via a diode 56a. Furthermore, in this embodiment, the support power supply 56 regulates 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 during abnormal control. Specifically, each gate driver 52 uses the power supplied from the support power supply 56 to cause current to flow through the gates of each switch SWH and SWL, thereby turning each switch SWH and SWL on and off.

[0042] The switching power supply 54 is connected to the microcomputer 51 in the low-voltage range and is configured so that the output voltage, etc., can be adjusted by the microcomputer 51. Specifically, the microcomputer 51 is configured to change the output voltage between normal drive control and external charging control. For example, during normal drive control, the microcomputer 51 outputs a voltage greater than the second threshold. Meanwhile, during external charging control, the microcomputer 51 outputs a voltage greater than the first threshold but below the second threshold. This reduces noise from the switching power supply 54 during external charging control compared to normal drive control.

[0043] However, as described above, if the output voltage of switching power supply 54 decreases during external charging, the margin between the output voltage and the first threshold for failure determination decreases. Consequently, the voltage is susceptible to noise or a decrease in the output of low-voltage battery 55, increasing the likelihood that power failure determination unit 57 will erroneously determine that switching power supply 54 has failed. In this case, gate driver 52 prioritizes abnormality control (short-circuit control), preventing external charging control.

[0044] Therefore, in this embodiment, even during external charging, power can be supplied from the support power supply 56 to the gate drivers 52. Specifically, each gate driver 52 in this embodiment is configured to receive power from the switching power supply 54 or the support power supply 56 with the higher output voltage during external charging.

[0045] For example, Figure 2 As shown, the switching power supply 54 is connected to the gate driver 52 via the diode 54a in the high voltage region, and the support power supply 56 is connected to the electrical path between the diode 54a and the gate driver 52 in the high voltage region via the diode 56a. Thus, each gate driver 52 can receive power from the switching power supply 54 or the support power supply 56, whichever has a higher output voltage.

[0046] Furthermore, the switching power supply 54 supplies power at a voltage higher than the second threshold in normal operation. During external charging, however, it supplies power at a voltage lower than the second threshold but higher than the first threshold. Furthermore, as described above, the support power supply 56 is also activated and supplies power during external charging. The output voltage of the support power supply 56 can be any voltage as long as it allows the gate driver 52 to operate properly. However, in this embodiment, it is set to be higher than the second threshold to account for the effects of noise and other factors.

[0047] Next, refer to Figure 3 The control flow for external charging will now be described. The microcomputer 51 determines whether the vehicle is in external charging mode (step S101). Specifically, if the host ECU 100 receives notification that the connector 220 of the charging device 200 is connected to the vehicle's power inlet 62 and is ready for power supply, the microcomputer 51 affirms this determination. If the determination in step S101 is negative, the microcomputer 51 performs normal control (step S102).

[0048] If the determination result of step S101 is affirmative (external charging in progress), the microcomputer 51 reduces the output voltage of the switching power supply 54 (step S103). Specifically, the microcomputer 51 outputs a voltage greater than the first threshold and less than the second threshold.

[0049] The microcomputer 51 then activates the support power supply 56, which also supplies power to the gate driver 52 (step S104). The microcomputer 51 then implements control related to external charging (step S105). For example, the microcomputer 51 outputs an OFF command to the upper arm switch SWH and lower arm switch SWL of each phase to cause the gate driver 52 to implement external charging control.

[0050] The following effects can be obtained by the structure of the first embodiment.

[0051] The gate driver 52 (drive control unit) can suppress the effects of back electromotive force by implementing short-circuit control during abnormal conditions, such as when the switching power supply 54 (first power supply) fails. In this case, the gate driver 52 utilizes power from the backup power supply 56 (second power supply) to implement short-circuit control, enabling reliable short-circuit control.

[0052] On the other hand, during external charging, the output voltage of the switching power supply 54 is lowered to reduce noise from the switching power supply 54. In this case, the upper arm switch SWH and the lower arm switch SWL may not be stably driven and controlled by the power supplied by the switching power supply 54. Therefore, the gate driver 52 is configured to be powered from the backup power supply 56 used for short-circuit control even during external charging. This ensures reliable drive control during external charging.

[0053] The circuit design requires insulation, as the switching power supply 54 is located in a low-voltage region and the gate driver 52 is located in a high-voltage region. Consequently, the switching power supply 54 generates high noise. On the other hand, the low-voltage configuration of the switching power supply 54 offers the advantage of reducing heat loss and power consumption even during extended periods of normal use.

[0054] The gate driver 52 and the backup power supply 56 are located in the same high-voltage area, eliminating the need for insulation considerations. Furthermore, since this is an emergency power supply, there are no concerns about heat loss or power loss. Consequently, a linear power supply can be used, resulting in low noise levels. This minimizes the effects of noise even when used during external charging.

[0055] In addition, since the support power supply 56 is configured in the high-voltage area, the heat loss is large and the power consumption is likely to increase. However, since it is used during limited periods such as when the switching power supply 54 fails or for external charging, that is, since it is an emergency power supply, this disadvantage can be tolerated.

[0056] During external charging, the switching power supply 54 supplies power at a voltage lower than the normal supply voltage (second threshold) and higher than the first threshold for abnormality detection. Therefore, during normal control, power can be stably supplied from the switching power supply 54 to the gate driver 52, while also reducing noise during external charging. Furthermore, abnormality detection of the switching power supply 54 can be simplified.

[0057] (Second embodiment) A part of the structure of the first embodiment described above may be modified. Hereinafter, a second embodiment in which a part of the structure of the first embodiment is modified will be described.

[0058] In the second embodiment, the microcomputer 51 stops the switching power supply 54 during external charging, and operates the support power supply 56 , and supplies power from the support power supply 56 to the gate driver 52 .

[0059] Furthermore, when a switching command (on command or off command) is input from the microcomputer 51 and a failure signal of the switching power supply 54 is input from the power failure determination unit 57, the gate driver 52 is configured to invalidate the failure signal (mask the failure signal).

[0060] Therefore, even if the switching power supply 54 is intentionally stopped by the microcomputer 51 during external charging and the power failure determination unit 57 outputs a failure signal, the gate driver 52 can perform external charging control instead of abnormality control.

[0061] Furthermore, if the switching power supply 54 actually fails, the power supply from the switching power supply 54 to the microcomputer 51 is also interrupted, so no switching command is output from the microcomputer 51. Specifically, if the switching power supply 54 actually fails, the gate driver 52 performs abnormal control in response to the input of the failure signal.

[0062] According to the configuration of the second embodiment described above, control of the switching power supply 54 can be simplified during external charging.

[0063] (Third embodiment) The configuration of the first embodiment may be partially modified. Hereinafter, a third embodiment will be described in which the configuration of the first embodiment is partially modified.

[0064] The power supply system 10 of the third embodiment includes a diagnostic function for diagnosing whether the backup power supply 56 is operating normally. This function will be described in detail below.

[0065] 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 is lower than the lower limit voltage for operation. Therefore, the microcomputer 51 executes a FAIL signal at a predetermined time (for example, when the vehicle is started). Figure 4 The diagnostic process shown in FIG. 2 is performed, and the operation of the switching power supply 54 is intentionally stopped (step S201 ).

[0066] Next, the microcomputer 51 activates the support power supply 56 (step S202 ), thereby supplying power from the support power supply 56 to the gate driver 52 , and determines whether the output of the FAIL signal has stopped (step S203 ).

[0067] If the result of this determination is positive, that is, if the output of the FAIL signal has stopped, the microcomputer 51 determines that the support power supply 56 is operating normally and shifts to normal control (step S204). On the other hand, if the result of the determination in step S202 is negative, that is, if the output of the FAIL signal has not stopped, the microcomputer 51 determines that the support power supply 56 is not operating normally and shifts to abnormal control (step S205).

[0068] According to the configuration of the third embodiment, the operation of the backup power supply 56 can be easily checked, and the gate driver 52 can reliably perform external charging control and abnormality control (short-circuit control).

[0069] (Variation) A modification example in which a part of the structure of the above-described embodiment is changed will be described.

[0070] In the second embodiment, when the gate driver 52 receives a switching command (on command or off command) from the microcomputer 51 and a failure signal of the switching power supply 54 from the power failure determination unit 57, the gate driver 52 sets the failure signal to be invalid. Figure 5 As shown, during external charging, the microcomputer 51 can also 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 for outputting 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, etc.

[0071] In the above embodiment, the support power supply 56 is connected to the gate driver 52 in the high voltage region. However, Figure 6 As shown, it can 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 determination unit 57 inputs 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.

[0072] In the above embodiment, when performing external charging control, the microcomputer 51 controls the switching power supply 54 to output a voltage that is greater than the first threshold and less than the second threshold. As a variation, when performing external charging control, the microcomputer 51 may intermittently output a voltage from the switching power supply 54.

[0073] In the above embodiment, the power supply failure determination unit 57 may determine that the switching power supply 54 has failed when the output voltage of the switching power supply 54 is below the second threshold value during normal operation, and may determine that the switching power supply 54 has failed when the output voltage of the switching power supply 54 is below the first threshold value during external charging. In other words, the threshold value may be changed between normal operation and external charging.

[0074] In the above embodiment, the power failure determination unit 57 may be provided inside the gate driver 52 .

[0075] The power supply system 10 of the above-described embodiment may be configured to enable neutral-point charging.

[0076] In the above embodiment, if Figure 7 As shown, the gate driver 52 may be connected to the switching power supply 54 and the support power supply 56 via a wired OR gate circuit 300 using transistors or the like.

[0077] In the above embodiment, an isolated power supply is used as the switching power supply 54 , but a non-isolated power supply may be used. In this case, a circuit for isolation must be provided between the switching power supply 54 and the gate driver 52 .

[0078] Hereinafter, characteristic structures extracted from the above-mentioned embodiments will be described. [Structure 1] A power supply system capable of performing external charging for charging a power storage device (40) via an external power supply (210) provided externally, the power supply system (10) comprising: A rotating electrical machine (20), the rotating electrical machine having an armature winding (21); an inverter (30) having an upper arm switch (SWH) and a lower arm switch (SWL) connected in series and performing power conversion between the power storage device and the rotating electric machine; a drive control unit (52) configured to drive and control the upper arm switch and the lower arm switch; a first power source (54) for supplying power to the drive control unit; and a second power supply (56) that supplies power to the drive control unit when short-circuiting control is performed to turn on one of the upper arm switch and the lower arm switch and to turn off the other arm switch; The first power supply is configured to supply power at a voltage higher than a first threshold value 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 implement the short-circuit control by supplying power from the second power supply when the first power supply fails. On the other hand, during external charging, the upper arm switch and the lower arm switch are driven and controlled by supplying power from the first power supply and the second power supply with a higher output voltage, or by supplying power from the second power supply. [Structure 2] The power supply system as described in Structure 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. [Structure 3] A power supply system as described in structure 1 or 2, wherein: The first power supply is configured to supply power at a voltage higher than a second threshold value in a normal state, and to supply power at a voltage lower than the second threshold value and higher than the first threshold value during external charging. When the output voltage of the first power supply is equal to or lower than the first threshold value, the drive control unit causes the first power supply to fail and performs the short-circuit control using the power supplied from the second power supply. [Structure 4] A power supply system as described in structure 1 or 2, wherein: It includes a voltage control unit (51) which indicates the output voltage of the first power supply. During external charging, the voltage control unit instructs the first power supply to output power at a voltage equal to or lower than the first threshold value, and notifies the drive control unit of the information. When the notification from the voltage control unit is received, the drive control unit does not perform the short-circuit control even if the power supplied from the first power supply is below the first threshold value, but instead drives and controls the upper arm switch and the lower arm switch using the power supplied from the second power supply. [Structure 5] A power supply system as described in structure 1 or 2, wherein: The invention comprises a switch control unit (51) for indicating the on / off status of the upper arm switch and the lower arm switch. The switch control unit is operated by the power from the first power supply. When there is an instruction from the switch control unit, the drive control unit does not perform the short-circuit control even if the output voltage of the first power supply is below the first threshold value, but instead controls the drive of the upper arm switch and the lower arm switch according to the instruction from the switch control unit. [Structure 6] The power supply system as described in any one of Structures 1 to 5, wherein: It includes a voltage control unit (51) which indicates the output voltage of the first power supply. The voltage control unit is configured to be able to perform abnormality diagnosis processing. During the abnormal diagnosis process, the voltage control unit instructs the first power supply to output power at a voltage lower than the first threshold value. Afterwards, when the power is supplied from the second power supply and the short-circuit control is implemented by the drive control unit, the second power supply is diagnosed as operating normally. On the other hand, when the short-circuit control is not implemented, it is diagnosed that an abnormality has occurred.

[0079] Although the present disclosure is described based on embodiments, it should be understood that the present disclosure is not limited to the above-described embodiments and structures. The present disclosure also includes various modifications and variations within the scope of equivalents. In addition, various combinations and methods, and further combinations and methods that include only one element, or more or less than the above elements, also fall within the scope and concept of the present disclosure.

Claims

1. A power supply system capable of performing external charging of a power storage device (40) by an external power supply (210) provided externally, the power supply system (10) comprising: A rotating electrical 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) configured to drive and control the upper arm switch and the lower arm switch; a first power source (54) that supplies power to the drive control unit; as well as a second power supply (56) that supplies power to the drive control unit when short-circuiting control is performed to turn on one of the upper arm switch and the lower arm switch and to turn off the other arm switch; The first power supply is configured to supply power at a voltage higher than a first threshold value 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 implement the short-circuit control by supplying power from the second power supply when the first power supply fails. On the other hand, during external charging, the upper arm switch and the lower arm switch are driven and controlled by supplying power from the first power supply and the second power supply with a higher output voltage, or by supplying power from the second power supply.

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.

3. The power supply system according to claim 1 or 2, wherein: The first power supply is configured to supply power at a voltage higher than a second threshold value in a normal state, and to supply power at a voltage lower than the second threshold value and higher than the first threshold value during external charging. When the output voltage of the first power supply is equal to or lower than the first threshold value, the drive control unit sets the first power supply to fail and performs the short-circuit control using the power supplied from the second power supply.

4. The power supply system according to claim 1 or 2, wherein: A voltage control unit (51) is included, wherein the voltage control unit indicates the output voltage of the first power supply, During external charging, the voltage control unit instructs the first power supply to output electric power at a voltage equal to or lower than the first threshold value, and notifies the drive control unit of the information. When the notification from the voltage control unit is received, the drive control unit does not perform the short-circuit control, but instead controls the drive of the upper arm switch and the lower arm switch using the power supplied from the second power supply, even if the power supplied from the first power supply is below the first threshold value.

5. The power supply system according to claim 1 or 2, wherein: A switch control unit (51) is included, which indicates the on / off status of the upper arm switch and the lower arm switch. The switch control unit is operated by power from the first power supply. When there is an instruction from the switch control unit, the drive control unit does not perform the short-circuit control even if the output voltage of the first power supply is below the first threshold value, but instead drives and controls the upper arm switch and the lower arm switch according to the instruction from the switch control unit.

6. The power supply system according to claim 1 or 2, wherein: A voltage control unit (51) is included, wherein the voltage control unit indicates the output voltage of the first power supply, The voltage control unit is configured to be able to perform abnormality diagnosis processing, During the abnormality diagnosis process, the voltage control unit instructs the first power supply to output power at a voltage lower than the first threshold value. Thereafter, when the power is supplied from the second power supply and the short-circuit control is implemented by the drive control unit, it is diagnosed that the second power supply is operating normally. On the other hand, when the short-circuit control is not implemented, it is diagnosed that an abnormality has occurred.

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