Power supply system and program

Abstract

A power supply system (30) is provided with: a first switch unit that switches between a first power storage unit (31) and a high-voltage circuit (75) between energization and interruption of energization; a second switch unit that switches between the first power storage unit and the second power storage unit (32) between energization and interruption of energization; a third switch unit for switching between the second power storage unit and a low-voltage circuit (76) and between the second power storage unit and the low-voltage circuit (76) and between the second power storage unit and the low-voltage circuit; a switch control unit (100); and a failure determination unit (100). When the second switch unit is turned off, the failure determination unit cuts off the energization between the first power storage unit and the second power storage unit. And at least one of a failure determination of the first switch unit by switching the on / off state of the first switch unit and a failure determination of the third switch unit by switching the on / off state of the third switch unit is performed.

Description

Citation of Related Applications

[0001] This application is based on Japanese Patent Application No. 2022-197449 filed on December 9, 2022, and incorporates its description herein by reference. Technical Field

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

[0003] Conventionally, as described in Patent Document 1, a method for determining the welding of a system main relay in a vehicle power supply system is known. Prior Art Documents Patent Documents

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-99129 Summary of the Invention In addition, development of a power supply system in which, in a power supply system having a plurality of power storage units, a part of the power storage units is disconnected from a high-voltage circuit and connected to a low-voltage circuit, and power is supplied to a low-voltage load is underway. In such a power supply system, if the welding determination method of Patent Document 1 is directly adopted, there is a technical problem that the high-voltage circuit and the low-voltage circuit are directly connected, and it cannot be directly adopted.

[0006] A main object of the present disclosure is to provide a power supply system and a program capable of safely determining a failure of a switch.

[0007] A power supply system according to a first aspect for solving the above technical problem is connected to a high-voltage circuit and a low-voltage circuit and has a plurality of power storage units. The above power supply system includes: A first switch unit that switches between energization and power-off between a first power storage unit among the plurality of power storage units and the high-voltage circuit; A second switch unit that switches between energization and power-off between the first power storage unit and a second power storage unit among the plurality of power storage units; and A third switch unit that switches between energization and power-off between the second power storage unit and the low-voltage circuit; and A switch control unit that controls the first switch unit, the second switch unit, and the third switch unit; and A failure determination unit that determines failures of the first switch unit, the second switch unit, and the third switch unit. When the above-mentioned failure determination unit cuts off the power supply between the first power storage unit and the second power storage unit by disconnecting the second switch unit, it performs at least one of the failure determination of the first switch unit by switching the on / off state of the first switch unit by the switch control unit and the failure determination of the third switch unit by switching the on / off state of the third switch unit by the switch control unit.

[0008] According to the above structure, since the high-voltage circuit and the low-voltage circuit are cut off by the second switch unit, the failure determination of the switch can be safely performed.

[0009] The power supply system of the second method for solving the above technical problem is connected to the high-voltage circuit and the low-voltage circuit and has a plurality of power storage units. The above power supply system includes: A first switch unit that switches the power supply on and off between the first power storage unit among the plurality of power storage units and the high-voltage circuit. A second switch unit that switches the power supply on and off between the first power storage unit and the second power storage unit among the plurality of power storage units; and A third switch unit that switches the power supply on and off between the second power storage unit and the low-voltage circuit; and A switch control unit that controls the first switch unit, the second switch unit, and the third switch unit; and A failure determination unit that performs failure determination of the first switch unit, the second switch unit, and the third switch unit. When the power supply between the first power storage unit and the high-voltage circuit is cut off by disconnecting the first switch unit, or when the power supply between the second power storage unit and the low-voltage circuit is cut off by disconnecting the third switch unit, the failure determination unit switches the on / off state of the second switch unit by the switch control unit to perform the failure determination of the second switch unit.

[0010] According to the above structure, since the high-voltage circuit and the low-voltage circuit are cut off by the first switch unit or the third switch unit, the failure determination of the switch can be safely performed.

[0011] The program of the first method for solving the above technical problem is implemented by the control device of the power supply system. The above power supply system is connected to the high-voltage circuit and the low-voltage circuit and includes: A plurality of power storage units; A first switch unit that switches the power supply on and off between the first power storage unit among the plurality of power storage units and the high-voltage circuit. A second switch unit that switches between energization and power-off between the first power storage unit and the second power storage unit among the plurality of power storage units; and A third switch unit that switches between energization and power-off between the second power storage unit and the low-voltage circuit, The program has a switch control process and a failure determination process, The switch control process controls the first switch unit, the second switch unit, and the third switch unit, The failure determination process performs failure determination of the first switch unit, the second switch unit, and the third switch unit, In the failure determination process, when the energization between the first power storage unit and the second power storage unit is cut off by disconnecting the second switch unit, at least one of the failure determination of the first switch unit by switching the on / off state of the first switch unit and the failure determination of the third switch unit by switching the on / off state of the third switch unit is performed.

[0012] According to the above structure, since the high-voltage circuit and the low-voltage circuit are cut off by the second switch unit, the failure determination of the switch can be performed safely.

[0013] The program of the second method for solving the above technical problem is implemented by a control device of a power supply system, The power supply system is connected to a high-voltage circuit and a low-voltage circuit, and includes: A plurality of power storage units; A first switch unit that switches between energization and power-off between the first power storage unit among the plurality of power storage units and the high-voltage circuit; A second switch unit that switches between energization and power-off between the first power storage unit and the second power storage unit among the plurality of power storage units; and A third switch unit that switches between energization and power-off between the second power storage unit and the low-voltage circuit, The program has a switch control process and a failure determination process, The switch control process controls the first switch unit, the second switch unit, and the third switch unit, The failure determination process performs failure determination of the first switch unit, the second switch unit, and the third switch unit, In the above-described failure determination process, when the energization between the first power storage unit and the high-voltage circuit is cut off by disconnecting the first switch unit, or when the energization between the second power storage unit and the low-voltage circuit is cut off by disconnecting the third switch unit, the on / off state of the second switch unit is switched to perform the failure determination of the second switch unit.

[0014] According to the above structure, since the high-voltage circuit and the low-voltage circuit are cut off by the first switch unit or the third switch unit, the failure determination of the switch can be safely performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above objects, other objects, features, and advantages of the present disclosure can be made more apparent by referring to the drawings and the following detailed description. The drawings are as follows. Figure 1 It is a structural diagram of a vehicle-mounted system according to the first embodiment. Figure 2 It is a diagram showing the connection state of the power supply system. Figure 3 It is a diagram showing the connection state of the power supply system. Figure 4 It is a diagram showing the connection state of the power supply system. Figure 5 It is a diagram showing the connection state of the power supply system. Figure 6 It is a diagram showing the connection state of the power supply system. Figure 7 It is a diagram showing the connection state of the power supply system. Figure 8 It is a diagram showing the connection state of the power supply system. Fig. 9 It is a flowchart of the starting process. Fig.10 It is a diagram showing the relationship between the state of the third switch unit in the normal state and the detection value. Fig.11 It is a diagram showing the relationship between the state of the second switch unit in the normal state and the detection value. Fig.12 It is a flowchart of the stop process. Fig.13 It is a diagram showing the relationship between the state of the third switch unit in Modification 1 and the detection value. Fig.14 It is a diagram showing the relationship between the state of the third switch unit in Modification 2 and the detection value. Fig.15 It is a diagram showing the relationship between the state of the third switch unit in Modification 3 and the detection value. Fig.16 It is a diagram showing the third voltage sensor in Modification 4. Fig.17 It is a diagram showing the relationship between the state of the third switch section in Modification 4 and the detected value. Fig.18 It is a diagram showing the relationship between the state of the third switch section in Modification 5 and the detected value. Fig.19 It is a diagram showing the relationship between the state of the second switch section in Modification 7 and the detected value. Fig. 20 It is a diagram showing the fourth voltage sensor in Modification 8. Fig.21 It is a diagram showing the relationship between the state of the second switch section in Modification 8 and the detected value. Fig. 22 It is a diagram showing the relationship between the state of the second switch section in Modification 9 and the detected value. Fig.23 It is a diagram showing the connection state of the power supply system in Modification 10. Fig.24 It is a diagram showing the connection state of the power supply system in Modification 11. Fig.25 It is a diagram showing the connection state of the power supply system in Modification 12. Fig.26 It is a diagram showing the connection state of the power supply system in Modification 13. Fig. 27 It is a diagram showing the switching sequence of each switch in Modification 14. Fig.28 It is a diagram showing the switching sequence of each switch in Modification 14. Fig.29 It is a diagram showing the switching sequence of each switch in Modification 15. Fig.30 It is a diagram showing the switching sequence of each switch in Modification 15. Fig.31 It is a diagram showing the switching sequence of each switch in Modification 16. Fig.32 It is a diagram showing the switching sequence of each switch in Modification 16. Fig.33 It is a diagram showing the switching sequence of each switch in Modification 17. Fig.34 It is a diagram showing the switching sequence of each switch in Modification 17. Fig.35 It is a diagram showing the switching sequence of each switch in Modification 17. Fig.36 It is a diagram showing the relationship between the state of the switch and the detected value in Modification 17. Fig.37It is a diagram showing the relationship between the states of the switches and the detected values in Modification 17. Fig.38 It is a diagram showing the switching sequence of each switch in Modification 18. Fig.39 It is a diagram showing the switching sequence of each switch in Modification 18. Fig.40 It is a diagram showing the switching sequence of each switch in Modification 18. Fig.41 It is a diagram showing the switching sequence of each switch in Modification 19. Fig.42 It is a diagram showing the switching sequence of each switch in Modification 19. Fig.43 It is a diagram showing the switching sequence of each switch in Modification 20. Fig.44 It is a diagram showing the switching sequence of each switch in Modification 20. Fig.45 It is a diagram showing the switching sequence of each switch in Modification 21. Fig.46 It is a diagram showing the switching sequence of each switch in Modification 21. Fig.47 It is a diagram showing the connection state of the power supply system of the modification. Fig.48 It is a diagram showing the connection state of the power supply system of the modification. Fig.49 It is a diagram showing the connection state of the power supply system of the modification. Fig.50 It is a diagram showing the connection state of the power supply system of the modification. Fig.51 It is a diagram showing the connection state of the power supply system of the modification. Fig.52 It is a diagram showing the connection state of the power supply system of the modification. Fig.53 It is a diagram showing the connection state of the power supply system of the modification. Fig.54 It is a diagram showing the connection state of the power supply system of the modification. Fig.55 It is a diagram showing the connection state of the power supply system of the modification. Fig.56 It is a diagram showing the connection state of the power supply system of the modification. Fig.57 It is a diagram showing the connection state of the power supply system of the modification. Fig.58 It is a diagram showing the connection state of the power supply system of the modification. Fig.59 It is a diagram showing the connection state of a power supply system of a modified example. Fig.60 It is a diagram showing the connection state of a power supply system of a modified example. Fig.61 It is a diagram showing the connection state of a power supply system of a modified example. Fig.62 It is a diagram showing the connection state of a power supply system of a modified example. Fig.63 It is a diagram showing the connection state of a power supply system of a modified example. Fig.64 It is a diagram showing the connection state of a power supply system of a modified example. Fig.65 It is a diagram showing the connection state of a power supply system of a modified example. Fig.66 It is a diagram showing the connection state of a power supply system of a modified example. Fig.67 It is a diagram showing the connection state of a power supply system of a modified example. Fig.68 It is a diagram showing the connection state of a power supply system of a modified example. Fig.69 It is a diagram showing the connection state of a power supply system of a modified example. Fig.70 It is a diagram showing the connection state of a power supply system of a modified example. Detailed implementation manners

[0016] With reference to the accompanying drawings, a plurality of embodiments and their modified examples will be described. In the plurality of embodiments and their modified examples, parts and / or related parts that are functionally and / or structurally corresponding are sometimes marked with the same reference numerals or reference numerals with more than one hundred different digits. For the corresponding parts and / or related parts, the descriptions of other embodiments can be referred to.

[0017] (First embodiment) Hereinafter, a first embodiment in which the power supply system of the present disclosure is embodied will be described with reference to the accompanying drawings. The power supply system of this embodiment is installed in a vehicle such as an electric vehicle or a hybrid vehicle and constitutes an in-vehicle system.

[0018] As Figure 1 shown, the in-vehicle system includes a motor 10, an inverter 20 (inverter circuit), a high-voltage power line H1, a high-voltage ground line L1, a low-voltage power line H2, a low-voltage ground line L2, a power supply system 30, and a DCDC converter 70 (voltage converter).

[0019] The electric motor 10 has a plurality of armature windings. In the present embodiment, the electric motor 10 is a three-phase synchronous machine, having armature windings 11 of U-phase, V-phase, and W-phase with a star connection and a rotor (not shown). The armature windings 11 of each phase are arranged such that they are electrically angled 120° apart from each other. The electric motor 10 is, for example, a permanent magnet synchronous machine. The rotor can transmit power to and from the drive wheels of the vehicle. Therefore, the electric motor 10 is a source for generating the torque that drives the vehicle.

[0020] The inverter 20 includes a series connection body of an upper arm switch SWH and a lower arm switch SWL corresponding to the three phases. An upper arm diode DH, which is a freewheeling diode, is reversely connected in parallel to the upper arm switch SWH, and a lower arm diode DL, which is a freewheeling diode, is reversely connected in parallel to the lower arm switch SWL. In the present embodiment, each of the switches SWH and SWL is an IGBT.

[0021] The inverter 20 has an inverter-side smoothing capacitor 21 (first smoothing capacitor). The high-potential side terminal of the inverter-side smoothing capacitor 21 is connected to the high-voltage power line H1. The low-potential side terminal of the inverter-side smoothing capacitor 21 is connected to the high-voltage ground line L1. Additionally, the inverter-side smoothing capacitor 21 can also be provided outside the inverter 20.

[0022] In each phase, the connection point of the emitter, which is the low-potential side terminal of the upper arm switch SWH, and the collector, which is the high-potential side terminal of the lower arm switch SWL, is connected to the first end of the armature winding 11 via a conductive member 23 such as a bus bar. The second ends of the armature windings 11 of each phase are connected to each other at the neutral point. Additionally, in the present embodiment, the number of turns of the armature windings 11 of each phase is set to be the same. Thus, for example, the inductance of the armature windings 11 of each phase is set to be the same.

[0023] The collector of the upper arm switch SWH of each phase is connected to the high-voltage power line H1. The emitter of the lower arm switch SWL of each phase is connected to the high-voltage ground line L1. The high-voltage ground line L1 is connected to the first grounding member FG. Therefore, the electric motor 10 is connected to the high-voltage power line H1 via the inverter 20. Additionally, either or both of the electric motor 10 and the inverter 20 can be included in the power supply system 30 or can be excluded from the power supply system 30.

[0024] A variety of high-voltage loads 71 (not shown) are connected between the high-voltage power line H1 and the high-voltage ground line L1. The high-voltage load 71 is an electrical load that requires a high voltage, such as an air compressor, etc. Additionally, the electric motor 10 and the DCDC converter 70 described later are also a type of high-voltage load 71. In the present embodiment, the high-voltage circuit 75 is composed of the electric motor 10, the inverter 20, the high-voltage load 71, and the electrical paths connecting them, and the high-voltage circuit 75 is connected to the power supply system 30 via the high-voltage power line H1 and the high-voltage ground line L1.

[0025] Various low-voltage loads 72 are connected between the low-voltage power line H2 and the low-voltage ground line L2. The low-voltage load 72 is an electrical load that requires a low voltage (lower than the high-voltage load 71), such as various control devices like an ECU. In addition, among the low-voltage loads 72, there are loads that require dark current (standby current) like an ECU. The low-voltage ground line L2 is connected to the second grounding member SG. The second grounding member SG is insulated from the first grounding member FG. In the present embodiment, the low-voltage circuit 76 is composed of the low-voltage load 72 and the electrical path connecting the low-voltage load 72, and the low-voltage circuit 76 is connected to the power supply system 30 via the low-voltage power line H2 and the low-voltage ground line L2.

[0026] The DCDC converter 70 has a function of converting the voltage of the input power. The DCDC converter 70 is connected between the high-voltage power line H1 and the high-voltage ground line L1, can step down the voltage of the power input from the high-voltage power line H1 side, and supply it to the low-voltage circuit 76 side including the low-voltage load 72 connected to the low-voltage power line H2 via the power transmission line L3.

[0027] On the contrary, the DCDC converter 70 is configured to be able to step up the voltage of the power input from the low-voltage power line H2 side through the power transmission line L3 and supply it to the high-voltage load 71 connected to the high-voltage power line H1. In addition, the DCDC converter 70 is controlled by the control device 100 described later. The DCDC converter 70 may be included in the power supply system 30 or may not be included in the power supply system 30. In addition, in the first embodiment, the DCDC converter 70 may not have a boosting function.

[0028] Next, the power supply system 30 will be described. The power supply system 30 includes a first battery 31 (equivalent to the "first battery unit"), a second battery 32 (equivalent to the "second battery unit"), and a third battery 33 (equivalent to the "third battery unit"). Each battery 31, 32, 33 serves as a power supply source for driving the rotation of the rotor of the motor 10. Each battery 31, 32, 33 is a battery pack formed as a series connection body of battery cells, which are single cells. The battery cells are, for example, secondary batteries such as lithium-ion batteries.

[0029] The first battery 31 has the highest output voltage among the batteries 31, 32, 33, for example, an output voltage of 400V. In addition, compared with the first battery 31, the output voltage of the second battery 32 is low, for example, an output voltage of 12V. The output voltage of the third battery 33 is arbitrary. In the present embodiment, for example, it is 200V. In addition, the voltage between the terminals of each battery 31 to 33 can be arbitrarily changed.

[0030] The power supply system 30 includes a first A switch SW1a disposed in a first A electrical path 1A connecting the positive terminal of the first storage battery 31 and the high-voltage power line H1. In the present embodiment, the energization and power-off of the first A electrical path 1A between the positive terminal of the first storage battery 31 and the high-voltage power line H1 are switched by the first A switch SW1a.

[0031] In addition, a series connection body of a pre-charge switch Pre_P and a resistor body R1 may be connected in parallel with the first A switch SW1a as in the present embodiment. In addition, the first A switch SW1a corresponds to the system main relay switch on the high-potential side.

[0032] The power supply system 30 includes a first B switch SW1b disposed in a first B electrical path 1B connecting the negative terminal of the first storage battery 31 and the high-voltage ground line L1. In the present embodiment, the energization and power-off in the first B electrical path 1B between the negative terminal of the first storage battery 31 and the high-voltage ground line L1 are switched by the first B switch SW1b.

[0033] The power supply system 30 includes a first C switch SW1c disposed in a first C electrical path 1C connecting the negative terminal of the first storage battery 31 and the positive terminal of a first series connection body 40 formed by the second storage battery 32 and the third storage battery 33. In the present embodiment, the energization and power-off in the first C electrical path 1C between the negative terminal of the first storage battery 31 and the positive terminal of the first series connection body 40 are switched by the first C switch SW1c.

[0034] In addition, the first series connection body 40 is formed by connecting the positive terminal of the second storage battery 32 in series at the negative terminal of the third storage battery 33. Therefore, in the present embodiment, the positive terminal of the first series connection body 40 corresponds to the positive terminal of the third storage battery 33, and the negative terminal of the first series connection body 40 corresponds to the negative terminal of the second storage battery 32. Moreover, it can be said that the first C switch SW1c has a function of switching the energization and power-off between the first storage battery 31 and the second storage battery 32.

[0035] The power supply system 30 includes a first D switch SW1d and a first E switch SW1e disposed in a first D electrical path 1D connecting the neutral point of the armature winding 11 of the motor 10 and the positive terminal of the first series connection body 40. In the first C electrical path 1C, one end of the first D electrical path 1D is connected between the first C switch SW1c and the positive terminal of the third storage battery 33. The energization and power-off of the first D electrical path 1D are switched by the first D switch SW1d and the first E switch SW1e.

[0036] In addition, in the first D electrical path 1D, a first E switch SW1e is provided on the neutral point side. Further, a neutral point side smoothing capacitor C1 (second smoothing capacitor) is provided between the first D electrical path 1D and the high-voltage grounding wire L1. The high-potential side terminal of the neutral point side smoothing capacitor C1 is connected between the first D switch SW1d and the first E switch SW1e in the first D electrical path 1D.

[0037] In addition, as Figure 1 shown, the armature winding 11 of the motor 10 is connected to the high-voltage grounding wire L1 via the inverter 20. Therefore, it can be said that if the lower-arm switch SWL of the inverter 20 is turned on, the first D electrical path 1D can be connected to the high-voltage grounding wire L1. Therefore, according to the connection state, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e have the function of switching the energization and power cut-off between the negative terminal of the first battery 31 and the high-voltage grounding wire L1.

[0038] The power supply system 30 includes a second A switch SW2a provided in a second A electrical path 2A connecting the negative terminal of the third battery 33 and the positive terminal of the second battery 32. In the present embodiment, the second A switch SW2a switches the energization and power cut-off of the second A electrical path 2A between the negative terminal of the third battery 33 and the positive terminal of the second battery 32.

[0039] In addition, as Figure 1 shown, a first C switch SW1c, a third battery 33, and a second A switch SW2a are connected in series between the first battery 31 and the second battery 32. Therefore, when the first C switch SW1c is turned on, the second A switch SW2a switches the energization and power cut-off between the first battery 31 and the second battery 32 instead of the first C switch SW1c.

[0040] The power supply system 30 includes a second B switch SW2b provided in a second B electrical path 2B connecting the negative terminal of the first series connection body 40 and the high-voltage grounding wire L1. By the second B switch SW2b, the energization and power cut-off in the second B electrical path 2B, that is, the energization and power cut-off between the negative terminal of the first series connection body 40 and the high-voltage grounding wire L1, that is, the second B electrical path 2B, can be switched. In addition, the second B switch SW2b corresponds to a system main relay switch on the low-potential side.

[0041] The power supply system 30 includes a third A switch SW3a provided in a third A electrical path 3A connecting the positive terminal of the second battery 32 and the low-voltage power line H2. In the present embodiment, the energization and interruption of the third A electrical path 3A between the positive terminal of the second battery 32 and the low-voltage power line H2 are switched by the third A switch SW3a.

[0042] In addition, one end of the third A electrical path 3A (the end on the second battery 32 side) is connected to a connection point P13 between the second A switch SW2a and the positive terminal of the second battery 32 in the second A electrical path 2A. In other words, one end of the second A electrical path 2A (the end on the second battery 32 side) is connected to the connection point P13 between the third A switch SW3a and the positive terminal of the second battery 32 in the third A electrical path 3A. That is, the electrical path from the connection point P13 to the positive terminal of the second battery 32 is shared between the second A electrical path 2A and the third A electrical path 3A, is a part of the second A electrical path 2A, and is also a part of the third A electrical path 3A. Hereinafter, the electrical path from the connection point P13 to the positive terminal of the second battery 32 may be referred to as a shared path L10.

[0043] The power supply system 30 includes a third B switch SW3b provided in a third B electrical path 3B connecting the negative terminal of the second battery 32 and the low-voltage ground line L2. In the present embodiment, the energization and interruption of the third B electrical path 3B between the negative terminal of the second battery 32 and the low-voltage ground line L2 are switched by the third B switch SW3b.

[0044] In the present embodiment, each of the switches SW1a, SW1b, SW1c, SW1d, SW1e, SW2a, SW2b, SW3a, and SW3b (hereinafter, sometimes collectively referred to as each switch SW) is a mechanical relay. Each switch SW blocks the bidirectional current flow when open and allows the bidirectional current flow when closed. In addition, each switch SW is not limited to a mechanical relay, and may be, for example, a semiconductor switching element.

[0045] In addition, the power supply system 30 includes various sensors. As Figure 1 shown, a first current sensor A11 is included in the first A electrical path 1A. In addition, a second current sensor A12 is included in the first D electrical path 1D. Further, a third current sensor A13 is included in the second A electrical path 2A.

[0046] Here, the configuration of the third current sensor A13 will be described in detail. The third current sensor A13 is arranged in the electrical path from the connection point P13 to the positive terminal of the second battery 32, that is, the common path L10. Therefore, the third current sensor A13 can measure the current flowing through the second A electrical path 2A and the current flowing through the third A electrical path 3A.

[0047] The measurement range of the third current sensor A13 is configured to be changeable. Specifically, the third current sensor A13 can change the measurement range when measuring the current flowing through the second A electrical path 2A and the measurement range when measuring the current flowing through the third A electrical path 3A. The measurement range when measuring the current flowing through the second A electrical path 2A is set to have a wider measurable range compared to the measurement range when measuring the current flowing through the third A electrical path 3A. For example, the measurement range when measuring the current flowing through the second A electrical path 2A is a range that can appropriately measure the current flowing through the second A electrical path 2A (for example, 100 A to 200 A). Similarly, the measurement range when measuring the current flowing through the third A electrical path 3A is a range that can appropriately measure the current flowing through the third A electrical path 3A (for example, several tens of A).

[0048] In addition, as the measurement range changes, the resolution of the third current sensor A13 also changes. Specifically, it is configured that when measuring the current flowing through the third A electrical path 3A, the resolution is changed to be smaller (finer) compared to when measuring the current flowing through the second A electrical path 2A, and smaller values can be detected with high precision. In addition, a first voltage sensor V1 for measuring the voltage (potential difference) therebetween is included between the high-voltage power line H1 and the high-voltage ground line L1. In addition, the first voltage sensor V1 is also a sensor for measuring the voltage between the terminals of the inverter-side smoothing capacitor 21. In addition, a second voltage sensor V2 for measuring the voltage (potential difference) therebetween is included between the first D electrical path 1D and the high-voltage ground line L1. In addition, the second voltage sensor V2 is also a sensor for measuring the voltage between the terminals of the neutral-point side smoothing capacitor C1. In addition, a third voltage sensor V3 for measuring the voltage (potential difference) therebetween is included between the low-voltage power line H2 and the low-voltage ground line L2 (second grounding member SG).

[0050] In addition, the power supply system 30 has a control device 100. The control device 100 is mainly composed of a microcomputer 101, and the microcomputer 101 includes a CPU, a RAM, a ROM, etc. The functions provided by the microcomputer 101 can be provided by software recorded in a physical memory device and a computer that executes the software, software only, hardware only, or a combination thereof. For example, when the microcomputer 101 is provided by an electronic circuit as hardware, it can be provided by a digital circuit or an analog circuit including a plurality of logic circuits. For example, the microcomputer 101 executes a program stored in a non-transitory tangible storage medium that is included in itself as a storage unit. The program includes, for example, the Fig. 9 , Fig.12 and other programs of the processes shown. By executing the program, the method (process) corresponding to the program is executed. The storage unit is, for example, a non-volatile memory. In addition, the program stored in the storage unit can be updated, for example, through a communication network such as the Internet by OTA (Over The Air).

[0051] Information (detection values) from various sensors is input to the control device 100. Various sensors include, for example, the above-mentioned current sensors A11 to A13 and voltage sensors V1 to V3. In addition, for example, among various sensors, although not shown, there are voltage sensors (voltage monitoring sensors) that detect the voltage between the terminals (and / or cell voltage) of each of the storage batteries 31, 32, 33, current sensors that detect the current flowing through each of the storage batteries 31, 32, 33, a rotation angle sensor that detects the rotation angle (electrical angle) of the rotor, and phase current sensors that detect the phase current flowing through the armature windings 11 of each phase.

[0052] The control device 100 performs various processes according to a program based on information such as detection values input from various sensors. Among the various processes performed, there is, for example, a process of controlling the inverter 20. Specifically, the control device 100 performs switching control of each of the switches SWH and SWL that make up the inverter 20 based on the detection values of the respective sensors so as to feedback-control the control amount of the motor 10 to a command value. The control amount is, for example, torque. In each phase, the upper-arm switch SWH and the lower-arm switch SWL are alternately turned on. Through this feedback control, the rotational power of the rotor is transmitted to the drive wheels, and the vehicle travels. Therefore, the control device 100 has a function as an inverter control unit.

[0053] In addition, as described above, the control device 100 executes processes related to voltage conversion by controlling the DCDC converter 70. Therefore, the control device 100 has a function as a voltage control unit.

[0054] In addition, the control device 100 is configured to be able to control the on / off states of the switches SW in the power supply system 30. Therefore, the control device 100 has a function as a switch control unit. Here, an example of how the control device 100 switches the on / off states of the switches SW in the power supply system 30 in the present embodiment will be described.

[0055] First, with reference to Figures 2 to 8 , the switching of the on / off states from when the vehicle is stopped to when the vehicle starts will be described. In Figures 2 to 8 , the flow of current is indicated by a single-dashed line. Additionally, as a premise, when the vehicle is stopped, the on / off states of the switches SW are as shown in Figure 2 . Here, when the vehicle is stopped means, for example, during the period when the ignition switch is off, the vehicle has been stopped for a specified time or more, or the shift lever is in the parking position, etc.

[0056] As shown in Figure 2 , when the vehicle is stopped, the control device 100 connects only a part of the storage batteries (the second storage battery 32) among the storage batteries 31 to 33 included in the power supply system 30 to the low-voltage power line H2 and the low-voltage ground line L2.

[0057] Specifically, as shown in Figure 2 , the control device 100 turns off the first A switch SW1a, the first B switch SW1b, the first C switch SW1c, the first D switch SW1d, the first E switch SW1e, the second A switch SW2a, and the second B switch SW2b, and turns on the third A switch SW3a and the third B switch SW3b. In the connection state of Figure 2 , low-voltage power is supplied from the second storage battery 32 to the low-voltage load 72 (low-voltage circuit 76) via the low-voltage power line H2. Additionally, as shown in Figure 2 , power is not supplied from the first storage battery 31 or the like to the high-voltage load 71 via the high-voltage power line H1.

[0058] When the vehicle is stopped and starting, the control device 100 connects a part of the storage batteries (the second storage battery 32) among the storage batteries 31 to 33 included in the power supply system 30 to the low-voltage power line H2, and connects a part or all of the remaining storage batteries (the first storage battery 31 in the present embodiment) to the high-voltage power line H1. Here, the moment of vehicle start is, for example, the moment when the ignition switch is turned on, the moment when the brake is released, the moment when the shift lever is in the drive position, etc. Additionally, the moment when a specified vehicle load (such as the operation of a sliding door or a key) starts can also be used as the moment of vehicle start.

[0059] Specifically, to prevent inrush current, the control device 100 turns on the pre-charge switch Pre_P, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e, and charges the inverter-side smoothing capacitor 21 via the inverter 20. Specifically, the charging is continued until the voltage between the terminals of the inverter-side smoothing capacitor 21 reaches a voltage equivalent to the voltage between the terminals of the first storage battery 31 (400V).

[0060] After that, the control device 100 turns on the first A switch SW1a and turns off the pre-charge switch Pre_P. That is, as Figure 3 shown, the control device 100 turns off the first B switch SW1b, the second A switch SW2a, and the second B switch SW2b, and turns on the first A switch SW1a, the first C switch SW1c, the first D switch SW1d, the first E switch SW1e, the third A switch SW3a, and the third B switch SW3b. In Figure 3 this connection state, a second storage battery 32 is connected between the low-voltage power supply line H2 and the low-voltage ground line L2, and a first storage battery 31 is connected between the high-voltage power supply line H1 and the neutral point of the motor 10.

[0061] In addition, in Figure 3 the connection state shown, the high-voltage ground line L1 and the low-voltage ground line L2 are insulated from each other. Thus, high-voltage power is supplied from the first storage battery 31 to the high-voltage load 71 via the high-voltage power supply line H1, and low-voltage power is supplied from the second storage battery 32 to the low-voltage load 72 via the low-voltage power supply line H2. That is, the energization between the first storage battery 31 and the second storage battery 32 is cut off, and the high-voltage power of the first storage battery 31 is not supplied to the low-voltage load 72.

[0062] Next, as Figure 4 shown, the control device 100 operates the DCDC converter 70, steps down the input voltage input to the DCDC converter 70, and supplies it to the low-voltage load 72 via the power transmission line L3. After supplying power from the DCDC converter 70 to the low-voltage circuit 76, as Figure 5 shown, the control device 100 maintains the energization between the first storage battery 31 and the high-voltage power supply line H1, and cuts off the energization between the second storage battery 32 and the low-voltage power supply line H2.

[0064] Specifically, as Figure 5As shown, the control device 100 turns off the first B switch SW1b, the second A switch SW2a, the second B switch SW2b, the third A switch SW3a, and the third B switch SW3b, and turns on the first A switch SW1a, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e. In Figure 5 In the connected state, a first battery 31 is connected between the high-voltage power supply line H1 and the neutral point of the motor 10. On the other hand, the energization between the low-voltage power supply line H2 and the positive terminal of the second battery 32 and between the low-voltage ground line L2 and the negative terminal of the second battery 32 is cut off. That is, the second battery 32 is disconnected from the low-voltage circuit 76.

[0065] After the energization between the second battery 32 and the low-voltage circuit 76 is cut off, the control device 100 boosts the applied voltage from the first battery 31 by operating the motor 10 and the inverter 20 as a boost converter (boost chopper), and charges the inverter-side smoothing capacitor 21 and the neutral-point side smoothing capacitor C1. That is, the control device 100 causes the armature winding of the motor 10 to function as the coil of the boost chopper, causes the lower-arm switch SWL (or the upper-arm switch SWH) of the inverter 20 to function as the input switch of the boost chopper, causes the upper-arm diode DH (or the lower-arm diode DL) of the inverter 20 to function as the freewheeling diode of the boost chopper, and boosts the applied voltage. Therefore, in the present embodiment, the motor 10 and the inverter 20 also function as a boosting device.

[0066] At this time, the voltage between the terminals of the inverter-side smoothing capacitor 21 becomes 612V, which is equivalent to the voltage across the two ends when the first battery 31 to the third battery 33 are connected in series, and the voltage between the terminals of the neutral-point side smoothing capacitor C1 is charged to 212V, which is equivalent to the voltage across the two ends when the second battery 32 to the third battery 33 are connected in series.

[0067] After the charging is completed, as Figure 6 shown, the control device 100 connects all the first battery 31 to the third battery 33 included in the power supply system 30 to the high-voltage power supply line H1. Specifically, as Figure 6 shown, the control device 100 turns off the first B switch SW1b, the third A switch SW3a, and the third B switch SW3b, and turns on the first A switch SW1a, the first C switch SW1c, the first D switch SW1d, the first E switch SW1e, the second A switch SW2a, and the second B switch SW2b.

[0068] In Figure 6In the connected state, a first storage battery 31, a third storage battery 33, and a second storage battery 32 are connected in series between a high-voltage power supply line H1 and a high-voltage ground line L1. That is, electric power of a high voltage (400V + 200V + 12V) is supplied from the second series connection body 50 of the first storage battery 31, the third storage battery 33, and the second storage battery 32 to the high-voltage load 71 of the high-voltage circuit 75 via the high-voltage power supply line H1. Thereby, high-voltage electric power is supplied to the motor 10 or the high-voltage load 71, and the vehicle can be appropriately driven.

[0069] In addition, as Figure 6 shown, the electric power supplied to the high-voltage circuit 75 is stepped down via the DCDC converter 70 and also supplied to the low-voltage load 72. In addition, the voltage between the terminals of the inverter-side smoothing capacitor 21 is charged to 612V, and the voltage between the terminals of the neutral-point side smoothing capacitor C1 is charged to 212V. Therefore, even when switched to Figure 6 the connected state, it is possible to prevent the current flow from becoming unstable due to the voltage difference.

[0070] After that, as Figure 7 shown, the control device 100 switches the first D switch SW1d from on to off, operates the motor 10 and the inverter 20, and discharges the charging voltage of the neutral-point side smoothing capacitor C1. After the discharge is completed, as Figure 8 shown, the control device 100 switches the first E switch SW1e from on to off.

[0071] As described above, in the first embodiment, the first A switch SW1a (or the pre-charge switch Pre_P), the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e correspond to the first switch unit that switches the energization and the cut-off of the energization between the first storage battery 31 and the high-voltage circuit 75. Hereinafter, in the first embodiment, the first A switch SW1a, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e may be simply referred to as the first switch unit.

[0072] In addition, in the first embodiment, the second A switch SW2a and the second B switch SW2b correspond to the second switch unit that switches the energization and the cut-off of the energization between the first storage battery 31 and the second storage battery 32. Hereinafter, in the first embodiment, the second A switch SW2a and the second B switch SW2b may be simply referred to as the second switch unit.

[0073] In addition, in the first embodiment, the third A switch SW3a and the third B switch SW3b correspond to a third switch unit that switches the energization and power-off between the second storage battery 32 and the low-voltage circuit 76. Hereinafter, in the first embodiment, the third A switch SW3a and the third B switch SW3b may be simply referred to as the third switch unit.

[0074] In addition, in the first embodiment, the first A switch SW1a corresponds to a first X switch that switches the energization and power-off between the positive terminal of the first storage battery 31 and the high-voltage power line H1, and the first A electrical path 1A connecting the positive terminal of the first storage battery 31 and the high-voltage power line H1 corresponds to the first X electrical path.

[0075] In addition, in the first embodiment, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e correspond to a first Y switch that switches the energization and power-off between the negative terminal of the first storage battery 31 and the high-voltage ground line L1, and the electrical path between the negative terminal of the first storage battery 31 and the high-voltage ground line L1 corresponds to the first Y electrical path.

[0076] In addition, in the first embodiment, the second A switch SW2a corresponds to a second X switch that switches the energization and power-off between the second storage battery 32 and the first storage battery 31, and the second A electrical path 2A between the second storage battery 32 and the first storage battery 31 corresponds to the second X electrical path.

[0077] In addition, in the first embodiment, the second B switch SW2b corresponds to a second Y switch that switches the energization and power-off between the terminal (negative terminal) on the side opposite to the second A switch SW2a among the two ends of the second storage battery 32 and the high-voltage ground line L1. In addition, in the first embodiment, the second B electrical path 2B between the terminal (negative terminal) on the side opposite to the second A switch SW2a among the two ends of the second storage battery 32 and the high-voltage ground line L1 corresponds to the second Y electrical path.

[0078] In addition, in the first embodiment, the third A switch SW3a corresponds to a third X switch that switches the energization and power-off between the positive terminal of the second storage battery 32 and the low-voltage power line H2, and the third A electrical path 3A connecting the positive terminal of the second storage battery 32 and the low-voltage power line H2 corresponds to the third X electrical path.

[0079] In addition, in the first embodiment, the third B switch SW3b corresponds to a third Y switch that switches the energization and power-off between the negative terminal of the second storage battery 32 and the low-voltage ground line L2, and the electrical path between the negative terminal of the second storage battery 32 and the low-voltage ground line L2 corresponds to the third Y electrical path.

[0080] Further, in the first embodiment, the second A switch SW2a, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e correspond to a neutral point connection switch unit that switches the energization and power cut-off between the neutral point of the motor 10 and either one or both of the first battery 31 and the second battery 32. Next, with reference to Figures 2 to 8 , the switching of the on-off state from when the vehicle is starting to when the vehicle stops will be described. The switching of the on-off state from when the vehicle is starting to when the vehicle stops is basically the reverse of the transition of the on-off state from when the vehicle stops to when it starts. Therefore, a simplified description will be given below.

[0082] When the vehicle is starting, the connection state becomes as described above Figure 8 . That is, the control device 100 connects the first battery 31, the third battery 33, and the second battery 32 in series between the high-voltage power line H1 and the high-voltage ground line L1. On the other hand, although the power supply system 30 and the low-voltage circuit 76 are not directly connected, the high-voltage power is stepped down by the DCDC converter 70 and supplied to the low-voltage load 72.

[0083] During starting, when the vehicle stops, the control device 100 first switches the first E switch SW1e from off to on as shown in Figure 7 . The moment when the vehicle stops is, for example, the moment when the ignition switch is turned off, or the moment when the shift lever is moved to the parking position, etc.

[0084] After switching the first E switch SW1e to on, the motor 10 and the inverter 20 are operated to charge the smoothing capacitor 21 on the inverter side. Then, the control device 100 charges until the voltage between the terminals of the smoothing capacitor 21 on the inverter side reaches a voltage equivalent to the voltage between the terminals of the first series connection body 40 (for example, 212V).

[0085] After the charging is completed, as shown in Figure 6 , the control device 100 switches the first D switch SW1d from off to on. After that, as shown in Figure 5 , the control device 100 switches the second A switch SW2a and the second B switch SW2b from on to off, maintains the energization between the first battery 31 and the high-voltage power line H1, and cuts off the energization between the first battery 31 and the second battery 32 and between the second battery 32 and the low-voltage ground line L2. That is, the second battery 32 is disconnected from the high-voltage circuit 75. After the energization between the second battery 32 and the high-voltage circuit 75 is cut off, the control device 100 discharges the inverter-side smoothing capacitor 21 by operating the motor 10 and the inverter 20. At this time, after maintaining the voltage between the terminals of the inverter-side smoothing capacitor 21 for a certain period, it is gradually discharged (voltage reduced) to a voltage (400V) equivalent to the voltage between the terminals of the first battery 31.

[0087] In addition, the control device 100 discharges the neutral-point side smoothing capacitor C1 by operating the motor 10 and the inverter 20. At this time, it is discharged until the voltage between the terminals of the neutral-point side smoothing capacitor C1 becomes zero.

[0088] After the discharge, as Figure 4 shown, the control device 100 switches the third A switch SW3a and the third B switch SW3b from off to on. Thus, with the first battery 31 connected between the high-voltage power line H1 and the neutral point of the motor 10, the second battery 32 is connected between the low-voltage power line H2 and the low-voltage ground line L2. Thereby, low-voltage power can be supplied from the second battery 32 to the low-voltage load 72 (low-voltage circuit 76).

[0089] After that, as Figure 3 shown, the control device 100 stops the operation of the DCDC converter 70 and also stops the power supply from the DCDC converter 70 to the low-voltage load 72. Thereby, low-voltage power is supplied from the second battery 32 to the low-voltage load 72. Then, as Figure 2 shown, the control device 100 switches the first A switch SW1a, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e from on to off. In addition, the control device 100 operates the motor 10 and the inverter 20 to discharge the inverter-side smoothing capacitor 21 and make the voltage between the terminals zero.

[0090] Thereby, as Figure 2 shown, only the second battery 32 is connected to the low-voltage power line H2 and the low-voltage ground line L2 to be in the on-off state during vehicle parking. In this state, power is supplied from the second battery 32 to the low-voltage load 72.

[0091] In addition, the power supply system 30 of the present embodiment is configured to be connectable to either the high-voltage circuit 75 or the low-voltage circuit 76 and supply power to either of them. Therefore, when any one of the switches SW is turned on and fails (welds), the high-voltage circuit 75 and the low-voltage circuit 76 are directly connected, and the power supply between the first battery 31 and the second battery 32 cannot be cut off. That is, there is a possibility that the high-voltage first battery 31 etc. are connected to the low-voltage load 72, and a possibility that the first grounding member FG and the second grounding member SG are connected. Therefore, it is necessary to turn on and off each switch SW to determine whether it operates normally, that is, to perform a failure determination of each switch SW.

[0092] However, as described above, the power supply system 30 is configured to be connectable to either the high-voltage circuit 75 or the low-voltage circuit 76. Therefore, in order to maintain the insulation between the first grounding member FG and the second grounding member SG (the high-voltage circuit 75 and the low-voltage circuit 76 are not connected), it is necessary to turn on and off each switch SW at an appropriate time during the failure determination. Therefore, in the present embodiment, the failure determination of each switch SW is performed at the times described below. Hereinafter, the failure determination of each switch SW implemented when the vehicle is started and when the vehicle is stopped will be described in detail. First, the start-up process will be described.

[0093] Fig. 9 is a flowchart of the start-up process that the control device 100 performs at a predetermined cycle while the vehicle is stopped. In addition, when the vehicle is stopped, as described above, it becomes Figure 2 the connection state shown, the first switch unit and the second switch unit are turned off, and the third switch unit is turned on. That is, only the second battery 32 is connected to the low-voltage power line H2.

[0094] The control device 100 determines whether the vehicle has started while the vehicle is parked (step S101). If the determination result is affirmative, as Figure 3 shown, the control device 100 connects the second battery 32 to the low-voltage power line H2 and connects the first battery 31 to the high-voltage power line H1 (step S102). That is, as described above, the control device 100 switches the first switch unit to on while keeping the third switch unit on and the second switch unit off. Thus, with the second battery 32 connected to the low-voltage circuit 76, the first battery 31 is connected to the high-voltage circuit 75.

[0095] In addition, since the second switch unit (the second A switch SW2a and the second B switch SW2b) is turned off, the power supply between the first battery 31 and the second battery 32 and between the high-voltage circuit 75 and the low-voltage circuit 76 is cut off. That is, high-voltage power is not directly supplied to the low-voltage circuit 76. In addition, in step S102 above, when switching the first switch unit to the on state, the control device 100 inputs and stores the detection values of various sensors. Then, after the switching, the control device 100 determines whether there is a fault in the first switch unit based on the stored detection values of various sensors (step S103). In step S103, the control device 100 determines whether current is flowing normally through the first A electrical path 1A according to the detection value of the first current sensor A11 when switching the first switch unit in step S102, thereby performing a fault determination of the first switch unit.

[0097] For example, when the detection value of the first current sensor A11 is not zero (or not within an error range close to zero, the same applies hereinafter) even though it is before switching the first switch unit to the on state (i.e., in the off state), that is, when an abnormal current is measured in the first A electrical path 1A, the control device 100 determines that there is a fault in the first switch unit. Additionally, for example, when the detection value of the first current sensor A11 is not a value above the threshold even after switching the first switch unit to the on state, that is, when current does not flow through the first A electrical path 1A, the control device 100 determines that there is a fault in the first switch unit. On the other hand, when the detection value of the first current sensor A11 changes from zero to a current value above the threshold as the first switch unit is switched to the on state, the control device 100 determines that the first switch unit is normal (not faulty).

[0098] When the result of the fault determination in step S103 by the control device 100 is that it is determined that there is a fault in the first switch unit (step S103: Yes), the control device 100 performs processing for coping with an abnormality in the power supply system 30 (step S104). In step S104, for example, it performs processing to notify a message indicating that there is an abnormality in the power supply system 30 and a message indicating that proper startup is not possible. In addition, it performs fail-safe related processing such as switching all switches SW to the off state to ensure safety. After that, the control device 100 ends (interrupts) the startup processing.

[0099] On the other hand, when the control device 100 determines that there is no fault in the first switch unit (step S103: No), it operates the inverter 20 and the like, supplies power from the first battery 31 to the high-voltage circuit 75, and charges the inverter-side smoothing capacitor 21 until the terminal voltage becomes 400V (step S105).

[0100] After the charging of the inverter-side smoothing capacitor 21 is completed, as Figure 4As shown, the control device 100 operates the DCDC converter 70 to step down the input voltage applied to the DCDC converter 70, and supplies it to the low-voltage load 72 (low-voltage circuit 76) via the power transmission line L3 (step S106). At this time, the control device 100 controls the DCDC converter 70 to step down the voltage to a voltage slightly higher than the inter-terminal voltage (12V) of the second battery 32, for example, 14V. Thus, when supplying power from the DCDC converter 70 to the low-voltage circuit 76, the current flows toward the second battery 32 side, and the second battery 32 is charged.

[0101] Next, as Figure 5 shown, with the second switch unit open, the control device 100 opens the third switch unit to cut off the power supply between the second battery 32 and the low-voltage power supply line H2 (step S107). In addition, in step S107, when switching the third switch unit to the open state, the control device 100 inputs and stores the detection values of various sensors.

[0102] Then, after the switching, the control device 100 determines whether there is a fault in the third switch unit based on the stored detection values of various sensors (step S108). In step S108, the control device 100 determines whether the power supply of the third A electrical path 3A is normally cut off according to the detection value of the third current sensor A13 when switching the third switch unit in step S107, thereby performing the fault determination of the third switch unit.

[0103] Here, with reference to Fig.10 an example of the method for determining a fault in the third switch unit in step S108 will be described in detail. Fig.10 The on / off states of the third A switch SW3a and the third B switch SW3b in the normal state and the corresponding detection values of the third current sensor A13 are shown.

[0104] In addition, as a prerequisite, when performing the fault determination of the third switch unit, the control device 100 switches the measurement range and resolution of the third current sensor A13 to the measurement range and resolution for measuring the current in the third A electrical path 3A. That is, the control device 100 narrows the measurement range of the third current sensor A13 and reduces the resolution. In addition, as described in step S106, in the present embodiment, the supply voltage from the DCDC converter 70 becomes a voltage slightly higher than the inter-terminal voltage (12V) of the second battery 32 (14V).

[0105] Therefore, as Fig.10As shown in the upper part of [], when the third switching unit (third A switch SW3a and third B switch SW3b) is turned on, current flows from the DC-DC converter 70 to the second battery 32, and the second battery 32 is charged. At this time, the detected value of the third current sensor A13 depends on the amount of current output from the DC-DC converter 70, but should be at least greater than 0 (for example, several tens of amperes). Therefore, when the detected value of the third current sensor A13 is zero despite the third switching unit being turned on, the control device 100 determines that there is a fault in the third switching unit.

[0106] In addition, when it is described as "depending on the DC-DC" in the figure, it means that when the supply voltage from the DC-DC converter 70 is higher than the voltage between the terminals of the second battery 32, the detected value of the third current sensor A13 depends on the amount of current output from the DC-DC converter 70, and when it is below the voltage between the terminals of the second battery 32, the detected value of the third current sensor A13 depends on the amount of current from the second battery 32.

[0107] In addition, starting from the state where the third switching unit is turned on, the control device 100 turns off the third A switch SW3a in step S107, and then turns off the third B switch SW3b, thereby turning off the third switching unit. Therefore, as Fig.10 As shown in the middle part of [], if the detected value of the third current sensor A13 in the state where the third A switch SW3a is turned off and the third B switch SW3b is turned on is not zero, the control device 100 determines that there is a fault in the third A switch SW3a, and if it is zero, it determines that there is no fault in the third A switch SW3a. When it is determined that there is a fault in the third A switch SW3a, it is determined that there is a fault in the third switching unit, and when it is determined that there is no fault in the third A switch SW3a, it is determined that there is no fault in the third switching unit. In addition, this fault determination method is an example, and a modified example of the fault determination method will be described later.

[0108] When the determination result in step S108 is affirmative (step S108: Yes), the control device 100 transfers to the process of step S104, and performs the process for coping with the abnormality of the power supply system 30 as described above (step S104). After that, the control device 100 ends (interrupts) the startup process.

[0109] On the other hand, when the control device 100 determines that there is no failure in the third switching unit (step S108: No), the control device 100 operates the motor 10 and the inverter 20, and charges the inverter-side smoothing capacitor 21 and the neutral-point side smoothing capacitor C1 (step S109). Specifically, the charging is performed until the voltage between the terminals of the inverter-side smoothing capacitor 21 becomes 612V and the voltage between the terminals of the neutral-point side smoothing capacitor C1 becomes 212V.

[0110] After the charging is completed, as Figure 6 shown, with the third switching unit in the OFF state, the control device 100 switches the second switching unit to ON and connects all of the first battery 31 to the third battery 33 included in the power supply system 30 to the high-voltage power line H1 (step S110). In addition, in step S110, when switching the second switching unit to ON, the control device 100 inputs and stores the detection values of various sensors.

[0111] Then, after the switching, the control device 100 determines whether there is a failure in the second switching unit based on the stored detection values of various sensors (step S111). In step S111, the control device 100 determines whether the current flows normally through the second A electrical path 2A according to the detection value of the third current sensor A13 when switching the second switching unit in step S110, thereby performing the failure determination of the second switching unit.

[0112] Here, with reference to Fig.11 an example of the failure determination method of the second switching unit in step S111 will be described in detail. Fig.11 shows the ON / OFF states of the second A switch SW2a and the second B switch SW2b in the normal state and the corresponding detection values of various sensors. In addition, as a prerequisite, when performing the failure determination of the second switching unit, the control device 100 switches the measurement range and resolution of the third current sensor A13 to the measurement range and resolution for measuring the current in the second A electrical path 2A. That is, the control device 100 expands the measurement range of the third current sensor A13 and increases the resolution.

[0113] At this time, as Fig.11 shown in the upper part, when the detection value of the third current sensor A13 is not zero (or not within the error range close to zero, the same applies hereinafter) although the second switching unit is OFF, the control device 100 determines that there is a failure in the second switching unit.

[0114] In addition, starting from the OFF state of the second switching unit, the control device 100 turns on the second A switch SW2a in step S110 and then turns on the second B switch SW2b, thereby turning on the second switching unit. Therefore, as Fig.11As shown in the middle part of , if the detected value of the third current sensor A13 in a state where the second A switch SW2a is turned on and the second B switch SW2b is turned off is not zero, the control device 100 determines that there is a fault in the second switch section.

[0115] In addition, if it can be determined that the detected value of the third current sensor A13 in a state where the second A switch SW2a is turned on and the second B switch SW2b is turned on is equal to or greater than a specified threshold value and the current is flowing normally, the control device 100 determines that there is no fault in the second switch section. On the other hand, when the detected value of the third current sensor A13 is zero despite the second switch section being turned on, it is determined that there is a fault in the second switch section. In addition, this fault determination method is an example, and a modified example of the fault determination method will be described later.

[0116] When it is determined that there is a fault in the second switch section (step S111: Yes), the control device 100 transfers to the process of step S104 and performs the process for coping with the abnormality of the power supply system 30 as described above (step S104). After that, the control device 100 ends (interrupts) the start-up process.

[0117] On the other hand, when it is determined that there is no fault in the second switch section (step S111: No), the control device 100 turns off the first D switch SW1d, operates the motor 10 and the inverter 20, and discharges the charging voltage of the neutral point side smoothing capacitor C1 (step S112).

[0118] After the discharge is completed, as Figure 8 shown, the control device 100 switches the first E switch SW1e from on to off (step S113) and ends the start-up process. When the start-up process ends, as Figure 8 shown, high-voltage electric power is supplied from the second series connection body 50 formed by connecting all the storage batteries 31, 32, and 33 in series to the high-voltage load 71 of the high-voltage circuit 75 via the high-voltage power line H1. Thereby, high-voltage electric power is supplied to the motor 10 or the high-voltage load 71, and the vehicle can be appropriately driven. In addition, as Figure 8 shown, since the electric power supplied to the high-voltage circuit 75 is stepped down by the DCDC converter 70 and also supplied to the low-voltage load 72, the low-voltage load 72 can be appropriately operated.

[0119] Next, with reference to Fig.12 , the fault determination of each switch SW performed when the vehicle is stopped will be described in detail. Fig.12 is a flowchart of the stop process that the control device 100 performs at regular intervals during vehicle start-up. In addition, when the vehicle starts, as described above, it becomes Figure 8In the connection state shown, all the storage batteries 31, 32, and 33 are connected in series to the high-voltage circuit 75. In addition, low-voltage power is supplied to the low-voltage load 72 via the DCDC converter 70.

[0120] First, the control device 100 determines whether the vehicle has stopped (step S201). If the determination result is negative, the control device 100 ends the stop process. On the other hand, if the determination result is positive, as Figure 7 shown, after the control device 100 switches the first E switch SW1e to the on state, the motor 10 and the inverter 20 are operated, and the neutral-point side smoothing capacitor C1 is charged (step S202).

[0121] After the charging is completed, as Figure 6 shown, the control device 100 switches the first D switch SW1d from the off state to the on state (step S203). After that, as Figure 5 shown, in a state where the third switch unit is disconnected, the control device 100 switches the second switch unit to the off state, and cuts off the power supply between the first storage battery 31 and the second storage battery 32 and between the second storage battery 32 and the low-voltage ground wire L2 (step S204). That is, the second storage battery 32 is disconnected from the high-voltage circuit 75. In addition, in step S204, when the second switch unit is switched to the off state, the control device 100 inputs and stores the detection values of various sensors.

[0122] Then, after the switching, the control device 100 determines whether there is a failure in the second switch unit based on the detection values of various sensors stored (step S205). In step S205, the control device 100 determines whether the power supply of the second A electrical path 2A is appropriately cut off according to the detection value of the third current sensor A13 when the second switch unit is switched, thereby performing the failure determination of the second switch unit.

[0123] Here, with reference to Fig.11 , an example of the failure determination method of the second switch unit in step S205 will be described in detail. In addition, as a prerequisite, when performing the failure determination of the second switch unit, that is, before the start of step S204, the control device 100 switches the measurement range and resolution of the third current sensor A13 to the measurement range and resolution for measuring the current of the second A electrical path 2A. That is, the control device 100 expands the measurement range of the third current sensor A13 and increases the resolution. At this time, as Fig.11As shown in the lower part of [Figure], when the detection value of the third current sensor A13 is zero even though the second switch unit is turned on (or within an error range close to zero, the same applies hereinafter), the control device 100 determines that there is a failure in the second switch unit.

[0125] Then, in step S204, starting from the state where the second switch unit is turned on, the control device 100 turns off the second B switch SW2b, and then turns off the second A switch SW2a, thereby turning off the second switch unit. Therefore, as Fig.11 shown in the middle part of [Figure], if the detection value of the third current sensor A13 in the state where the second A switch SW2a is turned on and the second B switch SW2b is turned off is not zero, the control device 100 determines that there is a failure in the second switch unit.

[0126] In addition, as Fig.11 shown in the upper part of [Figure], if it can be determined that the detection value of the third current sensor A13 is zero in the state where the second A switch SW2a is turned off and the second B switch SW2b is turned off, and the power supply is normally cut off, the control device 100 determines that there is no failure in the second switch unit. On the other hand, when the detection value of the third current sensor A13 is not zero even though the second switch unit is turned off, it is determined that there is a failure in the second switch unit. In addition, this failure determination method is an example, and a modified example of the failure determination method will be described later.

[0127] When it is determined that there is a failure in the second switch unit (step S205: Yes), the control device 100 performs a process for coping with an abnormality in the power supply system 30 (step S206). The process of step S206 is the same as that of step S104. After that, the control device 100 ends (interrupts) the stop process.

[0128] On the other hand, when it is determined that there is no failure in the second switch unit (step S205: No), the control device 100 operates the motor 10 and the inverter 20, and discharges the inverter-side smoothing capacitor 21 and the neutral-point side smoothing capacitor C1 (step S207). At this time, the control device 100 operates the motor 10 and the inverter 20, and gradually discharges the inverter-side smoothing capacitor 21 to a voltage equivalent to the terminal voltage of the first storage battery 31.

[0129] After the discharge, as Figure 4 shown, the control device 100 switches the third switch unit to the on state in the state where the second switch unit is turned off, and connects the second storage battery 32 between the low-voltage power line H2 and the low-voltage ground line L2 (step S208). As a result, low-voltage power from the second storage battery 32 can be supplied to the low-voltage load 72. In addition, in step S208, when switching the third switch unit to the on state, the control device 100 inputs and stores the detection values of various sensors.

[0130] Then, after the switching, the control device 100 determines whether there is a failure in the third switch unit based on the detected values of various sensors stored therein (step S209). In step S209, the control device 100 determines whether a normal current flows through the third A electrical path 3A according to the detected value of the third current sensor A13 when switching the third switch unit in step S208, thereby performing a failure determination of the third switch unit.

[0131] Here, with reference to Fig.10 , a detailed description will be given of an example of the method for determining a failure of the third switch unit in step S209. Fig.10 The on / off states of the third A switch SW3a and the third B switch SW3b in the normal state and the corresponding detected values of the third current sensor A13 are shown.

[0132] In addition, as a prerequisite, when performing a failure determination of the third switch unit, that is, before step S208 is implemented, the control device 100 switches the measurement range and resolution of the third current sensor A13 to the measurement range and resolution for measuring the current in the third A electrical path 3A. That is, the control device 100 narrows the measurement range of the third current sensor A13 and reduces the resolution. In addition, in the present embodiment, the supply voltage from the DCDC converter 70 becomes a voltage (14V) slightly higher than the inter-terminal voltage (12V) of the second battery 32.

[0133] As Fig.10 shown in the lower half of, when the detected value of the third current sensor A13 is not zero (or not within an error range close to zero, the same applies hereinafter) although the third switch unit (the third A switch SW3a and the third B switch SW3b) is off, the control device 100 determines that there is a failure in the third switch unit.

[0134] In addition, starting from the off state of the third switch unit, the control device 100 turns on the third B switch SW3b in step S208 and then turns on the third A switch SW3a, thereby turning on the third switch unit. Therefore, as Fig.10 shown in the middle part of, if the detected value of the third current sensor A13 is not zero in the state where the third A switch SW3a is off and the third B switch SW3b is on, the control device 100 determines that there is a failure in the third switch unit.

[0135] In addition, as Fig.10As shown in the upper part of [], if it can be determined that the detected value of the third current sensor A13 in the state where the third A switch SW3a is turned on and the third B switch SW3b is turned on is equal to or higher than a specified threshold value and the current is flowing normally, the control device 100 determines that there is no fault in the third switch unit. On the other hand, if the detected value of the third current sensor A13 is zero despite the third switch unit being turned on, it is determined that there is a fault in the third switch unit. In addition, this fault determination method is an example, and a modified example of the fault determination method will be described later.

[0136] When it is determined that there is a fault in the third switch unit (step S209: Yes), the control device 100 performs the same processing as described above for coping with the abnormality of the power supply system 30 (step S206). After that, the control device 100 ends (interrupts) the stop processing. On the other hand, when it is determined that there is no fault in the third switch unit (step S209: No), as Figure 3 shown, the control device 100 stops the operation of the DCDC converter 70 and stops the power supply from the DCDC converter 70 to the low-voltage load 72 (step S210). Thereby, power is supplied to the low-voltage load 72 from the second battery 32. Then, the control device 100 switches the first switch unit to the off state while the second switch unit is off, and cuts off the power supply between the first battery 31 and the high-voltage circuit 75 (step S211).

[0138] In addition, in step S211, when switching the first switch unit to the off state, the control device 100 inputs and stores the detected values of various sensors. Then, after switching the first switch unit, the control device 100 determines whether there is a fault in the first switch unit based on the stored detected values of various sensors (step S212). In step S212, the control device 100 determines whether the power supply to the first A electrical path 1A is appropriately cut off according to the detected value of the first current sensor A11 when switching the first switch unit in step S211, thereby performing the fault determination of the first switch unit.

[0139] For example, when the detection value of the first current sensor A11 is zero even though the first switching unit has not been switched to the off state yet (i.e., it is in the on state), that is, when no current flows through the first A electrical path 1A, the control device 100 determines that the first switching unit has a fault. Additionally, for example, when the detection value of the first current sensor A11 does not become zero even after the first switching unit is switched to the off state, that is, when the power supply to the first A electrical path 1A is not cut off, the control device 100 determines that the first switching unit has a fault. On the other hand, when the detection value of the first current sensor A11 becomes zero as the first switching unit is switched to the off state, the control device 100 determines that the first switching unit is normal (i.e., not faulty).

[0140] When it is determined that the first switching unit has a fault (step S212: Yes), the control device 100 performs the same processing as described above to handle the abnormality of the power supply system 30 (step S206). After that, the control device 100 ends (interrupts) the stop processing.

[0141] On the other hand, when it is determined that the third switching unit does not have a fault (step S212: No), the control device 100 discharges the inverter-side smoothing capacitor 21 by operating the motor 10 and the inverter 20 (step S213). Then, the stop processing is ended.

[0142] According to the above first embodiment, the following effects are achieved.

[0143] When the control device 100 cuts off the power supply between the first battery 31 and the second battery 32 and between the high-voltage circuit 75 and the low-voltage circuit 76 by disconnecting the second switching unit, it switches the on / off state of the first switching unit and performs a fault determination on the first switching unit.

[0144] Specifically, in step S102 of the startup processing, the control device 100 disconnects the second switching unit and turns on the first switching unit (switches SW1a, SW1c, SW1d, SW1e). In the next step S103, the control device 100 performs a fault determination on the first switching unit based on the detection value of the first current sensor A11 detected when the first switching unit is turned on. Additionally, in step S211 of the stop processing, the control device 100 disconnects the second switching unit and turns off the first switching unit (switches SW1a, SW1c, SW1d, SW1e). In the next step S212, the control device 100 performs a fault determination on the first switching unit based on the detection value of the first current sensor A11 detected when the first switching unit is turned off.

[0145] In addition, when the control device 100 cuts off the power supply between the first battery 31 and the second battery 32 and between the high-voltage circuit 75 and the low-voltage circuit 76 by disconnecting the second switching unit, it switches the on / off state of the third switching unit and performs a failure determination on the third switching unit.

[0146] Specifically, in step S107 of the startup process, the control device 100 disconnects the second switching unit and disconnects the third switching unit (switches SW3a, SW3b). In the next step S108, the control device 100 performs a failure determination on the third switching unit based on the detection value of the third current sensor A13 detected when disconnecting the third switching unit. In addition, in step S208 of the startup process, the control device 100 disconnects the second switching unit and turns on the third switching unit (switches SW3a, SW3b). In the next step S209, the control device 100 performs a failure determination on the third switching unit based on the detection value of the third current sensor A13 detected when turning on the third switching unit.

[0147] As described above, when the power supply between the first battery 31 and the second battery 32 and between the high-voltage circuit 75 and the low-voltage circuit 76 is cut off by the second switching unit, even if the on / off state of the first switching unit or the third switching unit is switched, the high-voltage circuit 75 and the low-voltage circuit 76 are not connected, and high voltage can be prevented from being applied to the low-voltage load 72. Therefore, the failure determination of the first switching unit and the third switching unit can be performed safely.

[0148] When the control device 100 cuts off the power supply between the second battery 32 and the low-voltage circuit 76 by disconnecting the third switching unit, it switches the on / off state of the second switching unit and performs a failure determination on the second switching unit.

[0149] Specifically, in step S110 of the startup process, the control device 100 disconnects the third switching unit and turns on the second switching unit (switches SW2a, SW2b). In the next step S111, the control device 100 performs a failure determination on the second switching unit based on the detection value of the third current sensor A13 detected when turning on the second switching unit.

[0150] In addition, in step S204 of the stop process, the control device 100 disconnects the third switching unit and disconnects the second switching unit (switches SW2a, SW2b). In the next step S205, the control device 100 performs a failure determination on the second switching unit based on the detection value of the third current sensor A13 detected when disconnecting the second switching unit.

[0151] Thus, when the energization between the second battery 32 and the low-voltage circuit 76 is cut off, even if the on / off control of the second switching unit is performed, the first battery 31 and the second battery 32, and the high-voltage circuit 75 and the low-voltage circuit 76 are not connected in the power supply system 30, and high voltage can be prevented from being applied to the low-voltage load 72. Therefore, the failure determination of the second switching unit can be performed safely.

[0152] As described in steps S102 to S103 and S208 to S212, the control device 100 performs the failure determination of the first switching unit during the period when the second switching unit is off and the third switching unit is on. That is, the control device 100 switches the on / off state of the first switching unit and performs the failure determination of the first switching unit when the energization between the first battery 31 and the second battery 32 and between the high-voltage circuit 75 and the low-voltage circuit 76 is cut off and power is supplied from the second battery 32 to the low-voltage circuit 76 side. Thereby, it is possible to prevent the interruption of the power supply to the low-voltage load 72 during the failure determination of the first switching unit.

[0153] In addition, as described in steps S106 to S108 and S208 to S209, when the second switching unit is off, the control device 100 turns on the first switching unit and steps down the high-voltage power by the DCDC converter 70 and supplies it to the low-voltage load 72, and during this period, the failure determination of the third switching unit is performed. That is, the control device 100 performs the failure determination of the third switching unit when the energization between the first battery 31 and the second battery 32 and between the high-voltage circuit 75 and the low-voltage circuit 76 is cut off and low-voltage power is supplied to the low-voltage circuit 76 side via the DCDC converter 70. Thereby, it is possible to prevent the interruption of the power supply to the low-voltage load 72 during the failure determination of the third switching unit.

[0154] A part of the third A electrical path 3A connecting the positive terminal of the second storage battery 32 and the low-voltage power supply line H2 is shared with a part of the electrical path that becomes energized when all the storage batteries 31 to 33 are connected between the high-voltage power supply line H1 and the high-voltage ground line L1. Specifically, the electrical path from the positive terminal of the second storage battery 32 to the connection point P13 is a shared path L10 shared between the third A electrical path 3A and the second A electrical path 2A. Moreover, a third current sensor A13 (shared current sensor) is provided in the shared path L10, and the control device 100 uses the detection value of the third current sensor A13 in the failure determination of the second switch unit and the failure determination of the third switch unit, respectively. Thereby, in the failure determination of the second switch unit and the failure determination of the third switch unit, it is not necessary to use the detection values of other current sensors. For example, it is not necessary to provide other current sensors in the second A electrical path 2A and the third A electrical path 3A. Therefore, the number of current sensors can be reduced and the wiring can be simplified.

[0155] In addition, the measurement range of the third current sensor A13 is configured to be changeable, and the resolution of the third current sensor A13 changes as the measurement range changes. Specifically, the measurement range when measuring the current flowing through the second A electrical path 2A is set to have a wider measurable range than the measurement range when measuring the current flowing through the third A electrical path 3A. For example, the measurement range when measuring the current flowing through the second A electrical path 2A is a range that can appropriately measure the current flowing through the second A electrical path 2A (for example, 100 A to 200 A). It is also configured that when measuring the current flowing through the third A electrical path 3A, the resolution can be changed to a smaller value and a smaller value can be measured compared to when measuring the current flowing through the second A electrical path 2A.

[0156] Then, the control device 100 changes the measurement range and resolution of the third current sensor A13 according to which of the second switch unit and the third switch unit the failure determination is being performed. For example, when the control device 100 performs the failure determination of the second switch unit, it expands the measurement range of the third current sensor A13 and increases the resolution, and when performing the failure determination of the third switch unit, it narrows the measurement range of the third current sensor A13 and decreases the resolution. Thereby, it is possible to be suitable for the measurement range and resolution of the flowing current, and the current can be detected with high precision.

[0157] When the control device 100 switches each switch SW and changes the number of batteries 31 to 33 energized with the high-voltage power line H1, the inverter 20 is controlled to boost or step down the voltage input to the motor 10 and the inverter 20 through the motor 10 and the inverter 20, thereby adjusting the voltage between the terminals of the inverter-side smoothing capacitor 21.

[0158] Specifically, after the implementation of step S102 (the first step) and before step S110 (the second step), in step S109, the control device 100 controls the inverter 20, and boosts the voltage input to the inverter 20 from the first battery 31 through the motor 10 and the inverter 20. Then, the control device 100 applies the boosted voltage to the inverter-side smoothing capacitor 21 and raises the voltage between the terminals of the inverter-side smoothing capacitor 21 to a voltage between the terminals of the inverter-side smoothing capacitor 21 equivalent to the voltage between the terminals of the second series connection body 50. Thereby, even if the second switch unit is turned on and all the batteries 31 to 33 are connected in series with respect to the high-voltage power line H1, it is possible to prevent the supply voltage supplied to the high-voltage circuit 75 from becoming unstable, and it is possible to stabilize the power supply to the high-voltage load 71. In addition, inrush current can be suppressed.

[0159] In addition, the control device 100 boosts the voltage between the terminals of the neutral-point side smoothing capacitor C1 through the motor 10 and the inverter 20 to a voltage between the terminals of the neutral-point side smoothing capacitor C1 equivalent to the voltage between the terminals of the first series connection body 40. Thereby, inrush current can be suppressed during switching.

[0160] After steps S202 and S203 (the fifth step) and before step S204 (the sixth step), the control device 100 discharges the first smoothing capacitor through the inverter 20 and the motor 10, or controls the inverter 20 to boost the voltage input to the inverter 20 from the first battery 31 through the inverter 20 and the motor 10, apply it to the inverter-side smoothing capacitor 21, and maintain the voltage between the terminals of the inverter-side smoothing capacitor 21 for a certain period, and then gradually discharge (step down). Thereby, even if the second switch unit is turned off and the second battery 32 and the third battery 33 are disconnected from the high-voltage power line H1 and all the batteries 31 to 33 are not connected in series, it is possible to prevent the supply voltage supplied to the high-voltage circuit 75 from becoming unstable. In addition, inrush current can be suppressed.

[0161] (Modification example) A modification example (another example of the embodiment) in which a part of the structure of the above embodiment is changed will be described.

[0162] (Modification example 1) ·A modification example (modification example 1) of the failure determination method for the third switch section of the above-described embodiment will be described. Fig.13 The on / off states of the third A switch SW3a and the third B switch SW3b in the normal state and the detection values of the third current sensor A13 corresponding thereto are shown.

[0163] First, modification example 1 in step S108 will be described. As Fig.13 shown in the upper half of, when the third switch section (the third A switch SW3a and the third B switch SW3b) is turned on, current flows from the DCDC converter 70 to the second battery 32, and the second battery 32 is charged. Therefore, when the detection value of the third current sensor A13 is zero although the third switch section is turned on, the control device 100 determines that there is a failure in the third switch section.

[0164] In addition, in modification example 1, starting from the state where the third switch section is turned on, the control device 100 turns off the third B switch SW3b in step S107, and then turns off the third A switch SW3a, thereby turning off the third switch section. Therefore, as Fig.13 shown in the middle part of, if the detection value of the third current sensor A13 in the state where the third B switch SW3b is turned off and the third A switch SW3a is turned on is not zero, the control device 100 determines that there is a failure in the third B switch SW3b, and if it is zero, it determines that there is no failure in the third B switch SW3b. When it is determined that there is a failure in the third B switch SW3b, it is determined that there is a failure in the third switch section, and when it is determined that there is no failure in the third B switch SW3b, it is determined that there is no failure in the third switch section. Thus, not only can the failure of the third switch section be determined, but also the failure of the third B switch SW3b can be determined.

[0165] Next, modification example 1 in step S209 will be described. As Fig.13 shown in the lower half of, when the detection value of the third current sensor A13 is not zero although the third switch section (the third A switch SW3a and the third B switch SW3b) is turned off, the control device 100 determines that there is a failure in the third switch section. In addition, starting from the state where the third switch section is turned off, the control device 100 turns on the third A switch SW3a in step S208, and then turns on the third B switch SW3b, thereby turning on the third switch section. Therefore, as Fig.13 shown in the middle part of, if the detection value of the third current sensor A13 in the state where the third A switch SW3a is turned on and the third B switch SW3b is turned off is not zero, the control device 100 determines that there is a failure in the third B switch SW3b and the third switch section. In addition, as Fig.13As shown in the upper part of [], if it can be determined that the detected value of the third current sensor A13 in the state where the third A switch SW3a and the third B switch SW3b are turned on is equal to or higher than a specified threshold value and the current is flowing normally, the control device 100 determines that there is no failure in the third switch unit. On the other hand, when the detected value of the third current sensor A13 is zero although the third switch unit is turned on, it is determined that there is a failure in the third switch unit.

[0166] (Modification 2) · A modification (Modification 2) of the failure determination method for the third switch unit in the above-described embodiment will be described. In the power supply system 30, although not shown, it includes a voltage monitoring sensor V100 that detects and monitors the voltage between the terminals of the secondary battery 32. In Modification 2, this voltage monitoring sensor V100 is used for failure determination. Hereinafter, with reference to Fig.14 a detailed description will be given. Fig.14 shows the on / off states of the third A switch SW3a and the third B switch SW3b during normal operation and the detected values of the voltage monitoring sensor V100 and the third current sensor A13 corresponding thereto.

[0167] First, Modification 2 in step S108 will be described. As Fig.14 shown in the upper part of [], when the detected value of the voltage monitoring sensor V100 is not the supply voltage (e.g., 14V) from the DCDC converter 70 although the third switch unit (the third A switch SW3a and the third B switch SW3b) is turned on, the control device 100 determines that there is a failure in the third switch unit. The case where it is not the supply voltage from the DCDC converter 70 means, for example, that when the detected value is lower than the supply voltage and the difference is equal to or higher than a threshold value, it is determined that it is not the supply voltage from the DCDC converter 70.

[0168] In addition, starting from the state where the third switch unit is turned on, the control device 100 turns off the third A switch SW3a in step S107 and then turns off the third B switch SW3b, thereby turning off the third switch unit. Therefore, as Fig.14As shown in the middle part of , if the detected value of the voltage monitoring sensor V100 in the state where the third A switch SW3a is off and the third B switch SW3b is on is not the inter-terminal voltage of the second battery 32 (e.g., 12 V), the control device 100 determines that the third A switch SW3a has a fault. If it is the inter-terminal voltage of the second battery 32, it is determined that the third A switch SW3a has no fault. Additionally, for example, when the third A switch SW3a is off, if the detected value of the voltage monitoring sensor V100 decreases by more than a specified value (e.g., 2 V or more), the control device 100 may also determine that the third A switch SW3a has no fault. Then, when it is determined that the third A switch SW3a has a fault, it is determined that the third switch section has a fault. When it is determined that the third A switch SW3a has no fault, it is determined that the third switch section has no fault.

[0169] Next, a second modification of step S209 will be described. As Fig.14 shown in the lower half of , when the detected value of the voltage monitoring sensor V100 is not the inter-terminal voltage of the second battery 32 although the third switch section is off, the control device 100 determines that the third switch section has a fault.

[0170] Additionally, starting from the state where the third switch section is off, the control device 100 turns on the third B switch SW3b in step S208 and then turns on the third A switch SW3a, thereby turning on the third switch section. Thus, as Fig.14 shown in the middle part of , if the detected value of the voltage monitoring sensor V100 in the state where the third A switch SW3a is off and the third B switch SW3b is on is not the inter-terminal voltage of the second battery 32, the control device 100 determines that the third switch section has a fault.

[0171] Furthermore, if it can be determined that the detected value of the voltage monitoring sensor V100 in the state where the third A switch SW3a is on and the third B switch SW3b is on is a value equivalent to the supply voltage from the DCDC converter 70, the control device 100 determines that the third switch section has no fault. Additionally, for example, when the third switch section is on, if the detected value of the voltage monitoring sensor V100 increases by more than a specified value (e.g., 2 V or more), it may also be determined that the third switch section has no fault. On the other hand, when the detected value of the voltage monitoring sensor V100 is the inter-terminal voltage of the second battery 32 although the third switch section is on, it is determined that the third switch section has a fault.

[0172] As described above, since the voltage monitoring sensor V100 that monitors the inter-terminal voltage of the second battery 32 can be used for fault determination, the third current sensor A13 can be omitted.

[0173] (Modification Example 3) · A modification example (Modification Example 3) of the failure determination method for the third switch section in the above-described embodiment will be described. In the power supply system 30, although not shown, a voltage monitoring sensor V100 that detects and monitors the voltage between the terminals of the second battery 32 is included. In Modification Example 3, this voltage monitoring sensor V100 is used for failure determination. Fig.15 The on / off states of the third A switch SW3a and the third B switch SW3b in the normal state and the detection values of the voltage monitoring sensor V100 corresponding thereto are shown. Modification Example 3 only differs in the on / off timing of the third A switch SW3a and the third B switch SW3b, and the way of considering failure determination is substantially the same as that of Modification Example 1 and the like. Therefore, detailed description is omitted. Thus, not only can the failure of the third switch section be determined, but also the failure of the third B switch SW3b can be determined.

[0174] (Modification Example 4) · A modification example (Modification Example 4) of the failure determination method for the third switch section in the above-described embodiment will be described. In Modification Example 4, as Fig.16 shown, the detection value of the third voltage sensor V13, one end of which is connected to a portion on the positive terminal side of the third A electrical path 3A closer to the second battery 32 than the third A switch SW3a and the other end of which is connected to a portion on the low-voltage ground wire L2 side closer to the third B switch SW3b than the third B electrical path 3B, is used for failure determination of the third switch section. Fig.17 The on / off states of the third A switch SW3a and the third B switch SW3b in the normal state and the detection values of the third voltage sensor V13 in Modification Example 4 corresponding thereto are shown.

[0175] First, Modification Example 4 in step S108 will be described. As Fig.17 shown in the upper half, when the third switch section (the third A switch SW3a and the third B switch SW3b) is on but the detection value of the voltage monitoring sensor V100 is not the supply voltage (for example, 14V) from the DCDC converter 70, the control device 100 determines that there is a failure in the third switch section.

[0176] In addition, as Fig.17 shown in the middle part, if the detection value of the third voltage sensor V13 in the state where the third A switch SW3a is off and the third B switch SW3b is on is not the voltage between the terminals of the second battery 32 (for example, 12V), the control device 100 determines that the third A switch SW3a has a failure, and if it is the voltage between the terminals of the second battery 32, it determines that the third A switch SW3a does not have a failure.

[0177] Moreover, as Fig.17As shown in the lower part of [], when the detected value of the third voltage sensor V13 is "indeterminate" in the state where the third A switch SW3a is off and the third B switch SW3b is off, the control device 100 determines that the third B switch SW3b has no fault. When it is not "indeterminate", it is determined that the third B switch SW3b has a fault. "Indeterminate" means that the value is uncertain. Although it may sometimes be zero, it is at least not the supply voltage from the DCDC converter 70 nor the voltage between the terminals of the second battery 32. Therefore, for example, when the detected value of the third voltage sensor V13 is not the supply voltage from the DCDC converter 70 and is also not the voltage between the terminals of the second battery 32, the control device 100 determines that the third B switch SW3b has no fault. When it is a certain value, it is only necessary to determine that the third B switch SW3b has a fault.

[0178] Then, when it is determined that the third A switch SW3a or the third B switch SW3b has a fault, it is determined that the third switch section has a fault. When it is determined that the third A switch SW3a and the third B switch SW3b have no faults, it is determined that the third switch section has no fault.

[0179] Next, a modification example 4 in step S209 will be described. As Fig.17 shown in the lower part of [], when the detected value of the third voltage sensor V13 is not indeterminate although the third switch section is off (for example, when it is the supply voltage from the DCDC converter 70 or the voltage between the terminals of the second battery 32), the control device 100 determines that the third switch section has a fault.

[0180] In addition, as Fig.17 shown in the middle part of [], if the detected value of the third voltage sensor V13 in the state where the third A switch SW3a is off and the third B switch SW3b is on is not the voltage between the terminals of the second battery 32, the control device 100 determines that the third B switch SW3b and the third switch section have faults.

[0181] In addition, if it can be determined that the detected value of the third voltage sensor V13 in the state where the third A switch SW3a is on and the third B switch SW3b is on corresponds to the supply voltage from the DCDC converter 70, the control device 100 determines that the third A switch SW3a and the third switch section have no faults. In the opposite case, the control device 100 determines that the third A switch SW3a and the third switch section have faults.

[0182] As described above, according to the third voltage sensor V13 of the modification example 4, it is possible to determine not only the fault of the third switch section but also which one of the third A switch SW3a and the third B switch SW3b has a fault.

[0183] Alternatively, one end of the third voltage sensor V13 can be connected to a position in the third A electrical path 3A closer to the low-voltage power line H2 side than the third A switch SW3a, and the other end can be connected to a position in the third B electrical path 3B closer to the negative terminal of the second battery 32 than the third B switch SW3b. In this case, similar to the modified example 4, it is also possible to determine which one of the third A switch SW3a and the third B switch SW3b has a fault.

[0184] (Modified Example 5) · A modification example (modified example 5) of the fault determination method for the third switch section of the above-described embodiment will be described. In the modified example 5, as Fig.16 shown, the detection value of the third voltage sensor V13 is used in the same manner as in the modified example 4. However, as Fig.18 shown, compared with the modified example 4, the on / off sequence of the third A switch SW3a and the third B switch SW3b is different. Therefore, in the modified example 5, although the fault determination of the third switch section can be performed, different from the modified example 4, it is not possible to determine which one of the third A switch SW3a and the third B switch SW3b has a fault. In addition, the way of considering the fault determination is only to change the third current sensor A13 to the third voltage sensor V13, which is substantially the same as the modified example 1 and the like, so the detailed description is omitted.

[0185] (Modified Example 6) · A modification example (modified example 6) of the fault determination method for the second switch section of the above-described embodiment will be described. In the above-described embodiment, the detection value of the third current sensor A13 is used, but in the modified example 6, any one of the detection values of the first voltage sensor V1, the second voltage sensor V2, and the second current sensor A12 can also be used. As Fig.11 shown, this is because if the second switch section is normal, the detection value can be changed by turning the second switch section on and off.

[0186] In addition, in the figure, "V1" is the column for the first voltage sensor V1, and "V2" is the column for the second voltage sensor V2. Additionally, in the columns "V1" and "V2", "depending on INV" indicates that the detected values of the first voltage sensor V1 and the second voltage sensor V2 are changed according to how the inverter 20 operates and how the voltage is boosted (or stepped down). Further, in the column "A12" of the second current sensor A12 in the figure, "-A11" indicates the negative value detected by the first current sensor A11. Also, in the column "A12" of the second current sensor A12 in the figure, "depending on INV" means that the amount of current flowing varies due to the control of the inverter 20. Therefore, in order to be able to determine the change in the detected value by the on / off operation of the second switch section, the control device 100 needs to appropriately control the inverter 20. Additionally, the way of considering the fault determination is substantially the same as that of the first embodiment that uses the detected value of the third current sensor A13, etc., so the detailed description is omitted.

[0187] (Modification Example 7) · A modification example (Modification Example 7) of the fault determination method for the second switch section of the above-described embodiment will be described. In Modification Example 7, as Fig.19 shown, any one of the detected values of the first voltage sensor V1, the second voltage sensor V2, and the second current sensor A12 is used, and the on / off sequence of the second A switch SW2a and the second B switch SW2b is changed. Additionally, the way of considering the fault determination is substantially the same as that of the first embodiment and Modification Example 6, etc., so the detailed description is omitted.

[0188] (Modification Example 8) · A modification example (Modification Example 8) of the fault determination method for the second switch section of the above-described embodiment will be described. In Modification Example 8, as Fig. 20 shown, the detected value of the fourth voltage sensor V14, which has one end connected to a portion on the positive terminal side of the second battery 32 that is closer to the second battery 32 than the second A switch SW2a in the second A electrical path 2A and the other end connected to a portion on the high-voltage ground wire L1 side that is closer to the high-voltage ground wire L1 than the second B switch SW2b in the second B electrical path 2B, is used for the fault determination of the second switch section.

[0189] Fig.21 The on / off states of the second A switch SW2a and the second B switch SW2b in the normal state and the corresponding detected values of the fourth voltage sensor V14 are shown. Here, a detailed description of Modification Example 8 in step S111 will be given with reference to Fig.21

[0190] As Fig.21As shown in the upper part of [], when the detection value of the fourth voltage sensor V14 is not "indeterminate" even though the second switching unit is open, it is determined that there is a fault in the second switching unit. For example, when it is the inter-terminal voltage of the second battery 32 (12V) or the value obtained by subtracting the inter-terminal voltage of the third battery 33 from the inter-terminal voltage of the neutral point side smoothing capacitor C1, it is determined that there is a fault in the second switching unit. In addition, the inter-terminal voltage of the neutral point side smoothing capacitor C1 is the detection value of the second voltage sensor V2, and the inter-terminal voltage of the third battery 33 is 200V.

[0191] In addition, starting from the state where the second switching unit is open, the control device 100 closes the second A switch SW2a in step S110, and then closes the second B switch SW2b, thereby closing the second switching unit. Therefore, as Fig.21 As shown in the middle part of [], if the detection value of the fourth voltage sensor V14 in the state where the second A switch SW2a is closed and the second B switch SW2b is open is not the value "V2 - 200" obtained by subtracting the inter-terminal voltage of the third battery 33 from the inter-terminal voltage of the neutral point side smoothing capacitor C1, the control device 100 determines that there is a fault in the second A switch SW2a and the second switching unit.

[0192] In addition, if the detection value of the fourth voltage sensor V14 in the state where the second A switch SW2a is closed and the second B switch SW2b is closed is the inter-terminal voltage of the second battery 32 (12V), the control device 100 determines that there is no fault in the second A switch SW2a, the second B switch SW2b, and the second switching unit. On the other hand, when the detection value of the fourth voltage sensor V14 is not the inter-terminal voltage of the second battery 32 (12V) even though the second switching unit is closed, it is determined that there is a fault in the second B switch SW2b and the second switching unit.

[0193] In addition, it is desirable to boost the inter-terminal voltage of the neutral point side smoothing capacitor C1 so that the difference between the value "V2 - 200" obtained by subtracting the inter-terminal voltage of the third battery 33 from the inter-terminal voltage of the neutral point side smoothing capacitor C1 and the inter-terminal voltage of the second battery 32 (12V) is significantly generated. Specifically, in step S109, it is desirable to control the inverter 20 or the like to boost the inter-terminal voltage of the neutral point side smoothing capacitor C1.

[0194] In addition, in steps S204 to S205, when the second switching unit is set to open for fault determination of the second switching unit, it is also possible to determine which one of the second A switch SW2a and the second B switch SW2b has a fault in the same manner.

[0195] As described above, according to Modification Example 8, it is possible to determine not only the failure of the second switch unit but also which one of the second A switch SW2a and the second B switch SW2b has a failure.

[0196] (Modification Example 9) · A modification example (Modification Example 9) of the failure determination method for the second switch unit in the above-described embodiment will be described. In Modification Example 9, the detection value of the fourth voltage sensor V14 described in Modification Example 8 is used. However, as Fig. 22 shown, compared with Modification Example 8, the on / off order of the second A switch SW2a and the second B switch SW2b is different.

[0197] In addition, as Fig. 22 shown, in Modification Example 9, it is possible to perform the failure determination of the third switch unit only by the detection value of the fourth voltage sensor V14. However, different from Modification Example 8, it is not possible to determine which one of the second A switch SW2a and the second B switch SW2b has a failure.

[0198] Therefore, the detection value of any one or two or more of the first voltage sensor V1, the second voltage sensor V2, the second current sensor A12, and the third current sensor A13 is combined with the detection value of the fourth voltage sensor V14 and used. That is, the failure determination of the second B switch SW2b is performed by the detection value of the fourth voltage sensor V14, and the failure determination of the second A switch SW2a can be performed by the detection value of any one or two or more of the first voltage sensor V1, the second voltage sensor V2, the second current sensor A12, and the third current sensor A13. Thus, as Fig. 22 shown, it is possible to determine which one of the second A switch SW2a and the second B switch SW2b has a failure.

[0199] (Modification Example 10) · In the power supply system 30 of the above-described first embodiment, it is also possible not to provide a switch for switching the energization and power-off between the second battery 32 and the third battery 33. For example, as Fig.23 shown, in the power supply system 30 of the first embodiment, the positive terminal of the second battery 32 and the negative terminal of the third battery 33 may be directly connected. In this case, it is only necessary to provide the second A switch SW2a between the first C switch SW1c and the third battery 33.

[0200] (Modification Example 11) · In the power supply system 30 of the above-described first embodiment, the arrangements of the second battery 32 and the third battery 33 may also be changed. For example, as Fig.24As shown, in the power supply system 30 of the first embodiment, it can also be configured to connect the first storage battery 31 → the second storage battery 32 → the third storage battery 33 in series from the high-voltage power line H1 side. In this case, a second A switch SW2a for switching the energization and power-off between them is provided between the negative terminal of the second storage battery 32 and the positive terminal of the third storage battery 33.

[0201] (Variant Example 12) · In the power supply system 30 of the above first embodiment, the configurations of the first storage battery 31, the second storage battery 32, and the third storage battery 33 can also be changed. For example, as Fig.25 shown, in the power supply system 30 of the first embodiment, it can also be configured in the order of the second storage battery 32 → the third storage battery 33 → the first storage battery 31 from the high-voltage power line H1 side. In addition, a series connection body of the pre-charge switch Pre_G and the resistor R1 is connected in parallel with the first B switch SW1b.

[0202] In this variant example 12, the first B switch SW1b, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e correspond to the first switch unit. In addition, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e correspond to the first X switch. In addition, the first B switch SW1b corresponds to the first Y switch. In addition, the second B switch SW2b corresponds to the second X switch, and the second A switch SW2a corresponds to the second Y switch.

[0203] (Variant Example 13) · In the power supply system 30 of the above first embodiment, the third storage battery 33 can also be omitted. For example, as Fig.26 shown, the third storage battery 33 of the power supply system 30 in the first embodiment can also be omitted.

[0204] (Variant Example 14) · In the above embodiment, the switching order of the on / off states of each switch SW can also be changed as shown in the following variant example 14. Refer to Figure 27 to Figure 28 , and the switching order (variant example 14) from when the vehicle is parked to when the vehicle starts is described. As a premise, when the vehicle is parked, the on / off states of each switch SW are as Fig. 27 shown in (a). That is, the third switch unit is turned on.

[0205] When the vehicle starts while the vehicle is parked, it transfers to Fig. 27The connection state shown in (b) thereof. That is, the control device 100 switches the pre-charge switch Pre_P, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e to the on state. Then, the control device 100 charges the inverter-side smoothing capacitor 21 so that the voltage between the terminals of the inverter-side smoothing capacitor 21 is equivalent to the voltage between the terminals of the first storage battery 31.

[0206] Then, after the charging is completed, it transfers to Fig. 27 The connection states shown in (c) to (d) thereof. That is, the control device 100 switches the first A switch SW1a to the on state, and then disconnects the pre-charge switch Pre_P. In addition, when switching the first switch unit to the on state, a failure determination of the first switch unit is performed in the same manner as in the first embodiment and the like. After the failure determination, the control device 100 supplies high-voltage power from the first storage battery 31 to the DCDC converter 70, the DCDC converter 70 steps down the high-voltage power, and supplies it to the low-voltage load 72.

[0207] Then, as Fig.28 Shown in (e) thereof, the control device 100 switches the third switch unit to the off state. At this time, a failure determination of the third switch unit is performed using the determination method described in the above embodiment or modification. After the failure determination, as Fig.28 Shown in (f) thereof, the control device 100 switches the first B switch SW1b to the on state. At this time, a failure determination of the first B switch SW1b can also be performed based on the detection value of the first current sensor A11 and the like.

[0208] After that, as Fig.28 Shown in (g) thereof, the control device 100 switches the first C switch SW1c to the off state, steps down the applied voltage from the first storage battery 31 through the motor 10 and the inverter 20, and charges the neutral-point side smoothing capacitor C1. Specifically, the voltage between the terminals of the neutral-point side smoothing capacitor C1 is boosted to a voltage equivalent to the voltage between the terminals of the first series connection body 40 (212V) composed of the second storage battery 32 and the third storage battery 33.

[0209] Next, as Fig.28 Shown in (h) thereof, the control device 100 switches the second B switch SW2b to the on state. At this time, a failure determination of the second B switch SW2b is performed based on the detection values of the second voltage sensor V2, the second current sensor A12, the third current sensor A13, or the fourth voltage sensor V14 of Modification 8. After the failure determination, the control device 100 boosts the supply voltage from the first series connection body 40 using the motor 10 and the inverter 20, and supplies it to the high-voltage power line H1. Thus, the first storage battery 31 and the first series connection body 40 are connected in parallel to the high-voltage power line H1.

[0210] In this modification 14, the precharge switch Pre_P, the first A switch SW1a, and the first B switch SW1b correspond to the first switch unit, and the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e correspond to the neutral point connection switch unit.

[0211] (Modification 15) · In the above-described embodiment, the switching order of the on / off states of each switch SW can also be modified as shown in the following modification 15. Refer to Figure 29 to Figure 30 , and the switching order (modification 15) from when the vehicle is stopped to when the vehicle starts is described. As a premise, when the vehicle is stopped, the on / off states of each switch SW are as Fig.29 shown in (a) of . That is, the third switch unit is turned on.

[0212] When the vehicle starts while the vehicle is stopped, it transfers to the Fig.29 connection state shown in (b) of . That is, the control device 100 switches the precharge switch Pre_P and the first B switch SW1b to on. Then, the control device 100 charges the inverter-side smoothing capacitor 21 so that the voltage between the terminals of the inverter-side smoothing capacitor 21 is equivalent to the voltage between the terminals of the first battery 31.

[0213] Then, after the charging is completed, it transfers to the Fig.29 connection states shown in (c) to (d) of . That is, the control device 100 switches the first A switch SW1a to on, and then disconnects the precharge switch Pre_P. In addition, Fig.29 the processing up to (a) to (d) of corresponds to the third step. In this modification 15, the precharge switch Pre_P, the first A switch SW1a, and the first B switch SW1b correspond to the first switch unit.

[0214] In addition, when switching the first switch unit to on, a failure determination of the first switch unit is performed in the same manner as in the first embodiment and the like. After the failure determination, the control device 100 supplies high-voltage power from the first battery 31 to the DCDC converter 70, the DCDC converter 70 steps down the high-voltage power, and supplies it to the low-voltage load 72.

[0215] Then, as Fig.30 shown in (e) of , the control device 100 switches the third switch unit to off. At this time, a failure determination of the third switch unit is performed using the determination method described in the above embodiment or modification. After the failure determination, as Fig.30As shown in (f) of FIG. , the control device 100 turns on the first E switch SW1e, controls the motor 10 and the inverter 20, and charges the neutral point side smoothing capacitor C1. Specifically, the voltage between the terminals of the neutral point side smoothing capacitor C1 is boosted to a voltage equivalent to the voltage between the terminals of the first series connection body 40 composed of the second battery 32 and the third battery 33 (212V).

[0216] After that, as shown in Fig.30 (g) of FIG. , the control device 100 turns on the second A switch SW2a, the first D switch SW1d, and the second B switch SW2b (equivalent to the fourth step). At this time, based on the detection values of the second voltage sensor V2, the second current sensor A12, the third current sensor A13, or the fourth voltage sensor V14 of the modified example 8, a failure determination of the second switch unit is performed.

[0217] After the failure determination, as shown in Fig.30 (h) of FIG. , the control device 100 boosts the supply voltage from the first series connection body 40 by using the motor 10 and the inverter 20, and supplies it to the high-voltage power line H1. Thus, the first battery 31 and the first series connection body 40 are connected in parallel with the high-voltage power line H1.

[0218] In this modified example 15, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e are equivalent to the neutral point connection switch unit. In addition, since the neutral point side smoothing capacitor C1 is boosted before connecting the first series connection body 40 to the neutral point of the motor 10, inrush current can be suppressed.

[0219] (Modified Example 16) · In the above-described embodiment, the switching order of the on / off states of each switch SW may be modified as shown in the following modified example 16. Referring to Figure 31 to Figure 32 , the switching order (modified example 16) from when the vehicle is starting to when the vehicle stops will be described.

[0220] As a premise of this modified example 16, during vehicle startup, it becomes the connection state of Fig.31 (a) of FIG. . Fig.31 (a) of FIG. is the same as the connection state of Fig.30 (h) of FIG. . When the vehicle stops starting from this state, the control device 100 turns off the first D switch SW1d, the second A switch SW2a, and the second B switch SW2b. At this time, a failure determination of the second switch unit may be performed in the same manner as in the above-described embodiment or modified example.

[0221] After the failure determination, as shown in Fig.31As shown in (c) thereof, the control device 100 controls the inverter 20 and discharges the neutral-point side smoothing capacitor C1. Then, as Fig.31 shown in (d) thereof, the control device 100 switches the third switch unit to on. At this time, the failure determination of the third switch unit is performed in the same manner as in the above-described embodiment or modification. In addition, the control device 100 switches the first E-switch SW1e to off. Next, in Fig.32 the state shown in (e) thereof, the control device 100 stops the operation of the DCDC converter 70 and stops the power supply from the DCDC converter 70 to the low-voltage load 72.

[0222] After that, as Fig.32 shown in (f) thereof, the control device 100 switches the first A-switch SW1a and the first B-switch SW1b to off. In this modification, the first A-switch SW1a and the first B-switch SW1b correspond to the first switch unit. At this time, the failure determination of the first switch unit may also be performed. Then, as Fig.32 shown in (g) thereof, the control device 100 controls the inverter 20 and discharges the inverter side smoothing capacitor 21, completing the switching and transferring to the state at the time of stop.

[0223] (Modification 17) ·In the above-described embodiment, the second A-switch SW2a may also be deleted, and the switching order of the on / off states of each switch SW may be modified as shown in the following Modification 17. Refer to Figure 33 to Figure 35 , and the switching order (Modification 17) from when the vehicle is stopped to when the vehicle starts is described. As a premise, when the vehicle is stopped, the on / off states of each switch SW are as Fig.33 shown in (a) thereof. That is, the third switch unit is on.

[0224] When the vehicle starts while the vehicle is stopped, it transfers to Fig.33 the connection state shown in (b) thereof. That is, the control device 100 switches the pre-charge switch Pre_P and the first B-switch SW1b to on. Then, the control device 100 charges the inverter side smoothing capacitor 21 so that the voltage between the terminals of the inverter side smoothing capacitor 21 is equivalent to the voltage between the terminals of the first storage battery 31.

[0225] Then, after the charging is completed, it transfers to Fig.33The connection state shown in (c) to (d). That is, the control device 100 switches the first A switch SW1a to the on state, and then disconnects the pre-charge switch Pre_P. In addition, when switching the first switch unit to the on state, the failure determination of the first switch unit is performed in the same manner as in the first embodiment and the like. After the failure determination, the control device 100 supplies high-voltage power from the first battery 31 to the DCDC converter 70, causes the DCDC converter 70 to step down the high-voltage power, and supplies it to the low-voltage load 72.

[0226] Then, as Fig.34 shown in (e), the control device 100 switches the third switch unit to the off state. At this time, the failure determination of the third switch unit is performed using the determination method described in the above embodiment or modification. After the failure determination, as Fig.33 shown in (f), the control device 100 switches the first E switch SW1e to the on state. After that, the control device 100 controls the motor 10 and the inverter 20 to step down the applied voltage from the first battery 31 and charge the neutral-point side smoothing capacitor C1. Specifically, the voltage between the terminals of the neutral-point side smoothing capacitor C1 is boosted to a voltage equivalent to the voltage between the terminals of the first series connection body 40 formed by the second battery 32 and the third battery 33 (212V).

[0227] After that, as Fig.34 shown in (g), the control device 100 switches the first D switch SW1d and the second B switch SW2b to the on state. At this time, the failure determination of the first D switch SW1d or the second B switch SW2b is performed.

[0228] The description of this failure determination is as follows. At this time, when switching on in the order of the first D switch SW1d → the second B switch SW2b, it is only necessary to perform the failure determination of the first D switch SW1d and the second B switch SW2b with reference to the detection value of any one of the voltage sensors V1, V2, and the current sensors A11 to A13. Fig.36 shows the relationship between the on / off states of the first D switch SW1d and the second B switch SW2b in the normal state and the respective detection values. When the detection values shown in Fig.36 (a) are not detected, the failure of the second B switch SW2b can be determined in the same manner as above. In addition, "depending on INV" means that the detection value changes according to how the inverter 20 is controlled. Therefore, it is desirable to control the inverter 20 to adjust the voltage or current so that the detection value changes when the on / off state is switched.

[0229] Alternatively, it is also possible to switch on in the order of the second B switch SW2b → the first D switch SW1d and perform the failure determination. Fig.37shows the relationship between the on / off states of the first D switch SW1d and the second B switch SW2b in the normal state and each detected value. When no detected value as shown in Fig.36 in (b) is detected, similarly to the above, a failure of the first D switch SW1d can be determined.

[0230] In addition, the detected value of the fourth voltage sensor V14 described in Modification 8 can also be used. Fig.37 (a) of shows the relationship between the on / off states of the first D switch SW1d and the second B switch SW2b in the normal state and each detected value when the first D switch SW1d and the second B switch SW2b are turned on in this order. As shown in Fig.37 (a) of, based on the detected value of the fourth voltage sensor V14, a failure determination of the first D switch SW1d and the second B switch SW2b can be performed. In addition, the failure determination method is the same as that in Modification 8 and the like.

[0231] In addition, Fig.37 (b) of shows the relationship between the on / off states of the first D switch SW1d and the second B switch SW2b in the normal state and each detected value when the second B switch SW2b and the first D switch SW1d are turned on in this order. As described in Modification 8 and the like, based only on Fig.37 the detected value of the fourth voltage sensor V14 in (b) of, a failure determination of the first D switch SW1d and the second B switch SW2b cannot be performed. Therefore, similarly to the above, if the detected value of the fourth voltage sensor V14 and the detected value of any one of the voltage sensors V1, V2, and current sensors A11 to A13 are used, a failure determination of the first D switch SW1d and the second B switch SW2b can be performed even if the switching order is changed.

[0232] After the failure determination, as shown in Fig.34 (h) of, the control device 100 switches the first B switch SW1b to off, boosts the applied voltage from the first series connection body 40 through the motor 10 and the inverter 20, and charges the inverter-side smoothing capacitor 21. At this time, the boosting is performed so that the voltage between the terminals of the inverter-side smoothing capacitor 21 becomes the voltage between the terminals of the second series connection body 50 (612V).

[0233] After that, as shown in Fig.35 (i) of, the control device 100 turns on the first C switch SW1c. At this time, a failure determination of the first C switch SW1c is performed by determining whether the detected value of any one of the first voltage sensor V1 and the current sensors A11 to A13 changes appropriately. Then, as shown in Fig.35As shown in (j) of FIG. 0, the control device 100 turns off the first D switch SW1d to discharge the neutral-point side smoothing capacitor C1, and turns off the first E switch SW1e. As a result, the first battery 31 to the third battery 33 are connected in series with the high-voltage power line H1.

[0234] In addition, in this modification, the first C switch SW1c and the second B switch SW2b correspond to the second switch unit. In addition, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e correspond to the neutral-point connection switch unit.

[0235] (Modification 18) ·In the above-described embodiment, the second A switch SW2a may be deleted, and the switching order of the on / off states of the respective switches SW may be modified as shown in the following Modification 18. Refer to Figures 38 to 40 , and the switching order (Modification 18) from when the vehicle is stopped to when the vehicle starts is described. As a premise, when the vehicle is stopped, the on / off states of the respective switches SW are as Fig.38 shown in (a) of FIG. That is, the third switch unit is turned on.

[0236] When the vehicle starts while the vehicle is stopped, it transfers to Fig.38 the connection state shown in (b) of FIG. That is, the control device 100 switches the pre-charge switch Pre_P and the first B switch SW1b to on. Then, the control device 100 charges the inverter side smoothing capacitor 21 so that the voltage between the terminals of the inverter side smoothing capacitor 21 is equivalent to the voltage between the terminals of the first battery 31.

[0237] Then, after the charging is completed, it transfers to Fig.38 the connection states shown in (c) to (d) of FIG. That is, the control device 100 switches the first A switch SW1a to on, and then turns off the pre-charge switch Pre_P. In addition, when switching the first switch unit to on, a failure determination of the first switch unit is performed in the same manner as in the first embodiment and the like. After the failure determination, the control device 100 supplies high-voltage power from the first battery 31 to the DCDC converter 70, the DCDC converter 70 steps down the high-voltage power, and supplies it to the low-voltage load 72.

[0238] Then, as Fig.39 shown in (e) of FIG., the control device 100 switches the third switch unit to off. At this time, a failure determination of the third switch unit is performed using the determination method described in the above embodiment or modification. After the failure determination, as Fig.39As shown in (f) thereof, the control device 100 turns on the first E switch SW1e. Then, the control device 100 controls the motor 10 and the inverter 20 to charge the neutral-point side smoothing capacitor C1. Specifically, the voltage between the terminals of the neutral-point side smoothing capacitor C1 is boosted to a voltage equivalent to the voltage between the terminals of the first series connection body 40 formed by the second battery 32 and the third battery 33 (212V).

[0239] After that, as shown in Fig.39 (g) thereof, the control device 100 turns on the first D switch SW1d and the second B switch SW2b. At this time, similarly to the modified example 17, a failure determination of the first D switch SW1d or the second B switch SW2b is performed.

[0240] After the failure determination, the control device 100, in the state shown in Fig.39 (h) thereof, boosts the applied voltage from the first series connection body 40 through the motor 10 and the inverter 20, and charges the inverter side smoothing capacitor 21. At this time, the boosting is performed so that the voltage between the terminals of the inverter side smoothing capacitor 21 becomes the voltage between the terminals of the second series connection body 50 (612V).

[0241] After that, as shown in Fig.40 (i) thereof, the control device 100 turns on the first C switch SW1c. At this time, a failure determination of the first C switch SW1c is performed by determining whether the detected value of any one of the first voltage sensor V1 and the current sensors A11 to A13 changes appropriately. Then, as shown in Fig.40 (j) thereof, the control device 100 turns off the first D switch SW1d to discharge the neutral-point side smoothing capacitor C1, and turns off the first E switch SW1e. As a result, the first battery 31 to the third battery 33 are connected in series with the high-voltage power line H1.

[0242] In addition, in this modified example, the first C switch SW1c and the second B switch SW2b correspond to the second switch unit. In addition, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e correspond to the neutral-point connection switch unit.

[0243] (Modified Example 19) · In the above-described embodiment, the second A switch SW2a may be deleted, and the switching order of the on / off states of each switch SW may be modified as shown in the following modified example 19. Refer to Figure 41 to Figure 42 , the switching order (modified example 19) from when the vehicle is stopped to when the vehicle starts is described. As a premise, when the vehicle is stopped, the on / off states of each switch SW are as shown in Fig.41 (a) thereof. That is, the third switch unit is turned on.

[0244] When the vehicle is parked and then starts, it transfers to Fig.41 the connection state shown in (b) of . That is, the control device 100 switches the pre-charge switch Pre_P and the first B switch SW1b to ON. Then, the control device 100 charges the inverter-side smoothing capacitor 21 so that the voltage between the terminals of the inverter-side smoothing capacitor 21 is equivalent to the voltage between the terminals of the first battery 31.

[0245] Then, after the charging is completed, it transfers to Fig.41 the connection states shown in (c) to (d) of . That is, the control device 100 switches the first A switch SW1a to ON, and then disconnects the pre-charge switch Pre_P. In addition, when switching the first switch unit to ON, the fault determination of the first switch unit is performed in the same manner as in the first embodiment and the like. After the fault determination, the control device 100 supplies high-voltage power from the first battery 31 to the DCDC converter 70, and the DCDC converter 70 steps down the high-voltage power and supplies it to the low-voltage load 72.

[0246] Then, as shown in (e) of Fig.42 the control device 100 switches the third switch unit to OFF. At this time, the fault determination of the third switch unit is performed using the determination method described in the above embodiment or modification. After the fault determination, as shown in (f) of Fig.42 the control device 100 switches the first E switch SW1e to ON. Then, the control device 100 controls the motor 10 and the inverter 20 to step down the applied voltage from the first battery 31 and charge the neutral-point side smoothing capacitor C1. Specifically, the voltage between the terminals of the neutral-point side smoothing capacitor C1 is boosted to a voltage equivalent to the voltage between the terminals of the first series connection body 40 (212V) composed of the second battery 32 and the third battery 33 for charging.

[0247] After that, as shown in (g) of Fig.42 the control device 100 switches the first D switch SW1d and the second B switch SW2b to ON. At this time, in the same manner as in Modification 17, the fault determination of the first D switch SW1d or the second B switch SW2b is performed.

[0248] After the fault determination, the control device 100 uses the motor 10 and the inverter 20 to boost the applied voltage from the first series connection body 40 to the same level as the voltage between the terminals of the first battery 31 and supply it to the high-voltage power line H1. Thus, the first battery 31 and the first series connection body 40 are connected in parallel to the high-voltage power line H1.

[0249] In addition, in this modification example, the first C switch SW1c and the second B switch SW2b correspond to the second switch section. In addition, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e correspond to the neutral point connection switch section.

[0250] (Modification Example 20) · In the above-described embodiment, the second A switch SW2a may also be deleted, and the switching order of the on / off states of each switch SW may be modified as shown in the following Modification Example 20. Refer to Figure 43 to Figure 44 , and the switching order (Modification Example 20) from during vehicle start to when the vehicle stops will be described. As a prerequisite, during vehicle start, the on / off states of each switch SW are as Fig.43 shown in (a). The first A switch SW1a, the second A switch SW2a, and the second B switch SW2b are turned on, and the batteries 31 to 33 are connected in series with the high-voltage power supply line H1.

[0251] During start, when the vehicle stops, as Fig.43 shown in (b), the control device 100 switches the first E switch SW1e to on, steps down the applied voltage through the inverter 20, and charges the neutral point side smoothing capacitor C1 so that the voltage between its terminals becomes 212V. After charging, the control device 100 turns on the first D switch SW1d, boosts the applied voltage from the first battery 31, and applies it to the inverter side smoothing capacitor 21.

[0252] After that, the control device 100 turns off the first C switch SW1c, steps down the voltage between the terminals of the inverter side smoothing capacitor 21 so that it becomes 400V, and then turns on the first B switch SW1b. At this time, a failure determination of the first B switch SW1b, the first C switch SW1c, and the first D switch SW1d may also be performed.

[0253] Next, as Fig.43 shown in (c), the control device 100 switches the first D switch SW1d and the second B switch SW2b to off. At this time, a failure determination of the first D switch SW1d and the second B switch SW2b may also be performed. Then, the control device 100 operates the inverter 20 to discharge the neutral point side smoothing capacitor C1, and then, as Fig.43 shown in (d), switches the first E switch SW1e to off.

[0254] Next, as Fig.44 shown in (e), the control device 100 turns on the third switch section. At this time, a failure determination of the third switch section is performed. In Fig.44In (f), the operation of the DCDC converter 70 is stopped, and the power supply from the DCDC converter 70 to the low-voltage load 72 is stopped.

[0255] Then, as shown in Fig.44 In (g), the control device 100 switches the first A switch SW1a and the first B switch SW1b to the off state. It is also possible to perform a failure determination on the first A switch SW1a and the first B switch SW1b. After that, the control device 100 operates the inverter 20 to discharge the inverter-side smoothing capacitor 21. Thus, as shown in Fig.44 In (h), the switching is completed, and the transition to the stop state is made.

[0256] In addition, in this modification, the first A switch SW1a and the first B switch SW1b correspond to the first switch unit. In addition, the first C switch SW1c, the first D switch SW1d, and the second B switch SW2b correspond to the second switch unit. In addition, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e correspond to the neutral-point connection switch unit.

[0257] (Modification 21) · In the above-described embodiment, the second A switch SW2a may be deleted, and the switching sequence of the on / off states of each switch SW may be modified as shown in the following Modification 21. Refer to Figure 45 to Figure 46 , the switching sequence (Modification 21) from when the vehicle is starting to when the vehicle stops will be described. As a premise, during vehicle startup, the on / off states of each switch SW are as shown in Fig.45 In (a). The first A switch SW1a, the first B switch SW1b, the first D switch SW1d, the first E switch SW1e, and the second B switch SW2b are on, and the first battery 31 and the first series connection body 40 are connected in parallel with the high-voltage power line H1.

[0258] During startup, when the vehicle stops, as shown in Fig.45 In (b), the control device 100 switches the first D switch SW1d and the second B switch SW2b to the off state. At this time, it is also possible to perform a failure determination on the first D switch SW1d and the second B switch SW2b. In this modification, the first C switch SW1c, the first D switch SW1d, and the second B switch SW2b correspond to the second switch unit.

[0259] The control device 100 discharges the neutral-point side smoothing capacitor C1 using the inverter 20 in the state shown in Fig.45 In (c). Then, as shown in Fig.45 In (d), the control device 100 switches the third switch unit to the on state. At this time, it is also possible to perform a failure determination on the third switch unit. Then, in Fig.46In the state shown in (e), the control device 100 stops the operation of the DCDC converter 70 and stops the power supply from the DCDC converter 70 to the low-voltage load 72.

[0260] Then, as Fig.46 shown in (f), the control device 100 switches the first A switch SW1a and the first B switch SW1b to the off state. In this modification, the first A switch SW1a and the first B switch SW1b correspond to the first switch unit. At this time, it is also possible to perform a failure determination on the first A switch SW1a and the first B switch SW1b.

[0261] After that, the control device 100 operates the inverter 20 to discharge the inverter-side smoothing capacitor 21. Thus, as Fig.46 shown in (g), the switching is completed. In addition, in this modification, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e correspond to the neutral point connection switch unit.

[0262] (Other modifications) · In the above-described embodiment or modification, the series connection body of the pre-charge switch and the resistor body may be respectively connected in parallel on both sides of the switch on the high-voltage power line side and the switch on the high-voltage ground line side. In addition, it is also possible to connect the series connection body of the pre-charge switch and the resistor body in parallel only at the switch on the high-voltage ground line side. In addition, it is also possible not to provide the series connection body of the pre-charge switch and the resistor body.

[0263] · In the above-described embodiment, instead of the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e, the first B switch SW1b may be used as the first Y switch that switches the energization and power-off between the positive terminal of the first battery 31 and the high-voltage power line H1. In this case, the second B electrical path 2B between the negative terminal of the first battery 31 and the high-voltage ground line L1 corresponds to the first Y electrical path.

[0264] · In the above-described embodiment, when the control device 100 cuts off the power supply between the first battery 31 and the high-voltage circuit 75 by disconnecting the first switch unit, the control device 100 may perform the on-off control of the second switch unit to perform the failure determination of the second switch unit.

[0265] · The power supply system 30 of the above-described first embodiment may also arbitrarily change its circuit structure as Figures 47 to 70 shown.

[0266] · In the above-described embodiments and modifications, the common path L10 is a common portion of the third A electrical path 3A and the second A electrical path 2A, but it may also be a common portion of the third B electrical path 3B and the second B electrical path 2B. Further, a third current sensor A13 may be disposed at this portion.

[0267] · In the above-described embodiments or modifications, each switch SW is not limited to being constituted by a single switch, and may be constituted by a series connection body of a plurality of switches or a parallel connection body of a plurality of switches.

[0268] · In the above-described embodiments or modifications, the switch of the inverter 20 is not limited to an IGBT, and for example, it may also be an N-channel MOSFET including a body diode.

[0269] · In the above-described embodiments or modifications, the motor is not limited to a star connection, and may also be a delta connection. Further, the motor and the inverter are not limited to a three-phase motor, and may also be a two-phase motor or a motor having four or more phases. Further, the motor is not limited to a permanent magnet type synchronous machine having a permanent magnet as an excitation pole in the rotor, and may also be a wound field type synchronous machine having an excitation winding as an excitation pole in the rotor. In this case, both an excitation winding and a permanent magnet may be provided in the rotor. Further, the motor is not limited to a synchronous machine, and may also be an induction machine.

[0270] · In the above-described embodiments or modifications, the power storage unit is not limited to a storage battery, and for example, it may also include a large-capacity electric double layer capacitor, or both a storage battery and an electric double layer capacitor.

[0271] · In the above-described embodiments or modifications, the moving body equipped with the power supply system is not limited to a vehicle, and for example, it may also be an aircraft or a ship. Further, the installation location of the power conversion device is not limited to a moving body, and may also be a stationary device.

[0272] · In the above-described embodiment, the control device 100 changes the measurement range and resolution of the third current sensor A13 according to which of the second switch unit and the third switch unit is determined to have a fault. As a modification, the control device 100 may also change the measurement range and resolution of the third current sensor A13 according to the on / off state of each switch SW. For example, when the first switch unit and the second switch unit are on, the third switch unit is off, and the power supply system 30 is connected to the high-voltage circuit 75, the measurement range of the third current sensor A13 may be expanded, and the resolution may be increased. Further, for example, when the second switch unit is off, the third switch unit is on, and the power supply system 30 is connected to the low-voltage circuit 76, the measurement range of the third current sensor A13 may be reduced, and the resolution may be decreased.

[0273] ·When performing fault determination in the above-described embodiments, the switching order of each switch SW can also be arbitrarily changed. For example, when performing fault determination on the third switch unit, it is also possible to turn on (or off) in the order of the third A switch SW3a → the third B switch SW3b at a certain time to perform fault determination, and turn on (or off) in the order of the third B switch SW3b → the third A switch SW3a at a different time to perform fault determination. The same applies to the case of determining the second switch unit. Thus, even if any one of the third A switch SW3a and the third B switch SW3b fails, it is possible to detect it.

[0274] ·The control unit and its method described in the present disclosure can also be implemented by a dedicated computer provided by configuring a processor and a memory, and the above processor is programmed to execute one or more functions embodied by a computer program. Alternatively, the control unit described in the present disclosure and the method of this control unit can be implemented by a dedicated computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit described in the present disclosure and the method of this control unit can be implemented by one or more dedicated computers, and the dedicated computer is composed of a combination of a processor programmed to execute one or more functions and a memory and a processor composed of one or more hardware logic circuits. In addition, the computer program can also be stored in a computer-readable non-transitory tangible recording medium as instructions executed by a computer.

[0275] Hereinafter, characteristic structures extracted from the above-described embodiments are described. [Structure 1] A power supply system, the power supply system (30) is connected to a high-voltage circuit (75) and a low-voltage circuit (76), and has a plurality of power storage units (31 to 32), The power supply system includes: A first switch unit that switches the energization and power-off between the first power storage unit among the plurality of power storage units and the high-voltage circuit; A second switch unit that switches the energization and power-off between the first power storage unit and the second power storage unit among the plurality of power storage units; and A third switch unit that switches the energization and power-off between the second power storage unit and the low-voltage circuit; A switch control unit (100) that controls the first switch unit, the second switch unit, and the third switch unit; and A fault determination unit (100) that performs fault determination on the first switch unit, the second switch unit, and the third switch unit, When the above-mentioned failure determination unit cuts off the power supply between the first power storage unit and the second power storage unit by disconnecting the second switch unit, it performs at least one of the failure determination of the first switch unit by switching the on / off state of the first switch unit through the switch control unit and the failure determination of the third switch unit by switching the on / off state of the third switch unit through the switch control unit. [Structure 2] A power supply system as described in Structure 1, wherein, When the above-mentioned failure determination unit cuts off the power supply between the first power storage unit and the high-voltage circuit by disconnecting the first switch unit, or cuts off the power supply between the second power storage unit and the low-voltage circuit by disconnecting the third switch unit, it switches the on / off state of the second switch unit through the switch control unit to perform the failure determination of the second switch unit. [Structure 3] A power supply system, the power supply system (30) is connected to a high-voltage circuit (75) and a low-voltage circuit (76), and has a plurality of power storage units (31-32), The above-mentioned power supply system includes: A first switch unit that switches the power supply and power cut-off between the first power storage unit among the plurality of power storage units and the high-voltage circuit; A second switch unit that switches the power supply and power cut-off between the first power storage unit and the second power storage unit among the plurality of power storage units; A third switch unit that switches the power supply and power cut-off between the second power storage unit and the low-voltage circuit; A switch control unit (100) that controls the first switch unit, the second switch unit, and the third switch unit; and A failure determination unit (100) that performs failure determination of the first switch unit, the second switch unit, and the third switch unit, When the above-mentioned failure determination unit cuts off the power supply between the first power storage unit and the high-voltage circuit by disconnecting the first switch unit, or cuts off the power supply between the second power storage unit and the low-voltage circuit by disconnecting the third switch unit, it switches the on / off state of the second switch unit through the switch control unit to perform the failure determination of the second switch unit. [Structure 4] A power supply system as described in any one of Structures 1 to 3, wherein, The above-mentioned high-voltage circuit includes a voltage converter (70), and the voltage converter can step down the input voltage and supply power to the low-voltage circuit. It includes a voltage control unit (100). When the first switch unit is turned on to energize between the first power storage unit and the high-voltage circuit, the voltage control unit steps down the input voltage applied to the voltage converter and supplies it from the voltage converter to the low-voltage circuit side. When the power connection between the first power storage unit and the second power storage unit is cut off by turning off the second switch unit, and when power is supplied from the second power storage unit to the low-voltage circuit side by turning on the third switch unit, the failure determination unit determines the failure of the first switch unit by switching the on / off state of the first switch unit through the switch control unit. Alternatively, when the power connection between the first power storage unit and the second power storage unit is cut off by turning off the second switch unit, and when power is supplied to the low-voltage circuit side via the voltage converter, the failure determination unit determines the failure of the third switch unit by switching the on / off state of the third switch unit through the switch control unit. [Structure 5] The power supply system according to any one of Structures 1 to 4, wherein The power supply system is connected to the high-voltage circuit via a high-voltage power line (H1) and a high-voltage ground line (L1), and is connected to the low-voltage circuit via a low-voltage power line (H2) and a low-voltage ground line (L2). The second switch unit includes: A second X switch that switches the energization and power cut-off of a second X electrical path provided between the second power storage unit and the first power storage unit; and A second Y switch that switches the energization and power cut-off of a second Y electrical path provided between the terminal on the opposite side of the second X electrical path among the two terminals of the second power storage unit and the high-voltage power line or the high-voltage ground line. The third switch unit includes: A third X switch that switches the energization and power cut-off of a third X electrical path provided between the positive terminal of the second power storage unit and the low-voltage power line; and A third Y switch that switches the energization and power cut-off of a third Y electrical path provided between the negative terminal of the second power storage unit and the low-voltage ground line. At least a part of the third X electrical path is shared with at least a part of the second X electrical path and the second Y electrical path, or at least a part of the third Y electrical path is shared with at least a part of the second X electrical path and the second Y electrical path. A common current sensor (A13) is provided in the common path (L10) of the sharing. The above-mentioned fault determination unit performs fault determination of the second switch unit based on the measurement result of the common current sensor when switching the on / off state of the second switch unit, and performs fault determination of the third switch unit based on the measurement result of the common current sensor when switching the on / off state of the third switch unit. [Structure 6] The power supply system as described in Structure 5, wherein The measurement range of the above-mentioned common current sensor is configured to be changeable, and the resolution of the above-mentioned common current sensor is configured to change with the change of the above-mentioned measurement range. The above-mentioned fault determination unit changes the measurement range of the above-mentioned common current sensor according to which of the second switch unit and the third switch unit is to be subjected to fault determination. [Structure 7] The power supply system as described in any one of Structures 1 to 6, wherein The above-mentioned power supply system is connected to the above-mentioned high-voltage circuit via a high-voltage power line (H1) and a high-voltage ground line (L1), and is connected to the above-mentioned low-voltage circuit via a low-voltage power line (H2) and a low-voltage ground line (L2). The above-mentioned third switch unit includes: A third X switch that switches the energization and power-off of a third X electrical path provided between the positive terminal of the second energy storage unit and the above-mentioned low-voltage power line; and A third Y switch that switches the energization and power-off of a third Y electrical path provided between the negative terminal of the second energy storage unit and the above-mentioned low-voltage ground line. It includes a third voltage sensor (V13) that measures voltage. One end of the above-mentioned third voltage sensor is connected to the positive terminal of the second energy storage unit, and the other end is connected to a portion of the above-mentioned third Y electrical path closer to the above-mentioned low-voltage ground line than the above-mentioned third Y switch, or one end of the above-mentioned third voltage sensor is connected to the negative terminal of the second energy storage unit, and the other end is connected to a portion of the above-mentioned third X electrical path closer to the above-mentioned low-voltage power line than the above-mentioned third X switch. The above-mentioned fault determination unit performs fault determination of the above-mentioned third X switch and the above-mentioned third Y switch based on the measurement result of the above-mentioned third voltage sensor. [Structure 8] The power supply system as described in Structure 7, wherein The above high-voltage circuit includes a voltage converter (70), and the voltage converter can step down the input voltage and supply power to the above low-voltage circuit. It includes a voltage control unit. When the first switching unit is turned on and the first power storage unit is energized with the high-voltage circuit, the voltage control unit steps down the input voltage input to the voltage converter and supplies it from the voltage converter to the low-voltage circuit side. The voltage control unit sets the voltage of the power supplied to the low-voltage circuit side to be higher than the voltage between the terminals of the second power storage unit. One end of the third voltage sensor is connected to the positive terminal of the second power storage unit, and the other end is connected to a portion on the side closer to the low-voltage ground wire than the third Y switch in the third Y circuit path. When the second switching unit is turned off and power is supplied to the low-voltage circuit side via the voltage converter, the failure determination unit performs failure determination of the third X switch based on the measurement result of the third voltage sensor when the third X switch is switched to off in a state where the third Y switch is turned on. After that, based on the measurement result of the third voltage sensor when the third X switch and the third Y switch are switched to off, the failure determination unit performs failure determination of the third Y switch. [Structure 9] The power supply system according to any one of Structures 1 to 8, wherein it includes a second voltage sensor, and the second voltage sensor monitors the voltage between the terminals of the second power storage unit. The failure determination unit performs failure determination of the third switching unit based on the measurement result of the second voltage sensor. [Structure 10] The power supply system according to any one of Structures 1 to 9, wherein the power supply system is connected to the high-voltage circuit via a high-voltage power line (H1) and a high-voltage ground wire (L1), and is connected to the low-voltage circuit via a low-voltage power line (H2) and a low-voltage ground wire (L2). The second switching unit includes: a second X switch that switches the energization and power-off of a second X electrical path provided between the second power storage unit and the first power storage unit; and a second Y switch that switches the energization and power-off of a second Y electrical path provided between the terminal on the side opposite to the second X electrical path among the two terminals of the second power storage unit and the high-voltage power line or the high-voltage ground wire. including a fourth voltage sensor (V14) that measures a voltage, One end of the fourth voltage sensor is connected to the terminal on the second X electrical path side of the second power storage unit, and the other end is connected to the side opposite to the second power storage unit side among both ends of the second Y switch in the second Y electrical path. The failure determination unit uses the measurement result of the fourth voltage sensor to perform failure determination on the second X switch and the second Y switch. [Structure 11] The power supply system as described in Structure 10, wherein The power supply system is connected to an inverter (20) via the high-voltage power line and the high-voltage ground line, and the inverter is connected to a motor (10). When the second switch unit is off, the failure determination unit steps up or steps down the voltage input to the motor and the inverter through the motor and the inverter, then turns on the second X switch, and performs failure determination on the second X switch according to the detection value of the fourth voltage sensor at the time of this switching. After that, the second X switch and the second Y switch are turned on, and failure determination on the second Y switch is performed according to the detection value of the fourth voltage sensor at the time of this switching. [Structure 12] A program implemented by a control device (10) of a power supply system. The power supply system (30) is connected to a high-voltage circuit (75) and a low-voltage circuit (76), and includes: Multiple power storage units (31 - 32); A first switch unit that switches the energization and power-off between a first power storage unit among the multiple power storage units and the high-voltage circuit; A second switch unit that switches the energization and power-off between the first power storage unit and a second power storage unit among the multiple power storage units; and A third switch unit that switches the energization and power-off between the second power storage unit and the low-voltage circuit. The program has a switch control process and a failure determination process. The switch control process controls the first switch unit, the second switch unit, and the third switch unit. The failure determination process performs failure determination on the first switch unit, the second switch unit, and the third switch unit. In the above-described failure determination process, when the energization between the first power storage unit and the second power storage unit is cut off by disconnecting the second switch unit, at least one of the failure determination of the first switch unit by switching the on / off state of the first switch unit and the failure determination of the third switch unit by switching the on / off state of the third switch unit is performed. [Structure 13] A program, which is executed by a control device (10) of a power supply system, The power supply system (30) is connected to a high-voltage circuit (75) and a low-voltage circuit (76), and includes: A plurality of power storage units (31 to 32); A first switch unit, which switches the energization and power cut-off between a first power storage unit among the plurality of power storage units and the high-voltage circuit; A second switch unit, which switches the energization and power cut-off between the first power storage unit and the second power storage unit among the plurality of power storage units; and A third switch unit, which switches the energization and power cut-off between the second power storage unit and the low-voltage circuit, The program has a switch control process and a failure determination process, The switch control process controls the first switch unit, the second switch unit, and the third switch unit, The failure determination process performs failure determination of the first switch unit, the second switch unit, and the third switch unit, In the above-described failure determination process, when the energization between the first power storage unit and the high-voltage circuit is cut off by disconnecting the first switch unit, or when the energization between the second power storage unit and the low-voltage circuit is cut off by disconnecting the third switch unit, the on / off state of the second switch unit is switched to perform the failure determination of the second switch unit.

[0276] Although the present disclosure has been described based on the 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 modified examples and modifications within the equivalent range. In addition, various combinations and modes, and further other combinations and modes including only one element, more than one element, or less than one element thereof also belong to the scope and ideological range of the present disclosure.

Claims

1. A power supply system, the power supply system (30) is connected to a high-voltage circuit (75) and a low-voltage circuit (76), and has a plurality of power storage units (31-32). The power supply system includes: A first switch unit that switches the energization and power-off between a first power storage unit among the plurality of power storage units and the high-voltage circuit; A second switch unit that switches the energization and power-off between the first power storage unit and a second power storage unit among the plurality of power storage units; A third switch unit that switches the energization and power-off between the second power storage unit and the low-voltage circuit; A switch control unit (100) that controls the first switch unit, the second switch unit, and the third switch unit; And A failure determination unit (100) that performs failure determination of the first switch unit, the second switch unit, and the third switch unit. When the energization between the first power storage unit and the second power storage unit is cut off by disconnecting the second switch unit, the failure determination unit performs at least one of the failure determination of the first switch unit by switching the on / off state of the first switch unit by the switch control unit and the failure determination of the third switch unit by switching the on / off state of the third switch unit by the switch control unit.

2. The power supply system according to claim 1, wherein When the energization between the first power storage unit and the high-voltage circuit is cut off by disconnecting the first switch unit, or when the energization between the second power storage unit and the low-voltage circuit is cut off by disconnecting the third switch unit, the failure determination unit performs the failure determination of the second switch unit by switching the on / off state of the second switch unit by the switch control unit.

3. A power supply system, the power supply system (30) is connected to a high-voltage circuit (75) and a low-voltage circuit (76), and has a plurality of power storage units (31-32). The power supply system includes: A first switch unit that switches the energization and power-off between a first power storage unit among the plurality of power storage units and the high-voltage circuit; A second switch unit that switches the energization and power-off between the first power storage unit and a second power storage unit among the plurality of power storage units; A third switch unit that switches the energization and power-off between the second power storage unit and the low-voltage circuit; A switch control unit (100) that controls the first switch unit, the second switch unit, and the third switch unit; And A failure determination unit (100) that performs failure determination of the first switch unit, the second switch unit, and the third switch unit. When the energization between the first power storage unit and the high-voltage circuit is cut off by disconnecting the first switching unit, or when the energization between the second power storage unit and the low-voltage circuit is cut off by disconnecting the third switching unit, the failure determination unit determines the failure of the second switching unit by switching the on / off state of the second switching unit through the switch control unit.

4. The power supply system according to any one of claims 1 to 3, characterized in that the high-voltage circuit includes a voltage converter (70) that can step down the input voltage and supply power to the low-voltage circuit, and includes a voltage control unit (100) that steps down the input voltage to the voltage converter and supplies it to the low-voltage circuit side from the voltage converter when the first switching unit is turned on and the energization between the first power storage unit and the high-voltage circuit is turned on, when the energization between the first power storage unit and the second power storage unit is cut off by disconnecting the second switching unit and power is supplied from the second power storage unit to the low-voltage circuit side by turning on the third switching unit, the failure determination unit determines the failure of the first switching unit by switching the on / off state of the first switching unit through the switch control unit, or when the energization between the first power storage unit and the second power storage unit is cut off by disconnecting the second switching unit and power is supplied to the low-voltage circuit side via the voltage converter, the failure determination unit determines the failure of the third switching unit by switching the on / off state of the third switching unit through the switch control unit.

5. The power supply system according to any one of claims 1 to 3, characterized in that the power supply system is connected to the high-voltage circuit via a high-voltage power line (H1) and a high-voltage ground line (L1), and is connected to the low-voltage circuit via a low-voltage power line (H2) and a low-voltage ground line (L2), the second switching unit includes: a second X switch that switches the energization and power cut-off of a second X electrical path provided between the second power storage unit and the first power storage unit; and a second Y switch that switches the energization and power cut-off of a second Y electrical path provided between the terminal on the opposite side of the two terminals of the second power storage unit from the second X electrical path and the high-voltage power line or the high-voltage ground line, the third switching unit includes: a third X switch that switches the energization and power cut-off of a third X electrical path provided between the positive terminal of the second power storage unit and the low-voltage power line; and a third Y switch that switches the energization and power cut-off of a third Y electrical path provided between the negative terminal of the second power storage unit and the low-voltage ground line, At least a part of the third X electrical path is shared with at least a part of the second X electrical path and the second Y electrical path, or at least a part of the third Y electrical path is shared with at least a part of the second X electrical path and the second Y electrical path. A shared current sensor (A13) is provided in the shared path (L10) of this sharing. Based on the measurement result of the shared current sensor when switching the on / off state of the second switch unit, the failure determination unit performs failure determination of the second switch unit, and based on the measurement result of the shared current sensor when switching the on / off state of the third switch unit, performs failure determination of the third switch unit.

6. The power supply system according to claim 5, wherein The measurement range of the shared current sensor is configured to be changeable, and the resolution of the shared current sensor is configured to change with the change of the measurement range. The failure determination unit changes the measurement range of the shared current sensor according to which one of the second switch unit and the third switch unit is to be subjected to failure determination.

7. The power supply system according to any one of claims 1 to 3, wherein The power supply system is connected to the high-voltage circuit via a high-voltage power line (H1) and a high-voltage ground line (L1), and is connected to the low-voltage circuit via a low-voltage power line (H2) and a low-voltage ground line (L2). The third switch unit includes: A third X switch that switches the energization and power-off of a third X electrical path provided between the positive terminal of the second energy storage unit and the low-voltage power line; and A third Y switch that switches the energization and power-off of a third Y electrical path provided between the negative terminal of the second energy storage unit and the low-voltage ground line. It includes a third voltage sensor (V13) that measures voltage. One end of the third voltage sensor is connected to the positive terminal of the second energy storage unit, and the other end is connected to a portion on the side closer to the low-voltage ground line than the third Y switch in the third Y electrical path, or one end of the third voltage sensor is connected to the negative terminal of the second energy storage unit, and the other end is connected to a portion on the side closer to the low-voltage power line than the third X switch in the third X electrical path. The failure determination unit performs failure determination of the third X switch and the third Y switch based on the measurement result of the third voltage sensor.

8. The power supply system according to claim 7, wherein The high-voltage circuit includes a voltage converter (70) that can step down the input voltage and supply power to the low-voltage circuit. It includes a voltage control unit that, when the first switch unit is turned on to energize between the first energy storage unit and the high-voltage circuit, steps down the input voltage input to the voltage converter and supplies it to the low-voltage circuit side. The voltage control unit sets the voltage of the power supplied to the low-voltage circuit side to be higher than the inter-terminal voltage of the second power storage unit. One end of the third voltage sensor is connected to the positive terminal of the second power storage unit, and the other end is connected to a portion of the third Y circuit path closer to the low-voltage ground wire side than the third Y switch. When the second switch unit is disconnected and power is supplied to the low-voltage circuit side via the voltage converter, the failure determination unit performs a failure determination of the third X switch based on the measurement result of the third voltage sensor when the third X switch is switched to the off state with the third Y switch turned on. Then, based on the measurement result of the third voltage sensor when the third X switch and the third Y switch are switched to the off state, the failure determination unit performs a failure determination of the third Y switch.

9. The power supply system according to any one of claims 1 to 3, characterized in that it includes a second voltage sensor that monitors the inter-terminal voltage of the second power storage unit. The failure determination unit performs a failure determination of the third switch unit based on the measurement result of the second voltage sensor.

10. The power supply system according to any one of claims 1 to 3, characterized in that the power supply system is connected to the high-voltage circuit via a high-voltage power line (H1) and a high-voltage ground wire (L1), and is connected to the low-voltage circuit via a low-voltage power line (H2) and a low-voltage ground wire (L2). The second switch unit includes: a second X switch that switches the energization and de-energization of a second X electrical path provided between the second power storage unit and the first power storage unit; and a second Y switch that switches the energization and de-energization of a second Y electrical path provided between the terminals on the side opposite to the second X electrical path among the two terminals of the second power storage unit and the high-voltage power line or the high-voltage ground wire. It includes a fourth voltage sensor (V14) that measures the voltage. One end of the fourth voltage sensor is connected to the terminal on the second X electrical path side of the second power storage unit, and the other end is connected to the side opposite to the second power storage unit side among the two ends of the second Y switch in the second Y electrical path. The failure determination unit uses the measurement result of the fourth voltage sensor to perform a failure determination of the second X switch and the second Y switch.

11. The power supply system according to claim 10, characterized in that the power supply system is connected to an inverter (20) via the high-voltage power line and the high-voltage ground wire, and the inverter is connected to a motor (10). When the second switch unit is turned off, the failure determination unit steps up or steps down the voltage input to the motor and the inverter through the motor and the inverter, and then turns on the second X switch. Based on the detection value of the fourth voltage sensor at the time of this switching, a failure determination of the second X switch is performed. After that, the second X switch and the second Y switch are turned on, and based on the detection value of the fourth voltage sensor at the time of this switching, a failure determination of the second Y switch is performed.

12. A program, which is executed by a control device (100) of a power supply system, The power supply system (30) is connected to a high-voltage circuit (75) and a low-voltage circuit (76), and includes: A plurality of power storage units (31 to 32); A first switch unit that switches the energization and power cut-off between a first power storage unit among the plurality of power storage units and the high-voltage circuit; A second switch unit that switches the energization and power cut-off between the first power storage unit and a second power storage unit among the plurality of power storage units; A third switch unit that switches the energization and power cut-off between the second power storage unit and the low-voltage circuit, The program has a switch control process and a failure determination process, The switch control process controls the first switch unit, the second switch unit, and the third switch unit, The failure determination process performs failure determination of the first switch unit, the second switch unit, and the third switch unit, In the failure determination process, when the energization between the first power storage unit and the second power storage unit is cut off by turning off the second switch unit, at least one of the failure determination of the first switch unit by switching the on / off state of the first switch unit and the failure determination of the third switch unit by switching the on / off state of the third switch unit is performed.

13. A program, which is executed by a control device (100) of a power supply system, The power supply system (30) is connected to a high-voltage circuit (75) and a low-voltage circuit (76), and includes: A plurality of power storage units (31 to 32); A first switch unit that switches the energization and power cut-off between a first power storage unit among the plurality of power storage units and the high-voltage circuit; A second switch unit that switches the energization and power cut-off between the first power storage unit and a second power storage unit among the plurality of power storage units; and A third switch unit that switches the energization and power cut-off between the second power storage unit and the low-voltage circuit, The program has a switch control process and a failure determination process, The switch control process controls the first switch unit, the second switch unit, and the third switch unit, The failure determination process performs failure determination of the first switch unit, the second switch unit, and the third switch unit, In the failure determination process, when the power supply between the first power storage unit and the high-voltage circuit is cut off by disconnecting the first switch unit, or when the power supply between the second power storage unit and the low-voltage circuit is cut off by disconnecting the third switch unit, the on / off state of the second switch unit is switched to determine the failure of the second switch unit.

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