Power supply system and program

Abstract

In a power supply system (30), at least a part of a third X electrical path is shared with at least a part of a second X electrical path and a second Y electrical path, and a shared current sensor (A13) is provided in the shared shared path (L10).

Description

Citation of Related Applications

[0001] This application is based on Japanese Patent Application No. 2022-197450 filed on December 9, 2022, and the content thereof is incorporated 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

[0005] 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, in order to perform failure determination, it is necessary to provide a plurality of current sensors, and there is room for improvement in the circuit configuration.

[0006] The main object of the present disclosure is to provide a power supply system and a program capable of reducing current sensors.

[0007] A power supply system according to a first aspect for solving the above technical problem is connected to a high-voltage circuit via a high-voltage power line and a high-voltage ground line, and is connected to a low-voltage circuit via a low-voltage power line and a low-voltage ground line, and includes 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; 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, The second switch unit includes: A second X switch that switches between 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 de-energization of a second Y electrical path between a 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 line. The third switch unit includes: A third X switch that switches the energization and de-energization of a third X electrical path 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 de-energization of a third Y electrical path 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 is provided in the shared path of the sharing.

[0008] Thereby, the number of current sensors can be reduced.

[0009] A program of the first mode 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 via a high-voltage power line and a high-voltage ground line, and is connected to a low-voltage circuit via a low-voltage power line and a low-voltage ground line, and includes a plurality of power storage units. The power supply system includes: A first switch unit that switches the energization and de-energization 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 de-energization 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 de-energization between the second power storage unit and the low-voltage circuit. The second switch unit includes: A second X switch that switches the energization and de-energization of a second X electrical path 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 between a 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 line. The above-mentioned third switch unit includes: A third X switch that switches the energization and de-energization 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 de-energization of a third Y electrical path provided between the negative terminal of the second power storage unit and the low-voltage ground line, The above-mentioned program performs switch control processing and fault determination processing, The above-mentioned switch control processing controls the above-mentioned first switch unit, the above-mentioned second switch unit, and the above-mentioned third switch unit, The above-mentioned fault determination processing performs fault determination on the above-mentioned first switch unit, the above-mentioned second switch unit, and the above-mentioned third switch unit, At least a part of the above-mentioned third X electrical path is shared with at least a part of the above-mentioned second X electrical path and the above-mentioned second Y electrical path, or at least a part of the above-mentioned third Y electrical path is shared with at least a part of the above-mentioned second X electrical path and the above-mentioned second Y electrical path, A shared current sensor is provided in the shared path of this sharing. In the above-mentioned fault determination processing, based on the measurement result of the above-mentioned shared current sensor when switching the on / off state of the above-mentioned second switch unit, fault determination of the above-mentioned second switch unit is performed, and based on the measurement result of the above-mentioned shared current sensor when switching the on / off state of the above-mentioned third switch unit, fault determination of the above-mentioned third switch unit is performed.

[0010] Thus, the number of current sensors can be reduced. Brief Description of the Drawings

[0011] With reference to the accompanying drawings and the following detailed description, the above-mentioned objects, other objects, features, and advantages of the present disclosure can be made more clear. The accompanying 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. Figure 9 It is a flowchart of the startup process. Figure 10 It is a diagram showing the relationship between the state of the third switch section in normal operation and the detected value. Figure 11 It is a diagram showing the relationship between the state of the second switch section in normal operation and the detected value. Figure 12 It is a flowchart of the stop process. Figure 13 It is a diagram showing the relationship between the state of the third switch section in Modification Example 1 and the detected value. Figure 14 It is a diagram showing the relationship between the state of the third switch section in Modification Example 2 and the detected value. Figure 15 It is a diagram showing the relationship between the state of the third switch section in Modification Example 3 and the detected value. Figure 16 It is a diagram showing the third voltage sensor in Modification Example 4. Figure 17 It is a diagram showing the relationship between the state of the third switch section in Modification Example 4 and the detected value. Figure 18 It is a diagram showing the relationship between the state of the third switch section in Modification Example 5 and the detected value. Figure 19 It is a diagram showing the relationship between the state of the second switch section in Modification Example 7 and the detected value. Figure 20 It is a diagram showing the fourth voltage sensor in Modification Example 8. Figure 21 It is a diagram showing the relationship between the state of the second switch section in Modification Example 8 and the detected value. Figure 22 It is a diagram showing the relationship between the state of the second switch section in Modification Example 9 and the detected value. Figure 23 It is a diagram showing the connection state of the power supply system in Modification Example 10. Figure 24 It is a diagram showing the connection state of the power supply system in Modification Example 11. Figure 25 It is a diagram showing the connection state of the power supply system in Modification Example 12. Figure 26 It is a diagram showing the connection state of the power supply system in Modification Example 13. Figure 27 It is a diagram showing the switching sequence of each switch in Modification Example 14. Figure 28It is a diagram showing the switching sequence of each switch in Modification 14. Figure 29 It is a diagram showing the switching sequence of each switch in Modification 15. Figure 30 It is a diagram showing the switching sequence of each switch in Modification 15. Figure 31 It is a diagram showing the switching sequence of each switch in Modification 16. Figure 32 It is a diagram showing the switching sequence of each switch in Modification 16. Figure 33 It is a diagram showing the switching sequence of each switch in Modification 17. Figure 34 It is a diagram showing the switching sequence of each switch in Modification 17. Figure 35 It is a diagram showing the switching sequence of each switch in Modification 17. Figure 36 It is a diagram showing the relationship between the state of the switch and the detected value in Modification 17. Figure 37 It is a diagram showing the relationship between the state of the switch and the detected value in Modification 17. Figure 38 It is a diagram showing the switching sequence of each switch in Modification 18. Figure 39 It is a diagram showing the switching sequence of each switch in Modification 18. Figure 40 It is a diagram showing the switching sequence of each switch in Modification 18. Figure 41 It is a diagram showing the switching sequence of each switch in Modification 19. Figure 42 It is a diagram showing the switching sequence of each switch in Modification 19. Figure 43 It is a diagram showing the switching sequence of each switch in Modification 20. Figure 44 It is a diagram showing the switching sequence of each switch in Modification 20. Figure 45 It is a diagram showing the switching sequence of each switch in Modification 21. Figure 46 It is a diagram showing the switching sequence of each switch in Modification 21. Figure 47 It is a diagram showing the connection state of the power supply system of the modification. Figure 48 It is a diagram showing the connection state of the power supply system of the modification. Figure 49It is a diagram showing the connection state of a power supply system of a modified example. Figure 50 It is a diagram showing the connection state of a power supply system of a modified example. Figure 51 It is a diagram showing the connection state of a power supply system of a modified example. Figure 52 It is a diagram showing the connection state of a power supply system of a modified example. Figure 53 It is a diagram showing the connection state of a power supply system of a modified example. Figure 54 It is a diagram showing the connection state of a power supply system of a modified example. Figure 55 It is a diagram showing the connection state of a power supply system of a modified example. Figure 56 It is a diagram showing the connection state of a power supply system of a modified example. Figure 57 It is a diagram showing the connection state of a power supply system of a modified example. Figure 58 It is a diagram showing the connection state of a power supply system of a modified example. Figure 59 It is a diagram showing the connection state of a power supply system of a modified example. Figure 60 It is a diagram showing the connection state of a power supply system of a modified example. Figure 61 It is a diagram showing the connection state of a power supply system of a modified example. Figure 62 It is a diagram showing the connection state of a power supply system of a modified example. Figure 63 It is a diagram showing the connection state of a power supply system of a modified example. Figure 64 It is a diagram showing the connection state of a power supply system of a modified example. Figure 65 It is a diagram showing the connection state of a power supply system of a modified example. Figure 66 It is a diagram showing the connection state of a power supply system of a modified example. Figure 67 It is a diagram showing the connection state of a power supply system of a modified example. Figure 68 It is a diagram showing the connection state of a power supply system of a modified example. Figure 69 It is a diagram showing the connection state of a power supply system of a modified example. Figure 70 It is a diagram showing the connection state of a power supply system of a modified example. Detailed implementation mode

[0012] With reference to the accompanying drawings, a plurality of embodiments and their modifications will be described. In the plurality of embodiments and their modifications, parts and / or related parts that are functionally and / or structurally corresponding may sometimes be marked with the same reference numerals or reference numerals that differ by more than one hundred digits. For corresponding parts and / or related parts, reference may be made to the descriptions of other embodiments.

[0013] (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.

[0014] 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).

[0015] The motor 10 has a plurality of armature windings. In this embodiment, the motor 10 is a three-phase synchronous machine and has 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 so as to be electrically angled 120° apart from each other. The 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 motor 10 is a source for generating torque for driving the vehicle.

[0016] The inverter 20 includes a series connection body of an upper-arm switch SWH and a lower-arm switch SWL corresponding to 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 this embodiment, each switch SWH, SWL is an IGBT.

[0017] 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. In addition, the inverter-side smoothing capacitor 21 may also be provided outside the inverter 20.

[0018] In each phase, the connection point between 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. In addition, in the present embodiment, the number of turns of the armature winding 11 of each phase is set to be the same. Thus, for example, the inductance of the armature winding 11 of each phase is set to be the same.

[0019] The collector of the upper-arm switch SWH of each phase is connected to the high-voltage power supply 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 motor 10 is connected to the high-voltage power supply line H1 via the inverter 20. In addition, either or both of the motor 10 and the inverter 20 may be included in the power supply system 30 or may not be included in the power supply system 30.

[0020] Various high-voltage loads 71 (not shown) are connected between the high-voltage power supply 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. In addition, the 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 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 supply line H1 and the high-voltage ground line L1.

[0021] Various low-voltage loads 72 are connected between the low-voltage power supply 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 such as an ECU. In addition, among the low-voltage loads 72, there are loads such as an ECU that require a dark current (standby current). 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 paths 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 supply line H2 and the low-voltage ground line L2.

[0022] 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 supply line H1 and the high-voltage ground line L1, can step down the voltage of the power input from the high-voltage power supply 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 supply line H2 via the power transmission line L3.

[0023] In addition, conversely, the DCDC converter 70 is configured to boost the voltage of the power input from the low-voltage power supply line H2 side through the power transmission line L3 and supply it to the high-voltage load 71 connected to the high-voltage power supply line H1. In addition, the DCDC converter 70 is controlled by the control device 100 described later. The DCDC converter 70 may 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.

[0024] Next, the power supply system 30 will be described. The power supply system 30 includes a first storage battery 31 (equivalent to the "first power storage unit"), a second storage battery 32 (equivalent to the "second power storage unit"), and a third storage battery 33 (equivalent to the "third power storage unit"). Each storage battery 31, 32, 33 serves as a power supply source for driving the rotation of the rotor of the motor 10. Each storage 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.

[0025] The first storage battery 31 has the highest output voltage among the storage batteries 31, 32, 33, for example, an output voltage of 400V. In addition, compared with the first storage battery 31, the output voltage of the second storage battery 32 is low, for example, an output voltage of 12V. The output voltage of the third storage battery 33 is arbitrary. In this embodiment, for example, it is 200V. In addition, the voltage between the terminals of each storage battery 31 to 33 can be arbitrarily changed.

[0026] The power supply system 30 includes a first A switch SW1a provided in the first A electrical path 1A connecting the positive terminal of the first storage battery 31 and the high-voltage power supply line H1. In this embodiment, the first A switch SW1a is used to switch 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 supply line H1.

[0027] In addition, a series connection body of a pre-charge switch Pre_P and a resistor R1 may be connected in parallel with the first A switch SW1a as in this embodiment. In addition, the first A switch SW1a is equivalent to the system main relay switch on the high-potential side.

[0028] The power supply system 30 includes a first B switch SW1b provided in the first B electrical path 1B connecting the negative terminal of the first storage battery 31 and the high-voltage ground line L1. In this embodiment, the first B switch SW1b is used to switch 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.

[0029] The power supply system 30 includes a first C switch SW1c disposed in a first C electrical path 1C that connects 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.

[0030] 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.

[0031] 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 that connects 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.

[0032] In addition, in the first D electrical path 1D, a first E switch SW1e is disposed on the neutral point side. Further, a neutral point side smoothing capacitor C1 (second smoothing capacitor) is disposed between the first D electrical path 1D and the high-voltage ground 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.

[0033] In addition, as Figure 1 shown, the armature winding 11 of the motor 10 is connected to the high-voltage ground 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 ground 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 a function of switching the energization and power-off between the negative terminal of the first storage battery 31 and the high-voltage ground wire L1.

[0034] The power supply system 30 includes a second A switch SW2a disposed 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 energization and interruption 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 are switched by the second A switch SW2a.

[0035] 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 interruption between the first battery 31 and the second battery 32 instead of the first C switch SW1c.

[0036] The power supply system 30 includes a second B switch SW2b disposed in a second B electrical path 2B connecting the negative terminal of the first series connection body 40 and the high-voltage ground wire L1. Through the second B switch SW2b, the energization and interruption in the second B electrical path 2B can be switched, that is, the energization and interruption between the negative terminal of the first series connection body 40 and the high-voltage ground wire L1, that is, the energization and interruption of the second B electrical path 2B. In addition, the second B switch SW2b is equivalent to the system main relay switch on the low-potential side.

[0037] The power supply system 30 includes a third A switch SW3a disposed 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.

[0038] 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 a 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, and is a part of the second A electrical path 2A and 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 represented as a shared path L10.

[0039] The power supply system 30 includes a third B switch SW3b disposed in a third B electrical path 3B connecting the negative terminal of the second battery 32 and the low-voltage ground wire L2. In the present embodiment, the third B switch SW3b is used to switch the energization and de-energization of the third B electrical path 3B between the negative terminal of the second battery 32 and the low-voltage ground wire L2.

[0040] 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 flow of bidirectional current when it is off and allows the flow of bidirectional current when it is on. In addition, each switch SW is not limited to a mechanical relay and may be, for example, a semiconductor switching element.

[0041] 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.

[0042] Here, the configuration of the third current sensor A13 will be described in detail. The third current sensor A13 is disposed in an electrical path, i.e., a common path L10, between the connection point P13 and the positive terminal of the second battery 32. 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.

[0043] 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 be wider 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 (e.g., 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 (e.g., several tens of A).

[0044] In addition, as the measurement range changes, the resolution of the third current sensor A13 also changes. Specifically, 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, enabling detection of smaller values with high precision.

[0045] In addition, a first voltage sensor V1 for measuring the voltage (potential difference) therebetween is included between the high-voltage power supply line H1 and the high-voltage ground line L1. 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. 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 supply line H2 and the low-voltage ground line L2 (second grounding member SG).

[0046] 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-temporary physical storage medium (non-transitory tangible storage medium) included in itself as a storage unit. The program contains, for example, the Figure 9 , Figure 12 and other 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 through a communication network such as the Internet by OTA (Over The Air).

[0047] Information (detection values) from various sensors is input to the control device 100. Various sensors include, for example, the aforementioned current sensors A11 to A13 and voltage sensors V1 to V3. Additionally, for example, among the 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, etc.

[0048] Based on information such as the detection values input from various sensors, the control device 100 performs various processes according to a program. 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 to feedback-control the control amount of the motor 10 to the 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 moves. Therefore, the control device 100 has a function as an inverter control unit.

[0049] In addition, as described above, the control device 100 performs processes related to voltage conversion by controlling the DCDC converter 70. Therefore, the control device 100 has a function as a voltage control unit.

[0050] Furthermore, the control device 100 is configured to be able to control the on / off states of the switches SW of 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 of the power supply system 30 in the present embodiment will be described.

[0051] First, with reference to Figures 2 to 8 , the switching of the on / off states when starting the vehicle from a parked state will be described. In Figures 2 to 8 , the flow of current is indicated by a single-dot chain line. Additionally, as a premise, when the vehicle is parked, the on / off states of the switches SW are as shown in Figure 2 . Here, when the vehicle is parked refers to, for example, when the ignition switch is off, the vehicle has been parked for a specified time or more, or the shift lever is in the parking position, etc.

[0052] As shown in Figure 2 , when the vehicle is parked, the control device 100 connects only a part of the storage batteries (the second storage battery 32) included in the power supply system 30 to the low-voltage power line H2 and the low-voltage ground line L2.

[0053] Specifically, as Figure 2 shown, the control device 100 disconnects 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 connects the third A switch SW3a and the third B switch SW3b. In Figure 2 this connection state, 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. In addition, as Figure 2 shown, 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.

[0054] When the vehicle is parked and when the vehicle starts, 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 this embodiment) to the high-voltage power line H1. Here, the moment when the vehicle starts 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 put into drive, etc. In addition, 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 when the vehicle starts.

[0055] Specifically, in order 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, charging is performed 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).

[0056] 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 disconnects the first B switch SW1b, the second A switch SW2a, and the second B switch SW2b, and connects 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, the second storage battery 32 is connected between the low-voltage power line H2 and the low-voltage ground line L2, and the first storage battery 31 is connected between the high-voltage power line H1 and the neutral point of the motor 10.

[0057] In addition, in Figure 3In the connection state shown, the high-voltage grounding wire L1 and the low-voltage grounding wire L2 are insulated from each other. Thus, high-voltage power is supplied from the first battery 31 to the high-voltage load 71 via the high-voltage power line H1, and low-voltage power is supplied from the second battery 32 to the low-voltage load 72 via the low-voltage power line H2. That is, the power conduction between the first battery 31 and the second battery 32 is cut off, and the high-voltage power of the first battery 31 is not supplied to the low-voltage load 72.

[0058] Next, as Figure 4 shown, the control device 100 operates the DCDC converter 70 to step down the input voltage input to the DCDC converter 70 and supply it to the low-voltage load 72 via the power transmission line L3.

[0059] After power is supplied from the DCDC converter 70 to the low-voltage circuit 76, as Figure 5 shown, the control device 100 maintains the power conduction between the first battery 31 and the high-voltage power line H1 and cuts off the power conduction between the second battery 32 and the low-voltage power line H2.

[0060] Specifically, as Figure 5 shown, the control device 100 disconnects 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 connects the first A switch SW1a, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e. In the Figure 5 connection state, the first battery 31 is connected between the high-voltage power line H1 and the neutral point of the motor 10. On the other hand, the power conduction between the low-voltage power line H2 and the positive terminal of the second battery 32 and between the low-voltage grounding wire 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.

[0061] After the power conduction between the second battery 32 and the low-voltage circuit 76 is cut off, the control device 100 operates the motor 10 and the inverter 20 as a boost converter (boost chopper) to boost the applied voltage from the first battery 31 and charge 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.

[0062] At this time, the voltage between the terminals of the smoothing capacitor 21 on the inverter side 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.

[0063] 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 line H1. Specifically, as Figure 6 shown, the control device 100 disconnects 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.

[0064] In Figure 6 this connection state, the first battery 31, the third battery 33, and the second battery 32 are connected in series between the high-voltage power line H1 and the high-voltage ground line L1. That is, electric power with a high voltage (400V + 200V + 12V) is supplied from the second series connection body 50 of the first battery 31, the third battery 33, and the second battery 32 to the high-voltage load 71 of the high-voltage circuit 75 via the high-voltage power line H1. Thus, high-voltage electric power is supplied to the motor 10 or the high-voltage load 71, and the vehicle can be appropriately driven.

[0065] 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 smoothing capacitor 21 on the inverter side 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 switching to Figure 6 this connection state, it is possible to prevent the current flow from becoming unstable due to the voltage difference.

[0066] 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.

[0067] 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 a first switch unit that switches the energization and de-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.

[0068] In addition, in the first embodiment, the second A switch SW2a and the second B switch SW2b correspond to a second switch unit that switches the energization and de-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.

[0069] 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 de-energization 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.

[0070] In addition, in the first embodiment, the first A switch SW1a corresponds to a first X switch that switches the energization and de-energization between the positive terminal of the first storage battery 31 and the high-voltage power supply line H1, and the first A electrical path 1A connecting the positive terminal of the first storage battery 31 and the high-voltage power supply line H1 corresponds to the first X electrical path.

[0071] 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 de-energization 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.

[0072] In addition, in the first embodiment, the second A switch SW2a corresponds to a second X switch that switches the energization and de-energization 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.

[0073] In addition, in the first embodiment, the second B switch SW2b is equivalent to a second Y switch that switches the energization and de-energization between the terminal (negative terminal) on the side opposite to the second A switch SW2a among the two ends of the second battery 32 and the high-voltage ground wire 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 battery 32 and the high-voltage ground wire L1 is equivalent to the second Y electrical path.

[0074] In addition, in the first embodiment, the third A switch SW3a is equivalent to a third X switch that switches the energization and de-energization between the positive terminal of the second battery 32 and the low-voltage power supply line H2, and the third A electrical path 3A connecting the positive terminal of the second battery 32 and the low-voltage power supply line H2 is equivalent to the third X electrical path.

[0075] In addition, in the first embodiment, the third B switch SW3b is equivalent to a third Y switch that switches the energization and de-energization between the negative terminal of the second battery 32 and the low-voltage ground wire L2, and the electrical path between the negative terminal of the second battery 32 and the low-voltage ground wire L2 is equivalent to the third Y electrical path.

[0076] In addition, 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 are equivalent to a neutral point connection switch unit that switches the energization and de-energization between the neutral point of the motor 10 and one or both of the first battery 31 and the second battery 32.

[0077] 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 opposite of the transition of the on-off state from when the vehicle stops to when it starts. Therefore, the following is a simplified description.

[0078] During vehicle start-up, the connection state becomes as described above Figure 8 . That is, in the control device 100, the first battery 31, the third battery 33, and the second battery 32 are connected in series between the high-voltage power supply line H1 and the high-voltage ground wire 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.

[0079] During start-up, when the vehicle stops, the control device 100 first operates as Figure 7As shown, the first E switch SW1e is switched from OFF to ON. 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 put into the parking position, etc.

[0080] After switching the first E switch SW1e to ON, the motor 10 and the inverter 20 are operated to charge the inverter-side smoothing capacitor 21. Then, the control device 100 charges 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 series-connected body 40 (for example, 212V).

[0081] After the charging is completed, as Figure 6 shown, the control device 100 switches the first D switch SW1d from OFF to ON. After that, as Figure 5 shown, the control device 100 switches the second A switch SW2a and the second B switch SW2b from ON to OFF, and maintains the power supply between the first battery 31 and the high-voltage power line H1, and cuts off the power supply 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.

[0082] After the power supply 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 (the voltage is reduced) to a voltage equivalent to the voltage between the terminals of the first battery 31 (400V).

[0083] 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, the discharge is performed until the voltage between the terminals of the neutral-point side smoothing capacitor C1 becomes zero.

[0084] 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. As a result, 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. Thus, low-voltage power can be supplied from the second battery 32 to the low-voltage load 72 (low-voltage circuit 76).

[0085] After that, 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. Thus, low-voltage power is supplied from the second battery 32 to the low-voltage load 72. Then, as Figure 2As 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 inter-terminal voltage zero.

[0086] Thereby, as Figure 2 shown, only the second battery 32 is connected to the low-voltage power supply 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.

[0087] 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.

[0088] 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 performed at the time of vehicle start and vehicle stop will be described in detail. First, the start-up process will be described.

[0089] Figure 9 is a flowchart of the start-up process that the control device 100 performs at a regular interval during vehicle stop. 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 off, and the third switch unit is on. That is, only the second battery 32 is connected to the low-voltage power supply line H2.

[0090] The control device 100 determines whether the vehicle has started during vehicle parking (step S101). If the determination result is affirmative, as Figure 3As shown, the control device 100 connects the second storage battery 32 to the low-voltage power supply line H2 and connects the first storage battery 31 to the high-voltage power supply line H1 (step S102). That is, as described above, the control device 100 switches the first switch unit to on in a state where the third switch unit is on and the second switch unit is off. Thereby, in a state where the second storage battery 32 is connected to the low-voltage circuit 76, the first storage battery 31 is connected to the high-voltage circuit 75.

[0091] In addition, since the second switch unit (second A switch SW2a and second B switch SW2b) is off, the power supply between the first storage battery 31 and the second storage 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.

[0092] In addition, in the above step S102, when switching the first switch unit to on, 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 failure 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 the current flows 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 the failure determination of the first switch unit.

[0093] 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) although the first switch unit is not switched to on (although it is off), that is, when an abnormal current is measured in the first A electrical path 1A, the control device 100 determines that there is a failure in the first switch unit. In addition, for example, when the detection value of the first current sensor A11 is not a value above the threshold even if the first switch unit is switched to on, that is, when the current does not flow through the first A electrical path 1A, the control device 100 determines that there is a failure 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 on, the control device 100 determines that the first switch unit is normal (not faulty).

[0094] When the result of the failure determination in step S103 by the control device 100 determines that there is a failure in the first switch unit (step S103: Yes), the process for coping with the abnormality of the power supply system 30 is implemented (step S104). In step S104, for example, the process of notifying a message that there is an abnormality in the power supply system 30 and a message that proper startup is not possible is implemented. In addition, the process related to fail-safe such as switching all the switches SW to the off state to ensure safety is implemented. After that, the control device 100 ends (interrupts) the startup process.

[0095] On the other hand, when the control device 100 determines that there is no failure in the first switch unit (step S103: No), it operates the inverter 20 and the like, supplies power from the first storage battery 31 to the high-voltage circuit 75, and charges the inverter-side smoothing capacitor 21 until the inter-terminal voltage becomes 400V (step S105).

[0096] After the charging of the inverter-side smoothing capacitor 21 is completed, 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 (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 to a voltage slightly higher than the inter-terminal voltage (12V) of the second storage battery 32, for example, 14V. Thus, when power is supplied from the DCDC converter 70 to the low-voltage circuit 76, the current flows toward the second storage battery 32 side, and the second storage battery 32 is charged.

[0097] Next, as Figure 5 shown, the control device 100 disconnects the third switch unit in the state where the second switch unit is disconnected, and cuts off the power supply between the second storage battery 32 and the low-voltage power supply line H2 (step S107). In addition, in step S107, when the third switch unit is switched to the off state, the control device 100 inputs and stores the detection values of various sensors.

[0098] Then, after the switching, the control device 100 determines whether there is a failure 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 failure determination of the third switch unit.

[0099] Here, with reference to Figure 10 an example of the failure determination method of the third switch unit in step S108 will be described in detail. Figure 10The 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 corresponding third current sensor A13 are shown.

[0100] In addition, as a prerequisite, when performing the failure 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 (14V) slightly higher than the inter-terminal voltage (12V) of the second battery 32.

[0101] Therefore, as Figure 10 As shown in the upper half of, when the third switch unit (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 charges the second battery 32. At this time, the detection value of the third current sensor A13 depends on the amount of current output from the DCDC converter 70, but should be at least greater than 0 (for example, several 10A). Therefore, when the detection value of the third current sensor A13 is zero despite the third switch unit being turned on, the control device 100 determines that there is a failure in the third switch unit.

[0102] In addition, when it is described as "depending on DCDC" in the figure, it means that when the supply voltage from the DCDC converter 70 is higher than the inter-terminal voltage of the second battery 32, the detection value of the third current sensor A13 depends on the amount of current output from the DCDC converter 70, and when it is below the inter-terminal voltage of the second battery 32, the detection value of the third current sensor A13 depends on the amount of current from the second battery 32.

[0103] 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 Figure 10As shown in the middle part of [Figure 0], if the detected value of the third current sensor A13 when the third A switch SW3a is off and the third B switch SW3b is on is not zero, the control device 100 determines that the third A switch SW3a has a fault. If it is zero, it determines that the third A switch SW3a has no fault. 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. In addition, this fault determination method is an example, and a modified example of the fault determination method will be described later.

[0104] 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 start-up process.

[0105] On the other hand, when the control device 100 determines that the third switch section has no fault (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, it charges 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.

[0106] After the charging is completed, as Figure 6 shown, with the third switch section off, the control device 100 switches the second switch section to on and connects all 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 switch section to on, the control device 100 inputs and stores the detected values of various sensors.

[0107] Then, after the switching, the control device 100 determines whether the second switch section has a fault based on the detected values of various sensors stored (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 detected value of the third current sensor A13 when switching the second switch section in step S110, thereby performing the fault determination of the second switch section.

[0108] Here, with reference to Figure 11 a detailed description will be given of an example of the fault determination method of the second switch section in step S111. Figure 11The on / off states of the second A switch SW2a and the second B switch SW2b during normal times and the detection values of various sensors corresponding thereto are shown. Additionally, as a prerequisite, when performing a failure determination on the second 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 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.

[0109] At this time, as shown in the upper half of Figure 11 , when the detection value of the third current sensor A13 is not zero although the second switch unit is off (or not 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.

[0110] Additionally, starting from the off state of the second switch 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 switch unit. Therefore, as shown in the middle part of Figure 11 , if the detection value of the third current sensor A13 is not zero in the state where the second A switch SW2a is on and the second B switch SW2b is off, the control device 100 determines that there is a failure in the second switch unit.

[0111] Furthermore, if it can be determined that the detection value of the third current sensor A13 is equal to or greater than a specified threshold in the state where the second A switch SW2a is on and the second B switch SW2b is on, and the current is flowing normally, 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 zero although the second switch unit is on, it is determined that there is a failure in the second switch unit. Additionally, this failure determination method is an example, and a modified example of the failure determination method will be described later. When it is determined that there is a failure in the second switch unit (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 startup process.

[0113] On the other hand, when it is determined that there is no failure in the second switch unit (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).

[0114] After the discharge is completed, as shown in Figure 8As shown, the control device 100 switches the first E-switch SW1e from on to off (step S113) and ends the starting process. At the end of the starting process, 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 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 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, the low-voltage load 72 can operate appropriately.

[0115] Next, with reference to Figure 12 , the failure determination of each switch SW performed when the vehicle stops will be described in detail. Figure 12 is a flowchart of the stop process that the control device 100 performs at regular intervals during vehicle starting. In addition, when the vehicle starts, as described above, it becomes Figure 8 the connection state shown, and all the storage batteries 31, 32, and 33 are connected in series with the high-voltage circuit 75. In addition, low-voltage power is supplied to the low-voltage load 72 via the DCDC converter 70.

[0116] 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 on, it operates the motor 10 and the inverter 20 and charges the neutral-point side smoothing capacitor C1 (step S202).

[0117] After the charging is completed, as Figure 6 shown, the control device 100 switches the first D-switch SW1d from off to on (step S203). After that, as Figure 5 shown, the control device 100 switches the second switch part to off while keeping the third switch part off, 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 part is switched to off, the control device 100 inputs and stores the detection values of various sensors.

[0118] Then, after the switching, the control device 100 determines whether there is a failure in the second switch unit based on the detected values of various sensors stored therein (step S205). In step S205, the control device 100 determines whether the energization of the second A electrical path 2A is appropriately cut off according to the detected value of the third current sensor A13 when the second switch unit is switched, thereby performing a failure determination of the second switch unit.

[0119] Here, with reference to Figure 11 , a detailed description will be given of an example of the method for determining a failure of the second switch unit in step S205. Additionally, 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 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.

[0120] At this time, as shown in the lower half of Figure 11 , when the detected value of the third current sensor A13 is zero (or within an error range close to zero, the same applies hereinafter) even though the second switch unit is turned on, the control device 100 determines that there is a failure in the second switch unit.

[0121] Then, in step S204, starting from the state where the second switch unit is turned on, the control device 100 disconnects the second B switch SW2b and then disconnects the second A switch SW2a, thereby disconnecting the second switch unit. Therefore, as shown in the middle part of Figure 11 , if the detected 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.

[0122] In addition, as shown in the upper half of Figure 11 , if it can be determined that the detected 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 energization 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 detected 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. Additionally, this failure determination method is an example, and a modified example of the failure determination method will be described later.

[0123] When it is determined that there is a failure in the second switching unit (step S205: Yes), the control device 100 performs a process for coping with the abnormality of 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.

[0124] On the other hand, when it is determined that there is no failure in the second switching 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.

[0125] After the discharge, as Figure 4 shown, the control device 100 switches the third switching unit to on in a state where the second switching unit is off, and connects the second storage battery 32 between the low-voltage power supply line H2 and the low-voltage ground line L2 (step S208). Thereby, the 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 switching unit to on, the control device 100 inputs and stores the detection values of various sensors.

[0126] Then, after the switching, the control device 100 determines whether there is a failure in the third switching unit based on the detection values of various sensors stored (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 detection value of the third current sensor A13 when switching the third switching unit in step S208, thereby performing the failure determination of the third switching unit.

[0127] Here, with reference to Figure 10 , a detailed description will be given of an example of the failure determination method of the third switching unit in step S209. Figure 10 Shows the on / off states of the third A switch SW3a and the third B switch SW3b in a normal state and the corresponding detection values of the third current sensor A13.

[0128] In addition, as a prerequisite, when performing the failure determination of the third switching 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 storage battery 32.

[0129] As Figure 10 shown in the lower half of, 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) even though the third switching 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 switching unit.

[0130] In addition, starting from the off state of the third switching 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 switching unit. Therefore, as Figure 10 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 off and the third B switch SW3b is on is not zero, the control device 100 determines that there is a failure in the third switching unit.

[0131] In addition, as Figure 10 shown in the upper half of, if it can be determined that the detection value of the third current sensor A13 in the state where the third A switch SW3a is on and the third B switch SW3b is 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 switching unit. On the other hand, when the detection value of the third current sensor A13 is zero even though the third switching unit is on, it is determined that there is a failure in the third switching unit. In addition, this failure determination method is an example, and a modified example of the failure determination method will be described later.

[0132] When it is determined that there is a failure in the third switching unit (step S209: Yes), the control device 100 performs the process for coping with the abnormality of the power supply system 30 (step S206) in the same manner as described above. After that, the control device 100 ends (interrupts) the stop process.

[0133] On the other hand, when it is determined that there is no failure in the third switching unit (step S209: No), as Figure 3As 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). Thus, the low-voltage load 72 is supplied with power from the second battery 32. Then, with the second switching unit open, the control device 100 switches the first switching unit to the open state to cut off the power supply between the first battery 31 and the high-voltage circuit 75 (step S211).

[0134] In addition, in step S211, when switching the first switching unit to the open state, the control device 100 inputs and stores the detection values of various sensors. Then, after switching the first switching unit, the control device 100 determines whether there is a fault in the first switching unit based on the stored detection 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 properly cut off according to the detection value of the first current sensor A11 when switching the first switching unit in step S211, thereby performing the fault determination of the first switching unit.

[0135] For example, when the detection value of the first current sensor A11 is zero even though it is before switching the first switching unit to the open state (even though it is on), that is, when no current flows through the first A electrical path 1A, the control device 100 determines that there is a fault in the first switching unit. In addition, for example, when the detection value of the first current sensor A11 is not zero even after switching the first switching unit to the open state, that is, when the power supply to the first A electrical path 1A is not cut off, the control device 100 determines that there is a fault in the first switching unit. 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 open state, the control device 100 determines that the first switching unit is normal (not faulty).

[0136] When it is determined that there is a fault in the first switching unit (step S212: 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.

[0137] On the other hand, when it is determined that there is no fault in the third switching unit (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.

[0138] According to the above first embodiment, the following effects are achieved.

[0139] 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 failure determination of the first switching unit.

[0140] Specifically, in step S102 of the start-up process, 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 failure determination of the first switching unit based on the detection value of the first current sensor A11 detected when the first switching unit is turned on. In addition, in step S211 of the stop process, 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 failure determination of the first switching unit based on the detection value of the first current sensor A11 detected when the first switching unit is turned off. 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 of the third switching unit.

[0142] Specifically, in step S107 of the start-up process, the control device 100 disconnects the second switching unit and turns off the third switching unit (switches SW3a, SW3b). In the next step S108, the control device 100 performs a failure determination of the third switching unit based on the detection value of the third current sensor A13 detected when the third switching unit is turned off. In addition, in step S208 of the start-up 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 of the third switching unit based on the detection value of the third current sensor A13 detected when the third switching unit is turned on.

[0143] 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.

[0144] 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.

[0145] Specifically, in step S110 of the start-up 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 the second switching unit is turned on.

[0146] In addition, in step S204 of the stop process, the control device 100 disconnects the third switching unit and turns off 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 the second switching unit is turned off.

[0147] In this way, when the power supply 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 implemented, 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.

[0148] As described in steps S102 - S103, S208 - S212, the control device 100 performs a failure determination on the first switching unit during the period when the second switching unit is off and the third switching unit is on. That is, 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 and power is supplied from the second battery 32 to the low-voltage circuit 76 side, the control device 100 switches the on / off state of the first switching unit and performs a failure determination on the first switching unit. Thereby, it is possible to prevent the power supply to the low-voltage load 72 from being interrupted during the failure determination of the first switching unit.

[0149] In addition, as described in steps S106 to S108 and S208 to S209, when the second switching unit is turned 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. During this period, the control device 100 performs a failure determination of the third switching unit. That is, 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, the control device 100 performs a failure determination of the third switching unit. Thereby, it is possible to prevent the power supply to the low-voltage load 72 from being interrupted during the failure determination of the third switching unit.

[0150] A part of the third A electrical path 3A connecting the positive terminal of the second battery 32 and the low-voltage power line H2 is shared with a part of the electrical path that becomes energized when all the batteries 31 to 33 are connected between the high-voltage power line H1 and the high-voltage ground line L1. Specifically, the electrical path from the positive terminal of the second 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 switching unit and the failure determination of the third switching unit, respectively. Thereby, in the failure determination of the second switching unit and the failure determination of the third switching 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.

[0151] 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 be wider 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, 100A to 200A). It is also configured that when measuring the current flowing through the third A electrical path 3A, the resolution can be changed to be smaller than when measuring the current flowing through the second A electrical path 2A, and a smaller value can be measured.

[0152] 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 is determined to be faulty. For example, when the control device 100 determines the fault of the second switch unit, it expands the measurement range of the third current sensor A13 and increases the resolution. When the control device 100 determines the fault of the third switch unit, it reduces the measurement range of the third current sensor A13 and decreases the resolution. Thereby, it is possible to achieve a measurement range and resolution suitable for the flowing current, and the current can be detected with high precision.

[0153] When the control device 100 switches each switch SW and changes the number of batteries 31 to 33 connected in series with the high-voltage power line H1, it controls the inverter 20 to step up 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.

[0154] Specifically, in step S109 after the implementation of step S102 (the first step) and before step S110 (the second step), the control device 100 controls the inverter 20, and steps up 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 stepped-up voltage to the inverter-side smoothing capacitor 21 and steps up the voltage between the terminals of the inverter-side smoothing capacitor 21 until the voltage between the terminals of the inverter-side smoothing capacitor 21 is equivalent to the voltage between the terminals of the second series connection body 50. Thereby, even when 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 make the power supply to the high-voltage load 71 stable. In addition, inrush current can be suppressed.

[0155] In addition, the control device 100 steps up the voltage between the terminals of the neutral-point side smoothing capacitor C1 through the motor 10 and the inverter 20 until the voltage between the terminals of the neutral-point side smoothing capacitor C1 is equivalent to the voltage between the terminals of the first series connection body 40. Thereby, inrush current can be suppressed during switching.

[0156] After the control device 100 performs 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 from the first storage battery 31 to the inverter 20 through the inverter 20 and the motor 10, apply the boosted voltage to the smoothing capacitor 21 on the inverter side, and maintain the voltage between the terminals of the smoothing capacitor 21 on the inverter side for a certain period and then gradually discharge (step down) it. Thereby, even if the second switch unit is turned off and the second storage battery 32 and the third storage battery 33 are disconnected from the high-voltage power line H1 and all the storage 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.

[0157] (Modification example) A modification example (another example of the embodiment) in which a part of the structure of the above-described embodiment is changed will be described.

[0158] (Modification example 1) · A modification example (modification example 1) of the method for determining a failure of the third switch unit in the above-described embodiment will be described. Figure 13 The on / off states of the third A switch SW3a and the third B switch SW3b in a normal state and the detection values of the third current sensor A13 corresponding thereto are shown.

[0159] First, modification example 1 in step S108 will be described. As Figure 13 shown in the upper half of, when the third switch unit (the third A switch SW3a and the third B switch SW3b) is turned on, current flows from the DCDC converter 70 to the second storage battery 32 and the second storage battery 32 is charged. Therefore, when the detection value of the third current sensor A13 is zero although the third switch unit is turned on, the control device 100 determines that there is a failure in the third switch unit.

[0160] In addition, in modification example 1, starting from the state where the third switch unit 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 unit. Therefore, as Figure 13As shown in the middle part of [], if the detected value of the third current sensor A13 in the state where the third B switch SW3b is off and the third A switch SW3a is on is not zero, the control device 100 determines that the third B switch SW3b has a fault. If it is zero, it determines that the third B switch SW3b has no fault. When it is determined that 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 B switch SW3b has no fault, it is determined that the third switch section has no fault. Thus, not only can the fault of the third switch section be determined, but also the fault of the third B switch SW3b can be determined.

[0161] Next, a modification example 1 in step S209 will be described. As Figure 13 shown in the lower half of [], when the detected 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 off, the control device 100 determines that the third switch section has a fault. In addition, starting from the off state of the third switch section, 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. Thus, as Figure 13 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 on and the third B switch SW3b is off is not zero, the control device 100 determines that the third B switch SW3b and the third switch section have a fault. In addition, as Figure 13 shown in the upper half 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 on and the third B switch SW3b is on is equal to or greater than a specified threshold value and the current is flowing normally, the control device 100 determines that the third switch section has no fault. On the other hand, when the detected value of the third current sensor A13 is zero although the third switch section is on, it is determined that the third switch section has a fault.

[0162] (Modification example 2) · A modification example (modification example 2) of the fault determination method for the third switch section 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 second battery 32. In modification example 2, this voltage monitoring sensor V100 is used for fault determination. Hereinafter, with reference to Figure 14 it will be described in detail. Figure 14 shows the on / off states of the third A switch SW3a and the third B switch SW3b in normal times and the detected values of the voltage monitoring sensor V100 and the third current sensor A13 corresponding thereto.

[0163] First, the second modification example in step S108 will be described. As Figure 14 shown in the upper part of Figure 14 , when the third switch unit (the third A switch SW3a and the third B switch SW3b) is turned on but the detected value of the voltage monitoring sensor V100 is not the supply voltage (e.g., 14V) from the DCDC converter 70, the control device 100 determines that there is a fault 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 greater than the threshold value, it is determined that it is not the supply voltage from the DCDC converter 70.

[0164] 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 Figure 14 shown in the middle part of Figure 14 , if the detected value of the voltage monitoring sensor V100 in the state where the third A switch SW3a is turned off and the third B switch SW3b is turned on is not the inter-terminal voltage of the second battery 32 (e.g., 12V), the control device 100 determines that there is a fault in the third A switch SW3a, and if it is the inter-terminal voltage of the second battery 32, it determines that there is no fault in the third A switch SW3a. In addition, for example, when the third A switch SW3a is turned off, if the detected value of the voltage monitoring sensor V100 decreases by more than a specified value (e.g., 2V or more), the control device 100 may also determine that there is no fault in the third A switch SW3a. Then, 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 switch 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 switch unit.

[0165] Next, the second modification example in step S209 will be described. As Figure 14 shown in the lower part of Figure 14 , when the third switch unit is turned off but the detected value of the voltage monitoring sensor V100 is not the inter-terminal voltage of the second battery 32, the control device 100 determines that there is a fault in the third switch unit.

[0166] In addition, starting from the state where the third switch unit is turned 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 unit. Therefore, as Figure 14 shown in the middle part of Figure 14 , if the detected value of the voltage monitoring sensor V100 in the state where the third A switch SW3a is turned off and the third B switch SW3b is turned on is not the inter-terminal voltage of the second battery 32, the control device 100 determines that there is a fault in the third switch unit.

[0167] Further, if it can be determined that the detected value of the voltage monitoring sensor V100 in the state where the third A switch SW3a and the third B switch SW3b are turned on is equivalent to the supply voltage value from the DCDC converter 70, the control device 100 determines that there is no fault in the third switch unit. Further, for example, when the third switch unit is turned on and the detected value of the voltage monitoring sensor V100 increases by a specified value or more (for example, 2V or more), it can also be determined that there is no fault in the third switch unit. On the other hand, when the detected value of the voltage monitoring sensor V100 is the voltage between the terminals of the secondary battery 32 despite the third switch unit being turned on, it is determined that there is a fault in the third switch unit.

[0168] As described above, since the voltage monitoring sensor V100 that monitors the voltage between the terminals of the secondary battery 32 can be used for fault determination, the third current sensor A13 can be omitted.

[0169] (Modification Example 3) · A modification example (Modification Example 3) of the fault 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 Example 3, this voltage monitoring sensor V100 is used for fault determination. Figure 15 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 voltage monitoring sensor V100 are shown. Modification Example 3 only has different on / off timings of the third A switch SW3a and the third B switch SW3b, and the way of considering fault determination is substantially the same as that of Modification Example 1 and the like. Therefore, the detailed description is omitted. Thus, not only can the fault of the third switch unit be determined, but also the fault of the third B switch SW3b can be determined.

[0170] (Modification Example 4) · A modification example (Modification Example 4) of the fault determination method for the third switch unit in the above-described embodiment will be described. In Modification Example 4, as Figure 16 shown, the detected value of the third voltage sensor V13, one end of which is connected to a portion on the positive terminal side of the secondary battery 32 closer to the third A switch SW3a in the third A electrical path 3A 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 in the third B electrical path 3B, is used for fault determination of the third switch unit. Figure 17 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 voltage sensor V13 in Modification Example 4 are shown.

[0171] First, Modification Example 4 in step S108 will be described. AsFigure 17 As shown in the upper half of [], when the detection value of the voltage monitoring sensor V100 is not the supply voltage from the DCDC converter 70 (e.g., 14V) even though the third switch section (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 section.

[0172] In addition, as Figure 17 shown in the middle part of [], if the detection value of the third voltage sensor V13 in the state where the third A switch SW3a is turned off and the third B switch SW3b is turned on is not the inter-terminal voltage of the second battery 32 (e.g., 12V), the control device 100 determines that there is a failure in the third A switch SW3a. If it is the inter-terminal voltage of the second battery 32, it determines that there is no failure in the third A switch SW3a.

[0173] Moreover, as Figure 17 shown in the lower half of [], when the detection value of the third voltage sensor V13 in the state where the third A switch SW3a is turned off and the third B switch SW3b is turned off is "indeterminate", the control device 100 determines that there is no failure in the third B switch SW3b. When it is not "indeterminate", it determines that there is a failure in the third B switch SW3b. "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 inter-terminal voltage of the second battery 32. Therefore, for example, when the detection value of the third voltage sensor V13 is not the supply voltage from the DCDC converter 70 and is not the inter-terminal voltage of the second battery 32, the control device 100 determines that there is no failure in the third B switch SW3b. When it is a certain value, it can be determined that there is a failure in the third B switch SW3b.

[0174] Then, when it is determined that there is a failure in the third A switch SW3a or the third B switch SW3b, it is determined that there is a failure in the third switch section. When it is determined that there is no failure in the third A switch SW3a and the third B switch SW3b, it is determined that there is no failure in the third switch section.

[0175] Next, a modification example 4 in step S209 will be described. As Figure 17 shown in the lower half of [], when the detection value of the third voltage sensor V13 is not indeterminate even though the third switch section is turned off (e.g., when it is the supply voltage from the DCDC converter 70 or the inter-terminal voltage of the second battery 32), the control device 100 determines that there is a failure in the third switch section.

[0176] In addition, as Figure 17As shown in the middle part of [Figure 0], if the detected value of the third voltage sensor V13 when 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 there is a fault in the third B switch SW3b and the third switch section.

[0177] In addition, if it can be determined that the detected value of the third voltage sensor V13 when the third A switch SW3a is on and the third B switch SW3b is on is equivalent to the supply voltage from the DCDC converter 70, the control device 100 determines that there is no fault in the third A switch SW3a and the third switch section. In the opposite case, the control device 100 determines that there is a fault in the third A switch SW3a and the third switch section.

[0178] As described above, according to the third voltage sensor V13 of Modification 4, it is possible not only to determine the fault of the third switch section but also to determine which one of the third A switch SW3a and the third B switch SW3b has a fault.

[0179] In addition, one end of the third voltage sensor V13 can be connected to a portion of 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 portion of 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, similarly to Modification 4, it is also possible to determine which one of the third A switch SW3a and the third B switch SW3b has a fault.

[0180] (Modification 5) · A modification (Modification 5) of the fault determination method of the third switch section in the above-described embodiment will be described. In Modification 5, as Figure 16 shown, the detected value of the third voltage sensor V13 is used in the same manner as in Modification 4. However, as Figure 18 shown, compared with Modification 4, the on / off sequence of the third A switch SW3a and the third B switch SW3b is different. Therefore, in Modification 5, although the fault determination of the third switch section can be performed, different from Modification 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 in Modification 1 and the like, so the detailed description is omitted.

[0181] (Modification 6) · A modification example (modification example 6) of the failure determination method for the second switch unit of the above-described embodiment will be described. In the above-described embodiment, the detected value of the third current sensor A13 is used. However, in modification example 6, any one of the detected values of the first voltage sensor V1, the second voltage sensor V2, and the second current sensor A12 may be used. As Figure 11 shown, this is because if the second switch unit is normal, the detected value can be changed by turning the second switch unit on and off.

[0182] 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. In addition, in the columns "V1" and "V2", "depending on INV" means 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). In addition, in the column "A12" of the second current sensor A12 in the figure, "-A11" means detecting the negative value of the first current sensor A11. In addition, in the column "A12" of the second current sensor A12 in the figure, "depending on INV" means that the amount of current flowing due to the control of the inverter 20 is different. Therefore, in order to be able to judge the change in the detected value by turning the second switch unit on and off, the control device 100 needs to appropriately control the inverter 20. In addition, the way of considering the failure determination is substantially the same as that in the first embodiment using the detected value of the third current sensor A13, etc., so the detailed description is omitted.

[0183] (Modification example 7) · A modification example (modification example 7) of the failure determination method for the second switch unit of the above-described embodiment will be described. In modification example 7, as Figure 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 order of the second A switch SW2a and the second B switch SW2b is changed. In addition, the way of considering the failure determination is substantially the same as that in the first embodiment and modification example 6, etc., so the detailed description is omitted.

[0184] (Modification example 8) · A modification example (modification example 8) of the failure determination method for the second switch unit of the above-described embodiment will be described. In modification example 8, as Figure 20 shown, the detected value of the fourth voltage sensor V14, one end of which is connected to a portion on the positive terminal side of the second battery 32 closer to the second A switch SW2a in the second A electrical path 2A and the other end of which is connected to a portion on the high-voltage ground wire L1 side closer to the second B switch SW2b in the second B electrical path 2B, is used to determine the failure of the second switch unit.

[0185] Figure 21 shows the on / off states of the second A switch SW2a and the second B switch SW2b in the normal state and the detected values of the corresponding fourth voltage sensor V14. Here, with reference to Figure 21 a detailed description will be given of Modification 8 in step S111.

[0186] As Figure 21 shown in the upper half of, when the detected value of the fourth voltage sensor V14 is not "indeterminate" although the second switch unit is off, it is determined that there is a fault in the second switch unit. For example, in the case of the voltage between the terminals of the second battery 32 (12V) or the value obtained by subtracting the voltage between the terminals of the third battery 33 from the voltage between the terminals of the neutral point side smoothing capacitor C1, it is determined that there is a fault in the second switch unit. In addition, the voltage between the terminals of the neutral point side smoothing capacitor C1 is the detected value of the second voltage sensor V2, and the voltage between the terminals of the third battery 33 is 200V.

[0187] In addition, starting from the state where the second switch unit is off, 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 switch unit. Therefore, as Figure 21 shown in the middle part of, if the detected value of the fourth voltage sensor V14 in the state where the second A switch SW2a is on and the second B switch SW2b is off is not the value "V2 - 200" obtained by subtracting the voltage between the terminals of the third battery 33 from the voltage between the terminals 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 switch unit.

[0188] In addition, if the detected value of the fourth voltage sensor V14 in the state where the second A switch SW2a is on and the second B switch SW2b is on is the voltage between the terminals 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 switch unit. On the other hand, when the detected value of the fourth voltage sensor V14 is not the voltage between the terminals of the second battery 32 (12V) although the second switch unit is on, it is determined that there is a fault in the second B switch SW2b and the second switch unit.

[0189] In addition, it is desirable to boost the voltage between the terminals of the neutral point side smoothing capacitor C1 so that the difference between the value "V2 - 200" obtained by subtracting the voltage between the terminals of the third battery 33 from the voltage between the terminals of the neutral point side smoothing capacitor C1 and the voltage between the terminals 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 voltage between the terminals of the neutral point side smoothing capacitor C1.

[0190] In addition, in steps S204 to S205, when the second switching unit is set to OFF for failure determination of the second switching unit, it is also possible to similarly determine which one of the second A switch SW2a and the second B switch SW2b has a failure.

[0191] As described above, according to Modification 8, it is possible not only to determine the failure of the second switching unit but also to determine which one of the second A switch SW2a and the second B switch SW2b has a failure.

[0192] (Modification 9) · A modification (Modification 9) of the failure determination method of the second switching unit in the above-described embodiment will be described. In Modification 9, the detection value of the fourth voltage sensor V14 described in Modification 8 is used. However, as Figure 22 shown, the ON / OFF order of the second A switch SW2a and the second B switch SW2b is different from that in Modification 8.

[0193] In addition, as Figure 22 shown, in Modification 9, it is possible to perform failure determination of the third switching unit only by the detection value of the fourth voltage sensor V14. However, different from Modification 8, it is not possible to determine which one of the second A switch SW2a and the second B switch SW2b has a failure.

[0194] 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 may 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 Figure 22 shown, it is possible to determine which one of the second A switch SW2a and the second B switch SW2b has a failure.

[0195] (Modification 10) · In the power supply system 30 of the first embodiment described above, a switch for switching the energization and energization cut-off between the second battery 32 and the third battery 33 may not be provided. For example, as Figure 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, only the second A switch SW2a needs to be provided between the first C switch SW1c and the third battery 33.

[0196] (Modification Example 11) · In the power supply system 30 of the above first embodiment, the arrangements of the second battery 32 and the third battery 33 can also be changed. For example, as Figure 24 shown, in the power supply system 30 of the first embodiment, it can also be arranged such that they are connected in series in the order of the first battery 31 → the second battery 32 → the third battery 33 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 battery 32 and the positive terminal of the third battery 33.

[0197] (Modification Example 12) · In the power supply system 30 of the above first embodiment, the arrangements of the first battery 31, the second battery 32, and the third battery 33 can also be changed. For example, as Figure 25 shown, in the power supply system 30 of the first embodiment, they can also be arranged in the order of the second battery 32 → the third battery 33 → the first 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.

[0198] In this modification 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.

[0199] (Modification Example 13) · In the power supply system 30 of the above first embodiment, the third battery 33 can also be omitted. For example, as Figure 26 shown, the third battery 33 of the power supply system 30 in the first embodiment can also be omitted.

[0200] (Modification 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 modification example 14. Refer to Figures 27 to 28 , and the switching order (modification example 14) 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 Figure 27 shown in (a). That is, the third switch unit is turned on.

[0201] When the vehicle starts while the vehicle is stopped, it transfers to Figure 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 battery 31.

[0202] Then, after the charging is completed, it transfers to Figure 27 The connection state 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, 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, the DCDC converter 70 steps down the high-voltage power, and supplies it to the low-voltage load 72.

[0203] Then, as Figure 28 Shown in (e) thereof, the control device 100 switches the third switch unit to the off state. At this time, the fault determination of the third switch unit is performed by using the determination method described in the above embodiment or modification. After the fault determination, as Figure 28 Shown in (f) thereof, the control device 100 switches the first B switch SW1b to the on state. At this time, the fault 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.

[0204] After that, as Figure 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 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 battery 32 and the third battery 33.

[0205] Next, as Figure 28 Shown in (h) thereof, the control device 100 switches the second B switch SW2b to the on state. 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 modification 8, the fault determination of the second B switch SW2b is performed. After the fault determination, 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 to the high-voltage power line H1.

[0206] In the modification example 14, the pre-charge 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.

[0207] (Modification example 15) · In the above-described embodiment, the switching order of the on / off states of the respective switches SW may be modified as shown in the following modification example 15. Refer to Figures 29 to 30 , and the switching order (modification example 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 the respective switches SW are as Figure 29 shown in (a) of . That is, the third switch unit is turned on.

[0208] When the vehicle starts while the vehicle is stopped, it transfers to the Figure 29 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 corresponds to the voltage between the terminals of the first battery 31.

[0209] Then, after the charging is completed, it transfers to the Figure 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 pre-charge switch Pre_P. In addition, Figure 29 the processes up to (a) to (d) of correspond to the third step. In this modification example 15, the pre-charge switch Pre_P, the first A switch SW1a, and the first B switch SW1b correspond to the first switch unit.

[0210] 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.

[0211] Then, as Figure 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 example. After the failure determination, as Figure 30As shown in (f) thereof, 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 storage battery 32 and the third storage battery 33 (212V).

[0212] After that, as Figure 30 shown in (g) thereof, 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 modification example 8, a failure determination of the second switch unit is performed.

[0213] After the failure determination, as Figure 30 shown in (h) thereof, 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 storage battery 31 and the first series connection body 40 are connected in parallel to the high-voltage power line H1.

[0214] In this modification 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.

[0215] (Modification example 16) · In the above-described embodiment, the switching order of the on / off states of each switch SW may also be modified as shown in the following modification example 16. Refer to Figures 31 to 32 for an explanation of the switching order (modification example 16) from when the vehicle is stopped to when the vehicle starts.

[0216] As a premise of this modification example 16, during vehicle start-up, it becomes Figure 31 the connection state of (a). Figure 31 The (a) of Figure 30 is the same as the connection state of (h) of

[0217] 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 also be performed in the same manner as in the above-described embodiment or modification example. Figure 31As shown in (c) thereof, the control device 100 controls the inverter 20 and discharges the neutral point side smoothing capacitor C1. Then, as Figure 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. Then, in Figure 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.

[0218] After that, as Figure 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 Figure 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.

[0219] (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 deformed as shown in the following Modification 17. Refer to Figures 33 to 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 Figure 33 shown in (a) thereof. That is, the third switch unit is on.

[0220] When the vehicle starts while the vehicle is stopped, it transfers to Figure 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 battery 31.

[0221] Then, after the charging is completed, it transfers to Figure 33The connection state shown in (c) to (d). 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, a 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, the DCDC converter 70 steps down the high-voltage power, and supplies it to the low-voltage load 72.

[0222] Then, as Figure 34 shown in (e), the control device 100 switches the third switch unit to off. At this time, a 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 Figure 33 shown in (f), the control device 100 switches the first E switch SW1e to on. 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 composed of the second battery 32 and the third battery 33 (212V).

[0223] After that, as Figure 34 shown in (g), the control device 100 switches the first D switch SW1d and the second B switch SW2b to on. At this time, a fault determination of the first D switch SW1d or the second B switch SW2b is performed.

[0224] An explanation of this fault determination is given. At this time, when switching on in the order of the first D switch SW1d → the second B switch SW2b, a fault determination of the first D switch SW1d and the second B switch SW2b can be performed with reference to the detection value of any one of the voltage sensors V1, V2, and the current sensors A11 to A13. Figure 36 shows the relationship between the on-off states of the first D switch SW1d and the second B switch SW2b in normal times and the respective detection values. When the detection values shown in Figure 36 (a) are not detected, the fault 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.

[0225] In addition, it is also possible to switch on in the order of the second B switch SW2b → the first D switch SW1d and determine the fault. Figure 37shows the relationship between the on / off states of the first D switch SW1d and the second B switch SW2b in normal operation and each detected value. When no detected value as shown in Figure 36 in (b) is detected, similar to the above, a failure of the first D switch SW1d can be determined.

[0226] In addition, the detected value of the fourth voltage sensor V14 described in Modification Example 8 can also be used. Figure 37 (a) of shows the relationship between the on / off states of the first D switch SW1d and the second B switch SW2b in normal operation 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 Figure 37 (a), 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 Example 8 and the like.

[0227] In addition, Figure 37 (b) of shows the relationship between the on / off states of the first D switch SW1d and the second B switch SW2b in normal operation 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 Example 8 and the like, based only on Figure 37 the detected value of the fourth voltage sensor V14 in (b), a failure determination of the first D switch SW1d and the second B switch SW2b cannot be performed. Therefore, similar to the above, if the detected value of the fourth voltage sensor V14, the detected value of any one of the voltage sensors V1, V2, and the current sensors A11 to A13 is 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.

[0228] After the failure determination, as shown in Figure 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).

[0229] After that, as shown in Figure 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 Figure 35As shown in (j), the control device 100 disconnects the first D switch SW1d to discharge the neutral point side smoothing capacitor C1, and disconnects the first E switch SW1e. Thus, the first battery 31 to the third battery 33 are connected in series with the high-voltage power line H1.

[0230] In addition, in this modification, 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.

[0231] (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 Figure 38 shown in (a). That is, the third switch section is turned on.

[0232] When the vehicle starts while the vehicle is stopped, it transfers to the Figure 38 connection state shown in (b). 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.

[0233] Then, after the charging is completed, it transfers to the Figure 38 connection states shown in (c) to (d). That is, the control device 100 switches the first A switch SW1a to on, and then disconnects the precharge switch Pre_P. In addition, when switching the first switch section to on, a failure determination of the first switch section 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.

[0234] Then, as Figure 39 shown in (e), the control device 100 switches the third switch section to off. At this time, a failure determination of the third switch section is performed using the determination method described in the above embodiment or modification. After the failure determination, as Figure 39As shown in (f) of , the control device 100 switches the first E switch SW1e to the on state. 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).

[0235] After that, as shown in Figure 39 (g) of , the control device 100 switches the first D switch SW1d and the second B switch SW2b to the on state. At this time, similar to Modification 17, a failure determination of the first D switch SW1d or the second B switch SW2b is performed.

[0236] After the failure determination, the control device 100, in the state shown in Figure 39 (h) of , 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).

[0237] After that, as shown in Figure 40 (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 Figure 40 (j) of , 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.

[0238] 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.

[0239] (Modification 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 Modification 19. Refer to Figures 41 to 42 , and the switching order (Modification 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 Figure 41 (a) of . That is, the third switch unit is turned on.

[0240] When the vehicle is parked and then starts, it transfers to Figure 41 the connection state shown in (b). 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.

[0241] Then, after the charging is completed, it transfers to Figure 41 the connection states shown in (c) to (d). 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 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.

[0242] Then, as shown in Figure 42 (e), the control device 100 switches the third switch unit to OFF. At this time, the failure determination of the third switch unit is performed by the determination method described in the above embodiment or the modification. After the failure determination, as shown in Figure 42 (f), the control device 100 switches the first E switch SW1e to ON. 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 charging is performed in such a way that 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.

[0243] After that, as shown in Figure 42 (g), the control device 100 switches the first D switch SW1d and the second B switch SW2b to ON. At this time, similar to Modification 17, the failure determination of the first D switch SW1d or the second B switch SW2b is performed.

[0244] After the failure 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.

[0245] In addition, in this modified 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.

[0246] (Modified 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 Modified Example 20. Refer to Figures 43 to 44 , and the switching order (Modified Example 20) from when the vehicle is starting to when the vehicle stops will be described. As a prerequisite, when the vehicle is starting, the on / off states of each switch SW are as Figure 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 storage batteries 31 to 33 are connected in series with the high-voltage power supply line H1.

[0247] When the vehicle stops during starting, as Figure 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 the terminals becomes 212V. After charging, the control device 100 turns on the first D switch SW1d, boosts the applied voltage from the first storage battery 31, and applies it to the inverter side smoothing capacitor 21.

[0248] After that, the control device 100 turns off the first C switch SW1c and steps down the voltage so that the voltage between the terminals of the inverter side smoothing capacitor 21 becomes 400V, and then turns on the first B switch SW1b. At this time, it is also possible to perform a failure determination on the first B switch SW1b, the first C switch SW1c, and the first D switch SW1d.

[0249] Next, as Figure 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, it is also possible to perform a failure determination on the first D switch SW1d and the second B switch SW2b. Then, the control device 100 operates the inverter 20 to discharge the neutral point side smoothing capacitor C1, and then, as Figure 43 shown in (d), switches the first E switch SW1e to off.

[0250] Next, as Figure 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 Figure 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.

[0251] Then, as Figure 44 shown 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 Figure 44 shown in (h), the switching is completed and the transition to the stop state is made.

[0252] In addition, in this modification, the first A switch SW1a and the first B switch SW1b correspond to the first switch section. In addition, the first C switch SW1c, the first D switch SW1d, 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.

[0253] (Modification 21) · 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 21. Refer to Figures 45 to 46 , and the switching order (Modification 21) from when the vehicle is starting to when the vehicle stops will be described. As a premise, when the vehicle is starting, the on / off states of the respective switches SW are as Figure 45 shown 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 turned on, and the first battery 31 and the first series connection body 40 are connected in parallel with the high-voltage power line H1.

[0254] During starting, when the vehicle stops, as Figure 45 shown 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 section.

[0255] The control device 100 discharges the neutral point side smoothing capacitor C1 using the inverter 20 in the state shown in Figure 45 (c). Then, as Figure 45 shown in (d), the control device 100 switches the third switch section to the on state. At this time, it is also possible to perform a failure determination on the third switch section. Then, in Figure 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.

[0256] Then, as Figure 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 example, 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 of the first A switch SW1a and the first B switch SW1b.

[0257] After that, the control device 100 operates the inverter 20 to discharge the inverter-side smoothing capacitor 21. Thus, as Figure 46 shown in (g), the switching is completed. In addition, in this modification example, the first C switch SW1c, the first D switch SW1d, and the first E switch SW1e correspond to the neutral point connection switch unit.

[0258] (Other modification examples) · In the above-described embodiment or modification example, the series connection bodies 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.

[0259] · 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 for switching the energization and the cut-off of the energization between the positive terminal of the first battery 31 and the high-voltage power line and 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.

[0260] · In the above-described embodiment, when the control device 100 cuts off the energization between the first battery 31 and the high-voltage circuit 75 by turning off 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.

[0261] · As Figures 47 to 70 shown, the power supply system 30 of the above-described first embodiment may arbitrarily change its circuit structure.

[0262] · In the above-described embodiments and variations, 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. Moreover, a third current sensor A13 may be provided at this portion.

[0263] · In the above-described embodiments or variations, each switch SW is not limited to being constituted by a single switch, and may also be constituted by a series connection body of a plurality of switches or a parallel connection body of a plurality of switches.

[0264] · In the above-described embodiments or variations, 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.

[0265] · In the above-described embodiments or variations, the motor is not limited to a star connection, and may also be a delta connection. In addition, as the motor and the inverter, they are not limited to a three-phase motor, and may also be a two-phase motor or a motor with four or more phases. In addition, as the motor, it 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. In addition, as the motor, it is not limited to a synchronous machine, and may also be an induction machine.

[0266] · In the above-described embodiments or variations, 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.

[0267] · In the above-described embodiments or variations, the moving body equipped with the power supply system is not limited to a vehicle, and for example, it may also be an airplane or a ship. In addition, the installation location of the power conversion device is not limited to a moving body, and may also be a stationary device.

[0268] · In the above-described embodiment, the control device 100 changes the measurement range and resolution of the third current sensor A13 according to which one of the second switch unit and the third switch unit is determined to have a fault. As this variation, 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. In addition, 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.

[0269] ·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 perform fault determination by turning on (or off) in the order of the third A switch SW3a → the third B switch SW3b at a certain moment, and performing fault determination by turning on (or off) in the order of the third B switch SW3b → the third A switch SW3a at a different moment. 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, detection can be performed.

[0270] ·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, it can also be that the control unit described in the present disclosure and the method of this control unit are implemented by a dedicated computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, it can also be that the control unit described in the present disclosure and the method of this control unit are implemented by one or more dedicated computers provided by a combination of a processor programmed to execute one or more functions and a memory and a processor configured with 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 to be executed by a computer.

[0271] Hereinafter, characteristic structures extracted from the above-described embodiments are described. [Structure 1] A power supply system The above power supply system (30) is connected to a high-voltage circuit (75) via a high-voltage power line (H1) and a high-voltage ground line (L1), and is connected to a low-voltage circuit (76) via a low-voltage power line (H2) and a low-voltage ground line (L2), and includes a plurality of power storage units (31 to 32), The above 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 above 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 above low-voltage circuit; and A switch control unit (100) that controls the first switch unit, the second switch unit, and the third switch unit, The above-mentioned second switching 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 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 supply line or the high-voltage ground wire, The above-mentioned third switching unit includes: A third X switch that switches the energization and de-energization of a third X electrical path provided between the positive terminal of the second power storage unit and the low-voltage power supply line; and A third Y switch that switches the energization and de-energization of a third Y electrical path provided between the negative terminal of the second power storage unit and the low-voltage ground wire, At least a part of the above-mentioned 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 above-mentioned 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. [Structure 2] The power supply system described in Structure 1, wherein, The measurement range of the above-mentioned shared current sensor is configured to be changeable according to the on-off states of the first switching unit, the second switching unit, and the third switching unit, and the resolution of the above-mentioned shared current sensor changes as the measurement range changes. [Structure 3] The power supply system described in Structure 1 or 2, wherein, It includes a fault determination unit (100), and the fault determination unit performs fault determination on the first switching unit, the second switching unit, and the third switching unit, The fault determination unit performs fault determination on the second switching unit based on the measurement result of the shared current sensor when switching the on-off state of the second switching unit, and performs fault determination on the third switching unit based on the measurement result of the shared current sensor when switching the on-off state of the third switching unit. [Structure 4] The power supply system described in Structure 3, wherein, The measurement range of the above-mentioned common current sensor is configured to be changeable according to the on / off states of the above-mentioned first switch unit, the above-mentioned second switch unit, and the above-mentioned third switch unit, and the resolution of the above-mentioned common current sensor changes as the measurement range changes. The above-mentioned fault determination unit changes the measurement range of the above-mentioned common current sensor according to which of the above-mentioned second switch unit and the above-mentioned third switch unit is determined to have a fault. [Structure 5] A program, which is executed by a control device (100) of a power supply system (30). The above-mentioned power supply system is connected to a high-voltage circuit (75) via a high-voltage power line (H1) and a high-voltage ground line (L1), and is connected to a low-voltage circuit (76) via a low-voltage power line (H2) and a low-voltage ground line (L2), and includes a plurality of power storage units (31 - 32). The above-mentioned power supply system includes: A first switch unit, which switches the energization and power cut-off between a first power storage unit among the above-mentioned plurality of power storage units and the above-mentioned high-voltage circuit. A second switch unit, which 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, which switches the energization and power cut-off between the second power storage unit and the above-mentioned low-voltage circuit. The above-mentioned second switch unit includes: A second X switch, which 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, which 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 above-mentioned high-voltage power line or the above-mentioned high-voltage ground line. The above-mentioned third switch unit includes: A third X switch, which 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 above-mentioned low-voltage power line; and A third Y switch, which 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 above-mentioned low-voltage ground line. The above-mentioned program executes a switch control process and a fault determination process. The above-mentioned switch control process controls the above-mentioned first switch unit, the above-mentioned second switch unit, and the above-mentioned third switch unit. The above failure determination process performs failure determination on the above first switch unit, the above second switch unit, and the above third switch unit. At least a part of the above third X electrical path is shared with at least a part of the above second X electrical path and the above second Y electrical path, or at least a part of the above third Y electrical path is shared with at least a part of the above second X electrical path and the above second Y electrical path. A shared current sensor (A13) is provided in the shared path (L10) of this sharing. In the above failure determination process, based on the measurement result of the above shared current sensor when switching the on / off state of the above second switch unit, failure determination of the above second switch unit is performed, and based on the measurement result of the above shared current sensor when switching the on / off state of the above third switch unit, failure determination of the above third switch unit is performed.

[0272] Although the present disclosure has been described based on embodiments, it should be understood that the present disclosure is not limited to the above embodiments and structures. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations, methods, and further combinations and methods including only one element, more than one element, or less than one element thereof also fall within the scope and ideological scope of the present disclosure.

Claims

1. A power supply system, the power supply system (30) is connected to a high-voltage circuit (75) via a high-voltage power line (H1) and a high-voltage ground line (L1), and is connected to a low-voltage circuit (76) via a low-voltage power line (H2) and a low-voltage ground line (L2), and includes a plurality of power storage units (31-32). The power supply system includes: A first switch unit that switches the energization and de-energization 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 de-energization 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 de-energization between the second power storage unit and the low-voltage circuit; and A switch control unit (100) that controls the first switch unit, the second switch unit, and the third switch unit. 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 line. The third switch unit includes: A third X switch that switches the energization and de-energization 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 de-energization 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.

2. The power supply system according to claim 1, wherein The measurement range of the shared current sensor is configured to be changeable according to the on / off states of the first switch unit, the second switch unit, and the third switch unit, and the resolution of the shared current sensor changes with the change of the measurement range.

3. The power supply system according to claim 1 or 2, wherein It includes a fault determination unit (100) that performs fault determination on the first switch unit, the second switch unit, and the third switch unit. The failure determination unit performs failure 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 failure 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.

4. The power supply system according to claim 3, wherein the measurement range of the common current sensor is configured to be changeable according to the on / off states of the first switch unit, the second switch unit, and the third switch unit, and the resolution of the common current sensor changes as the measurement range changes, the failure determination unit changes the measurement range of the common current sensor according to which one of the second switch unit and the third switch unit is to be subjected to failure determination.

5. A program executed by a control device (100) of a power supply system (30), the power supply system is connected to a high-voltage circuit (75) via a high-voltage power line (H1) and a high-voltage ground line (L1), and is connected to a low-voltage circuit (76) via a low-voltage power line (H2) and a low-voltage ground line (L2), and includes a plurality of power storage units (31 to 32), the power supply system includes: a first switch unit that switches on and off the power supply between a first power storage unit among the plurality of power storage units and the high-voltage circuit; a second switch unit that switches on and off the power supply 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 on and off the power supply between the second power storage unit and the low-voltage circuit, the second switch unit includes: a second X switch that switches on and off the power supply 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 on and off the power supply of a second Y electrical path provided between a terminal on the side opposite to the second X electrical path of 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 on and off the power supply 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 on and off the power supply of a third Y electrical path provided between the negative terminal of the second power storage unit and the low-voltage ground line, the program executes 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. 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. In the failure determination process, based on the measurement result of the shared current sensor when switching the on / off state of the second switch unit, the failure determination of the second switch unit is performed, and based on the measurement result of the shared current sensor when switching the on / off state of the third switch unit, the failure determination of the third switch unit is performed.

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