Power supply device

Abstract

Provided is a power supply device capable of maintaining power supply to a load. A power supply device (10) includes a first switch (31) provided in a first conductive path (81), a second switch (32) provided in a second conductive path (82), a power storage unit (34) that supplies power to a load (93) via a third conductive path (83), and a reverse flow prevention unit (35) that prevents the flow of current from the power storage unit (34) to the first switch (31) via the third conductive path (83) and the flow of current from the power storage unit (34) to the second switch (32) via the third conductive path (83).

Description

Technical Field

[0001] This disclosure relates to power supply equipment. Background Technology

[0002] Patent Document 1 discloses an on-board power supply device. This on-board power supply device includes: a main power supply unit that supplies output power from a first on-board power source to the input side of a critical load via a main path through a main semiconductor switch; and a secondary power supply unit that supplies output power from a second on-board power source to the input side of the critical load via a secondary path through a secondary semiconductor switch. Furthermore, the on-board power supply device includes a bypass power supply unit that supplies output power from the second on-board power source radially to the input side of the critical load via a bypass path that bypasses the main semiconductor switch and the secondary semiconductor switch.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2023-15871 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the structure of Patent Document 1, two systems are set up as the power supply path for the load to achieve power redundancy, but the countermeasures to suppress the power reduction during power switching are not sufficient.

[0008] This disclosure is made based on the above circumstances, and its purpose is to provide a power supply device capable of maintaining power supply to a load.

[0009] Methods for solving problems

[0010] The power supply device disclosed herein is included in a vehicle system, the vehicle system comprising: a first power supply unit; a second power supply unit; a load; a first conductive path from which power is supplied; a second conductive path from which power is supplied; and a third conductive path disposed between the connection point of the first conductive path and the second conductive path and the load, wherein the power supply device comprises: a first switch disposed in the first conductive path; a second switch disposed in the second conductive path; a power storage unit for supplying power to the load via the third conductive path; and a reverse current prevention unit for preventing current from flowing from the power storage unit to the first switch via the third conductive path and preventing current from flowing from the power storage unit to the second switch via the third conductive path.

[0011] Invention Effects

[0012] The technology disclosed herein is capable of maintaining the power supply to the load. Attached Figure Description

[0013] Figure 1 This is a block diagram that schematically illustrates an on-board system including the power supply device of the first embodiment.

[0014] Figure 2 This is a block diagram that schematically illustrates an on-board system including the power supply device of the second embodiment.

[0015] Figure 3 This is a block diagram that schematically illustrates an on-board system including a power supply device according to the third embodiment. Detailed Implementation

[0016] The following are examples and illustrations of embodiments of this disclosure.

[0017] [1] A power supply device is included in a vehicle system, the vehicle system comprising: a first power supply unit; a second power supply unit; a load; a first conductive path for receiving power from the first power supply unit; a second conductive path for receiving power from the second power supply unit; and a third conductive path disposed between the connection point of the first conductive path and the second conductive path and the load, wherein the power supply device comprises: a first switch disposed in the first conductive path; a second switch disposed in the second conductive path; a power storage unit for supplying power to the load via the third conductive path; and a reverse current prevention unit for preventing current from flowing from the power storage unit to the first switch via the third conductive path and preventing current from flowing from the power storage unit to the second switch via the third conductive path.

[0018] In the power supply device described in [1] above, if a ground fault or other event occurs in the first conductive circuit on the side closer to the first power supply unit than the first switch, causing a power failure in the first power supply unit, the first conductive circuit can be disconnected by the first switch. Furthermore, after the power failure of the first power supply unit, power can be supplied to the load from the energy storage unit via the third conductive circuit. Similarly, in the case of a power failure in the second power supply unit, the second conductive circuit can be disconnected by the second switch, and power can be supplied to the load from the energy storage unit after a power failure. Moreover, the reverse current prevention unit prevents current from flowing from the energy storage unit to the first switch via the third conductive circuit and prevents current from flowing from the energy storage unit to the second switch via the third conductive circuit. Therefore, in the power supply device, a structure capable of maintaining power supply to the load can be realized.

[0019] [2] According to the power supply device of [1], the reverse current prevention unit is provided in the third conductive circuit between the energy storage unit and the connection point.

[0020] In the power supply device described in [2] above, by providing a backflow prevention unit in the third conductive path, a structure that prevents backflow from the energy storage unit to the first and second conductive paths can be achieved. Therefore, the power supply device has a simplified structure compared to the case where backflow prevention units are provided in both the first and second conductive paths.

[0021] [3] The power supply device according to [1] or [2], wherein a third switch is provided in series with the reverse current prevention unit in the third conductive circuit.

[0022] In the power supply device described in [3] above, by using a third switch to cut off the third conductive path, it is possible to prevent overcurrent from flowing from the first conductive path side and the second conductive path side to the load side in the event of a load grounding fault.

[0023] [4] The power supply device according to any one of [1] to [3], wherein the power supply device includes a housing component that houses the first switch, the second switch, the energy storage unit and the reverse current prevention unit, and the power supply device is configured as a junction box.

[0024] In the power supply device described above [4], the first switch, the second switch, the energy storage unit and the reverse current prevention unit can be integrated into the junction box, thereby achieving a compact device and a simplified structure.

[0025] [5] A power supply device according to any one of [1] to [4], wherein the power supply device comprises: a fourth conductive path electrically connected to both ends of the reverse current prevention section; and a resistor disposed in the fourth conductive path, the fourth conductive path being connected to the third conductive path at a second connection point, the energy storage section being electrically connected in the fourth conductive path between the second connection point and the resistor, the power supply device comprising a second reverse current prevention section disposed in the fourth conductive path between the second connection point and the energy storage section, the second reverse current prevention section preventing current from flowing from the third conductive path through the second connection point to the energy storage section.

[0026] In the power supply device described in [5] above, a resistor is provided in the fourth conductive path electrically connected to both ends of the reverse current prevention section. Therefore, when power supply begins from at least one of the first power supply section and the second power supply section, it is possible to prevent inrush current from the side of the fourth conductive path opposite to the second connection point to the energy storage section. In addition, a second reverse current prevention section is provided in the fourth conductive path between the second connection point and the energy storage section, so that inrush current from the second connection point side to the energy storage section can be prevented in the fourth conductive path.

[0027] [6] The power supply device according to [5], wherein the power supply device includes a fourth switch, the fourth switch being disposed in the third conductive circuit between the second connection point and the load.

[0028] In the power supply device of [6] described above, by using the fourth switch to cut off the third conductive path, it is possible to prevent the flow of current from at least one of the first power supply unit and the second power supply unit to the load side via the resistor and the second reverse current prevention unit, as well as the flow of current to the load side via the reverse current prevention unit.

[0029] [Details of the embodiments disclosed herein]

[0030] 1. First Implementation Method

[0031] 1-1. Overview of the vehicle-mounted system 100

[0032] exist Figure 1 The diagram shows an in-vehicle system 100 including a power supply device 10. The in-vehicle system 100 is a system mounted on a vehicle. The in-vehicle system 100 includes a first power supply unit 91, a second power supply unit 92, and a load 93. The in-vehicle system 100 is capable of supplying power from the first power supply unit 91 to the load 93, and is also capable of supplying power from the second power supply unit 92 to the load 93.

[0033] The vehicle-mounted system 100 includes a first conductive path 81, a second conductive path 82, and a third conductive path 83. The first conductive path 81 and the second conductive path 82 are disposed between a first power supply unit 91 and a second power supply unit 92. One end of the first conductive path 81 is electrically connected to the first power supply unit 91. One end of the second conductive path 82 is electrically connected to the second power supply unit 92. The other end of the first conductive path 81 and the other end of the second conductive path 82 are electrically connected at a first connection point 71. The first connection point 71 corresponds to the "connection point" of this disclosure. The third conductive path 83 is disposed between the first connection point 71 and a load 93. One end of the third conductive path 83 is electrically connected to the first connection point 71. The other end of the third conductive path 83 is electrically connected to the load 93.

[0034] In this disclosure, the "electrical connection" is preferably a structure in which the potentials of both connected objects are equal and they are connected in a mutually conductive state (a state in which current flows). However, it is not limited to this structure. For example, the "electrical connection" may also be a structure in which an electrical component is sandwiched between two connected objects and the two connected objects are connected in a conductive state.

[0035] The first conductive path 81 has a first electrical path 81A and a second electrical path 81B. The first electrical path 81A constitutes one end of the first conductive path 81 (the first power supply section 91 side). The second electrical path 81B constitutes the other end of the first conductive path 81 (the first connection point 71 side).

[0036] The second conductive path 82 has a third electrical path 82A and a fourth electrical path 82B. The third electrical path 82A constitutes one end of the second conductive path 82 (the second power supply section 92 side). The fourth electrical path 82B constitutes the other end of the second conductive path 82 (the first connection point 71 side).

[0037] The first power supply unit 91 supplies power to the first conductive circuit 81. The first power supply unit 91 is, for example, a high-voltage battery. The first power supply unit 91 can be composed of secondary batteries such as lithium-ion batteries and sodium-ion batteries, or it can be composed of other types of batteries. The high-potential side terminal of the first power supply unit 91 is electrically connected to one end of the first conductive circuit 81.

[0038] The second power supply unit 92 supplies power to the second conductive circuit 82. The second power supply unit 92 is, for example, a low-voltage battery. The second power supply unit 92 can be composed of a secondary battery such as a lithium-ion battery or a lead-acid battery, or other types of batteries. For example, the output voltage of the second power supply unit 92 is lower than the output voltage of the first power supply unit 91. The high-potential side terminal of the second power supply unit 92 is electrically connected to one end of the second conductive circuit 82.

[0039] Load 93 is, for example, an electrical load used in a vehicle. Load 93 is, for example, an electric brake, etc.

[0040] 1-2. Structure of power supply device 10

[0041] The power supply device 10 is, for example, an electrical connection box, more specifically, a junction box. The power supply device 10 is electrically connected to the first power supply unit 91, the second power supply unit 92, and the load 93.

[0042] The power supply device 10 has a housing component 20, a first terminal 21, a second terminal 22, and a third terminal 23. The housing component 20 constitutes the outer casing of the power supply device 10. The first terminal 21, the second terminal 22, and the third terminal 23 are disposed on the housing component 20. The first terminal 21 is disposed between the first power supply unit 91 and the first switch 31 (described later) (midway in the first electrical path 81A). The first power supply unit 91 is electrically connected to the first terminal 21 and is supplied with power from the first power supply unit 91. The second terminal 22 is disposed between the second power supply unit 92 and the second switch 32 (described later) (midway in the third electrical path 82A). The second power supply unit 92 is electrically connected to the second terminal 22 and is supplied with power from the second power supply unit 92. The third terminal 23 is disposed between the load 93 and the second connection point 72 (described later) (midway in the third conductive path 83). The load 93 and the energy storage unit 34 (described later) are electrically connected to the third terminal 23.

[0043] The power supply device 10 has a first switch 31, a second switch 32 and a control unit 33.

[0044] A first switch 31 is disposed in a first conductive path 81. The first switch 31 is located between a first electrical path 81A and a second electrical path 81B. One end of the first switch 31 is electrically connected to the first electrical path 81A. The other end of the first switch 31 is electrically connected to the second electrical path 81B. The first switch 31 switches between a first enabled state and a first disabled state. The first enabled state allows bidirectional current flow through itself, while the first disabled state disables current flow from the second electrical path 81B to the first electrical path 81A. In this embodiment, when the first switch 31 is in the first disabled state, it allows current to flow from the first electrical path 81A to the second electrical path 81B. The first switch 31 includes, for example, a MOSFET. The first switch 31 is in the first enabled state when the MOSFET is turned on. The first switch 31 is in the first disabled state when the MOSFET is turned off. The first switch 31 is, for example, an IPD (Intelligent Power Device) with built-in protection circuitry.

[0045] A second switch 32 is disposed in the second conductive path 82. The second switch 32 is located between the third electrical path 82A and the fourth electrical path 82B. One end of the second switch 32 is electrically connected to the third electrical path 82A. The other end of the second switch 32 is electrically connected to the fourth electrical path 82B. The second switch 32 switches between a second enabled state and a second disabled state. The second enabled state allows bidirectional current flow through itself, while the second disabled state disables current flow from the fourth electrical path 82B to the third electrical path 82A. In this embodiment, when the second switch 32 is in the second disabled state, it allows current to flow from the third electrical path 82A to the fourth electrical path 82B. The second switch 32 includes, for example, a MOSFET. The second switch 32 is in the second enabled state when the MOSFET is in the ON state. The second switch 32 is in the second disabled state when the MOSFET is in the OFF state. The second switch 32 is, for example, an IPD (Intelligent Power Device) with built-in protection circuitry.

[0046] The control unit 33 is an information processing device with information processing, calculation, and control functions. The control unit 33 may be configured primarily as a microcomputer, and includes a CPU (Central Processing Unit) and a memory such as ROM (Read Only Memory) or RAM (Random Access Memory). The control unit 33 has the function of sending control signals to the first switch 31 and the second switch 32 to control operations.

[0047] When the first switch 31 is in the first enabled state and the second switch 32 is in the second enabled state, the control unit 33 can supply power to the dual-direction load 93 from the first power supply unit 91 and the second power supply unit 92. When the first switch 31 is in the first enabled state and the second switch 32 is in the second enabled state, it is preferable to supply power to the load 93 from the first power supply unit 91.

[0048] The power supply device 10 has an anomaly detection unit (not shown). The anomaly detection unit functions to determine whether a ground fault has occurred in the first electrical path 81A or the third electrical path 82A. Hereinafter, a structure for determining whether a ground fault has occurred in the third electrical path 82A is illustrated, but a similar structure for determining whether a ground fault has occurred in the first electrical path 81A can also be provided.

[0049] The anomaly detection unit includes, for example, a current detection unit (current sensor, not shown) provided in the second conductive path 82 (e.g., the fourth electrical path 82B). The current detection unit detects the magnitude and direction of the current flowing into the second conductive path 82. It detects the current flowing from the second power supply unit 92 side to the first connection point 71 side, and also detects the current flowing from the first connection point 71 side to the second power supply unit 92 side. For example, if a ground fault occurs in the third electrical path 82A when the first switch 31 is in the first enabled state and the second switch 32 is in the second enabled state, the current from the first power supply unit 91 and the current from the second power supply unit 92 flow into the third electrical path 82A. If the anomaly detection unit detects the current flowing from the first connection point 71 side to the second power supply unit 92 side through the current detection unit, it can determine that a ground fault has occurred in the third electrical path 82A. In addition, the anomaly detection unit can also determine that a grounding fault has occurred in the third electrical path 82A if the current detection unit detects a current flowing from the first connection point 71 side to the second power supply unit 92 side and the current value exceeds the threshold current.

[0050] The anomaly detection unit includes, for example, a voltage detection unit (voltage detection circuit) not shown, provided in the second conductive path 82. The voltage detection unit detects the voltage in the second conductive path 82 (more specifically, the third electrical path 82A). For example, in the case of a ground fault in the second conductive path 82 when the first switch 31 is in the first enabled state and the second switch 32 is in the second enabled state, current from the first power supply unit 91 and current from the second power supply unit 92 flow into the second conductive path 82. If the voltage in the second conductive path 82 falls below a threshold voltage, it can be determined that a ground fault has occurred in the third electrical path 82A.

[0051] The power supply device 10 also includes an energy storage unit 34 and a backflow prevention unit 35. The housing component 20 houses the first switch 31, the second switch 32, the control unit 33, the energy storage unit 34, and the backflow prevention unit 35.

[0052] The energy storage unit 34 supplies power to the load 93 via the third conductive path 83. The energy storage unit 34 is, for example, composed of a double-layer capacitor. The energy storage unit 34 may also be a structure formed by connecting multiple double-layer capacitors in series. One end of the energy storage unit 34 is electrically connected to the third conductive path 83. The energy storage unit 34 is connected to the third conductive path 83 via a conductive path 34A. One end of the conductive path 34A is connected to the second connection point 72 in the third conductive path 83. The other end of the conductive path 34A is connected to one end of the energy storage unit 34.

[0053] A reverse current prevention unit 35 is disposed in the third conductive path 83 between the energy storage unit 34 and the first connection point 71. The reverse current prevention unit 35 prevents current from flowing from the energy storage unit 34 to the first switch 31 via the third conductive path 83 and from the energy storage unit 34 to the second switch 32 via the third conductive path 83. The reverse current prevention unit 35 is constructed, for example, of a rectifier diode (e.g., an ideal diode) such as a PN junction diode. The anode of the reverse current prevention unit 35 is electrically connected to the first connection point 71. A voltage based on the power supply voltage of the first power supply unit 91 and a voltage based on the power supply voltage of the second power supply unit 92 are applied to the anode of the reverse current prevention unit 35. The cathode of the reverse current prevention unit 35 is electrically connected to the second connection point 72.

[0054] 1-3. Operating Example of Power Supply Device 10

[0055] When the start condition is met, the control unit 33 switches the first switch 31 from a first off state to a first enabled state, and switches the second switch 32 from a second off state to a second enabled state. As a result, power from the first power supply unit 91 or the second power supply unit 92 is supplied to the load 93. The start condition may be, for example, the vehicle's start switch switching from an off state to an on state, or other conditions. In an engine-mounted vehicle, the start switch is the ignition switch; in an electric vehicle, it is the power switch.

[0056] For example, when the first switch 31 is in the first enabled state and the second switch 32 is in the second enabled state, in the event of a ground fault in the third electrical path 82A, current from the first power supply unit 91 and current from the second power supply unit 92 flow to the third electrical path 82A. As a result, current flows from the first connection point 71 side to the second power supply unit 92 side, the aforementioned fault detection unit detects the ground fault, and the control unit 33 switches the second switch 32 from the second enabled state to the second disabled state. Thus, the flow of current from the first connection point 71 side to the second power supply unit 92 side is cut off, and power from the first power supply unit 91 is supplied to the load 93.

[0057] As described above, in the power supply device 10, if a ground fault or other event occurs in the third electrical path 82A and the power supply to the second power supply unit 92 fails, the second conductive path can be disconnected by the second switch 32. Furthermore, after the power supply to the second power supply unit 92 fails, power can be supplied to the load 93 from the energy storage unit 34 via the third conductive path 83, thus seamlessly maintaining the power supply to the load 93. Specifically, after a ground fault or other event is detected by the fault detection unit, power can be supplied to the load 93 from the energy storage unit 34 until the second switch 32 is switched from the second permitted state to the second disconnected state.

[0058] Furthermore, the reverse current prevention unit 35 prevents current from flowing from the energy storage unit 34 to the first switch 31 via the third conductive path 83 and from the energy storage unit 34 to the second switch 32 via the third conductive path 83. As a result, the power supplied from the energy storage unit 34 is directed only to the load 93.

[0059] For example, after switching the second switch 32 to the second off state, the control unit 33 may maintain the second switch 32 in the second off state even if there is no current flowing from the first connection point 71 side to the second power supply unit 92 side. After switching the second switch 32 to the second off state, the control unit 33 may restore the second switch 32 to the second allowed state if a recovery condition is met. The recovery condition may be, for example, a condition that is met after a predetermined time. The recovery condition may also be that the output voltage of the second power supply unit 92 becomes a recovery voltage or higher. The recovery condition may also be that the temperature of the second switch 32 becomes a recovery temperature or higher.

[0060] Furthermore, the power supply device 10 can perform the same control as in the case of a ground fault in the third electrical path 82A, even in the event of a ground fault in the first electrical path 81A. For example, when the first switch 31 is in the first permitted state and the second switch 32 is in the second permitted state, in the event of a ground fault in the first electrical path 81A, current from the first power supply unit 91 and current from the second power supply unit 92 flow to the first electrical path 81A. As a result, current flows from the first connection point 71 side to the first power supply unit 91 side, the aforementioned fault detection unit detects the ground fault, and the control unit 33 switches the first switch 31 from the first permitted state to the first disconnected state. Thus, the flow of current from the first connection point 71 side to the first power supply unit 91 side is cut off, and power from the second power supply unit 92 is supplied to the load 93.

[0061] Furthermore, after a power failure in the first power supply unit 91, power can be supplied from the energy storage unit 34 to the load 93 via the third conductive path 83, thus seamlessly maintaining the power supply to the load 93. Specifically, after a ground fault or similar issue is detected by the anomaly detection unit, power can be supplied from the energy storage unit 34 to the load 93 until the first switch 31 is switched from the first permitted state to the first disconnected state. Moreover, the reverse current prevention unit 35 prevents current from flowing from the energy storage unit 34 to the first switch 31 via the third conductive path 83 and from the energy storage unit 34 to the second switch 32 via the third conductive path 83. As a result, the power supplied from the energy storage unit 34 is directed solely to the load 93.

[0062] 1-4. Examples of the effects of power supply device 10

[0063] In the power supply device 10, if a ground fault or other event occurs in the first conductive path 81 on the side closer to the first power supply unit 91 than the first switch 31, causing a power failure in the first power supply unit 91, the first conductive path 81 can be disconnected by the first switch 31. Furthermore, after the power failure of the first power supply unit 91, power can be supplied to the load 93 from the energy storage unit 34 via the third conductive path 83, thus maintaining the power supply to the load 93. Similarly, in the case of a power failure in the second power supply unit 92, the second conductive path 82 can be disconnected by the second switch 32, maintaining the power supply from the energy storage unit 34 to the load 93 after a power failure. Moreover, the reverse current prevention unit 35 prevents current from flowing from the energy storage unit 34 to the first switch 31 via the third conductive path 83 and from the energy storage unit 34 to the second switch 32 via the third conductive path 83. Therefore, the power supply device 10 can realize a structure that can maintain the power supply to the load 93.

[0064] In the power supply device 10, a backflow prevention unit 35 is provided in the third conductive path 83 between the energy storage unit 34 and the first connection point 71. Therefore, by providing the backflow prevention unit 35 in the third conductive path 83, a structure that prevents backflow from the energy storage unit 34 to the first conductive path 81 and the second conductive path 82 can be achieved in the power supply device 10. Thus, compared to a case where the backflow prevention unit 35 is provided on both the first conductive path 81 and the second conductive path 82, the power supply device 10 has a simplified structure.

[0065] 2. Second Implementation Method

[0066] The power supply device 210 in the second embodiment differs from the first embodiment in that it has a third switch 236 provided in the third conductive path 83. Furthermore, in the second embodiment, structures identical to those in the first embodiment are labeled with the same reference numerals, and detailed descriptions are omitted.

[0067] like Figure 2 As shown, the vehicle system 200 includes a power supply device 210. The power supply device 210 also includes a third switch 236. The housing component 20 houses a first switch 31, a second switch 32, a control unit 33, a power storage unit 34, a backflow prevention unit 35, and the third switch 236.

[0068] The third switch 236 is located in the third conductive circuit 83 and is connected in series with the reverse current prevention unit 35 between the first connection point 71 and the reverse current prevention unit 35. One end of the third switch 236 is electrically connected to the first connection point 71. The other end of the third switch 236 is electrically connected to the anode of the reverse current prevention unit 35. The third switch 236 switches between a third allowable state and a third cut-off state. The third allowable state allows bidirectional current flow through itself, while the third cut-off state cuts off current flow from the first connection point 71 side to the reverse current prevention unit 35 side. The third switch 236 includes, for example, a MOSFET. The third switch 236 becomes the third allowable state when the MOSFET is turned on. The third switch 236 becomes the third cut-off state when the MOSFET is turned off. The third switch 236 is, for example, an IPD (Intelligent Power Device) with built-in protection circuitry.

[0069] The control unit 33 sends a control signal to the third switch 236 to control the operation. The third switch 236 may also be configured as a pair of MOSFETs having parasitic diodes facing opposite directions.

[0070] For example, the power supply device 210 considers situations where a ground fault occurs in the load 93 while the start condition is met, the first switch 31 is in the first permitted state, the second switch 32 is in the second permitted state, and power from the first power supply unit 91 or the second power supply unit 92 is supplied to the load 93. Here, a ground fault in the load 93 can be detected by providing an anomaly detection unit with the same structure as the aforementioned anomaly detection unit in the third conductive path 83. For example, if the current flowing from the second connection point 72 side to the load 93 side exceeds a threshold current, the anomaly detection unit can determine that a ground fault has occurred in the load 93. Furthermore, for example, if the voltage in the third conductive path 83 is below a threshold voltage, it can be determined that a ground fault has occurred in the third conductive path 83.

[0071] When the anomaly detection unit detects a ground fault in the load 93, the control unit 33 switches the third switch 236 from the third enabled state to the third disabled state. This cuts off the flow of current from the first connection point 71 to the load 93. Thus, by using the third switch 236 to disconnect the third conductive path 83, it is possible to prevent overcurrent from flowing from the first conductive path 81 and the second conductive path 82 to the load 93 in the event of a ground fault in the load 93.

[0072] Furthermore, when the first switch 31 is configured to allow current to flow from the first electrical path 81A to the second electrical path 81B in the first off state, that is, when it is a MOSFET with a parasitic diode that allows current to flow from the first electrical path 81A to the second electrical path 81B, by setting the third switch 236 to the third off state, it is possible to prevent the flow of dark current from the first power supply section 91 or the second power supply section 92.

[0073] 3. Third Implementation Method

[0074] The power supply device 310 of the third embodiment differs from that of the first embodiment in that it has an additional structural component. Furthermore, in the third embodiment, the same reference numerals are used for the same structures as in the first embodiment, and detailed descriptions are omitted.

[0075] like Figure 3 As shown, the vehicle system 300 also includes a fourth conductive path 384. The fourth conductive path 384 is electrically connected to both ends of the backflow prevention unit 35. One end of the fourth conductive path 384 is connected to the second conductive path (fourth electrical path 82B) at the third connection point 373. The other end of the fourth conductive path 384 is connected to the third conductive path 83 at the second connection point 372.

[0076] The power supply device 310 also includes a resistor 337, a second backflow prevention unit 338, and a fourth switch 339. The housing component 20 houses the first switch 31, the second switch 32, the control unit 33, the energy storage unit 34, the backflow prevention unit 35, the resistor 337, the second backflow prevention unit 338, and the fourth switch 339.

[0077] The energy storage unit 34 is connected to the fourth conductive path 384 via a conductive path 334A. One end of the conductive path 334A is connected to the fourth connection point 374 in the fourth conductive path 384. The other end of the conductive path 334A is connected to one end of the energy storage unit 34. The energy storage unit 34 is electrically connected in the fourth conductive path 384 between the second connection point 372 and the resistor 337 (described later).

[0078] Resistor 337 is disposed in the fourth conductive path 384 between the second connection point 372 and the fourth connection point 374. One end of resistor 337 is electrically connected to the second connection point 372. The other end of resistor 337 is electrically connected to the fourth connection point 374.

[0079] The second reverse current prevention unit 338 is disposed in the fourth conductive path 384 between the second connection point 372 and the energy storage unit 34. The second reverse current prevention unit 338 prevents current from flowing from the third conductive path 83 through the second connection point 372 to the energy storage unit 34. The second reverse current prevention unit 338 is, for example, a rectifier diode (e.g., an ideal diode) such as a PN junction diode. The anode of the second reverse current prevention unit 338 is electrically connected to the fourth connection point 374. The cathode of the second reverse current prevention unit 338 is electrically connected to the second connection point 372.

[0080] In the power supply device 310, a resistor 337 is provided in the fourth conductive path 384, which is electrically connected to both ends of the reverse current prevention unit 35. Therefore, when power supply from at least one of the first power supply unit 91 and the second power supply unit 92 begins, it is possible to prevent inrush current from the side of the fourth conductive path 384 opposite to the second connection point 372 to the energy storage unit 34. In addition, a second reverse current prevention unit 338 is provided in the fourth conductive path 384 between the second connection point 372 and the energy storage unit 34, thereby preventing inrush current from the second connection point 372 side to the energy storage unit 34 in the fourth conductive path 384.

[0081] A fourth switch 339 is disposed in the third conductive path 83 between the second connection point 372 and the load 93. One end of the fourth switch 339 is electrically connected to the second connection point 372. The other end of the fourth switch 339 is electrically connected to the load 93. The fourth switch 339 switches between a fourth enable state and a fourth cut-off state, wherein the fourth enable state allows bidirectional current flow through itself, and the fourth cut-off state cuts off current flow from the load 93 side to the first connection point 71 side. The fourth switch 339 includes, for example, a MOSFET. The fourth switch 339 becomes the fourth enable state when the MOSFET is turned on. The fourth switch 339 becomes the fourth cut-off state when the MOSFET is turned off. The fourth switch 339 is, for example, an IPD (Intelligent Power Device) with built-in protection circuitry.

[0082] The control unit 33 sends a control signal to the fourth switch 339 to control the operation. The fourth switch 339 may also be configured as a pair of MOSFETs having parasitic diodes facing opposite directions.

[0083] In the power supply device 310, by using the fourth switch 339 to disconnect the third conductive path 83, it is possible to prevent the flow of current from at least one of the first power supply unit 91 and the second power supply unit 92 to the load 93 side via the resistor 337 and the second reverse current prevention unit 338, and the flow of current to the load 93 side via the reverse current prevention unit 35. Thus, by using the fourth switch 339 to disconnect the third conductive path 83, it is possible to prevent overcurrent from flowing from the first conductive path 81 side and the second conductive path 82 side to the load 93 side in the event of a ground fault in the load 93.

[0084] <Other Implementation Methods>

[0085] This disclosure is not limited to the embodiments described above and the accompanying drawings. For example, the features of the embodiments described above or later can be combined in all possible ways without contradiction. Furthermore, any feature in the embodiments described above or later can be omitted unless explicitly stated as essential. Moreover, the embodiments described above can also be modified as follows.

[0086] In the first to third embodiments described above, the backflow prevention unit 35 is provided in the third conductive path 83. In contrast, the backflow prevention unit 35 may be provided in at least one of the first conductive path 81 and the second conductive path 82, or in place of the third conductive path 83, in addition to the structure of being provided in the third conductive path 83. When the backflow prevention unit 35 is provided in the first conductive path 81, the anode of the backflow prevention unit 35 is electrically connected to the first power supply unit 91, and the cathode is electrically connected to the first connection point 71. Similarly, when the backflow prevention unit 35 is provided in the second conductive path 82, the anode of the backflow prevention unit 35 is electrically connected to the second power supply unit 92, and the cathode is electrically connected to the first connection point 71.

[0087] In the first to third embodiments described above, the first power supply unit 91 is configured as a storage battery. Alternatively, the first power supply unit 91 may also include a storage battery and a voltage conversion unit. The voltage conversion unit is, for example, configured as a DC-DC converter. The voltage conversion unit boosts or bucks the voltage input from the storage battery side and outputs it to the first conductive path 81 side. Furthermore, the voltage conversion unit performs a conversion operation that boosts or bucks the voltage input from the first conductive path 81 side and outputs it to the storage battery side.

[0088] In the first to third embodiments described above, the first switch 31 is configured to allow current to flow from the first electrical path 81A to the second electrical path 81B in the first off state. Conversely, the first switch 31 may also be configured to cut off the flow of current from the second electrical path 81B to the first electrical path 81A in the first off state. For example, the first switch 31 may also be configured as a pair of MOSFETs in a series configuration having parasitic diodes facing opposite directions (paired state).

[0089] In the first to third embodiments described above, the second switch 32 is configured to allow current to flow from the third electrical path 82A to the fourth electrical path 82B in the second off state. Conversely, the second switch 32 may also be configured to cut off the flow of current from the fourth electrical path 82B to the third electrical path 82A in the second off state. For example, the second switch 32 may also be configured as a pair of MOSFETs having parasitic diodes facing opposite directions.

[0090] In the first to third embodiments described above, the first switch 31 and the second switch 32 are configured as MOSFETs. In contrast, the first switch 31 and the second switch 32 can also be configured as mechanical switches.

[0091] In the first to third embodiments described above, the reverse current prevention unit 35 is configured as a diode. In contrast, the reverse current prevention unit 35 may also be configured as a parasitic diode of a MOSFET disposed between the first connection point 71 and the second connection point 72 in the third conductive path 83.

[0092] In the first to third embodiments described above, a conductive path may also be provided that branches from the first conductive path 81 or the second conductive path 82 to supply power to a load different from the load 93.

[0093] In the third embodiment described above, one end of the fourth conductive path 384 is connected to the second conductive path 82. Alternatively, one end of the fourth conductive path 384 can be connected to the first conductive path 81.

[0094] Label Explanation

[0095] 10: Power supply equipment

[0096] 20: Housing components

[0097] 21: First terminal

[0098] 22: Second terminal

[0099] 23: Third terminal

[0100] 31: First Switch

[0101] 32: Second switch

[0102] 33: Control Department

[0103] 34: Battery Storage Unit

[0104] 34A: Conductive path

[0105] 35: Backflow prevention part

[0106] 71: First connection point (connection point)

[0107] 72: Second connection point

[0108] 81: First conductive path

[0109] 81A: First electrical path

[0110] 81B: Second Electrical Path

[0111] 82: Second conductive path

[0112] 82A: Third Electrical Path

[0113] 82B: Fourth Electrical Path

[0114] 83: Third conductive path

[0115] 91: First Power Supply Section

[0116] 92: Second Power Supply Section

[0117] 93: Load

[0118] 100: In-vehicle system

[0119] 200: In-vehicle system

[0120] 210: Power supply equipment

[0121] 236: Third Switch

[0122] 300: In-vehicle system

[0123] 310: Power supply equipment

[0124] 334A: Conductive path

[0125] 337: Resistor

[0126] 338: Second Backflow Prevention Section

[0127] 339: Fourth Switch

[0128] 372: Second connection point

[0129] 373: Third connection point

[0130] 374: Fourth Connection Point

[0131] 384: Fourth conductive path.

Claims

1. A power supply device included in a vehicle-mounted system, the vehicle-mounted system comprising: a first power supply unit; a second power supply unit; a load; a first conductive path from which power is supplied; a second conductive path from which power is supplied; and a third conductive path disposed between a connection point of the first conductive path and the second conductive path and the load, wherein... The power supply device includes: A first switch is disposed in the first conductive path; A second switch is provided in the second conductive path; The energy storage unit supplies power to the load via the third conductive circuit; and The backflow prevention unit prevents current from flowing from the energy storage unit to the first switch via the third conductive path and from the energy storage unit to the second switch via the third conductive path.

2. The power supply device according to claim 1, wherein, The backflow prevention unit is disposed in the third conductive circuit between the energy storage unit and the connection point.

3. The power supply device according to claim 1 or claim 2, wherein, A third switch is provided in series with the reverse current prevention unit in the third conductive circuit.

4. The power supply device according to claim 1 or claim 2, wherein, The power supply device includes a housing component that houses the first switch, the second switch, the energy storage unit, and the reverse current prevention unit. The power supply device is configured as a junction box.

5. The power supply device according to claim 1 or claim 2, wherein, The power supply device includes: The fourth conductive path is electrically connected to both ends of the backflow prevention section; and A resistor is provided in the fourth conductive path. The fourth conductive path is connected to the third conductive path at the second connection point. The energy storage unit is electrically connected in the fourth conductive circuit between the second connection point and the resistor. The power supply device includes a second backflow prevention unit, which is disposed in the fourth conductive path between the second connection point and the energy storage unit to prevent current from flowing from the third conductive path through the second connection point to the energy storage unit.

6. The power supply device according to claim 5, wherein, The power supply device includes a fourth switch, which is disposed in the third conductive circuit between the second connection point and the load.

Images