Electrical power system

Abstract

To provide an electrical power system which limits electric power consumption.SOLUTION: An electrical power system 1 mounted on a vehicle includes a plurality of loads 61-66 connected to a main electric power source 10 via an electric wire 20, and a switch connected to the electric wire 20 between the main electric power source 10 and the plurality of loads 61-66. Switches of a plurality of switches which are constantly ON during a travel of a vehicle are semiconductor switches 41-46.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power supply system. [Background technology]

[0002] For example, the in-vehicle power supply system described in Patent Document 1 includes a power supply hub connected to a main power supply line wired to a battery, electronic devices connected to each of the power supply hubs, relays that turn on and off the power supply to each electronic device, and a control device that controls the power supply to each electronic device by controlling the on and off of the relays. A mechanical relay is used as the relay for electronic devices with a current consumption of 10 A or more, and a semiconductor relay is used as the relay for electronic devices with a current consumption of less than 10 A. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-020614 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-described on-board power supply system, if the mechanical relay is a relay that must be constantly on while the vehicle is running, there is a problem in that power consumption increases.

[0005] An object of the present invention is to provide a power supply system that reduces power consumption. [Means for solving the problem]

[0006] The present invention solves the above problem by providing a switch connected to wiring between a main power source and a plurality of loads, and by making one of the plurality of switches that is constantly on while the vehicle is running a semiconductor switch. Effect of the Invention

[0007] The present invention can reduce power consumption. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram of a power supply system according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] FIG. 1 is a block diagram of a power supply system 1 according to the present invention. The power supply system according to this embodiment is mounted on a vehicle. The power supply system 1 includes a main power supply 10, wiring 20, a battery fuse terminal (BFT) 30, semiconductor switches (semiconductor SW) 41-46, relay switches 51 and 52, a transfer relay 53, and loads 61-69. The power supply system 1 is mounted on a vehicle driven by a gasoline engine or a diesel engine (ICE vehicle), a hybrid vehicle, an electric vehicle without an internal combustion engine, or the like. The power supply system 1 supplies electric power from the main power supply to the loads 61-69.

[0010] The main power supply 10 is a battery that can be charged by an external charging device and / or regeneration of a motor, and includes a secondary battery such as a lithium-ion battery. When the power supply system 1 is mounted on an ICE vehicle, the main power supply 10 can also be charged by a charger (such as an alternator) that converts the rotational energy of the engine into electrical energy. One end of the main power supply 19 is grounded, and the other end is electrically connected to loads 61 to 69 via wiring 20. The wiring 20 is a wiring for supplying the power of the main power supply 10 to a plurality of loads 61 to 69 mounted on the vehicle. The wiring 20 includes branch wirings that branch off from a branch point. In the example of FIG. 1, the wiring 20 includes a branch point between the main power supply 10 and the BFT 20, and includes branch wirings 21 to 26 that branch off from this branch point. The branch wirings 21 to 23 include a branch point downstream of the BFT 30, and are branched off into a plurality of branch wirings 21a, 21b, 22a, 22b, 23a, and 23b at each branch point.

[0011] The BFT 30 is connected between the main power supply 10 and the loads 61 to 67, and has a plurality of fuses. The plurality of fuses are connected to the branch wirings 21 to 26. When a large current exceeding the rated current flows through the branch wirings 21 to 26, the fuse melts to cut off the current, thereby protecting the electric wires, loads, and various switches connected downstream of the fuses.

[0012] The semiconductor switches 41-46 are transistor switches such as MOSFETs or power devices (IPDs) built into control ICs. The power consumption of the semiconductor switches 41-46 is smaller than that of the relay switches 51 and 52 and the transfer relay 53 described below. The semiconductor switches 41-46 are connected to a switch portion that is always on while the vehicle is running. The semiconductor switches 41-46 are switched on and off according to a control command from a controller provided in the vehicle. The semiconductor switches 41-46 are always on while the vehicle is running, and are turned off when the vehicle is parked and the vehicle controller (ECU) is in sleep mode.

[0013] The semiconductor switches 41 and 42 are connected to the branch wirings 21a and 21b, respectively, between the main power supply 10 and the loads 61 and 62. The semiconductor switches 43 and 44 are connected to the branch wirings 22a and 22b, respectively, between the main power supply 10 and the loads 63 and 64. Furthermore, the semiconductor switches 45 and 46 are connected to the branch wirings 23a and 23b, respectively, between the main power supply 10 and the loads 65 and 66. The semiconductor switch 41 is a switch corresponding to the load 61, and similarly, the semiconductor switches 42 to 46 are switches corresponding to the loads 62 to 66, respectively.

[0014] The relay switches 51 and 52 are mechanical switches (mechanical relays) and have coils. The relay switches 51 and 52 are connected to the wirings 24 and 25, and the loads 67 and 68 are connected to the downstream sides of the relay switches 51 and 52.

[0015] The transfer relay 53 is a relay switch having transfer contacts (contact A and contact B). The transfer relay 53 is a switch that is both normally closed and normally open, and has a coil. When no current flows through the coil (normal state), the transfer relay 53 cuts off the connection between the one point and the contact A, and conducts between the one point and the contact B. On the other hand, when current flows through the coil, the transfer relay 53 conducts between the one point and the contact A, and cuts off the connection between the one point and the contact B. The downstream side of the transfer relay 53 is connected to the load 69 and to ground via a resistor.

[0016] The loads 61-66 are connected downstream of the wiring network in a state in which they can receive power from the main power source 10 while the vehicle is running. The multiple loads 61-66 are connected to branch wirings 21a, 21b, 22a, 22b, 23a, and 23b branched from a branch point included in the wiring, respectively. The loads 61 and 62 are loads related to the power train, such as a power steering system (EPS), a meter, and engine-related parts (fuel pump).

[0017] In a vehicle (ICE vehicle), such loads related to the power train are connected to the main power source 10 via an IGN relay that is turned on / off in conjunction with the operation of an ignition switch (IGN switch). Conventionally, a mechanical relay has been used for the ignition switch (IGN relay). In this embodiment, semiconductor switches 41 and 42 are connected to switch parts (switch parts corresponding to the IGN relay) connected to the loads 61 and 62 related to the power train, respectively. The semiconductor switches 41 and 42 are always on while the vehicle is running, but the semiconductor switches 41 and 42 do not need to energize the coils when they are on, and therefore consume less power than a mechanical relay, so that the overall power consumption can be suppressed. Furthermore, the semiconductor switches 41 and 42 are connected to branch wirings 21a and 21b, and the switch parts corresponding to the loads 61 and 62 are the semiconductor switches 41 and 42. The current flowing through the branch wirings 21a and 21b is lower than the current flowing through the upstream side of the wiring 20. Therefore, the power consumption of the semiconductor switches 41 and 42 can be suppressed.

[0018] The loads 63 and 64 are loads related to the navigation system and the entertainment system, such as audio equipment and displays.

[0019] Such a navigation system and entertainment system are connected to the main power supply 10 via an ACC relay. Conventionally, a mechanical relay has been used for the ACC relay. In this embodiment, semiconductor switches 43, 44 are connected to switch parts (switch parts corresponding to the ACC relay) connected to the loads 63, 64, respectively. The semiconductor switches 43, 44 are always on while the vehicle is running, but since the power consumption of the semiconductor switches 43, 44 is low, the overall power consumption can be suppressed. Furthermore, the semiconductor switches 43, 44 are connected to the branch wirings 22a, 22b, and the switch parts corresponding to the loads 63, 64 are the semiconductor switches 43, 44. This allows the power consumption of the semiconductor switches 43, 44 to be suppressed.

[0020] The loads 65, 66 are loads having a common function such as a plurality of lamps (illumination function in the case of lamps), and are distributed and arranged in various parts of the vehicle. The loads 65, 66 are connected to the main power source 10 via the branch wirings 23a, 23b. For example, if a relay or a semiconductor switch is connected so that a plurality of loads are collectively turned on / off by the relay or the semiconductor switch, the loss (current x current squared) of the contact part of the relay or the semiconductor switch becomes large due to the large current flowing through the contact part. On the other hand, by connecting the semiconductor switches 45, 46 to the branch wirings 23a, 23b respectively so as to correspond to each of the loads 65, 66, the current flowing through the semiconductor switches 45, 46 becomes small, and the power consumption of the contact parts of the semiconductor switches 45, 46 becomes small. As a result, the overall power consumption can be suppressed.

[0021] Load 67 is a load such as a horn that has a large current pulsation when the load is activated. Relay switch 51 is connected in correspondence with load 67. If load 67 with a large current pulsation is connected downstream of the switch, the voltage change will be large when the load is activated, and a large current may flow through the switch. If a semiconductor switch is used in such a switch portion, an excessive load may be applied to the semiconductor switch. For this reason, in this embodiment, the switch connected in correspondence with load 67 is relay switch 51.

[0022] The load 68 is a load that is operated while the vehicle is parked, such as an alarm system or a door handle opening / closing system. The alarm system is a system that prevents break-ins and theft while the vehicle is parked. The door handle opening / closing system is a system that detects a user with a key approaching a parked vehicle and causes the door handle to pop out from the door. The relay switch 52 is a mechanical relay having a permanent magnet, and is connected to the load 68. The relay switch 52 can maintain an on state by utilizing the magnetic force of the permanent magnet (it is a normally on switch). If a semiconductor switch is used for such a switch portion, power will be consumed while the vehicle is parked. Furthermore, if a normally on switch is to be replaced with a semiconductor switch, a large-scale circuit configuration is required. Therefore, in this embodiment, the switch connected to the load 68 is the relay switch 52.

[0023] The load 69 is, for example, a motor. The power generated by the motor during regeneration is used to charge the main power supply 10, but when the main power supply 10 is fully charged, the main power supply 10 cannot be charged with the regenerative power. A transfer relay is used for the switch included in the brake circuit, and in a normal state, the brake circuit closes the contacts so as to conduct between the load 69 and the main power supply 10. When the regenerative power is to flow to the ground, the transfer relay is switched to conduct between the load 69 and the ground. A transfer relay 53 is connected to a switch that requires such circuit switching, instead of a semiconductor switch. Note that the wiring of the power supply system 1 shown in FIG. 1 is an example, and the number of switches such as the semiconductor switches 41 to 46 and the relay switches 51 and 52, and the number of the loads 61 to 69 are not limited to those shown in FIG. 1.

[0024] As described above, the power supply system 1 according to this embodiment includes a plurality of loads 61-68 connected to the main power supply 10 via the wiring 20, and switches connected to the wiring 20 between the main power supply 10 and the plurality of loads 61-68. Among the plurality of switches, the switches that are always on while the vehicle is running are the semiconductor switches 41-44. By using the semiconductor switches 41-44 as switches that are always on while the vehicle is running, it is possible to reduce power consumption. Furthermore, in this embodiment, the semiconductor switches 41-44 are used as switches that are always on while the vehicle is running and through which a large current flows, so that power consumption can be reduced.

[0025] In this embodiment, the loads 61-66 are connected to branch wirings 21a, 21b, 22a, 22b, 23a, and 23b branched from a branch point included in the wiring 20, respectively, and the switches connected to the loads 61-66 are semiconductor switches 41-46. The current waves flowing through the branch wirings 21a, 21b, 22a, 22b, 23a, and 23b are lower than the current flowing on the upstream side of the wiring 20. Therefore, semiconductor elements with low withstand voltage can be used for the semiconductor switches 41-46. Furthermore, the current flowing is low, so the power consumption of the semiconductor switches 41-46 can be suppressed.

[0026] In this embodiment, the multiple loads 65, 66 have a common function and are distributed in the vehicle, and the multiple switches connected to the multiple loads 65, 66 are the semiconductor switches 45, 46. When the loads 65, 66 having the same function are distributed, the current flowing through the loads 65, 66 is reduced because the loads 65, 66 are connected to the main power supply 10 via branch wiring. Therefore, by connecting the semiconductor switches 45, 46, power consumption can be reduced.

[0027] In this embodiment, the circuit section including the switch has a transfer contact, and the switch included in the circuit section is a relay switch. Since the transfer relay 53 includes a normally closed circuit, replacing it with a semiconductor switch requires a large-scale circuit configuration, which has the disadvantage of limiting the types of loads that can be connected, and there is a risk of the circuit becoming more complicated or the cost increasing. In this embodiment, a mechanical relay is used for circuits that are inappropriate for semiconductorization.

[0028] In this embodiment, the switch connected corresponding to the load 67 with large current pulsation is the relay switch 51. A mechanical relay is used for the switch with high withstand voltage.

[0029] In this embodiment, the switch that is always on or continues to be on for a long time while the vehicle is parked is the relay switch 52 having a permanent magnet, which makes it possible to reduce power consumption while the vehicle is parked.

[0030] In this embodiment, the switches connected to correspond to a load that has a large current flow and operates intermittently may be relay switches 51 and 52. Examples of such loads include a starter switch for starting an engine, a PTC heater, a wiper, a washer motor, a defogger, a mirror heater, a power window, a radiator fan, a DC outlet, and a blower motor. In order to apply a semiconductor switch to a switch connected to correspond to such a load, a semiconductor element with a high withstand voltage is required. In addition, since the semiconductor switch operates intermittently, the conduction time of the semiconductor switch is short, and the effect of suppressing power consumption is limited. Therefore, the switch connected to correspond to such a load may be a relay switch.

[0031] Although the embodiments of the present invention have been described above, these embodiments are described to facilitate understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design modifications and equivalents that fall within the technical scope of the present invention. [Explanation of symbols]

[0032] 1 Power System 10 Main power 20 Wiring 21~26, 21а, 21b, 22а, 22b, 23а, 23b Branch wiring 30 Battery Fuse Terminal (BFT) 41~46 Semiconductor switches 51, 52 Relay switch 53 Transfer relay 61~69 Load

Claims

1. A power supply system mounted on a vehicle, A plurality of loads connected to a main power supply via wiring; a switch connected to the wiring between the main power supply and the plurality of loads; A power supply system, wherein the switch that is constantly on while the vehicle is running among the plurality of switches is a semiconductor switch.

2. 2. The power supply system according to claim 1, the plurality of loads are connected to branch wirings branched from a branch point included in the wiring, The power supply system, wherein the plurality of switches connected to the plurality of loads respectively correspond to the semiconductor switches.

3. 3. The power supply system according to claim 1, The plurality of loads have a common function and are distributed in the vehicle; The power supply system, wherein the plurality of switches connected to the plurality of loads respectively correspond to the semiconductor switches.

4. 3. The power supply system according to claim 1, A power supply system in which a circuit portion including the switch has a transfer contact, and the switch included in the circuit portion is a relay switch.

5. 3. The power supply system according to claim 1, The load is a load that has a large current pulsation when the load is in operation, and the switch connected corresponding to the load having the large current pulsation is a relay switch.

6. 3. The power supply system according to claim 1, A power supply system, wherein the switch that is always on while the vehicle is parked is a relay switch having a permanent magnet.

7. 3. The power supply system according to claim 1, A power supply system, wherein the switch is a semiconductor switch when the plurality of loads connected downstream of the switch are loads related to a power train.

8. 3. The power supply system according to claim 1, A power supply system, wherein the switch is a semiconductor switch when the plurality of loads connected downstream of the switch are loads related to a navigation system and an entertainment system.

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