Vehicle Power System

Abstract

To provide a vehicle power supply system that can control a DCDC converter and an alternator in cooperation between them with a simple configuration at low cost.SOLUTION: A vehicle power supply system includes: a DCDC converter for supplying power from a battery to first and second devices; an alternator connected to the DCDC converter in parallel and capable of supplying generated power to the first and second devices; and a controller for detecting a switch operation for activating and stopping the second device. The alternator supplies generated power to both first and second devices when the controller detects the switching operation of activating the second device.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a power supply system mounted on a vehicle. [Background technology]

[0002] Patent Document 1 discloses a vehicle power supply system configured to provide an alternator in parallel with a DC-DC converter in vehicles such as hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs) to address power shortages in the auxiliary equipment system that arise when additional mounted equipment is added. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent application No. 2020-074737 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned Patent Document 1 discloses a method for cooperatively controlling the power generation of an alternator in accordance with the load state of a DC-DC converter, but this method has problems in that the configuration of the power supply system is complicated and the cost is high.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a vehicle power supply system that can cooperatively control a DC-DC converter and an alternator with a simple configuration and low cost. [Means for solving the problem]

[0006] In order to solve the above problems, one aspect of the disclosed technology is a vehicle power supply system that includes a DC-DC converter that supplies battery power to a first device and a second device, an alternator that is connected in parallel with the DC-DC converter and is capable of supplying generated power to the first device and the second device, and a control unit that detects a switch operation that starts and stops the second device, and the alternator supplies the generated power to the first device and the second device when the control unit detects a switch operation that starts the second device. [Effects of the Invention]

[0007] According to the vehicle power supply system of the present disclosure, the supply of generated power from the alternator to the first and second devices is triggered by a switch operation that starts the second device, thereby enabling cooperative control of the DC-DC converter and the alternator with a simple configuration and low cost. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram of a vehicle power supply system and its peripheral components according to an embodiment of the present disclosure; [Figure 2A] Flowchart of power control process executed by a vehicle power supply system [Figure 2B] Flowchart of power control process executed by a vehicle power supply system DETAILED DESCRIPTION OF THE INVENTION

[0009] The vehicle power supply system of the present disclosure includes a DC-DC converter that supplies power from a battery to a load and an alternator connected in parallel to the DC-DC converter. When a power shortage occurs due to the operation of a specific load, the system detects a switch operation to start the specific load and supplies the generated power of the alternator to the load in parallel with the power of the DC-DC converter. This enables coordinated control of the DC-DC converter and alternator with a simple configuration and low cost. It is possible. Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0010] [Embodiment] <Configuration> Fig. 1 is a functional block diagram showing a schematic configuration of a vehicle power supply system 100 and its peripheral components according to one embodiment of the present disclosure. The functional block illustrated in Fig. 1 includes the vehicle power supply system 100, a power source 200, an auxiliary device 310, and mounted devices 320. The vehicle power supply system 100 is mounted on a vehicle such as a hybrid vehicle or a plug-in hybrid vehicle.

[0011] The vehicle power supply system 100 is configured to control the power supply to the auxiliary equipment 310 and the mounted equipment 320. The vehicle power supply system 100 includes a first battery 110, a second battery 120, a DC-DC converter 130, an alternator 140, and a control unit 150.

[0012] The first battery 110 is a secondary battery configured to be chargeable and dischargeable, such as a lithium-ion battery or a nickel-metal hydride battery. The first battery 110 can output stored power to the DC-DC converter 130. An example of this first battery 110 is a high-voltage drive battery (high-voltage battery) that supplies power for running the vehicle.

[0013] The second battery 120 is a secondary battery configured to be rechargeable, such as a lead battery or a lithium-ion battery. The second battery 120 can output stored electric power to the auxiliary device 310 and the mounted device 320. The second battery 120 can also be charged with electric power from the first battery 110 supplied via the DC-DC converter 130 and electric power generated by the alternator 140. An example of the second battery 120 is an auxiliary battery that supplies electric power to loads such as the auxiliary device 310 and the mounted device 320.

[0014] The DCDC converter 130 is a voltage converter that is provided between the first battery 110 and the auxiliary device 310 and the mounted device 320, and converts the power of the first battery 110 into power with a voltage suitable for the auxiliary device 310 and the mounted device 320, and outputs the power to the auxiliary device 310 and the mounted device 320. The operation of this DCDC converter 130 is controlled by instructions from the control unit 150 in response to requests from the auxiliary device 310 and / or the mounted device 320. An example of this DCDC converter 130 is a step-down DCDC converter that steps down the voltage of the first battery 110 and outputs the voltage to the auxiliary device 310 and the mounted device 320.

[0015] The alternator 140 is a generator that can generate electricity in response to the operation (drive) of the power source 200. The alternator 140 is connected in parallel with the DC-DC converter 130 so that it can output its own generated power together with the power of the DC-DC converter 130 to the auxiliary equipment 310 and the mounted equipment 320. The control unit 150 controls whether the alternator 140 is allowed to output the generated power.

[0016] The control unit 150 controls the operation of the DC-DC converter 130 and the alternator 140. More specifically, the control unit 150 instructs the DC-DC converter 130 to supply power from the first battery 110 to the auxiliary device 310 and the mounted device 320 in accordance with the power requirements of the auxiliary device 310 and / or the mounted device 320. The control unit 150 also controls the operation (power generation state) of the alternator 140 based on the operating status of the mounted device 320. During this control, the control unit 150 can acquire physical quantities (voltage, current, temperature, etc.) of the second battery 120 via a detection sensor (not shown) or the like, and can also acquire the operating status of the mounted device 320 by detecting the on / off state of the start switch 330. The control by the control unit 150 will be described later.

[0017] The above-mentioned control unit 150 can be configured by an electronic control unit (ECU) that typically includes a processor such as a microcomputer, a memory, an input / output interface, etc. This electronic control unit can realize some or all of the functions performed by the above-mentioned control unit 150 by having the processor read and execute a program stored in the memory.

[0018] Power source 200 is an internal combustion engine such as an engine or an electric motor such as a motor. Power source 200 can activate / stop itself based on an activation request / stop request output from control unit 150. This power source 200 can generate power for running the vehicle, and is configured to be used for supplying power to auxiliary equipment 310 and mounted equipment 320 and for charging second battery 120.

[0019] The auxiliary device 310 is a load (first device) such as an electronic device or equipment that consumes power and is installed in the vehicle. The auxiliary device 310 is configured to operate using power from the first battery 110 and the second battery 120, which are supplied via the DC-DC converter 130. Examples of the auxiliary device 310 include electronic devices that are installed as standard equipment in the vehicle, such as headlamps, wipers, meters, and ECUs.

[0020] The mounted equipment 320 is a load (second equipment) such as an electronic device or equipment mounted on the vehicle that consumes power. In principle, the mounted equipment 320 is configured to operate using power from the first battery 110 and the second battery 120 supplied via the DC-DC converter 130. However, depending on how the mounted equipment 320 is used, the power from the first battery 110 and the second battery 120 alone may be insufficient. An example of the mounted equipment 320 is an electronic device such as an additional lamp mounted on the vehicle as an optional feature. The mounted equipment 320 also includes an activation switch 330 that controls the conduction / non-conduction of power for its own drive. When mounted on the vehicle, the activation switch 330 is configured to notify the control unit 150 of the vehicle power supply system 100 of the on / off state. The activation switch 330 may be provided on the vehicle side instead of the mounted equipment 320. In this case, the connection destination (e.g., a connector) of the mounted equipment 320 is predetermined.

[0021] <Control> Next, the control performed by vehicle power supply system 100 according to this embodiment will be described with further reference to Figures 2A and 2B. Figures 2A and 2B are flowcharts illustrating the procedure for power control performed by vehicle power supply system 100. The process shown in Figure 2A and the process shown in Figure 2B are connected by a connector X.

[0022] (Step S201) The control unit 150 determines whether or not it has detected an operation (ON operation) of the start switch 330 that starts the mounted equipment 320. The control unit 150 can determine the ON operation, for example, by detecting an ON signal that flows in a direct line connected to the mounted equipment 320 in response to an ON operation of the start switch 330. If the control unit 150 detects an operation of the start switch 330 that starts the mounted equipment 320 (step S201, Yes), the process proceeds to step S202; otherwise (step S201, No), the control unit 150 waits until the start switch 330 is turned ON.

[0023] (Step S202) The control unit 150 requests the power source 200 to operate. Upon receiving this request, the power source 200 continues operation if it is already operating, or starts operation if it is not yet operating. The alternator 140 operates in response to the operation of the power source 200, and the alternator 140 generates (generates) electricity according to the operation of the power source 200. When the control unit 150 requests the power source 200 to operate, the process proceeds to step S203.

[0024] (Step S203) The control unit 150 supplies (outputs) the power generated by the alternator 140 to the auxiliary equipment 310 and the mounted equipment 320. This allows the DC-DC converter 130 and the alternator 140 to supply power in parallel to the auxiliary equipment 310 and the mounted equipment 320. When the control unit 150 supplies the power generated by the alternator 140 to the auxiliary equipment 310 and the mounted equipment 320, the process proceeds to step S204.

[0025] (Step S204) The control unit 150 determines whether or not it has detected an operation (off operation) of the start switch 330 to stop the mounted equipment 320. The control unit 150 can determine the off operation, for example, by detecting an OFF signal that flows in a direct line connected to the mounted equipment 320 in response to an off operation of the start switch 330. If the control unit 150 detects an operation of the start switch 330 to stop the mounted equipment 320 (Yes in step S204), the process proceeds to step S205; otherwise (No in step S204), the control unit 150 continues operation of the power source 200 (continues supplying power from the alternator 140 to the auxiliary equipment 310 and the mounted equipment 320) until the start switch 330 is turned on.

[0026] (Step S205) The control unit 150 requests the power source 200 to stop. Upon receiving this request, the power source 200 determines whether it is possible to stop its operation in response to the request. Specifically, the power source 200 determines whether it is possible to stop its own operation based on whether it has received an operation request from another device or system other than the vehicle power supply system 100. An example of a state in which the power source 200 cannot be stopped and an operation request is required is when the amount of stored power in the first battery 110 is low and there is a risk of the battery running out unless it is charged. When the control unit 150 requests the power source 200 to stop, the process proceeds to step S206.

[0027] (Step S206) The power source 200 determines whether to stop or continue operation. This determination is made based on whether or not there is an operation request to the power source 200, as described above. If the power source 200 determines to stop operation (step S206, stop), the process proceeds to step S207. On the other hand, if the power source 200 determines to continue operation (step S206, operate), the process proceeds to step S208.

[0028] (Step S207) In response to the stop of operation of the power source 200, the control unit 150 stops the supply (output) of the generated electric power of the alternator 140 to the auxiliary equipment 310 and the mounted equipment 320. This allows the electric power of only the DC-DC converter 130 to be supplied to the auxiliary equipment 310. When the control unit 150 stops the supply of the generated electric power of the alternator 140, this power control ends.

[0029] (Step S208) As the power source 200 continues to operate, the control unit 150 continues to supply (output) the generated power of the alternator 140 to the auxiliary device 310 and the mounted device 320. This causes the DC-DC converter 130 and the alternator 140 to supply power in parallel to the auxiliary device 310. When the control unit 150 maintains the supply of generated power from the alternator 140, this power control ends.

[0030] [Actions and Effects] As described above, the vehicle power supply system 100 according to one embodiment of the present disclosure has a configuration in which the DC-DC converter 130 that supplies power from the first battery 110 to the auxiliary equipment 310 and the mounted equipment 320 and the alternator 140 that can supply generated power to the auxiliary equipment 310 and the mounted equipment 320 are connected in parallel, and detects the operating state of the mounted equipment 320 by operation of the start switch 330. Then, by detecting an on operation of the start switch 330 that starts the mounted equipment 320, the vehicle power supply system 100 starts the power source 200 and controls the alternator 140 to generate power.

[0031] In this way, simply by detecting the on / off operation of the physical start switch 330 (eliminating the excitation current limiting function and drooping state monitoring function in the above Patent Document 1), it is possible to determine whether the DC-DC converter 130 is in a state where it is likely to experience a power shortage, and the DC-DC converter 130 and the alternator 140 can output power in parallel to the auxiliary equipment 310 and the mounted equipment 320. Therefore, the DC-DC converter 130 and the alternator 140 can be cooperatively controlled with a simple configuration and at low cost.

[0032] One embodiment of the present disclosure has been described above, but the present disclosure can be understood not only as a vehicle power supply system, but also as a method executed by a vehicle power supply system equipped with a processor, memory, etc., a program for executing this method, a computer-readable non-transitory storage medium storing the program, and a vehicle equipped with the vehicle power supply system. [Industrial Applicability]

[0033] The vehicle power supply system of the present disclosure can be used in vehicles equipped with a power supply system including a DC-DC converter and an alternator. [Explanation of symbols]

[0034] 100 Vehicle power supply system 110 Battery No. 1 120 Second Battery 130 DC-DC converter 140 Alternator 150 control section 200 Power source 310 Auxiliary Equipment 320 Bodywork Equipment 330 Start switch

Claims

1. a DC-DC converter that supplies battery power to the first device and the second device; an alternator connected in parallel with the DC-DC converter and capable of supplying generated power to the first device and the second device in response to an operation of a power source; a control unit that detects a switch operation for starting and stopping the second device and controls power generation by the alternator, The control unit When the switch operation for starting the second device is detected, a request is made to the power source to operate so that the alternator supplies generated power to the first device and the second device; when detecting the switch operation to stop the second device, requesting the power source to stop generating power from the alternator to the first device and the second device; Vehicle power system.

2. When the control unit detects the switch operation to stop the second device, if the power source cannot be stopped, the control unit continues supplying the generated power from the alternator to the first device and the second device regardless of the stop request.

10. The vehicle power supply system of claim 1.

3. The state in which the power source cannot be stopped is a state in which the amount of stored electricity in the battery is below a predetermined value at which there is a possibility that the battery will run out.

3. The vehicle power supply system according to claim 2.

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