Solar charging system

Abstract

This solar charging system provides an improved charging efficiency for high-voltage batteries while enhancing the stability of auxiliary batteries. [Solution] A solar charging system mounted on a vehicle, comprising a solar panel, an auxiliary battery, a high-voltage battery, and a control unit that controls the destination of the power generated by the solar panel, wherein the control unit supplies the power generated by the solar panel only to the auxiliary battery when the charge level of the auxiliary battery is less than a first threshold, and supplies the power generated by the solar panel in parallel to the auxiliary battery and the high-voltage battery when the charge level of the auxiliary battery is equal to or greater than the first threshold.

Description

Technical Field

[0001] The present disclosure relates to a solar charging system that controls the supply of electric power generated by a solar panel mounted on a vehicle.

Background Art

[0002] Patent Document 1 discloses a solar charging system capable of realizing efficient power supply based on the state of power consumption in in-vehicle devices that receive power supply from a plurality of batteries respectively. In this solar charging system, when solar power generation is possible, the generated power supplied from the solar panel to the high-voltage battery and the auxiliary battery is controlled based on the power required for the power supply system of the high-voltage battery and the power required for the power supply system of the auxiliary battery.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a solar charging system including a high-voltage battery and an auxiliary battery, when the charge amount of the auxiliary battery is lower than the target value when the power generation by the solar panel ends, in order to prevent depletion of the auxiliary battery and enhance stability, charging of the auxiliary battery using the power of the high-voltage battery (boost charging) may be executed. The implementation of such boost charging is undesirable because it reduces the efficiency of solar charging.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to provide a solar charging system capable of enhancing the stability of the auxiliary battery while improving the charging efficiency of the high-voltage battery.

Means for Solving the Problems

[0006] To solve the above problems, one aspect of the disclosed technology is a solar charging system mounted on a vehicle, comprising a solar panel, an auxiliary battery, a high-voltage battery, and a control unit that controls the destination of the power generated by the solar panel, wherein the control unit supplies the power generated by the solar panel only to the auxiliary battery when the charge level of the auxiliary battery is less than a first threshold, and supplies the power generated by the solar panel in parallel to the auxiliary battery and the high-voltage battery when the charge level of the auxiliary battery is equal to or greater than the first threshold. [Effects of the Invention]

[0007] According to the solar charging system of this disclosure, priority is given to supplying generated power to the auxiliary battery, and only after a predetermined charge level (first threshold) is secured in the auxiliary battery is the generated power supplied to the high-voltage battery. This makes it possible to improve the stability of the auxiliary battery while improving the charging efficiency of the high-voltage battery. [Brief explanation of the drawing]

[0008] [Figure 1] Block diagram of a solar charging system according to one embodiment of the present disclosure. [Figure 2] Flowchart of the solar charging control process performed by the solar charging system [Figure 3] Flowchart of the processing steps for control performed when a specific action is detected by a solar charging system. [Modes for carrying out the invention]

[0009] The solar charging system disclosed herein prioritizes charging the auxiliary battery, and only after a predetermined state of charge (SOC) is secured in the auxiliary battery does it enable charging of the high-voltage battery. This charging control enhances the stability of the auxiliary battery while improving the charging efficiency of the high-voltage battery. Hereinafter, one embodiment of this disclosure will be described in detail with reference to the drawings.

[0010] <Embodiment> [composition] Figure 1 is a block diagram showing a schematic configuration of a solar charging system 100 according to one embodiment of the present disclosure. The solar charging system 100 illustrated in Figure 1 comprises a solar panel 110, a solar power generation control unit 120, a high-voltage battery 130, a DC-DC converter 140, an auxiliary battery 150, and a charging control unit 160.

[0011] This solar charging system 100 can be installed, for example, in vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs).

[0012] The solar panel 110 is a power generation device that generates electricity when exposed to sunlight, and is typically a solar cell module, which is an assembly of solar cells. The electricity generated by the solar panel 110 is output to the solar power generation control unit 120. This solar panel 110 can be installed, for example, on the roof of a vehicle.

[0013] The solar power generation control unit 120 is configured to control the power generation of the solar panel 110 and output the power generated by the solar panel 110 to the charging control unit 160. This solar power generation control unit 120 has an MPPT function that controls the power generated by the solar panel 110 using a maximum power point tracking method, and a detection function that detects information related to the power generation of the solar panel 110 (voltage, current, temperature, etc.).

[0014] The high-voltage battery 130 is a rechargeable secondary battery, such as a lithium-ion battery. This high-voltage battery 130 is connected to a main engine (not shown) for driving the vehicle and can supply the power necessary for the operation of this main engine. The high-voltage battery 130 is connected to the solar power generation control unit 120 via a charge control unit 160 and a DC-DC converter 140 so that it can be charged by the power generated by the solar panel 110. An example of the high-voltage battery 130 is a drive battery for driving an electric motor.

[0015] The DC-DC converter 140 is a bidirectional power converter capable of converting input power into power of a predetermined voltage and outputting it. One end of the DC-DC converter 140 is connected to a charge control unit 160, and the other end is connected to a high-voltage battery 130. The DC-DC converter 140 can supply the power generated by the solar panel 110, which is output by the charge control unit 160 connected to one end, to the high-voltage battery 130 connected to the other end. When supplying power in this way, the DC-DC converter 140 performs a boost operation, increasing the voltage of the power input to one end to obtain the output voltage at the other end. The DC-DC converter 140 can also supply power from the high-voltage battery 130 connected to the other end to an auxiliary battery 150 via the charge control unit 160 connected to one end (pump charging). When supplying power in this way, the DC-DC converter 140 performs a step-down operation, decreasing the voltage of the power input to the other end to obtain the output voltage at one end.

[0016] The auxiliary battery 150 is a rechargeable secondary battery, such as a lithium-ion battery or a lead-acid battery. This auxiliary battery 150 is connected to auxiliary equipment (not shown) other than the main equipment described above, and can supply the power necessary for the operation of this auxiliary equipment. The auxiliary battery 150 is connected to the solar power generation control unit 120 via the charge control unit 160 so that it can be charged by the power generated by the solar panel 110. The auxiliary battery 150 is also connected to the high-voltage battery 130 via the charge control unit 160 and the DC-DC converter 140 so that it can be charged by the power stored in the high-voltage battery 130 and can supply its own stored power to the high-voltage battery 130. The auxiliary battery 150 uses a battery with a specified voltage lower than that of the high-voltage battery 130. The state of charge (SOC) of this auxiliary battery 150 is monitored by sensors (not shown).

[0017] The charging control unit 160 is configured to control the destination of the power generated by the solar panel 110 to one or both of the accessory battery 150 and the high-voltage battery 130. This charging control unit 160 is connected to the solar power generation control unit 120, the DCDC converter 140, and the accessory battery 150, and includes switches for switching their connection states, a microcomputer for controlling this switch, etc. (none of which are shown).

[0018] [Control] Next, referring further to FIGS. 2 and 3, the control performed in the solar charging system 100 according to this embodiment will be described.

[0019] FIG. 2 is a flowchart for explaining the processing procedure of solar charging control executed by the charging control unit 160 of the solar charging system 100. The solar charging control illustrated in this FIG. 2 is repeatedly executed during the period when the solar panel 110 is generating a predetermined amount of power.

[0020] (Step S201) The charging control unit 160 acquires the charge amount of the accessory battery 150. The charge amount of the accessory battery 150 can be acquired based on the detection values of various sensors provided in the accessory battery 150.

[0021] When the charging control unit 160 acquires the charge amount of the accessory battery 150, the process proceeds to step S202.

[0022] (Step S202) The charging control unit 160 determines whether the charge amount of the accessory battery 150 is equal to or greater than the first threshold value. This determination is made to confirm whether the charge amount of the accessory battery 150 has reached a predetermined control target value. Therefore, this first threshold value can be set as the target charge amount that can ensure the stability of the accessory battery 150.

[0023] If the charge control unit 160 determines that the charge level of the auxiliary battery 150 is equal to or greater than the first threshold (step S202, yes), the process proceeds to step S203. On the other hand, if the charge control unit 160 determines that the charge level of the auxiliary battery 150 is less than the first threshold (step S202, no), the process proceeds to step S204.

[0024] (Step S203) The charging control unit 160 supplies the power generated by the solar panel 110 to the DC-DC converter 140 to charge the high-voltage battery 130, and to the auxiliary battery 150 to ensure (maintain) its charge level. In other words, the high-voltage battery 130 is charged using the power generated by the solar panel 110, and the auxiliary battery 150 is used to supply power to auxiliary equipment connected to the auxiliary battery 150.

[0025] In this control, it is desirable that the charging control unit 160 appropriately controls the amount of power supplied to the auxiliary battery 150 so that the power supplied from the solar power generation control unit 120 to the high-voltage battery 130 is such that the conversion efficiency of the DC-DC converter 140 is high (above a predetermined second threshold) (prioritizing the conversion efficiency of the DC-DC converter 140).

[0026] Once the charge control unit 160 has charged the high-voltage battery 130 and supplied power to the auxiliary battery 150, the process returns to step S201.

[0027] (Step S204) The charging control unit 160 supplies the power generated by the solar panel 110 only to the auxiliary battery 150 in order to charge the auxiliary battery 150. In other words, the power generated by the solar panel 110 is not supplied to the high-voltage battery 130, and charging using the power generated by the solar panel 110 is performed only on the auxiliary battery 150.

[0028] Once the charging control unit 160 has charged only the auxiliary battery 150, the process returns to step S201.

[0029] Figure 3 is a flowchart illustrating the processing procedure for specific operation detection control performed by the charge control unit 160 of the solar charging system 100. The specific operation detection control illustrated in Figure 3 is initiated when the charge control unit 160 detects a specific operation in the vehicle.

[0030] A specific operation refers to a user or system operation that involves power consumption of the auxiliary battery 150. Examples include operations such as locking / unlocking the vehicle's doors or opening the vehicle's doors (turning on the lights), where auxiliary equipment is activated and power supply from the auxiliary battery 150 to the equipment is expected. This specific operation is detected using various sensors installed in the vehicle.

[0031] (Step S301) The charging control unit 160 determines whether or not it is currently performing (in progress) a solar charging process that supplies power generated by the solar panel 110 to the battery.

[0032] If the charging control unit 160 determines that solar charging is in progress (step S301, yes), the process proceeds to step S302. On the other hand, if the charging control unit 160 determines that solar charging is not in progress (step S301, no), this specific operation detection control ends.

[0033] (Step S302) The charging control unit 160 determines whether or not it is currently charging the high-voltage battery 130 using the power generated by the solar panel 110 when solar charging is in progress.

[0034] If the charging control unit 160 determines that the high-voltage battery 130 is being charged (step S302, yes), the process proceeds to step S303. On the other hand, if the charging control unit 160 determines that the high-voltage battery 130 is not being charged (step S302, no), the process proceeds to step S305.

[0035] (Step S303) The charging control unit 160 determines whether the auxiliary battery 150 can be charged when the high-voltage battery 130 is being charged. This determination determines whether the auxiliary battery 150 can be charged further beyond a first threshold, which is the target charge amount. Since the auxiliary battery 150 can be charged to its full charge capacity, whether or not it can be charged can be determined by whether or not the current charge amount of the auxiliary battery 150 is less than its full charge capacity.

[0036] If the charging control unit 160 determines that the auxiliary battery 150 is rechargeable (step S303, yes), the process proceeds to step S304. On the other hand, if the charging control unit 160 determines that the auxiliary battery 150 is not rechargeable (step S303, no), the process proceeds to step S305.

[0037] (Step S304) The charging control unit 160 stops charging the high-voltage battery 130 using the power generated by the solar panel 110, and uses the power generated by the solar panel 110 only to charge the auxiliary battery 150. In other words, the power generated by the solar panel 110 is not supplied to the high-voltage battery 130, and charging using the power generated by the solar panel 110 is performed only on the auxiliary battery 150. Note that instead of completely stopping the charging of the high-voltage battery 130, measures may be taken to limit charging, such as reducing the charging current.

[0038] When the charging control unit 160 stops charging the high-voltage battery 130 and charging is performed only on the auxiliary battery 150, this specific operation detection control is terminated.

[0039] (Step S305) The charging control unit 160 continues to charge and / or supply power to the high-voltage battery 130 and / or auxiliary battery 150 using the power generated by the solar panel 110. Specifically, if it is determined in step S302 that the high-voltage battery 130 is not being charged, it continues to charge and / or supply power to the auxiliary battery 150, and if it is determined in step S303 that the auxiliary battery 150 is not rechargeable, it continues to charge the high-voltage battery 130.

[0040] When the charging control unit 160 continues to charge and supply power to each battery, this specific operation detection control terminates.

[0041] <Effects and Actions> As described above, according to the solar charging system 100 according to one embodiment of the present disclosure, when the charge level of the auxiliary battery 150 is less than a first threshold, the power generated by the solar panel 110 is supplied only to the auxiliary battery 150, and when the charge level of the auxiliary battery 150 is equal to or greater than the first threshold, the power generated by the solar panel 110 is supplied in parallel to both the auxiliary battery 150 and the high-voltage battery 130.

[0042] This control system prioritizes charging the auxiliary battery 150, preventing the charge level of the auxiliary battery 150 from falling below the target value when power generation by the solar panel 110 ends. This suppresses the occurrence of pump-charging of the auxiliary battery 150 by the high-voltage battery 130, thereby improving the stability of the auxiliary battery 150 while also improving the charging efficiency of the high-voltage battery 130.

[0043] Furthermore, according to the solar charging system 100 of this embodiment, if a specific operation is detected while power is being supplied to the high-voltage battery 130 using the power generated by the solar panel 110, the power supply to the high-voltage battery 130 is stopped (or limited) and power supply to the auxiliary battery 150 is prioritized.

[0044] This control prevents the charge level of the auxiliary battery 150 from falling extremely low from the target value, even when auxiliary equipment that consumes power from the auxiliary battery 150 is in operation. This reduces concerns that the auxiliary battery 150 may be depleted due to the operation of equipment, thereby improving the stability of the auxiliary battery 150 while also improving the charging efficiency of the high-voltage battery 130.

[0045] Although one embodiment of the disclosed technology has been described above, the disclosure can be understood not only as a solar charging system, but also as a solar charging control method, a program for the method, a computer-readable non-temporary storage medium storing the program, and a vehicle equipped with the solar charging system. [Industrial applicability]

[0046] The solar charging system described herein can be used in vehicles equipped with solar panels, etc. [Explanation of Symbols]

[0047] 100 Solar Charging Systems 110 Solar Panels 120 Solar power generation control unit 130 High-voltage battery 140 DC-DC converters 150 Auxiliary Battery 160 Charging Control Unit

Claims

1. A solar charging system mounted on a vehicle, Solar panels and Auxiliary battery and High-voltage battery and The system includes a control unit that controls the destination of the power generated by the solar panel, The control unit, If the charge level of the auxiliary battery is less than the first threshold, the power generated by the solar panel is supplied only to the auxiliary battery. When the charge level of the auxiliary battery is equal to or greater than the first threshold, the power generated by the solar panel is supplied in parallel to the auxiliary battery and the high-voltage battery. Solar charging system.

2. The control unit supplies to the high-voltage battery the amount of power generated by the solar panel such that the conversion efficiency of the DCDC converter, which converts the power into power suitable for the high-voltage battery, is equal to or greater than a second threshold. The solar charging system according to claim 1.

3. If the control unit detects a specific operation while supplying power to the high-voltage battery, it will stop or limit the power supply to the high-voltage battery and prioritize the power supply to the auxiliary battery. The solar charging system according to claim 1 or 2.

4. The aforementioned specific operation is an operation related to the power consumption of the auxiliary battery. The solar charging system according to claim 3.

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