Solar charging device

Abstract

To provide a solar charging device which can decrease loss of an opportunity to generate power through a solar panel.SOLUTION: A solar charging device mounted on a vehicle comprises: a solar panel; a battery for driving; an auxiliary machine battery; a first DCDC converter (first DDC) arranged between the solar panel and the auxiliary machine battery; a second DCDC converter (second DDC) arranged between the battery for driving and the auxiliary machine battery; and a control unit which controls the first DDC and the second DDC. The control unit supplies, when generated output of the solar panel is larger than consumption power of the auxiliary machine load connected with the auxiliary machine battery, the auxiliary machine battery through the first DDC with the generated output of the solar panel. The control unit supplies, when the generated output of the solar panel is smaller than the consumption power of the auxiliary machine load, the auxiliary machine battery through the first DDC with the generated output of the solar panel and supplies the auxiliary machine battery through the second DDC with electric power of the battery for driving.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a solar charging device 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 control device that controls a solar DCDC converter, a high-voltage DCDC converter, and an accessory DCDC converter provided between a solar panel, a high-voltage battery, and an accessory battery, so that the generated electric power of the solar panel can be suitably supplied to the high-voltage battery or the accessory battery.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration described in Patent Document 1, it is necessary to stop the solar DCDC converter depending on the operating states of the high-voltage DCDC converter and the accessory DCDC converter, such as when power transfer is performed between the high-voltage battery and the accessory battery. In such a case, even when the solar panel is in a state where it can generate electricity, it is impossible to generate electric power, resulting in a loss of the opportunity to generate electricity.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to provide a solar charging device capable of reducing the loss of the opportunity to generate electricity by a solar panel.

Means for Solving the Problems

[0006] To solve the above problems, one aspect of the disclosed technology is a solar charging device mounted on a vehicle, comprising a solar panel, a driving battery, an auxiliary battery, a first DCDC converter provided between the solar panel and the auxiliary battery, a second DCDC converter provided between the driving battery and the auxiliary battery, and a control unit for controlling the first DCDC converter and the second DCDC converter. When the generated power of the solar panel is greater than the power consumption of the auxiliary load connected to the auxiliary battery, the control unit supplies the generated power of the solar panel to the auxiliary battery via the first DCDC converter. When the generated power of the solar panel is less than the power consumption of the auxiliary load, the control unit supplies the generated power of the solar panel to the auxiliary battery via the first DCDC converter and supplies the power of the driving battery to the auxiliary battery via the second DCDC converter.

Advantages of the Invention

[0007] According to the solar charging device of the present disclosure, it is possible to reduce the loss of power generation opportunities by the solar panel.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2A

Figure 2B

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0009] The solar charging device according to the present disclosure executes the supply of the generated power of the solar panel based on the state of power transfer between the drive battery and the auxiliary battery in the vehicle system. Thereby, the consistency between the power control operation of the vehicle and the solar power generation operation can be ensured, and the loss of power generation opportunities due to the solar panel can be reduced. Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0010] <Embodiment> [Configuration] FIG. 1 is a block diagram showing a schematic configuration of a solar charging device 1 according to an embodiment of the present disclosure. The solar charging device 1 illustrated in FIG. 1 includes a solar module 10, an auxiliary battery 20, a drive battery 30, a battery bidirectional DCDC converter (battery bidirectional DDC) 40, and a control unit 50. In FIG. 1, the connection lines through which power is transmitted are shown by solid lines, and the connection lines through which control signals other than power are transmitted are shown by broken lines. This solar charging device 1 is mounted on a vehicle such as a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), and an electric vehicle (BEV), for example.

[0011] The solar module 10 is a power generation device that generates power by receiving sunlight, and outputs the generated power to an auxiliary battery 20, an auxiliary load 100, etc. connected to the solar module 10. This solar module 10 includes a solar panel 11, a solar DCDC converter (solar DDC) 12, and a solar control unit 13 in its configuration.

[0012] The solar panel 11 is a device that can generate power according to the amount of sunlight irradiated, and is typically an assembly of solar cells. The power generated by the solar panel 11 is output to the solar DCDC converter 12. This solar panel 11 is installed on, for example, the roof of a vehicle.

[0013] The solar DC-DC converter 12 is a power converter (first DC-DC converter) that inputs the power generated by the solar panel 11 and converts and outputs the input power to a predetermined voltage. This solar DC-DC converter 12 controls the conversion and output of the generated power according to instructions from the solar control unit 13. The output of the solar DC-DC converter 12 is supplied to the auxiliary battery 20, the auxiliary load 100, and the drive battery 30 via the battery bidirectional DC-DC converter 40.

[0014] The solar control unit 13 is an electronic control device (first control unit) composed of a processor such as a CPU and controls the operation of the solar DC-DC converter 12. This solar control unit 13 can acquire information on the power generated by the solar panel 11. The generated power of the solar panel 11 can be calculated from, for example, the measured values of current sensors and voltage sensors (not shown) provided in the solar panel 11 or the solar control unit 13. In addition, the solar control unit 13 can acquire information on the power consumed by the auxiliary load 100 and the auxiliary battery 20. The power consumption by the auxiliary load 100 and the auxiliary battery 20 can be calculated based on, for example, the output voltage and the outflow current of the solar DC-DC converter 12.

[0015] In addition, the solar control unit 13 communicates (such as CAN communication or LIN communication) with a control unit 50 that controls the power supply of the vehicle provided independently of the solar module 10, and cooperatively controls the charging and discharging operations of the power in the vehicle. This solar control unit 13, together with the control unit 50, constitutes a control unit that preferably controls the power generated by solar power and the power stored in each battery.

[0016] The auxiliary battery 20 is a rechargeable secondary battery such as a lithium-ion battery or a lead-acid battery. This auxiliary battery 20 is connected to the solar DCDC converter 12 of the solar module 10 so as to be chargeable by the electric power generated by the solar panel 11. Further, the auxiliary battery 20 is connected to the battery bidirectional DCDC converter 40 so as to be chargeable by the electric power stored in the drive battery 30. Further, the auxiliary battery 20 can supply the electric power necessary for the operation of the auxiliary load 100 to the auxiliary load 100.

[0017] The drive battery 30 is a rechargeable secondary battery such as a lithium-ion battery or a nickel-metal hydride battery. This drive battery 30 is connected to the solar DCDC converter 12 of the solar module 10 via the battery bidirectional DCDC converter 40 so as to be chargeable by the electric power generated by the solar panel 11. Further, the drive battery 30 is connected to a main device (not shown) for driving the vehicle and can supply the electric power necessary for the operation of this main device. Examples of the main device include a starter motor and a driving electric motor. The drive battery 30 is a high-voltage battery having a higher rated voltage than the auxiliary battery 20.

[0018] The battery bidirectional DCDC converter 40 is a power converter (second DCDC converter) that can convert the input power into power of a predetermined voltage and output it based on an instruction from the control unit 50. One end of this battery bidirectional DCDC converter 40 (referred to as the primary side) is connected to the solar module 10, the auxiliary battery 20, and the auxiliary load 100, and the other end (referred to as the secondary side) is connected to the driving battery 30. The battery bidirectional DCDC converter 40 can supply the output power of the solar module 10 connected to the primary side to the driving battery 30 connected to the secondary side (boost operation), and can also supply the power of the driving battery 30 connected to the secondary side to the auxiliary battery 20 and the auxiliary load 100 connected to the primary side (buck operation). During this power supply, the battery bidirectional DCDC converter 40 boosts the output voltage of the solar module 10, which is the input voltage on the primary side, as the output voltage on the secondary side (during boost operation), and also steps down the voltage of the driving battery 30, which is the input voltage on the secondary side, as the output voltage on the primary side (during buck operation).

[0019] The control unit 50 is an electronic control device (second control unit) configured to include a processor, a memory, an input / output interface, etc., and to control the operation of the battery bidirectional DCDC converter 40. For example, an HV-ECU that controls the hybrid driving of the vehicle can be used for this control unit 50. The control unit 50 communicates (such as CAN communication or LIN communication) with the solar control unit 13 of the solar module 10, which together constitutes a control unit, and controls the charging and discharging operations of electric power in the vehicle in cooperation. The control executed by this solar control unit 13 and the control unit 50 will be described later.

[0020] The auxiliary load 100 is various auxiliary devices mounted on the vehicle. The auxiliary load 100 operates by receiving the supply of power generated by the solar panel 11 of the solar module 10 or the power stored in the auxiliary battery 20. Examples of such auxiliary devices include lighting devices such as headlamps and interior lights, air conditioning devices such as heaters and air conditioners, and systems for autonomous driving and advanced driver assistance.

[0021] [Control] Next, with further reference to FIGS. 2A, 2B, 3, and 4, the control performed by the solar charging device 1 according to the present embodiment will be described. FIGS. 2A and 2B are flowcharts for explaining the processing procedures of the charging control executed by the solar control unit 13 and the control unit 50 that constitute the control unit. The processing in FIG. 2A and the processing in FIG. 2B are respectively connected by the connectors X and Y. FIG. 3 is a diagram showing the power flow when the battery bidirectional DCDC converter 40 is performing a boosting operation. FIG. 4 is a diagram showing the power flow when the battery bidirectional DCDC converter 40 is performing a bucking operation.

[0022] The charging control illustrated in FIGS. 2A and 2B is started, for example, when the solar control unit 13 that has stopped (slept) some or all of its functions wakes up (wakes up) the stopped functions by becoming capable of generating electricity due to sunlight irradiation.

[0023] (Step S201) The solar control unit 13 calculates the generated power Wgen, which is the power generated by the solar panel 11. When the generated power Wgen of the solar panel 11 is calculated by the solar control unit 13, the process proceeds to step S202.

[0024] (Step S202) The solar control unit 13 determines whether the generated power Wgen of the solar panel 11 exceeds a predetermined first threshold value Wsol. This determination is made to determine whether the solar panel 11 is generating sufficient power to enable efficient charge control. For example, if the generated power Wgen of the solar panel 11 is less than the power required for the charging operation of the solar module 10, power extraction from the auxiliary battery 20 will occur, and more battery power will be consumed than can be obtained from solar power generation, rendering the charge control meaningless. Therefore, the first threshold value Wsol can be set to a value equal to or greater than the power at which charge control can be performed without power extraction from the auxiliary battery 20. When the solar control unit 13 determines that the generated power Wgen of the solar panel 11 exceeds the first threshold value Wsol (Wgen > Wsol) (step S202, yes), the process proceeds to step S204. On the other hand, when the solar control unit 13 determines that the generated power Wgen of the solar panel 11 does not exceed the first threshold value Wsol (Wgen ≤ Wsol) (step S202, no), the process proceeds to step S203.

[0025] (Step S203) Since the solar control unit 13 cannot perform efficient charge control by solar panel power generation, it stops the operation of a predetermined part or all of the functions and puts them into sleep. Thereby, this charge control ends.

[0026] (Step S204) The solar control unit 13 requests the control unit 50 to start power generation by the solar panel 11, that is, to start outputting the generated power Wgen to the auxiliary battery 20 and the like. When the solar control unit 13 requests the start of power generation of the solar panel 11, the process proceeds to step S205.

[0027] (Step S205) Upon receiving a power generation start request from the solar panel 11 from the solar control unit 13, the control unit 50 determines whether power generation by the solar panel 11 (output of generated power Wgen) is possible. This determination is made based on, for example, the state of the drive battery 30 and the operating state of the vehicle. When the control unit 50 determines that solar power generation is possible (step S205, yes), the process proceeds to step S206. On the other hand, when the control unit 50 determines that solar power generation is not possible (step S205, no), the process proceeds to step S207.

[0028] (Step S206) The control unit 50 notifies the solar control unit 13 that solar power generation is permitted. When the control unit 50 notifies the permission of solar power generation, the process proceeds to step S208.

[0029] (Step S207) The control unit 50 notifies the solar control unit 13 that solar power generation is not permitted. When the control unit 50 notifies the non - permission of solar power generation, the process proceeds to step S203.

[0030] (Step S208) Based on the permission notification of solar power generation received from the control unit 50, the solar control unit 13 starts power generation by the solar panel 11. For this power generation, well - known maximum power point tracking (MPPT) control or the like can be used. When the solar control unit 13 starts solar power generation, the process proceeds to step S209.

[0031] (Step S209) The solar control unit 13 controls the solar DCDC converter 12 so that the output voltage of the solar DCDC converter 12 is converted to a predetermined voltage. The predetermined voltage is typically the rated voltage of the auxiliary battery 20 (e.g., 12V or 48V). When the output voltage of the solar DCDC converter 12 is controlled by the solar control unit 13, the process proceeds to step S210.

[0032] (Step S210) The control unit 50 controls the battery bidirectional DCDC converter 40 to control the voltage Vaux of the auxiliary battery 20 to be a voltage Vtgt which is a predetermined constant value. This voltage Vtgt is the target value of voltage control and is arbitrarily set based on the performance of the auxiliary battery 20 and the specifications of the vehicle on which it is mounted. When the voltage Vaux of the auxiliary battery 20 is controlled to the voltage Vtgt by the control unit 50, the process proceeds to step S211.

[0033] (Step S211) The control unit 50 determines whether the voltage Vaux of the auxiliary battery 20 is equal to or higher than a predetermined second threshold value Vhigh. This determination is made to determine whether the generated power Wgen of the solar panel 11 can be effectively utilized only for power supply to the auxiliary battery 20 and the auxiliary load 100. For example, when the state of charge (SOC) of the auxiliary battery 20 is close to full charge, a state may occur in which a part (or all) of the generated power Wgen of the solar panel 11 must be discarded only for power supply to the auxiliary battery 20 and the auxiliary load 100, and there is a possibility that the generated power cannot be effectively utilized. Therefore, the second threshold value Vhigh can be set to the voltage value when the auxiliary battery 20 is in a state close to full charge (for example, the state of charge is 85 to 95%). When the control unit 50 determines that the voltage Vaux of the auxiliary battery 20 is equal to or higher than the second threshold value Vhigh (Vaux≥Vhigh) (step S211, yes), the process proceeds to step S212. On the other hand, when the control unit 50 determines that the voltage Vaux of the auxiliary battery 20 is less than the second threshold value Vhigh (Vaux<Vhigh) (step S211, no), the process proceeds to step S213.

[0034] (Step S212) The control unit 50 controls the battery bidirectional DCDC converter 40 in a boosting operation. By this boosting control, as indicated by the arrow in FIG. 3, the surplus power of the generated power Wgen of the solar panel 11 that is not consumed by the auxiliary battery 20 and the auxiliary load 100 can be output to the driving battery 30 to charge the driving battery 30. When the battery bidirectional DCDC converter 40 is controlled by the control unit 50 in a boosting operation, the process proceeds to step S201.

[0035] (Step S213) The control unit 50 controls the battery bidirectional DCDC converter 40 in a bucking operation. By this bucking control, as indicated by the arrow in FIG. 4, the power shortage portion among the power required for the consumption of the auxiliary battery 20 and the auxiliary load 100 that cannot be satisfied only by the generated power Wgen of the solar panel 11 can be provided from the driving battery 30. Thereby, the power reduction of the auxiliary battery 20 can be suppressed. When the battery bidirectional DCDC converter 40 is controlled by the control unit 50 in a bucking operation, the process proceeds to step S201.

[0036] In the above embodiment, the case where the DCDC converter inserted between the auxiliary battery 20 and the driving battery 30 is the battery bidirectional DCDC converter 40 capable of both boosting and bucking has been described. However, if power transfer from the auxiliary battery 20 to the driving battery 30 is not required, a bucking-only DCDC converter that can perform power transfer only from the driving battery 30 to the auxiliary battery 20 may be inserted between the auxiliary battery 20 and the driving battery 30.

[0037] Also, in the above embodiment, the solar control unit 13 is provided in the solar module 10, but it can also be provided separately from the solar module 10 or included in the control unit 50.

[0038] <Function and Effect> As described above, according to the solar charging device 1 according to an embodiment of the present disclosure, the battery bidirectional DCDC converter 40, which is a standard component of a vehicle, is used in the solar power generation system. Thereby, the consistency between the power control operation of the vehicle and the solar power generation operation can be ensured, and the loss of power generation opportunities by the solar panel 11 can be reduced.

[0039] Further, in the solar charging device 1 according to the present embodiment, since the power is not directly supplied from the solar module 10 to the driving battery 30 but the battery bidirectional DCDC converter 40 is interposed, a dedicated boost DCDC converter for solar power that was conventionally required becomes unnecessary. Thereby, it is possible to contribute to cost reduction of the solar power generation system, reduction of the number of components, improvement of component mountability, and the like.

[0040] Further, in the solar charging device 1 according to the present embodiment, the solar panel 11, the solar DCDC converter 12, and the solar control unit 13 are integrated as the solar module 10. Thereby, introduction of the solar power generation system into the vehicle and enhancement of the power generation amount can be easily performed.

[0041] As described above, an embodiment of the present disclosure technology has been described. However, the present disclosure can be understood not only as a solar charging device but also as a charging control method, a control program for the method, a computer-readable non-transitory storage medium storing the control program, a vehicle equipped with the solar charging device, and the like.

Industrial Applicability

[0042] The solar charging device of the present disclosure can be used in vehicles equipped with solar panels and the like.

Explanation of Signs

[0043] 1 Solar charging device 10 Solar module 11 Solar panel 12 Solar DCDC converter 13 Solar control unit 20 Auxiliary battery 30 Driving battery 40 Battery bidirectional DCDC converter 50 Control unit 100 Auxiliary load

Claims

1. A solar charging device mounted on a vehicle, a solar panel, a driving battery, an auxiliary battery, a first DC / DC converter provided between the solar panel and the auxiliary battery, a second DC / DC converter provided between the driving battery and the auxiliary battery, and a control unit for controlling the first DC / DC converter and the second DC / DC converter. The control unit when the generated power of the solar panel is greater than the power consumption of an auxiliary load connected to the auxiliary battery, supplies the generated power of the solar panel to the auxiliary battery via the first DC / DC converter, when the generated power of the solar panel is less than the power consumption of the auxiliary load, supplies the generated power of the solar panel to the auxiliary battery via the first DC / DC converter and supplies the power of the driving battery to the auxiliary battery via the second DC / DC converter, A solar charging device.

2. When the generated power of the solar panel is greater than the power consumption of the auxiliary load, the control unit supplies the generated power of the solar panel to the auxiliary battery via the first DC / DC converter and supplies the generated power of the solar panel to the driving battery via the first DC / DC converter and the second DC / DC converter. The solar charging device according to Claim 1.

3. The control unit includes a first control unit for controlling the first DC / DC converter and a second control unit for controlling the second DC / DC converter, and the first DC / DC converter and the first control unit are modularized together with the solar panel. The solar charging device according to claim 2.

4. The first control unit receives permission for power generation from the second control unit and supplies the generated power of the solar panel to the auxiliary battery via the first DC-DC converter. The solar charging device according to claim 3.

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