Solar charging system

Abstract

To provide a solar charging system that can achieve a cost reduction and downsizing by reducing a total number of components used for power generation control of a plurality of solar panels.SOLUTION: In a solar charging system including a plurality of solar modules that generate electric power using sunlight, at least one master solar module of the plurality of solar modules comprises: a master solar panel; a sensor for acquiring an electric power generation state of the master solar panel; an instruction unit that instructs power generation control of the master solar panel based on the electric power generation state acquired by the sensor; and a master power generation controlling unit that controls the electric power generation of the master solar panel according to an instruction from the instruction uni. A slave solar module other than the master solar module among the plurality of solar modules comprises: a slave solar panel; and a slave power generation controlling unit that controls the electric power generation of the slave solar panel using the instruction from the instruction unit of the master solar module, respectively.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a solar charging system mounted on a vehicle or the like.

Background Art

[0002] Patent Document 1 discloses an in-vehicle solar charging system provided with a plurality of solar panels. In the solar charging system described in Patent Document 1, each of the solar control devices provided for each solar panel executes maximum power point tracking (MPPT) control for the solar panel that is the control target of the device itself. In this MPPT control, in order to accurately search for the maximum power point when the output voltage of the solar panel changes due to environmental changes such as changes in the solar radiation state, a scan process for scanning the output voltage of the solar panel is performed to find the optimal point on the P-V curve.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The solar charging system described in Patent Document 1 has a configuration in which a plurality of solar control devices control their respective solar panels. In such a configuration, components such as sensors for acquiring the power generation state of the solar panel and configurations for performing scan processing are required for each solar panel. Therefore, in a solar charging system including a plurality of solar panels as disclosed in Patent Document 1, problems such as an increase in system cost and an increase in system scale (number of elements) remain.

[0005] This disclosure was made in view of the above-mentioned problems, and aims to provide a solar charging system that can reduce the cost and scale of the system by reducing the number of components used to control the power generation of solar panels in a system that includes multiple solar panels. [Means for solving the problem]

[0006] To solve the above problems, one aspect of the disclosed technology is a solar charging system comprising a plurality of solar modules that generate electricity using sunlight, wherein at least one master solar module among the plurality of solar modules comprises a master solar panel, a sensor that acquires the power generation status of the master solar panel, an instruction unit that instructs the master solar panel to control power generation based on the power generation status acquired by the sensor, and a master power generation control unit that controls the power generation of the master solar panel according to the instructions of the instruction unit, and each of the slave solar modules other than the master solar module comprises a slave solar panel and a slave power generation control unit that controls the power generation of the slave solar panel using the instructions of the instruction unit of the master solar module. [Effects of the Invention]

[0007] According to the above disclosure, in a solar charging system that includes multiple solar panels, the number of components such as sensors used to control the power generation of the solar panels can be reduced. This makes it possible to reduce the cost and scale of the solar charging system. [Brief explanation of the drawing]

[0008] [Figure 1] Block diagram showing a schematic configuration example of a solar charging system according to one embodiment of this disclosure. [Figure 2A] This diagram shows an example of mounting multiple solar panels on a vehicle in a multi-system configuration. [Figure 2B] This diagram shows an example of mounting multiple solar panels on a vehicle using a multi-connection structure. [Figure 3] Block diagram showing another schematic configuration example of the solar charging system according to this embodiment. [Figure 4] Flowchart of scan processing control performed by a solar charging system [Modes for carrying out the invention]

[0009] The solar charging system comprising multiple solar panels as described herein uses the same power generation control instructions for a specific solar panel to control the power generation of other solar panels that have a correlation in terms of solar radiation conditions with that specific solar panel. By sharing power generation control instructions among several solar panels in this way, it is possible to reduce some of the components, such as sensors, that were conventionally installed on each solar panel. 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 illustrating the schematic configuration of a solar charging system 1 according to one embodiment of the present disclosure. The solar charging system 1 illustrated in Figure 1 comprises a master solar module 10, a plurality of slave solar modules 20 and 30, a battery 50, and load equipment 60. In Figure 1, connection lines through which power is transmitted are shown with thick solid lines, and connection lines through which control signals, detected values, etc., other than power are transmitted and received are shown with thin solid lines. This solar charging system 1 can be installed in vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs).

[0011] The master solar module 10, slave solar module 20, and slave solar module 30 are power generation devices that generate electricity when exposed to sunlight. The master solar module 10 is the main solar module that controls the operation of all the solar modules, while the slave solar module 20 and slave solar module 30 are subordinate solar modules whose operation is controlled by the master solar module 10. The electricity generated by the master solar module 10, slave solar module 20, and slave solar module 30 is output to batteries 50 and load equipment 60 connected to these solar modules.

[0012] The master solar module 10 includes a master solar panel 101, a master power generation control unit 102, a sensor 103, and an indicator unit 104.

[0013] The master solar panel 101 is a device that can generate electricity in proportion to the amount of sunlight it receives, and is typically an assembly of solar cells.

[0014] The master power generation control unit 102 is configured to control the power generation of the master solar panel 101 and is typically a power converter such as a DC-DC converter. The master power generation control unit 102 receives the power generated by the master solar panel 101 as input and, according to instructions (control) from the instruction unit 104, converts this input power generation to a predetermined voltage and outputs it. The output of the master power generation control unit 102 is supplied to the battery 50 and the load equipment 60.

[0015] Sensor 103 is configured to acquire the power generation status of the master solar panel 101. This sensor 103 can acquire physical quantities such as the output voltage, output current, temperature, and power generated of the master solar panel 101 as part of the power generation status. Various detection elements such as voltage sensors and current sensors are used in sensor 103.

[0016] The instruction unit 104 is configured to control the master power generation control unit 102. Based on the power generation state of the master solar panel 101 acquired by the sensor 103, the instruction unit 104 instructs the control of the master power generation control unit 102. This control includes controlling to output a voltage command value for power generation to the DCDC converter constituting the master power generation control unit 102, and MPPT control for performing a scan process to search for the maximum power point of the master solar panel 101, etc. Further, the instruction unit 104 also instructs the control it gives to the master power generation control unit 102 to the slave solar module 20 and the slave solar module 30.

[0017] The slave solar module 20 includes a slave solar panel 201 and a slave power generation control unit 202 in its configuration. Further, the slave solar module 30 includes a slave solar panel 301 and a slave power generation control unit 302 in its configuration. In the present embodiment, each slave solar module included in the solar charging system 1 has the same configuration.

[0018] The slave solar panel 201 and the slave solar panel 301 are devices that can generate electric power according to the amount of sunlight irradiation, and are typically an assembly of solar cells.

[0019] The slave power generation control unit 202 is configured to control the power generation of the slave solar panel 201, and is typically a power converter such as a DCDC converter. This slave power generation control unit 202 inputs the power generated by the slave solar panel 201, and converts and outputs this input power generation power to a predetermined voltage according to the instruction (control) received from the instruction unit 104 of the master solar panel 101. The output of the slave power generation control unit 202 is supplied to the battery 50 and the load device 60.

[0020] The slave power generation control unit 302 is a configuration for controlling the power generation of the slave solar panel 301, and is typically a power converter such as a DC-DC converter. This slave power generation control unit 302 inputs the power generated by the slave solar panel 301, and converts the input generated power to a predetermined voltage and outputs it according to an instruction (control) received from the instruction unit 104 of the master solar panel 101. The output of the slave power generation control unit 302 is supplied to the battery 50 and the load device 60.

[0021] In the solar charging system 1 according to the present embodiment, the master solar panel 101 included in the master solar module 10, the slave solar panel 201 included in the slave solar module 20, and the slave solar panel 301 included in the slave solar module 30 have a predetermined correlation in the solar radiation situation. Examples of the predetermined correlation in this solar radiation situation include that the way sunlight hits the master solar panel 101 is the same as or approximate to (such as irradiation amount, irradiation angle, irradiation area, etc.) the way sunlight hits the slave solar panel 201 and the slave solar panel 301, or that it is possible to infer the way sunlight hits the slave solar panel 201 and the slave solar panel 301 from the way sunlight hits the master solar panel 101.

[0022] The master solar panel 101, the slave solar panel 201, and the slave solar panel 301 may be arranged side by side in different places and installed flat, or may be installed stacked in the same place and three-dimensionally. FIG. 2A shows an example image of the case where the master solar panel 101, the slave solar panel 201, and the slave solar panel 301 are arranged side by side on the roof of a vehicle (multi-system structure). FIG. 2B shows an example image of the case where the master solar panel 101, the slave solar panel 201, and the slave solar panel 301 are installed stacked on the roof of a vehicle (multi-junction structure). In addition, examples of places where solar panels are installed on a vehicle include the bonnet, back door, trunk, window, etc. other than the roof.

[0023] For example, in a multi-system structure where panels are installed in different locations (Figure 2A), if the normal direction and curvature of the surface of the master solar panel 101 match or approximate the normal direction and curvature of the surfaces of the slave solar panels 201 and 301, then a correlation can be said to exist in the solar radiation conditions. On the other hand, in a multi-junction structure where panels are installed stacked in the same location (Figure 2B), the normal direction and curvature of the surfaces of the master solar panel 101 and the slave solar panels 201 and 301 already match, so a correlation can be said to exist in the solar radiation conditions. However, in the case of such a multi-junction structure, the amount of light that passes through the master solar panel 101 and reaches the slave solar panels 201 and 301 is less than the amount of light received by the master solar panel 101. Therefore, it is advisable to know the light transmittance and light attenuation rate of the master solar panel 101 in advance in order to estimate the amount of light received by the slave solar panels 201 and 301 (or vice versa) from the amount of light received by the master solar panel 101.

[0024] The battery 50 is a rechargeable secondary battery, such as a lithium-ion battery or a lead-acid battery. The battery 50 is connected to the master solar module 10, the slave solar module 20, and the slave solar module 30, and is configured to charge the power generated by the master solar panel 101 via the master power generation control unit 102, the slave solar panel 201 via the slave power generation control unit 202, and the slave solar panel 301 via the slave power generation control unit 302.

[0025] The load equipment 60 is a variety of devices connected to the battery 50 and powered by the electricity supplied from the battery 50. This load equipment 60 does not necessarily have to be included as part of the configuration of the solar charging system 1.

[0026] In Figure 1, the solar charging system 1 shows an example where the operation of two slave solar modules 20 and 30 is controlled by a master solar module 10. However, the number of slave solar modules controlled by the master solar module 10 is not limited to these. Also, as illustrated in the solar charging system 2 in Figure 3, there may be multiple master solar modules controlling the slave solar modules. In Figure 3, it is sufficient that there is a correlation in solar radiation conditions between the master solar panel of the first master solar module 11 and the slave solar panels of the first slave solar modules 21 and 31, respectively. Similarly, it is sufficient that there is a correlation in solar radiation conditions between the master solar panel of the second master solar module 12 and the slave solar panels of the second slave solar modules 22, 32, and 42, respectively.

[0027] Furthermore, while Figure 1 shows a solar charging system 1 where only the master solar module 10 is equipped with a sensor (sensor 103) that detects the physical quantities of the solar panel, each slave solar module 20 or 30 may be equipped with a sensor that only detects information not related to the power generation control of the solar panel. For example, the slave solar modules 20 or 30 may be equipped with a temperature sensor for the purpose of measuring the temperature of the environment in which the solar panel is installed.

[0028] [control] Referring further to Figure 4, the control performed in the solar charging system 1, which includes a master solar module 10 and slave solar modules 20 and 30, will be described. Figure 4 is a flowchart showing the steps of the scan processing control performed by the solar charging system 1 according to this embodiment. The scan processing control illustrated in Figure 4 is started, for example, when the solar charging system 1 is started up and is repeatedly performed until the solar charging system 1 is stopped.

[0029] (Step S401) The instruction unit 104 of the master solar module 10 determines whether it is time to perform the scan process on the master solar panel 101. This timing can be predetermined and fixed so that the scan process can be performed periodically. If the instruction unit 104 determines that it is time to perform the scan process on the master solar panel 101 (step S401, yes), the process proceeds to step S402.

[0030] (Step S402) The master power generation control unit 102 of the master solar module 10 performs a scan process of the master solar panel 101 based on the instructions given by the instruction unit 104. Meanwhile, the slave power generation control unit 202 of the slave solar module 20 and the slave power generation control unit 302 of the slave solar module 30 continue to perform power generation control of the slave solar panels 201 and 301 based on the current voltage command value. Once the master power generation control unit 102 has performed the scan process of the master solar panel 101, the process proceeds to step S403.

[0031] (Step S403) The instruction unit 104 of the master solar module 10 instructs the master power generation control unit 102 to perform control (voltage command value) based on the results of the performed scan process. In response to this instruction, the master power generation control unit 102 performs power generation control of the new master solar panel 101 based on the scan process results. The instruction unit 104 also instructs the slave power generation control unit 202 of the slave solar module 20 and the slave power generation control unit 302 of the slave solar module 30 to perform control (voltage command value) based on the results of the performed scan process. It is desirable that this instruction reflects the differences in control amounts between the master solar panel 101 and the slave solar panels 201 and 301, based on pre-determined information such as the normal direction, curvature, light transmittance, and light attenuation of the solar panel surface. In response to this instruction, the slave power generation control unit 202 performs power generation control of the new slave solar panel 201 based on the scan process results, and the slave power generation control unit 302 performs power generation control of the new slave solar panel 301 based on the scan process results. Once power generation control for each solar module is performed, the process returns to step S401.

[0032] <Effects and Actions> As described above, according to a solar charging system according to one embodiment of the present disclosure, for a plurality of solar modules correlated with solar radiation conditions, only the main solar module (master) is equipped with a sensor that acquires the power generation status of the solar panel and an instruction unit that instructs the control of power generation of the solar panel based on the power generation status acquired by the sensor, and the subordinate solar modules (slaves) control the power generation of the solar panel based on instructions from the instruction unit of the main solar module.

[0033] This configuration allows several subordinate solar modules to share the instructions for controlling the power generation of the solar panels in the main solar module (master). Therefore, the number of sensors and other components previously configured for controlling the solar panel's power generation in the subordinate solar modules can be reduced. Consequently, the cost and scale of the solar charging system can be reduced.

[0034] <Application Examples> Furthermore, in configurations including multiple master solar modules, such as the solar charging system 2 illustrated in Figure 3, it is also possible to perform advanced solar panel power generation control, as described below.

[0035] For example, consider a configuration including a first master solar module 11 and a second master solar module 12, where a malfunction or other abnormality occurs in the sensor of the first master solar module 11. In such a case, the control commands of the second master solar module 12 may be controlled to also be applied to the first slave solar modules 21 and 31, which are under the control of the malfunctioning first master solar module 11. For this control, it is necessary to electrically connect the control output of the first master solar module 11 and the control output of the second master solar module 12 via a switching element or the like. Furthermore, it is desirable to adjust the control commands to be applied so as to perform appropriate power generation control by multiplying them by a predetermined coefficient or assigning a predetermined weight, depending on the difference between the solar radiation conditions for the first master solar module 11 and the solar radiation conditions for the second master solar module 12. These coefficients and weights can be set based on differences such as the temperature of the solar panels, the actual power generation, and the location where the solar panels are placed.

[0036] Although one embodiment of the present disclosure has been described above, the present disclosure can be understood as a solar charging system, a method performed by the solar charging system, a program for performing the method, a computer-readable non-temporary recording medium storing the program, and a vehicle equipped with the solar charging system. [Industrial applicability]

[0037] This disclosure can be used in solar charging systems equipped with multiple solar modules, etc. [Explanation of symbols]

[0038] 1, 2 Solar charging system 10, 11, 12 Master Solar Modules 20, 21, 22, 30, 31, 32, 42 slave solar modules 50 batteries 60 Load equipment 101 Master Solar Panel 102 Master Power Generation Control Unit 103 Sensor 104 Instruction section 201, 301 Slave Solar Panels 202, 302 Slave power generation control unit

Claims

1. A solar charging system comprising multiple solar modules that generate electricity using sunlight, Of the aforementioned plurality of solar modules, at least one master solar module is: Master solar panel and A sensor that acquires the power generation status of the master solar panel, An instruction unit that instructs the master solar panel to control power generation based on the power generation state acquired by the sensor, The system includes a master power generation control unit that controls the power generation of the master solar panel in accordance with the instructions of the instruction unit, Of the aforementioned plurality of solar modules, the slave solar modules other than the master solar module are, each, Slave solar panel and The system comprises a slave power generation control unit that controls the power generation of the slave solar panel using the instructions of the instruction unit of the master solar module, The master solar panel and the slave solar panel are arranged in a three-dimensional, overlapping structure that has a correlational relationship between them in terms of solar radiation conditions. Solar charging system.

2. The master solar panel is installed on the uppermost surface of the structure, The solar charging system according to claim 1.

3. The correlation in the aforementioned solar radiation conditions is a relationship that allows us to infer how sunlight hits the slave solar panel from how sunlight hits the master solar panel. The solar charging system according to claim 2.

4. The way in which sunlight strikes the slave solar panel is estimated based on the light transmittance or light attenuation rate of the master solar panel. The solar charging system according to claim 3.

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