Scan control device

Abstract

To provide a scan control device which can suppress a reduction in power generation efficiency of an entire system even when there is a solar module which cannot accurately track the maximum power point of a solar panel.SOLUTION: A scan control device controls scan processing of scanning the output voltage of each solar panel executed by each power generation control unit to search for a maximum power point in a system in which a plurality of solar modules are connected, each including a solar panel, a sensor for acquiring the power generation state of the solar panel, and a power generation control unit for controlling the power generation of the solar panel on the basis of the power generation state. The scan control device comprises: a determination unit for determining whether or not the power generation state of each solar panel satisfies a prescribed condition; and an indication unit which, when there is a solar module whose power generation state of the soler panel does not satisfy a prescribed condition and which is a control object, indicates power generation control of the solar panel based on the result of the scan processing in a specific solar module to the power generation control unit of the solar module being the control object.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a scan control device provided in a solar charging system mounted on a vehicle or the like. [Background technology]

[0002] Patent Document 1 discloses an in-vehicle solar charging system equipped with multiple solar panels. In the solar charging system described in Patent Document 1, each solar control device provided for each solar panel executes maximum power point tracking (MPPT) control for the solar panel that is the control target of the device. In this MPPT control, in order to search for the maximum power point with high accuracy when the output voltage of the solar panel changes due to environmental changes such as changes in solar radiation conditions, a scan process is performed to scan the output voltage of the solar panel and find the optimal point on the PV curve. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-141545 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the solar charging system described in Patent Document 1, multiple solar control devices each independently perform MPPT control of the solar panel to be controlled, but cooperative processing is not performed between the multiple solar control devices. Therefore, if there is a solar module that cannot accurately track the maximum power point of the solar panel due to a sensor failure or control abnormality, the scanning accuracy of that solar panel will decrease, the scanning frequency will increase, and the scanning time will increase, resulting in a problem of a decrease in the power generation efficiency of the entire solar charging system.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a scan control device that can suppress a decrease in power generation efficiency of the entire solar charging system even if a solar module is present that cannot accurately track the maximum power point of the solar panel. [Means for solving the problem]

[0006] In order to solve the above problems, one aspect of the disclosed technology is a scan control device that controls a scan process executed by each power generation control unit to scan the output voltage of each solar panel to search for a maximum power point in a system in which multiple solar modules are connected, the solar modules including a solar panel, a sensor for acquiring the power generation state of the solar panel, and a power generation control unit for controlling the power generation of the solar panel based on the power generation state of the solar panel, and the scan control device includes a judgment unit that judges whether the power generation state of each solar panel satisfies predetermined conditions, and, if there is a solar module to be controlled for which the judgment unit has judged that the power generation state of the solar panel does not satisfy the predetermined conditions, an instruction unit that instructs the power generation control unit of the solar module to be controlled to control the power generation of the solar panel based on the result of the scan process in a specific solar module different from the solar module to be controlled. Effect of the Invention

[0007] According to the scan control device of the present disclosure, even if there is a solar module that cannot accurately track the maximum power point of the solar panel, it is possible to suppress a decrease in the power generation efficiency of the entire solar charging system. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a solar charging system including a scan control device according to an embodiment of the present invention; [Figure 2A] A diagram showing an example of multiple solar panels mounted on a vehicle in a multi-system structure. [Figure 2B]A diagram showing an example of multiple solar panels mounted on a vehicle in a multi-junction structure. [Diagram 3] 1 is a flowchart showing the scan process control performed by the scan control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] When there is a solar module that does not perform well in MPPT control among multiple solar modules, the scanning control device of the present disclosure applies the results of scanning the other solar modules that have no problems in MPPT control to the power generation control of the solar module that does not perform well in MPPT control. This control suppresses the decrease in power generation efficiency of the solar charging system as a whole. Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0010] <Embodiment> [composition] Fig. 1 is a block diagram showing a schematic configuration of a solar charging system 1 including a scan control device 50 according to an embodiment of the present disclosure. The solar charging system 1 illustrated in Fig. 1 includes a first solar module 10, a second solar module 20, a battery 30, a load device 40, and a scan control device 50. In Fig. 1, a connection line through which power is transmitted is indicated by a thick solid line, and a connection line through which control signals and detection values ​​other than power are transmitted and received is indicated by a dotted line. This solar charging system 1 can be mounted on vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs).

[0011] The first solar module 10 and the second solar module 20 are power generation devices that generate power when irradiated with sunlight, and can output the generated power to a battery 30 and a load device 40 that are connected to the first solar module 10 and the second solar module 20. Note that, although an example in which the solar charging system 1 includes two modules, the first solar module 10 and the second solar module 20, is described in FIG. 1, the number of solar modules is not limited to two, and may be three or more.

[0012] The first solar module 10 includes a first solar panel 11, a first DCDC converter 12, a first sensor 13, and a first control unit 14. The second solar module 20 includes a second solar panel 21, a second DCDC converter 22, a second sensor 23, and a second control unit 24.

[0013] The first solar panel 11 and the second solar panel 21 are devices capable of generating power according to the amount of sunlight irradiation, and are typically an assembly of solar cells. The first solar panel 11 and the second solar panel 21 may be installed in a planar arrangement in different locations, or may be installed three-dimensionally in the same location. FIG. 2A shows an example of an image in which the first solar panel 11 and the second solar panel 21 are installed in a line on the roof of a vehicle (multi-system structure). FIG. 2B shows an example of an image in which the first solar panel 11 and the second solar panel 21 are installed in a line on the roof of a vehicle (multi-junction structure).

[0014] It is desirable that the first solar panel 11 and the second solar panel 21 are installed in a place where they have a correlation with each other in terms of the solar radiation conditions. The fact that there is a correlation in the solar radiation conditions can be expressed by, for example, that the way the sunlight hits both panels is almost the same, or that it is possible to estimate the way the sunlight hits one panel from the way the sunlight hits the other panel. More specifically, for example, in the case of a multi-system structure (FIG. 2A) in which the panels are installed side by side in different locations, if the normal direction and curvature of the surface of the first solar panel 11 and the normal direction and curvature of the surface of the second solar panel 21 match or are close to each other, it can be said that there is a correlation in the solar radiation conditions. When three or more solar panels are installed, it is desirable that each solar panel has a correlation with at least one other solar panel in terms of the solar radiation conditions. On the other hand, in the case of a multi-junction structure (FIG. 2B) in which the panels are installed in the same place, the normal direction and curvature of the surface of the first solar panel 11 and the second solar panel 21 already match, so it can be said that there is a correlation in the solar radiation conditions. However, in the case of such a multi-junction structure, the amount of light that passes through the first solar panel 11 and reaches the second solar panel 21 is less than the amount of light received by the first solar panel 11, so it is advisable to know in advance the light transmittance and light attenuation rate of the first solar panel 11 in order to estimate the amount of light received by the second solar panel 21 from the amount of light received by the first solar panel 11 (or vice versa). Note that, in addition to the roof, other locations where solar panels may be installed on a vehicle include the hood, back door, trunk, and windows.

[0015] The first DCDC converter 12 and the second DCDC converter 22 are configured to independently control the power generation of the first solar panel 11 and the second solar panel 21. The first DCDC converter 12 is a power converter for inputting the power generated by the first solar panel 11, converting the input power to a predetermined voltage, and outputting it. The first DCDC converter 12 controls the conversion and output of the generated power according to control (instruction) from the first control unit 14. The output of the first DCDC converter 12 is supplied to the battery 30 and the load device 40. The second DCDC converter 22 is a power converter for inputting the power generated by the second solar panel 21, converting the input power to a predetermined voltage, and outputting it. The second DCDC converter 22 controls the conversion and output of the generated power according to control (instruction) from the second control unit 24. The output of the second DCDC converter 22, together with the output of the first DCDC converter 12, is supplied in parallel to the battery 30 and the load device 40.

[0016] The first sensor 13 and the second sensor 23 are configured to individually acquire the power generation states of the first solar panel 11 and the second solar panel 21. The first sensor 13 can acquire physical quantities such as the output voltage, output current, temperature, and generated power of the first solar panel 11 as the power generation state of the first solar panel 11. The second sensor 23 can acquire physical quantities such as the output voltage, output current, temperature, and generated power of the second solar panel 21 as the power generation state of the second solar panel 21. Various detection elements such as a voltage sensor and a current sensor can be used for the first sensor 13 and the second sensor 23.

[0017] The first control unit 14 and the second control unit 24 are configured to independently control the operation of the first DCDC converter 12 and the second DCDC converter 22. The first control unit 14 controls (and instructs) the first DCDC converter 12 based on the power generation state of the first solar panel 11 acquired by the first sensor 13. This control includes control of outputting a voltage command value for power generation to the first DCDC converter 12 and MPPT control of performing a scan process to search for the maximum power point of the first solar panel 11. The second control unit 24 controls (and instructs) the second DCDC converter 22 based on the power generation state of the second solar panel 21 acquired by the second sensor 23. This control includes control of outputting a voltage command value for power generation to the second DCDC converter 22 and MPPT control of performing a scan process to search for the maximum power point of the second solar panel 21. Well-known technology can be used for the MPPT control of this embodiment.

[0018] The above-mentioned first DCDC converter 12 and first control unit 14 function as a power generation control unit that controls the power generation of the first solar panel 11. The above-mentioned second DCDC converter 22 and second control unit 24 function as a power generation control unit that controls the power generation of the second solar panel 21.

[0019] The battery 30 is a secondary battery configured to be chargeable and dischargeable, such as a lithium ion battery or a lead storage battery. The battery 30 is connected to the first solar module 10 and the second solar module 20, and is configured to be able to charge the battery 30 with the power generated by the first solar panel 11 via the first DCDC converter 12, and to be able to charge the battery 30 with the power generated by the second solar panel 21 via the second DCDC converter 22.

[0020] The load devices 40 are various types of devices that are connected to the battery 30 and operate on power supplied from the battery 30.

[0021] The scan control device 50 monitors the power generation states of the first solar panel 11 and the second solar panel 21 in the first solar module 10 and the second solar module 20, and appropriately controls the scanning process of the MPPT control performed by the first DCDC converter 12 and the second DCDC converter 22. This scan control device 50 is typically configured as an electronic control unit (ECU) including a processor, memory, and an input / output interface, and the processor reads and executes a program stored in the memory to realize the functions of a determination unit 51 and an instruction unit 52 described below.

[0022] The determination unit 51 determines whether the power generation state of each of the first solar panel 11 and the second solar panel 21 satisfies a predetermined condition. Examples of the predetermined condition include an output voltage of the solar panel being within a predetermined range of values ​​that are estimated to be possible when the solar module is normal, and an output power of the solar panel being equal to or greater than a minimum power value that is estimated to be possible under the current solar radiation conditions when the solar module is normal. The determination unit 51 may also determine the arrival of a time to execute a scan process in the first solar module 10 and the second solar module 20.

[0023] When the judgment unit 51 judges that the power generation state of the solar panel does not satisfy a predetermined condition in one of the solar modules of the first solar panel 11 and the second solar panel 21, the instruction unit 52 instructs the control unit of the one solar module to control the power generation of the solar panel using the result of the scan process in the other solar module. For example, when the power generation state of the first solar panel 11 does not satisfy a predetermined condition, the instruction unit 52 instructs the first control unit 14 of the first solar module 10 to control the power generation of the first solar panel 11 using the result of the scan process in the second solar module 20.

[0024] In addition, if the solar charging system 1 has three or more solar modules, if the judgment unit 51 judges that there is at least one solar module whose solar panel power generation state does not satisfy the specified conditions, the instruction unit 52 will transmit the results of the scanning process for the solar modules that satisfy the specified conditions and are correlated with the solar panel's solar radiation conditions to the solar modules that do not satisfy the specified conditions, and instruct them to control them. The control performed by the scan controller 50 will be described in detail below.

[0025] [control] Further referring to Fig. 3, the control performed in the solar charging system 1 equipped with a plurality of solar modules will be described. Fig. 3 is a flowchart showing the procedure of the scan process control executed by the scan control device 50 according to the present embodiment. The scan process control illustrated in Fig. 3 is started, for example, when the solar charging system 1 is started, and is repeatedly executed until the solar charging system 1 is stopped.

[0026] (Step S301) The judgment unit 51 of the scan control device 50 judges whether or not it is time to execute a scan process in a plurality of solar modules (including the first solar module 10 and the second solar module 20). This timing can be given in advance as a fixed timing so that the scan process can be executed periodically. The timing to execute the scan process may be notified to the scan control device 50 from the solar modules, or may be managed by the scan control device 50. If the judgment unit 51 judges that it is time to execute the scan process (Yes in step S301), the process proceeds to step S302.

[0027] (Step S302) The judgment unit 51 of the scan control device 50 judges whether or not there is a solar module (hereinafter referred to as a "solar module to be controlled") whose solar panel power generation state does not satisfy a predetermined condition among the multiple solar modules. Examples of the predetermined condition not being satisfied include a case where the output voltage of the solar panel is significantly different from a voltage value estimated in advance, or a case where the power generation power of the solar panel is smaller than a minimum power value estimated in advance. As shown in FIG. 1, when the solar charging system 1 includes two solar modules, a first solar module 10 and a second solar module 20, the judgment unit 51 may judge whether or not the power generation state of one of the solar panels of the first solar module 10 and the second solar module 20 does not satisfy a predetermined condition.

[0028] If the judgment unit 51 judges that there is a solar module whose power generation state of the solar panel does not satisfy the predetermined condition (step S302, Yes), the process proceeds to step S303. On the other hand, if the judgment unit 51 judges that there is no solar module whose power generation state of the solar panel does not satisfy the predetermined condition (step S302, No), the process proceeds to step S306.

[0029] (Step S303) The instruction unit 52 of the scan control device 50 controls (instructs) to execute a scan process on solar modules (hereinafter referred to as "non-control target solar modules") among the multiple solar modules, in which the power generation state of the solar panel other than the control target solar module satisfies a predetermined condition. This control (instruction) executes a scan process of MPPT control on each of the non-control target solar modules. When the scan process is executed on the non-control target solar modules according to the instruction of the instruction unit 52, the process proceeds to step S304.

[0030] (Step S304) The instruction unit 52 of the scan control device 50 acquires the result of the scan process performed on a specific solar module from the specific solar module among the non-control target solar modules that have undergone the scan process. This specific solar module is a solar module that has a correlation in solar radiation conditions with the control target solar module. The correlation in solar radiation conditions is as described above. When the instruction unit 52 acquires the scan process result of the specific solar module, the process proceeds to step S305.

[0031] (Step S305) The instruction unit 52 of the scan control device 50 instructs the control unit of the solar module to be controlled to control the power generation of the solar panel based on the results of the scan process of the specific solar module.

[0032] Specifically, for example, when the solar panel of the solar module to be controlled and the solar panel of the specific solar module have a multi-system structure (FIG. 2A), the instruction unit 52 can instruct the control unit of the solar module to be controlled to use the voltage command value of the DCDC converter at which the maximum power point is obtained in the solar panel of the specific solar module as the voltage command value of the DCDC converter of the solar module to be controlled. Also, for example, when the solar panel of the solar module to be controlled and the solar panel of the specific solar module have a multi-junction structure (FIG. 2B), the instruction unit 52 can derive a new voltage command value that reflects the light transmittance and light attenuation rate of the solar panel in the voltage command value of the DCDC converter at which the maximum power point is obtained in the solar panel of the specific solar module, and can instruct the control unit of the solar module to be controlled to use the derived new voltage command value as the voltage command value of the DCDC converter of the solar module to be controlled.

[0033] On the other hand, the instruction unit 52 of the scan control device 50 instructs the control units of the solar modules that are not the subject of control to control the power generation of the solar panels based on the results of the scan processing obtained in each solar module.

[0034] When the instruction unit 52 issues instructions to control the power generation of the solar panels to the solar modules to be controlled and the solar modules not to be controlled, the process proceeds to step S301.

[0035] (Step S306) The instruction unit 52 of the scan control device 50 instructs the control units of all the solar modules included in the solar charging system 1 to control the power generation of the solar panels based on the results of the scan processing of each solar module. When the instruction unit 52 instructs all the solar modules to control the power generation of the solar panels, the process proceeds to step S301.

[0036] In the above-described processing flow, the process of determining whether it is time to execute the scanning process in step S301 may be performed after the process of determining whether there is a solar module whose solar panel power generation state does not satisfy a predetermined condition in step S302.

[0037] In addition, in the specific example of step S305 in the above-mentioned processing flow, the instruction unit 52 performs control to directly instruct the voltage command value of the DCDC converter that has obtained the maximum power point in the solar panel of a specific solar module without performing a scan process on the solar module to be controlled. However, in addition to this control, for example, when the state of the solar module to be controlled is such that the sensor is normal but the MPPT control is unstable, the control may be such that the solar module to be controlled performs a scan process in which the search range is narrowed or the search interval is widened based on the voltage command value of the DCDC converter that has obtained the maximum power point in the solar panel of a specific solar module.

[0038] <Actions and Effects> As described above, according to the scan control device of one embodiment of the present disclosure, when a solar module (control target) that does not satisfy specified conditions is present among the multiple solar modules equipped in a solar charging system, power generation of the solar panel of the solar module (control target) that does not satisfy the specified conditions is controlled based on the results of the scan processing on a solar module (specific) that has a correlation in solar radiation conditions between the solar modules (non-control target) that satisfy the specified conditions and the solar module (control target) that does not satisfy the specified conditions.

[0039] With this control, even if there is a solar module in the solar charging system that cannot accurately track the maximum power point because a sensor has broken down and cannot be used, or because an abnormality has occurred in the system's control ECU, such as unstable MPPT control, the control value actually measured in another solar module that is presumed to have similar solar radiation conditions and the same control direction can be used for the operation of that solar module. This makes it possible to avoid undesirable processing such as performing a scan process in a low-precision state, performing the scan process frequently until a satisfactory result is obtained, or performing the scan process continuously for a long time due to deterioration of the tracking performance, and therefore suppressing the decrease in power generation efficiency of the solar charging system as a whole (improved controllability, improved power generation).

[0040] The above describes one embodiment of the present disclosure, but the present disclosure can be understood as a scan control device, a solar charging system equipped with a scan control device, a method executed by the scan control device, a program for executing the method, a computer-readable non-transitory recording medium storing the program, and a vehicle equipped with a solar charging system including a scan control device. [Industrial Applicability]

[0041] The scan control device of the present disclosure can be used in a solar charging system equipped with multiple solar modules. [Explanation of symbols]

[0042] 1 Solar charging system 10, 20 solar modules 11, 21 Solar panels 12, 22 DC-DC converter 13, 23 Sensor 14, 24 Control section 30 Battery 40 Load equipment 50 Scan control device 51 Judgment Department 52 Instruction Department

Claims

1. A scan control device controls a scan process executed by each of the power generation control units to scan an output voltage of each of the solar panels to search for a maximum power point in a system in which a plurality of solar modules are connected, the scan control unit including the solar panels, a sensor for acquiring a power generation state of the solar panels, and a power generation control unit for controlling power generation of the solar panels based on the power generation state of the solar panels, a determination unit that determines whether or not the power generation state of each of the solar panels satisfies a predetermined condition; a power generation control unit that controls the power generation of the solar panel based on the results of the scan process in a specific solar module that is different from the solar module to be controlled when the judgment unit judges that the power generation state of the solar panel of the solar module to be controlled does not satisfy the specified condition, and an instruction unit that instructs the power generation control unit of the solar module to be controlled to control the power generation of the solar panel based on the results of the scan process in a specific solar module that is different from the solar module to be controlled.

2. The sensor acquires an output voltage of the solar panel as the power generation state, The scan control device according to claim 1 , wherein the predetermined condition includes that the output voltage of the solar panel is within a predetermined range of values ​​that can be taken when the solar module is normal.

3. The sensor acquires the power generation power of the solar panel as the power generation state, The scan control device according to claim 1 , wherein the predetermined condition includes a condition in which the generated power of the solar panel is equal to or greater than a minimum power value that can be attained under current solar radiation conditions when the solar module is normal.

4. The scan control device according to claim 1 , wherein the specific solar module is a module having a correlation in terms of solar radiation conditions with the solar module to be controlled.

5. The scan control device according to claim 4 , wherein the solar module to be controlled and the specific solar module have a laminated and bonded structure.

Images