JP2017153284A - Photovoltaic power generation system, method for controlling the same, and movable body having photovoltaic power generation system mounted thereon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to cause an operating point of a solar battery to easily follow a maximum power point through MPPT control.SOLUTION: A photovoltaic power generation system 1 is mounted on a movable body. The photovoltaic power generation system 1 comprises a solar battery block 11, a DC/DC converter 12, and a control part 14. The solar battery block 11 includes a plurality of strings and has bypass diodes connected in parallel at both ends of the strings. The DC/DC converter 12 performs MPPT control of changing an operating point of a power generated in the solar cell block within a predetermined range. The control part 14 calculates a predicted voltage value of the solar cell block 11 according to the bypass diode in a bypass state of the bypass diodes in the solar battery block 11. Upon acquisition of the predicted voltage value from the control part 14, the DC/DC converter 12 controls an output voltage value of the solar battery block 11 with the predicted voltage value as a reference.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a photovoltaic power generation system, a method for controlling the photovoltaic power generation system, and a moving body equipped with the photovoltaic power generation system.

  In recent years, in order to use the generated power of a solar cell as a power source for charging and powering a battery, a mobile body equipped with a solar cell has been proposed. For example, there is a vehicle as one form of the moving body, and a vehicle equipped with a solar cell has been proposed (Patent Document 1).

JP 2007-110038 A

  By the way, in the solar battery, light energy is converted into electric energy by the photovoltaic effect of the power generation element of the solar battery cell. Therefore, the solar cell has a so-called current-voltage characteristic due to the power generation element. Therefore, in the solar cell, the generated power is determined by a load connected to the solar cell (for example, an operating voltage when the converter extracts power from the solar cell). Furthermore, the current-voltage characteristics of the solar cell vary depending on the temperature, the amount of solar radiation, and the like.

  Therefore, in a photovoltaic power generation system, MPPT (Maximum Power Point Tracking) control is often employed. The MPPT control is a current value and voltage value (hereinafter collectively referred to as “maximum power point”) at which the solar cell can maximize the generated power, and a solar cell operating current value and operating voltage value (hereinafter collectively referred to as “operating point”). Is controlled to follow. The MPPT control is performed, for example, by a converter connected to the solar cell controlling the output voltage of the solar cell.

  Here, the solar cell mounted on the moving body is different from the solar cell fixedly installed on the roof of a house or the like, and the light receiving environment changes variously. For example, in a moving body, the surface on which sunlight hits always changes depending on the traveling direction of the moving body. For example, when the moving body is a vehicle, there are many factors that cast a shadow on the solar cell, such as a guardrail and a building, on the roadway on which the vehicle travels.

  Therefore, since the light receiving environment of the solar cell mounted on the moving body changes more variously than the fixedly installed solar cell, the above-mentioned current-voltage characteristics also change variously. As a result, the maximum power point also varies. Change. Therefore, in a solar cell mounted on a moving body, it may be more difficult to make the operating point of the solar cell follow the maximum power point by MPPT control than a solar cell fixedly installed.

  An object of the present invention made in view of such points is a photovoltaic power generation system capable of easily following an operating point of a solar cell to a maximum power point by MPPT control, a control method thereof, and a movement equipped with the photovoltaic power generation system To provide a body.

  A solar power generation system according to an embodiment of the present invention is a solar power generation system mounted on a moving body, and includes a plurality of strings, and bypass diodes connected in parallel to both ends of the strings. A bypass that is in a bypass state among the battery block, a converter that performs MPPT control for changing an operating point of the generated power of the solar battery block within a predetermined range, and controls an output voltage value of the solar battery block A controller that calculates an expected voltage value of the solar cell block according to a diode, and when the converter obtains the expected voltage value from the controller, the converter The output voltage value is controlled.

  Moreover, the control method of the solar power generation system according to an embodiment of the present invention is a control method of the solar power generation system mounted on the mobile body, and the solar power generation system has a plurality of strings, A step of calculating a predicted voltage value of the solar cell block according to a bypass diode in a bypass state among the bypass diodes, comprising a solar cell block in which bypass diodes are connected in parallel at both ends of the string; Controlling the output voltage value of the solar cell block based on the expected voltage value.

  Moreover, the mobile body equipped with the photovoltaic power generation system according to one embodiment of the present invention is a mobile body equipped with a solar cell system, and the solar cell system has a plurality of strings, and both ends of the strings. A solar cell block in which bypass diodes are connected in parallel to each other, a converter that performs MPPT control to vary an operating point of the generated power of the solar cell block within a predetermined range, and controls an output voltage value of the solar cell block, A control unit that calculates an expected voltage value of the solar cell block according to a bypass diode in a bypass state among the bypass diodes, and the converter obtains the expected voltage value from the control unit, The output voltage value of the solar cell block is controlled based on the expected voltage value.

  According to the photovoltaic power generation system, the control method thereof, and the mobile body equipped with the photovoltaic power generation system according to one embodiment of the present invention, the operating point of the solar cell can easily follow the maximum power point by MPPT control. .

It is a figure which shows an example of schematic structure of the solar energy power generation system which concerns on one Embodiment of this invention. It is an image figure which shows an example of a mode that the solar cell block of FIG. 1 was installed in the vehicle. It is a figure which shows an example of the connection of the bypass diode connected in parallel with the both ends of the string in the solar cell block installed in the left side part of a vehicle, and a voltage acquisition part. It is a figure which shows an example of schematic structure of a DC / DC converter. It is a figure which shows an example of the electric current-voltage characteristic and electric power-voltage characteristic of a solar cell block when each string is generating electric power normally. It is a figure which shows an example of the electric current-voltage characteristic and electric power-voltage characteristic of the solar cell block 11-E when abnormality generate | occur | produces in the string E3 and only two strings are generating electric power. It is a flowchart which shows an example of operation | movement of the solar energy power generation system which concerns on one Embodiment of this invention. It is a flowchart which shows an example of operation | movement of the solar energy power generation system which concerns on one Embodiment of this invention. It is a flowchart which shows an example of operation | movement of the solar energy power generation system which concerns on one Embodiment of this invention. It is a figure which shows schematic structure of the DC / DC converter which concerns on a modification.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, it is assumed that the moving body is a vehicle.

[System configuration]
FIG. 1 is a diagram illustrating an example of a schematic configuration of a solar power generation system 1 according to an embodiment of the present invention. The solar power generation system 1 is a solar power generation system mounted on a vehicle (moving body), and the solar cell blocks 11-1 to 11-N are attached to the exterior of each surface of the vehicle. In FIG. 1, a solid line connecting each functional block indicates a power line, and a broken line indicates a control line. An example of the moving body may be an object whose position moves, for example, a ship, an aircraft, a satellite device, a flying object, and the like, and the photovoltaic power generation system 1 can be mounted on such a moving body.

  The solar power generation system 1 includes solar cell blocks 11-1 to 11-N, DC / DC converters 12-1 to 12-N, a battery 13, a control unit 14, and a storage unit 15.

  The solar cell block 11 includes a voltage acquisition unit 10 and a plurality of strings. Each string has a configuration in which a plurality of solar cells are arranged in parallel and / or in series. Bypass diodes are connected in parallel across the string. Both ends of a bypass diode connected in parallel to both ends of the string in the solar cell block 11 are connected to the voltage acquisition unit 10 (see FIG. 3 described later), and both ends of the bypass diode (that is, both ends of the string). Voltage). The voltage acquisition unit 10 outputs the acquired voltage across the bypass diode to the control unit 14. In the example of FIG. 1, the solar cell block 11 which has the voltage acquisition part 10 shows the example which is N pieces to the solar cell blocks 11-1 to 11-N which respectively have the voltage acquisition parts 10-1 to 10-N. However, the solar cell block 11 may be an arbitrary number. An installation example of the solar cell block 11 on the vehicle will be described later.

  The DC / DC converter 12 converts the voltage value of the power supplied from the solar cell block 11 into a predetermined voltage value, and then supplies the converted DC power to the battery 13. In the example of FIG. 1, DC / DC converters 12-1 to 12 -N corresponding to each of the N solar cell blocks 11-1 to 11 -N are shown.

  Further, the DC / DC converter 12 performs MPPT control that varies the operating point of the solar cell block 11 within a predetermined range based on the control of the control unit 14 so that the generated power of the solar cell block 11 is maximized. . In the present embodiment, the DC / DC converter 12 outputs the output voltage value of the solar cell block 11 so that the operating voltage value of the operating point of the solar cell block 11 follows the voltage value of the maximum power point of the solar cell block 11. It is assumed that MPPT control is performed by controlling. Moreover, when the DC / DC converter 12 acquires the expected voltage value from the control unit 14, the DC / DC converter 12 controls the output voltage value of the solar cell block 11 based on the acquired predicted voltage value. The expected voltage value is a value near the voltage value of the maximum power point of the solar cell block 11 calculated by the control unit 14 when the current-voltage characteristic of the solar cell block 11 changes. Details of the expected voltage value will be described later.

  The battery 13 is charged by DC power supplied from the DC / DC converters 12-1 to 12-N. In the present embodiment, the battery 13 is charged with the generated power of the solar cell, but the present invention is not limited to this. For example, if the vehicle equipped with the solar power generation system 1 is a hybrid vehicle or an electric vehicle, the power generated by the solar battery may be supplied to the power motor. Further, the generated power may be supplied to an electric compressor of a vehicle air conditioner. Since the power motor and the electric compressor as described above operate with DC power, the generated power of the solar cell is supplied after being converted into an appropriate voltage value. In addition, what is necessary is just to supply after converting into alternating current power via a DC / AC converter, when using generated electric power for the external apparatus connected to AC outlet.

  The control unit 14 controls and manages the entire photovoltaic power generation system 1 and can be configured by, for example, a processor.

  The control unit 14 detects a bypass diode in a bypass state based on the voltage across the bypass diode acquired by the voltage acquisition unit 10. Further, the control unit 14 calculates an expected voltage value of the solar cell block 11 according to the detected bypass diode in the bypass state, and outputs the calculated expected voltage value to the DC / DC converter 12. In the example of FIG. 1, the control unit 14 calculates an expected voltage value for each of the solar cell blocks 11-1 to 11 -N based on the voltage across the bypass diode acquired by the voltage acquisition units 10-1 to 10 -N. calculate. Then, the control unit 14 outputs the calculated predicted voltage values to the DC / DC converters 12-1 to 12-N, respectively. Details of the expected voltage value and the processing of the control unit 14 will be described later.

  The storage unit 15 stores information that is necessary for processing of the photovoltaic power generation system 1 and a program that describes processing details for realizing each function of the photovoltaic power generation system 1. The storage unit 15 stores, for example, rated voltage values of the solar cell blocks 11-1 to 11-N.

  Here, with reference to FIG. 2, an example of a state in which the solar cell block 11 is installed in the vehicle is shown. In the example illustrated in FIG. 2, it is assumed that the solar cell blocks 11 are respectively disposed on the five surfaces of the vehicles A to E illustrated in FIG. As for five surfaces of the vehicle, A is a front part, B is a roof part, C is a rear part, D is a right side part, and E is a left side part. In this embodiment, although the solar cell block 11 is installed for every different surface, it is not limited to this, You may install a different solar cell block 11 on the same surface.

  FIG. 2B shows an image diagram of the strings in the solar cell blocks 11-A to 11-E installed on the surfaces A to E of the vehicle. As shown in FIG. 2B, the number of strings in the solar cell block 11 may be different depending on the area of each surface on the vehicle. For example, in the example shown in FIG. 2 (b), the solar cell block 11-A installed in the front part includes four strings A1 to A4, and includes a roof part, a rear part, a right side part, and a left side part. The installed solar cell blocks 11-B to 11-E include six, two, three, and three strings, respectively. The strings in the solar cell block 11 are connected in series with a necessary number of strings in order to obtain a desired DC voltage. For example, all the strings D1 to D3 in the solar cell block 11-D installed on the right side surface part are connected in series. Further, for example, in the strings in the solar cell block 11-B installed in the roof portion, the strings B1 to B3 and the strings B4 to B6 are connected in series, and the series connection of the strings B1 to B3 and the strings B4 to B6 are connected. The series connection is a configuration connected in parallel. In FIG. 2B, the wiring between the strings and the bypass diode and the voltage acquisition unit connected in parallel to both ends of the strings are omitted.

  Then, with reference to FIG. 3, the connection of the bypass diode connected in parallel with the both ends of the string in the solar cell block 11 and the voltage acquisition part 10 is demonstrated. FIG. 3 shows, as an example, a connection between the bypass diode connected in parallel to both ends of the string in the solar cell block 11-E installed on the left side surface portion of the vehicle and the voltage acquisition unit 10-E.

  As shown in FIG. 3, the three strings E1 to E3 included in the solar cell block 11-E are connected in series. Further, bypass diodes BD1 to BD3 are connected in parallel to both ends of each of the strings E1 to E3. Both ends of the bypass diodes BD1 to BD3 and the voltage acquisition unit 10-E are connected by wiring, and the voltage acquisition unit 10-E can acquire the voltages of both ends of the bypass diodes BD1 to BD3.

  The bypass diode may be connected in parallel to the plurality of strings. For example, in FIG. 3, the bypass diode BD2 is omitted, and the bypass diode BD1 is connected to the end of the string E1 to which the voltage acquisition unit 10 is connected (the end opposite to the side to which the string E2 is connected) and the string E3. It may be connected between the end of the string E2 to be connected. For example, the bypass diode BD1 may be connected in parallel to the plurality of strings by arranging a plurality of strings instead of the single string E1.

  In FIG. 3, when the solar cell block 11-E faces the direction of sunlight and the strings E1 to E3 are normally generating power, both ends of the strings E1 to E3 (both ends of the bypass diodes BD1 to BD3). A voltage of about several volts to several tens volts is generated.

  On the other hand, in FIG. 3, when there is a string that does not generate power due to some abnormality, the current of another normally generating string bypasses the string that cannot generate power and is connected in parallel to the string that cannot generate power. It flows to the bypass diode. At this time, a voltage of less than 1 volt (including a negative potential) is generated at both ends of the bypass diode connected in parallel to the string that cannot generate power. For example, if some abnormality occurs in the string E3 and the string E3 is not generating power, both ends of the bypass diode BD3 are less than 1 volt (for example, if +10 volt when generating power normally, − 0.6 volts) is generated.

  The control unit 14 acquires the voltage across the bypass diode connected in parallel to both ends of each string in the solar cell block 11 via the voltage acquisition unit 10. And the control part 14 detects that the bypass diode is a bypass state, for example when the value of the both-ends voltage of the acquired bypass diode is less than a predetermined threshold value (for example, 1 volt).

  The voltage less than 1 volt is an example, and the voltage value when the bypass diode is in the bypass state is a value corresponding to the characteristics of the bypass diode. In this embodiment, the value is an absolute value of the voltage, and the bypass state is detected based on whether the value is less than a predetermined threshold. However, the present invention is not limited to this. For example, the voltage value is a “positive” value. If it is normal, the value “negative” may be detected as a bypass state. Alternatively, it may be detected simply by a “negative” sign.

  Next, an example of a schematic configuration of the DC / DC converter 12 will be described with reference to FIG. The DC / DC converter 12 includes a coil 110, a capacitor 111, a switching element 112, a diode 113, a capacitor 114, a voltage measurement unit 120, a current measurement unit 121, a voltage measurement unit 122, a communication unit 130, an MPPT control unit 131, and a power control unit. 132. The input terminals P1 and P2 are connected to the output side of the solar cell block 11, and the output terminals P3 and P4 are connected to the input side of the battery 13. The terminal P5 is connected to the control unit 14. Moreover, in FIG. 4, the solid line which connects each functional block shows a power line, and a broken line shows a control line.

  The coil 110 stores magnetic energy by the current from the solar cell block 11 when the switching element 112 is on. When the switching element 112 is turned off, an induced electromotive force is generated in the coil 110, and the voltage of the DC power from the solar cell block 11 is boosted. The boosted DC power is supplied to the battery 13 via the backflow prevention diode 113. The capacitor 111 smoothes the voltage of the DC power on the input side of the DC / DC converter 12.

  The switching element 112 is turned on / off according to the control of the power control unit 132. The diode 113 is connected so that current does not flow backward from the output side of the DC / DC converter 12 to the input side. The capacitor 114 smoothes the DC power voltage on the output side of the DC / DC converter 12.

  The voltage measuring unit 120 measures the output voltage value (operating voltage value) of the solar cell block 11 and outputs the measured value to the MPPT control unit 131. The current measuring unit 121 measures the output current value (operating current value) of the solar cell block 11 and outputs the measured value to the MPPT control unit 131. The voltage measuring unit 122 measures the voltage value of the DC power after boosting, and outputs the measured value to the power control unit 132.

  The communication unit 130 receives a control signal from the control unit 14 (see FIG. 1). In addition, the communication unit 130 receives an expected voltage value from the control unit 14.

  Based on the control of the control unit 14 (see FIG. 1), the MPPT control unit 131 adjusts the solar cell block 11 so that the operating voltage value of the solar cell block 11 follows the voltage value of the maximum power point of the solar cell block 11. Controls the output voltage value.

  The MPPT control unit 131 uses, for example, the output voltage value (operating voltage value) and the output current value (operating current value) of the solar cell block 11 acquired from the voltage measuring unit 120 and the current measuring unit 121, and uses the solar cell block 11. The generated power is calculated. Then, the MPPT control unit 131 adjusts the operating voltage value of the solar cell block 11 by controlling the output power value of the solar cell block 11 so that the calculated generated power is maximized. The MPPT control unit 131 outputs a control signal to the power control unit 132 in order to control the output power value of the solar cell block 11. The power control unit 132 changes the on / off state of the switching element 112 according to the control signal.

  In the present embodiment, for example, a hill climbing method may be employed in the MPPT control. The hill-climbing method will be briefly described. First, the MPPT control unit 131 controls the output voltage value of the solar cell block 11 to change the operating voltage value of the solar cell block 11 with a predetermined voltage width. Next, the MPPT control unit 131 compares the generated power at the operating voltage value after the change with the generated power at the operating voltage value before the change in the solar cell block 11. Then, when the generated power at the operating voltage value after the change is larger than the generated power at the operating voltage value before the change, the MPPT control unit 131 causes the current operating voltage value to become the operating voltage value after the change. The output voltage value of the solar cell block 11 is controlled. When the MPPT control unit 131 repeats this, the operating point of the solar cell block 11 follows the maximum power point, and the generated power of the solar cell block 11 is optimized. In the following description, it is assumed that the MPPT control unit 131 performs MPPT control by the hill climbing method.

  Further, when the MPPT control unit 131 acquires the expected voltage value from the communication unit 130, the MPPT control unit 131 performs MPPT control based on the expected voltage value.

  The power control unit 132 performs on / off control of the switching element 112 based on the control signal acquired from the MPPT control unit 131 and the voltage value acquired from the voltage measurement unit 123. The output voltage value of the solar cell block 11 is controlled by the power control unit 132, for example, by changing the duty ratio of the pulse signal that performs on / off control of the switching element 112 according to the control signal of the MPPT control unit 131. Is done.

(Operating principle of photovoltaic power generation system)
Next, the operation principle of the photovoltaic power generation system 1 according to this embodiment will be described. Below, with reference to FIG.5 and FIG.6, the solar cell block 11-E is demonstrated to an example. First, with reference to FIG. 5, the case where each string E1-E3 of the solar cell block 11-E is generating electric power normally is demonstrated.

  FIG. 5 is a diagram illustrating an example of current-voltage characteristics and power-voltage characteristics of the solar cell block 11-E when the strings E1 to E3 are normally generating power. In FIG. 5, the horizontal axis represents voltage, and the vertical axis represents current and power. Moreover, in FIG. 5, a continuous line is a power-voltage curve (PV curve), and a broken line is a current-voltage curve (IV curve).

  As shown in FIG. 5, the black circles on the PV curve are points where the generated power of the solar cell block 11-E becomes the maximum with the power value Pm. That is, the black circle on the PV curve is the maximum power point of the solar cell block 11-E. The black circle and white circle on the IV curve are points corresponding to the black circle and white circle on the PV curve, respectively. The DC / DC converter 12 changes the operating voltage value of the solar cell block 11 by a predetermined voltage width ΔV by the hill-climbing method, and if the voltage value Vm corresponding to the power value Pm moves, the voltage value of Vm is Adjustment is made so that the operating voltage value of the solar cell block 11 is obtained.

  Next, a case where an abnormality has occurred in the string E3 will be described with reference to FIG.

  FIG. 6 is a diagram illustrating an example of current-voltage characteristics and power-voltage characteristics of the solar cell block 11-E when abnormality occurs in the string E3 and only two strings E1 and E2 generate power. . In FIG. 6, the horizontal axis represents voltage, and the vertical axis represents current and power. In FIG. 6, the solid line is a power-voltage curve (P-V curve), and the broken line is a current-voltage curve (IV curve).

  As shown in FIG. 6, when an abnormality occurs in the string E3 and the number of strings that generate electricity changes from three of the strings E1 to E3 to two of the strings E1 and E2, the current of the solar cell block 11-E -Voltage characteristics and power-voltage characteristics vary from the output characteristics shown in FIG. As the output characteristics of the solar cell block 11-E change, the maximum power point of the solar cell block 11-E also changes, so the optimum operating voltage value of the solar cell block 11-E also changes. For example, in FIG. 5, the maximum power point is a black circle of the power value Pm on the PV curve, and the power value Vm corresponding to the power value Pm is the optimum operating voltage value. Is a black circle of the power value Pm1 on the PV curve, and the power value Vm1 corresponding to the power value Pm1 is the optimum operating voltage value.

  Here, when the solar cell block 11-E has the output characteristics shown in FIG. 6, the DC / DC converter 12 causes the solar cell block 11 to have an operating voltage value of the solar cell block 11-E equal to the voltage value Vm1. It is desirable to control the output power value of -E. However, the output characteristic of the solar cell block 11-E may suddenly change from the output characteristic shown in FIG. 5 to the output characteristic shown in FIG. 6 due to, for example, a shadow falling on the string E3. At this time, in the hill-climbing method, it may be difficult to make the operating point of the solar cell block 11-E follow the maximum power point.

  For example, the solar cell block 11-E has the output characteristics shown in FIG. 5, and the DC / DC converter is operated so that the voltage value Vm shown in FIG. 5 becomes the operating voltage value of the solar cell block 11-E. It is assumed that the output voltage value of the battery block 11-E is controlled. At this time, when the output characteristic of the solar cell block 11-E suddenly changes from the output characteristic shown in FIG. 5 to the output characteristic shown in FIG. 6, immediately after the output characteristic of the solar cell block 11-E changes, The operating voltage value of the battery block 11-E is in the vicinity of the voltage value Vm. In such a case, it is difficult to shift the operating voltage value of the solar cell block 11-E from the voltage value Vm to the voltage value Vm1 by the hill-climbing method. This is because, as shown in FIG. 6, the power value corresponding to the predetermined voltage width ΔV near the voltage value Vm is almost equal to 0, and in the hill-climbing method, the operating voltage value is changed by the predetermined voltage width ΔV, This is because a difference cannot be detected even if the generated power after the change and the generated power before the change are compared.

  Assuming such a situation, it is conceivable to set the predetermined voltage width ΔV large in advance. However, when the predetermined voltage width ΔV is set large, the operating point of the solar cell block 11-E is the maximum operating point when the change in the output characteristics of the solar cell block 11-E as shown in FIG. 5 is small. May deviate greatly. Further, in order to cope with a sudden change in the output characteristics of the solar cell block 11-E, it is conceivable to set in advance a cycle for changing the operating voltage value of the solar cell block 11-E. However, if the cycle for changing the operating voltage value of the solar cell block 11-E is set short, the power change of the solar cell block 11-E may not be calculated appropriately.

  Therefore, in the present embodiment, first, the control unit 14 (see FIG. 1) calculates a voltage value near the voltage value Vm1 shown in FIG. 6 as an expected voltage value. Next, in the DC / DC converter 12, the MPPT control unit 131 acquires an expected voltage value via the communication unit 130. Thereafter, the MPPT control unit 131 performs MPPT control with reference to an expected voltage value that is a voltage value near the acquired voltage value Vm1. Thereby, in this embodiment, even if the optimal operating voltage value of the solar cell block 11-E suddenly changes from the voltage value Vm to the voltage value Vm1, it is easy to follow the maximum power point. Hereinafter, details of the function of the control unit 14 and calculation of the expected voltage value will be described based on Examples 1 to 5.

Example 1
First, Example 1 will be described. In Example 1, each string in the solar cell block 11 is assumed to have the same level of generated power. In Example 1, in addition to the rated voltage value of the solar cell block 11 described above, the storage unit 15 determines the total number n of bypass diodes in the solar cell block 11 and the maximum operating voltage value Vpm of the solar cell block 11. It shall be remembered.

  First, the control unit 14 reads and acquires the total number n of bypass diodes in the solar cell block 11 from the storage unit 15. In addition, the control unit 14 reads out and obtains the rated voltage value of the solar cell block 11 from the storage unit 15. And the control part 14 outputs the rated voltage value of the solar cell block 11 to the DC / DC converter 12, and makes the DC / DC converter 12 perform MPPT control for a predetermined time. The predetermined time is, for example, about several seconds. For example, the DC / DC converter 12 performs MPPT control using the rated voltage value of the solar cell block 11 as a starting point so that the generated power of the solar cell block 11 is maximized.

  Next, in the solar cell block 11, the control unit 14 reads out and acquires the number m ′ of bypass diodes that were in the previous bypass state from the storage unit 15. When this process is first performed, the control unit 14 acquires 0 instead of the number m ′ of bypass diodes that were in the previous bypass state.

  Thereafter, the control unit 14 acquires the number m of bypass diodes currently in the bypass state in the solar cell block 11. For example, the control unit 14 acquires the voltage across the bypass diode from the voltage acquisition unit 10, and if the acquired voltage across the bypass diode is less than a predetermined threshold, the control unit 14 confirms that the bypass diode is in the bypass state. To detect. Then, the control unit 14 acquires the number m of bypass diodes in the bypass state by specifying the number of bypass diodes in the detected bypass state.

  Then, the control unit 14 determines whether or not the number m ′ of bypass diodes that were in the previous bypass state matches the number m of bypass diodes that are currently in the bypass state.

  If the controller 14 determines that the number m ′ of bypass diodes that were in the previous bypass state matches the number m of bypass diodes that are currently in the bypass state, the controller 14 directly performs MPPT control on the DC / DC converter 12 for a predetermined time. Let it continue.

  On the other hand, when the control unit 14 determines that the number m ′ of bypass diodes that were in the previous bypass state does not match the number m of bypass diodes that are currently in the bypass state, the control unit 14 determines the number m of bypass diodes that are currently in the bypass state. The data is stored in the storage unit 15. Further, the control unit 14 reads out and acquires the maximum operating voltage value Vpm of the solar cell block 11 from the storage unit 15.

  Here, the maximum operating voltage value Vpm will be described. In Example 1, the maximum operating voltage value Vpm is, for example, the optimum operating voltage value of the solar cell block 11 when there is no bypass diode in the bypass state (m = 0) in the MPPT control (the solar cell block 11 of FIG. 5). In the example of −E, the voltage value is Vm). The optimum operating voltage value of the solar cell block 11 is acquired from the DC / DC converter 12 and stored in the storage unit 15 when MPPT control is performed when there is no bypass diode in the bypass state (m = 0). It may be left. Alternatively, the maximum operating voltage value Vpm may be the open circuit voltage value of the solar cell block 11 or the rated voltage value of the solar cell block 11. The open circuit voltage value and the rated voltage value may be stored in advance in the storage unit 15 as data acquired from the outside, or sequentially acquired as actual measurement data in the storage unit 15. May be.

Next, the control unit 14 subtracts the number m of bypass diodes currently in the bypass state from the total number n of bypass diodes, and further multiplies the value divided by the total number n by the maximum operating voltage value Vpm. The expected voltage value Vpm1 is calculated. For example, the control unit 14 calculates the expected voltage value Vpm1 using the following equation (1).

Vpm1 = Vpm × (nm) / n (1)

In Expression (1), Vpm1 is the expected voltage value, Vpm is the maximum operating voltage value, n is the total number of bypass diodes in the solar cell block 11, and m is the number of bypass diodes in the bypass state. For example, in the example of the solar cell block 11-E illustrated in FIG. 6, the expected voltage value is calculated as Vpm1 = Vpm × (2/3).

  Thereafter, the control unit 14 outputs the calculated expected voltage value Vpm1 to the DC / DC converter 12 so as to be a reference in the MPPT control. When the DC / DC converter 12 acquires the expected voltage value Vpm1 from the control unit 14, the DC / DC converter 12 performs MPPT control based on the expected voltage value Vpm1. For example, the DC / DC converter 12 performs MPPT control using the predicted voltage value Vpm1 as a starting point, and corrects an error between the operating voltage value of the solar cell block 11 and the predicted voltage value Vpm1.

(Example 2)
Next, Example 2 will be described. Similarly to Example 1, Example 2 also assumes that each string in the solar cell block 11 has the same level of generated power. In the following, differences from the first embodiment will be mainly described. In the second embodiment, in addition to the contents of the first embodiment, the storage unit 15 stores the voltage value Ve for one string at the maximum operating voltage value Vpm of the solar cell block 11.

Here, the maximum operating voltage value Vpm in the second embodiment will be described. Also in the second embodiment, the maximum operating voltage value Vpm can be the same as that in the first embodiment, but can also be calculated using the following equation (2).

Vpm = Ve × n (2)

In Equation (2), Vpm is the maximum operating voltage value, n is the total number of bypass diodes in the solar cell block 11, Ve is one string at the maximum operating voltage value Vpm of the solar cell block 11 (for example, as shown in FIG. 3). This is the voltage value of the string E1). In the example of FIG. 3, the maximum operating voltage value is Vpm = Ve × 3. Further, the voltage value Ve for one string may be the open circuit voltage value of the string or the rated voltage value of the string. The open circuit voltage value and the rated voltage value may be stored in advance in the storage unit 15 as data acquired from the outside, or sequentially acquired as actual measurement data in the storage unit 15. May be.

In the second embodiment, the control unit 14 multiplies the total number n of bypass diodes by the number m of bypass diodes currently in the bypass state, and multiplies the voltage value Ve for one string, thereby obtaining an expected voltage value Vpm1. Is calculated. For example, the control unit 14 calculates the expected voltage value Vpm1 using the following equation (3).

Vpm1 = Ve × (nm) (3)

In Equation (3), Vpm1 is the expected voltage value, Ve is the voltage value of one string at the maximum operating voltage value, n is the total number of bypass diodes in the solar cell block 11, and m is the bypass diode in the bypass state. It is a number. For example, in the example of the solar cell block 11-E illustrated in FIG. 6, the expected voltage value is calculated as Vpm1 = Ve × 2.

(Example 3)
Next, Example 3 will be described. The third embodiment is suitable when different strings are mixed in the solar cell block 11 due to, for example, a difference in the number of solar cells constituting the string or a difference in materials included in the string. In the following, differences from the first embodiment will be mainly described. In Example 3, the strings in the solar cell block 11 are denoted as strings Ei (i = 1 to n), and bypass diodes connected in parallel to both ends of each string Ei are bypass diodes BDi ( i = 1 to n). In Example 3, in addition to the rated voltage value of the solar cell block 11 described above, the storage unit 15 determines the maximum operating voltage value Vpm of the solar cell block 11 and the voltage value of each string Ei at the maximum operating voltage value Vpm. It shall be remembered.

  In Example 3, in the solar cell block 11, the control unit 14 acquires the bypass diode BDi that was in the previous bypass state. When this process is first performed, the control unit 14 acquires 0 instead of the bypass diode BDi that was in the bypass state last time.

  Next, the control unit 14 acquires the bypass diode BDi that is currently in the bypass state in the solar cell block 11. For example, the control unit 14 acquires the voltage across the bypass diode from the voltage acquisition unit 10, and if the acquired voltage across the bypass diode is less than a predetermined threshold, the control unit 14 confirms that the bypass diode is in the bypass state. To detect. And the control part 14 acquires bypass diode BDi which is a bypass state by specifying the bypass diode which is the detected bypass state. In addition, the control part 14 acquires 0, when the bypass diode of a bypass state does not exist.

  Thereafter, the control unit 14 determines whether or not the bypass diode BDi that was in the previous bypass state matches the bypass diode BDi that is currently in the bypass state.

  When it is determined that the bypass diode BDi in the previous bypass state and the bypass diode BDi in the current bypass state match each other, the control unit 14 causes the DC / DC converter 12 to continue the MPPT control as it is for a predetermined time.

  On the other hand, if the control unit 14 determines that the bypass diode BDi that was in the previous bypass state and the bypass diode BDi that is currently in the bypass state do not match, the control unit 14 stores the bypass diode BDi that is in the current bypass state in the storage unit 15. Keep it. Further, the control unit 14 reads out and acquires the maximum operating voltage value Vpm of the solar cell block 11 from the storage unit 15. In the third embodiment, the maximum operating voltage value Vpm similar to that in the first embodiment can be used.

Next, the control unit 14 calculates the expected voltage value Vpm1 by subtracting the voltage value Ei of the string in which the bypass diode BDi currently in the bypass state is connected at both ends from the maximum operating voltage value Vpm. For example, the control unit 14 calculates the expected voltage value Vpm1 using the following equation (4).

Vpm1 = Vpm−Ei (4)

In Expression (4), Vpm1 is an expected voltage value, Vpm is a maximum operating voltage value, and Ei is a voltage value of a string in which a bypass diode Bi that is currently in a bypass state is connected to both ends. For example, in the example of the solar cell block 11-E illustrated in FIG. 6, the expected voltage value is calculated as Vpm1 = Vpm-E3.

Example 4
Next, Example 4 will be described. In Example 4, for example, in order to install the solar cell block 11 on a surface having a curvature such as a door portion of a vehicle, strings composed of different series numbers of solar cells are mixed in the solar cell block 11. It is suitable when it becomes. Moreover, Example 4 is suitable also when the bypass diode is connected to the some string in parallel in the solar cell block 11. FIG. In the following, differences from the first embodiment will be mainly described. In the following description, the solar cell block 11 will be described with reference to an example in which there are two sets of strings composed of different numbers of series solar cells, but the present invention is not limited to this. Moreover, in Example 4, the strings in the solar cell block 11 are expressed as strings Ej (j = 1 to k) and strings Eq (q = k + 1 to n). Here, the string Ej and the string Eq are strings formed of different numbers of series solar cells. In addition, bypass diodes connected in parallel to both ends of each string Ej are denoted as bypass diodes BDj (j = 1 to k), and bypass diodes connected to both ends of each string Eq are bypass diodes BDq (q = k + 1 to n). In Example 4, in addition to the rated voltage value of the solar cell block 11 described above, the storage unit 15 includes the maximum operating voltage value Vpm of the solar cell block 11 and the voltage values of the strings Ej and Eq at the maximum operating voltage value Vpm. Is remembered.

  In the fourth embodiment, the control unit 14 acquires the bypass diodes BDj and BDq that were in the previous bypass state in the solar cell block 11. When processing is performed for the first time, the control unit 14 acquires 0 instead of the bypass diodes BDj and BDq that were previously in the bypass state.

  Next, the control unit 14 acquires the bypass diodes BDj and BDq that are currently in the bypass state in the solar cell block 11. The control unit 14 acquires the bypass diodes BDj and BDq that are currently in the bypass state in the same manner as in the third embodiment. In addition, the control part 14 acquires 0, when the bypass diode of a bypass state does not exist.

  Thereafter, the control unit 14 determines whether or not the bypass diode BDj that was in the previous bypass state and the bypass diode BDj that is currently in the bypass state match.

  When it is determined that the bypass diode BDj that was in the previous bypass state and the bypass diode BDj that is in the current bypass state match, the control unit 14 determines that the bypass diode BDq that was in the previous bypass state and the bypass diode BDq that is in the current bypass state Are determined to match each other. When it is determined that the bypass diode BDq that was in the previous bypass state and the bypass diode BDq that is currently in the bypass state match, the control unit 14 causes the DC / DC converter 12 to continue the MPPT control as it is for a predetermined time.

  On the other hand, when it is determined that the bypass diode BDj in the previous bypass state and the bypass diode BDj in the current bypass state do not match, and the bypass diode BDq in the previous bypass state and the bypass diode BDq in the current bypass state Are determined to be inconsistent, the bypass diodes BDj and BDq that are currently in the bypass state are stored in the storage unit 15. Further, the control unit 14 reads out and acquires the maximum operating voltage value Vpm of the solar cell block 11 from the storage unit 15. In the fourth embodiment, the maximum operating voltage value Vpm similar to that in the first embodiment can be used.

Next, the control unit 14 calculates the expected voltage value Vpm1 by subtracting the voltage values Ej and Eq of the string in which the bypass diodes BDj and BDq that are currently in the bypass state are connected to both ends from the maximum operating voltage value Vpm. To do. The control unit 14 calculates the predicted voltage value Vpm1 using, for example, the following equation (5).

Vpm1 = Vpm− (Ej + Eq) (5)

In Expression (5), Vpm1 is an expected voltage value, and Vpm is a maximum operating voltage value. Ej is the voltage value of the string with the bypass diode Bj currently in the bypass state connected to both ends, and Eq is the voltage value of the string with the bypass diode BDq currently in the bypass state connected to both ends. For example, in the example of FIG. 3, when the strings E1 and E2 are configured with different numbers of solar cells, and the bypass diodes BD1 and BD2 are in the bypass state, the expected voltage value is Vpm1 = Vpm− (E1 + E2) Is calculated.

(Example 5)
In the fifth embodiment, an example in which the predicted voltage value calculated in the first to fourth embodiments is corrected and MPPT control is performed based on the corrected predicted voltage value will be described. In the fifth embodiment, the storage unit 15 stores a correction coefficient α (for example, 0.8 ≦ α ≦ 1.2) in addition to the contents stored in the storage unit 15 in the first to fourth embodiments. And

  First, the control unit 14 calculates an expected voltage value Vpm1 according to the first to fourth embodiments. And the control part 14 reads and acquires the correction coefficient (alpha) from the memory | storage part 15, and correct | amends the estimated voltage value Vpm1 using the correction coefficient (alpha).

For example, the control unit 14 uses the following formula (6) in the first embodiment, uses the following formula (7) in the second embodiment, uses the following formula (8) in the third embodiment, and uses the following formula (8) in the fourth embodiment. The predicted voltage value Vpm1 is corrected using the following equation (9) to calculate a corrected voltage value Vpm1 ′.

Vpm1 ′ = (Vpm × (nm) / n) × α (6)
Vpm1 ′ = Ve × (n−m) × α (7)
Vpm1 ′ = (Vpm−Ei) × α (8)
Vpm1 ′ = (Vpm− (Ej + Eq)) × α (9)

In Expressions (6) to (9), Vpm1 ′ is a correction voltage value corrected using the correction coefficient α. The elements described in each of the formulas (6) to (9) are the same as the elements described in the above formulas (1), (2), (4), and (5). is there.

  Thereafter, the control unit 14 outputs the correction voltage value Vpm1 'to the DC / DC converter 12 so as to be a reference in the MPPT control. When the DC / DC converter 12 acquires the correction voltage value Vpm1 'from the control unit 14, the DC / DC converter 12 performs MPPT control based on the correction voltage value Vpm1'.

  For example, the control unit 14 selects the correction coefficient α so that the correction voltage value Vpm1 ′ is smaller than the expected voltage value Vpm1 (for example, α = 0.8 (α <1)), and calculates the correction voltage value Vpm1 ′. To do. In this case, the DC / DC converter 12 performs MPPT control on the basis of the low voltage value side in the power-voltage characteristics of the solar cell block 11 (in the vicinity of the arrow X in the example of FIG. 6). Furthermore, in the power-voltage characteristic of the solar cell block 11, the change in the power value with respect to the voltage value is small on the side where the voltage value is low. Thereby, the loss of the generated electric power value which arises by changing the operating voltage value at the time of the DC / DC converter 12 performing MPPT control can be reduced.

  Further, the control unit 14 may calculate, for example, two correction voltage values Vpm1 ′ (respectively, correction voltage values Vpm1a ′ and Vpm1b ′). In this case, for example, the control unit 14 selects and calculates the correction coefficient α so that the correction voltage value Vpm1a ′ is smaller than the expected voltage value Vpm1 (for example, α = 0.8 (α <1)). Then, the control unit 14 selects and calculates the correction coefficient α so that the correction voltage value Vpm1b ′ is larger than the expected voltage value Vpm1 (for example, α = 1.2 (α> 1)). Then, the control unit 14 outputs the correction voltage values Vpm1a ′ and Vpm1b ′ to the DC / DC converter 12, and MPPT with reference to the correction voltage value Vpm1a ′ or Vpm1b ′ on which the generated power of the solar cell block 11 is increased. Control may be performed.

[System operation]
Hereinafter, operation | movement of the solar energy power generation system 1 which concerns on one Embodiment of this invention is demonstrated. First, the operation | movement in Example 1 and 2 of the solar power generation system 1 is demonstrated.

(Examples 1 and 2)
FIG. 7 is a flowchart showing an example of the operation of the photovoltaic power generation system 1 according to one embodiment of the present invention.

  First, the control unit 14 reads and acquires the total number n of bypass diodes in the solar cell block 11 from the storage unit 15 (step S101). Moreover, the control part 14 reads and acquires the rated voltage value of the solar cell block 11 from the memory | storage part 15 (step S102). And the control part 14 outputs the rated voltage value of the solar cell block 11 to the DC / DC converter 12, and makes the DC / DC converter 12 perform MPPT control for a predetermined time (step S103). For example, the DC / DC converter 12 performs MPPT control using the rated voltage value of the solar cell block 11 as a starting point so that the generated power of the solar cell block 11 is maximized.

  Next, in the solar cell block 11, the control unit 14 reads and acquires the number m ′ of bypass diodes that were in the previous bypass state from the storage unit 15 (step S104). When performing the process of step S103 for the first time, the control part 14 acquires 0 instead of the number m 'of bypass diodes which were the bypass states last time.

  Thereafter, the control unit 14 acquires the number m of bypass diodes currently in the bypass state in the solar cell block 11 (step S105). Then, the control unit 14 determines whether or not the number m ′ of bypass diodes that were in the previous bypass state matches the number m of bypass diodes that are currently in the bypass state (step S106).

  When it is determined that the number m ′ of bypass diodes that were in the previous bypass state matches the number m of bypass diodes that are currently in the bypass state (step S106: Yes), the control unit 14 repeats the processing from step S103. Do.

  When the maximum power point of the solar cell block 11 does not change by performing the processes of steps S103 to S106 in this way, the DC / DC converter 12 continues the MPPT control as it is.

  On the other hand, when the control unit 14 determines that the number m ′ of bypass diodes that were in the previous bypass state does not match the number m of bypass diodes that are currently in the bypass state (step S106: No), the process of step S107 is performed. Proceed to

  In the process of step S107, the control unit 14 causes the storage unit 15 to store the number m of bypass diodes currently in the bypass state acquired in the process of step S104. Further, in the process of step S108, the control unit 14 reads out and acquires the maximum operating voltage value Vpm of the solar cell block 11 from the storage unit 15.

  In the process of step S109, the control unit 14 calculates the expected voltage value Vpm1 of the solar cell block 11. In the first embodiment, the control unit 14 calculates the expected voltage value Vpm1 using the above formula (1), for example. In the second embodiment, the control unit 14 calculates the expected voltage value Vpm1 using, for example, the above equation (3).

  In the process of step S110, the control unit 14 outputs the predicted voltage value calculated in the process of step S109 to the DC / DC converter 12 so as to be a reference in the MPPT control. When the DC / DC converter 12 obtains the expected voltage value from the control unit 14, it performs MPPT control based on the expected voltage value in the process of step S103 performed again. For example, the DC / DC converter 12 performs MPPT control using an expected voltage value as a starting point.

  By performing the processing of steps S103 to S110 in this way, even if the maximum power point of the solar cell block 11 suddenly changes due to, for example, a shadow falling on the string, the operating point of the solar cell block 11 is changed to the maximum power point. Can be easily followed.

  In addition, when correcting the expected voltage value Vpm1 in Example 5, it can carry out in the process of step S109.

(Example 3)
FIG. 8 is a flowchart showing an example of the operation of the photovoltaic power generation system 1 according to an embodiment of the present invention. The strings in the solar cell block 11 are denoted as strings Ei (i = 1 to n), and bypass diodes BDi (i = 1 to n) are connected in parallel to both ends of each string Ei. ).

  The processes in steps S201 and S202 shown in FIG. 8 are the same as the processes in steps S102 and S103 shown in FIG.

  In the solar cell block 11, the control unit 14 reads and acquires the bypass diode BDi that was in the previous bypass state from the storage unit 15 (step S203). When performing the process of step S203 for the first time, the control part 14 acquires 0 instead of the bypass diode BDi which was the previous bypass state.

  Next, the control unit 14 acquires the bypass diode BDi that is currently in the bypass state in the solar cell block 11 (step S204). In addition, the control part 14 acquires 0, when the bypass diode of a bypass state does not exist.

  Thereafter, the control unit 14 determines whether or not the bypass diode BDi that was in the previous bypass state matches the bypass diode BDi that is currently in the bypass state (step S205).

  When it is determined that the bypass diode BDi that was in the previous bypass state matches the bypass diode BDi that is currently in the bypass state (step S205: Yes), the control unit 14 repeats the processing from step S202.

  In this way, when the maximum power point of the solar cell block 11 does not change by performing the processes of steps S202 to S205, the DC / DC converter 12 continues the MPPT control as it is.

  On the other hand, when it is determined that the bypass diode BDi that was in the previous bypass state and the bypass diode BDi that is currently in the bypass state do not match each other (step S205: No), the control unit 14 proceeds to the process of step S206.

  The control unit 14 performs the processes of steps S206 and S207 in the same manner as the processes of steps S107 and 108 shown in FIG.

  In the process of step S208, the control unit 14 calculates the expected voltage value Vpm1 of the solar cell block 11. For example, the control unit 14 calculates the expected voltage value Vpm1 using the above equation (4). The processing in step S209 is the same as the processing in step S110 shown in FIG.

  By performing the processing of steps S202 to S209 in this way, even if the maximum power point of the solar cell block 11 suddenly changes due to, for example, a shadow falling on the string, the operating point of the solar cell block 11 is changed to the maximum power point. Can be easily followed.

  In addition, when correcting the expected voltage value Vpm1 in the fifth embodiment, it can be performed by the process of step S208.

Example 4
FIG. 9 is a flowchart showing an example of the operation of the photovoltaic power generation system 1 according to an embodiment of the present invention. In the following description, the solar cell block 11 will be described with reference to an example in which there are two sets of strings composed of different numbers of series solar cells, but the present invention is not limited to this. In the following, the strings in the solar cell block 11 are expressed as strings Ej (j = 1 to k) and strings Eq (q = k + 1 to n). Here, the string Ej and the string Eq are strings formed of different numbers of series solar cells. In addition, bypass diodes connected in parallel to both ends of each string Ej are denoted as bypass diodes BDj (j = 1 to k), and bypass diodes connected to both ends of each string Eq are bypass diodes BDq (q = k + 1 to n).

  The processes in steps S301 and S302 shown in FIG. 9 are the same as the processes in steps S102 and S103 shown in FIG.

  The control unit 14 acquires the bypass diodes BDj and BDq that were in the previous bypass state and the bypass diodes BDj and BDq that are currently in the bypass state, similarly to the processing in steps S203 and S204 illustrated in FIG. 8 (steps S303 and S304). ).

  Next, the control unit 14 determines whether or not the bypass diode BDj that was in the previous bypass state matches the bypass diode BDj that is currently in the bypass state (step S305). When it is determined that the bypass diode BDj that was in the previous bypass state and the bypass diode BDj that is currently in the bypass state match each other (step S305: Yes), the control unit 14 proceeds to the process of step S306. On the other hand, when it is determined that the bypass diode BDj that was in the previous bypass state and the bypass diode BDj that is currently in the bypass state do not match each other (S305: No), the control unit 14 proceeds to the process of step S307.

  In the process of step S306, the control unit 14 determines whether or not the bypass diode BDq that was in the previous bypass state matches the bypass diode BDq that is currently in the bypass state. When it is determined that the bypass diode BDq that was in the previous bypass state and the bypass diode BDq that is currently in the bypass state match each other (step S306: Yes), the control unit 14 repeatedly performs the processing from step S302.

  By performing the processing of steps S302 to S306 in this way, when there is no abnormality in the string of the solar cell block 11 and the maximum power point of the solar cell block 11 does not change, the DC / DC converter 12 continues the MPPT control as it is. .

  On the other hand, when the control unit 14 determines that the bypass diode BDq that was in the previous bypass state does not match the bypass diode BDq that is currently in the bypass state (step S306: No), the process of step S307 is performed. Proceed to

  The control unit 14 performs the processes of steps S307 and S308 in the same manner as the processes of steps S107 and 108 shown in FIG.

  In the process of step S309, the control unit 14 calculates the expected voltage value Vpm1 of the solar cell block 11. For example, the control unit 14 calculates the expected voltage value Vpm1 using the above equation (5). The process of step S310 is the same as the process of step S110 shown in FIG.

  By performing the processing of steps S302 to S310 in this way, even if the maximum power point of the solar cell block 11 suddenly changes due to, for example, a shadow falling on the string, the operating point of the solar cell block 11 is changed to the maximum power point. Can be easily followed.

  In addition, when correcting the expected voltage value Vpm1 in the fifth embodiment, it can be performed by the process of step S309.

  In the above embodiment, the moving body is described as being a vehicle, but is not limited to this. The moving body may be an object whose position moves, and may be a ship, an aircraft, a satellite device, a flying object, or the like.

  As described above, in the solar power generation system 1 according to one embodiment of the present invention, the control unit 14 determines the solar cell block 11 according to the bypass diode in the bypass state among the bypass diodes in the solar cell block 11. The expected voltage value is calculated. And DC / DC converter 12 will acquire the expected voltage value from control part 14, and will control the output voltage value of solar cell block 11 on the basis of the expected voltage value. Thereby, for example, even if the maximum power point of the solar cell block 11 suddenly changes due to a shadow falling on the string, the DC / DC converter 12 easily follows the operating point of the solar cell block 11 to the maximum power point. Can be made.

  Furthermore, in the photovoltaic power generation system 1 according to an embodiment of the present invention, the solar cell block 11 can be efficiently generated, which is advantageous when the generated power of the solar cell block 11 is used as a fuel for a moving object. .

(Modification)
FIG. 10 is a diagram illustrating a schematic configuration of a DC / DC converter 12a according to a modification. 10 that are the same as those shown in FIG. 4 are given the same reference numerals, and descriptions thereof are omitted.

  The DC / DC converter 12a includes a coil 110, a capacitor 111, a switching element 112, a diode 113, a capacitor 114, a voltage measurement unit 120, a current measurement unit 121, a voltage measurement unit 122, a communication unit 130, a control unit 14a, and an MPPT control unit 131. The power control unit 132 is included. Further, the terminal P5 is connected to the voltage acquisition unit 10 of the solar cell block 11.

  The control unit 14a has the same function as the control unit 14 shown in FIG. That is, the DC / DC converter 12a according to the modification has a configuration in which the control unit 14 shown in FIG. 1 is incorporated in each of the DC / DC converters 12-1 to 12-N shown in FIG.

  Even in a solar power generation system that employs such a DC / DC converter 12a, the same control and effects as those of the solar power generation system 1 described above can be realized.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, the functions included in each component, each step, etc. can be rearranged so that there is no logical contradiction, and multiple components, steps, etc. can be combined or divided into one It is. Further, although the present invention has been described mainly with respect to the apparatus, the present invention can also be realized as a method, a program executed by a processor included in the apparatus, or a storage medium storing the program, and is within the scope of the present invention. It should be understood that these are also included.

DESCRIPTION OF SYMBOLS 1 Solar power generation system 10 Voltage acquisition part 11 Solar cell block 12 DC / DC converter (converter)
13 Battery 14 Control unit 15 Storage unit

Claims (12)

A photovoltaic power generation system mounted on a moving body,
A solar cell block having a plurality of strings and having bypass diodes connected in parallel to both ends of the strings;
A converter that performs MPPT control to vary the operating point of the generated power of the solar cell block within a predetermined range, and controls the output voltage value of the solar cell block;
A control unit that calculates an expected voltage value of the solar cell block according to a bypass diode in a bypass state among the bypass diodes, and
The converter, when obtaining the expected voltage value from the control unit, controls the output voltage value of the solar cell block based on the expected voltage value.   2. The photovoltaic power generation system according to claim 1, wherein the control unit calculates an expected voltage value of the solar cell block according to the number of bypass diodes in the bypass state.   3. The photovoltaic power generation system according to claim 1, wherein the control unit detects the bypass diode that is in a bypass state based on a voltage across the bypass diode, and identifies the number of bypass diodes that are in the bypass state. A solar power generation system characterized by that.   4. The photovoltaic power generation system according to claim 3, wherein the control unit detects a bypass state when a value of a voltage across the bypass diode is less than a predetermined threshold. 5. . In the solar power generation system according to any one of claims 1 to 4,
A storage unit for storing a maximum operating voltage value of the solar cell block;
The control unit subtracts the number of bypass diodes in the bypass state from the total number of bypass diodes, and further multiplies the maximum operating voltage value by the value obtained by dividing the total number of bypass diodes. A photovoltaic power generation system characterized by calculating In the solar power generation system according to any one of claims 1 to 4,
A storage unit that stores a maximum operating voltage value of the solar cell block and a voltage value for the one string at the maximum operating voltage value;
The control unit calculates the expected voltage value by multiplying the number obtained by subtracting the number of bypass diodes in a bypass state from the total number of bypass diodes by a voltage value corresponding to one string. Solar power generation system. In the solar power generation system according to any one of claims 1 to 4,
A storage unit that stores a maximum operating voltage value of the solar cell block and a voltage value of each of the strings at the maximum operating voltage value;
The control unit calculates the expected voltage value by subtracting the voltage value of the string in which the bypass diode in the bypass state is connected at both ends from the maximum operating voltage value. Photovoltaic system. In the solar power generation system according to any one of claims 1 to 4,
A storage unit that stores the maximum operating voltage value of the solar cell block and the voltage value of the string at the maximum voltage value for each different series number of solar cells in the solar cell included in the string. Prepared,
The control unit subtracts the voltage value of the string in which the bypass diodes in the bypass state are connected at both ends for each different series number of the solar battery cells from the maximum operating voltage, thereby obtaining the expected voltage. A photovoltaic power generation system characterized by calculating a value.   8. The photovoltaic power generation system according to claim 1, wherein the control unit corrects the expected voltage value, and the converter uses the expected voltage value corrected by the control unit as a reference. A photovoltaic power generation system characterized by controlling the output voltage value of a battery block. A method for controlling a photovoltaic power generation system mounted on a moving body, the photovoltaic power generation system comprising a plurality of strings, and a solar cell block having bypass diodes connected in parallel to both ends of the strings ,
Calculating an expected voltage value of the solar cell block according to a bypass diode in a bypass state among the bypass diodes;
Controlling the output voltage value of the solar cell block based on the expected voltage value;
Control method for solar power generation system including A mobile body equipped with a solar cell system, the solar cell system comprising:
A solar cell block having a plurality of strings and having bypass diodes connected in parallel to both ends of the strings;
A converter that performs MPPT control to vary the operating point of the generated power of the solar cell block within a predetermined range, and controls the output voltage value of the solar cell block;
A control unit that calculates an expected voltage value of the solar cell block according to a bypass diode in a bypass state among the bypass diodes, and
When the converter acquires the predicted voltage value from the control unit, the converter controls the output voltage value of the solar cell block based on the predicted voltage value.   The mobile body carrying the solar power generation system of Claim 11 WHEREIN: The said mobile body is a vehicle, The mobile body carrying the solar power generation system characterized by the above-mentioned.

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