JP2014195386A - Photovoltaic power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photovoltaic power generation system capable of efficiently generating the power by using plural photovoltaic power generation parts which generates the power using the sunlight.SOLUTION: An integrated control section 20 generates and registers a partial shade pattern and identifies a partial shade pattern which is applied on the day of control. The integrated control section 20 measures and records the power of the respective cells. The integrated control section 20 performs a determination processing to determine whether estimation timing has reached according to the determined estimation timing based on a piece of weather information. Determining as estimation timing, the integrated control section 20 determines the state of the respective cells and determines whether there is any pattern deviation. When there is any pattern deviation, the integrated control section 20 creates a cell pattern and refines cell patterns according to the applied partial shade pattern, and performs a power calculation processing of the refined cell pattern. The integrated control section 20 determines a cell pattern of maximum power and transmits a switching signal to the respective cells. In this case, each solar cell module 10 switches.

Description

  The present invention relates to a photovoltaic power generation system.

  Solar power generation is attracting attention for environmental protection and energy security. The power generation unit of this solar power generation facility is usually composed of a plurality of solar cell elements. The elements and their aggregates are called cells, modules, and arrays depending on the scale and form. A single element of a solar cell is called a “cell”. This cell converts sunlight into electrical energy by the photovoltaic effect. A configuration in which cells are connected in series to obtain a desired voltage is called a “module” or “panel”. A module in which a plurality of modules are arranged and connected in series is called a “string”. A string in which strings are connected in parallel is called an “array”.

  The place where such a solar cell is installed may fall in the shadow of a building or a cloud. When a shadow is projected on a part of the solar cell, the power generation characteristics deteriorate. In addition, when the solar cell fails due to long-term use, the power generation characteristics deteriorate. When a solar cell with deteriorated power generation characteristics is used as it is, other solar cells connected in series are also affected by the deteriorated solar cells and the characteristics are deteriorated.

  In FIG. 12, the output characteristic of the electric power in a solar cell is shown. Here, the output current is shown with respect to the output voltage. This output characteristic varies depending on the amount of solar radiation. As shown in FIG. 12, when the solar radiation amount is 1000 W / m ^ 2, the maximum power point tracking operates at a high voltage, but the solar radiation amount falls, for example, 750 W / m ^ 2. In this case, the maximum power point tracking voltage decreases. Furthermore, when the amount of solar radiation decreases to 500 W / m ^ 2, the output current of other solar cells is dragged to the operating point of the output of this solar cell, so that the overall output characteristics are degraded. .

  For this reason, no matter what kind of shadow is applied to the light receiving surface, a technique for always capturing the maximum power point has been studied (see, for example, Patent Document 1). In the solar cell module described in this document, a plurality of solar cells are arranged in a grid pattern and sequentially connected in series. Then, switching means for switching adjacent solar cells to serial connection or parallel connection, current measuring means for measuring the current value of the solar battery cells, and switching of the switching means based on the current value measured by the current measuring means Switching control means for performing control. This switching control means allows the adjacent solar cells in the shade until the added value of the current values detected from the solar cells in the shade becomes the current value detected from the solar cells in the sun. The switching means is controlled to switch from the serial connection to the parallel connection.

  In addition, a solar power generation system that is easy to maintain and stably maintains power generation efficiency has been studied (see, for example, Patent Document 2). In the technology described in this document, the photovoltaic power generation system includes a first switch that connects or disconnects between output lines that are connected in parallel to the power output terminals of the positive electrode and the negative electrode of the solar cell string. And a second switch for short-circuiting or opening the power output terminals. Further, a comparator for outputting a comparison signal obtained by comparing the voltage value between the detection terminals at a predetermined location of the solar cell string with a predetermined value, and a comparison signal is input. Based on this input signal, the first switch and the first switch And a controller for controlling opening and closing of the second switch. A solar cell string in which the voltage value between the detection terminals is equal to or lower than a predetermined value is determined to be abnormal, the power output terminal of the solar cell string is cut off from the output line, and the power output terminals are short-circuited. Moreover, the identification code of the solar cell string determined to be abnormal is displayed on the display.

  In addition, a solar power generation device for taking out the maximum power from the solar cell array has been studied (see, for example, Patent Document 3). In the technique described in this document, in a solar power generation apparatus using a plurality of unit solar cell modules, a part or all of adjacent unit solar cell modules are connected via a switch. Furthermore, in this solar power generation device, the series-parallel structure of the unit solar cell modules is changed by turning on / off or switching the switches.

JP 2012-204651 A JP-A-7-177852 Japanese Unexamined Patent Publication No. 2000-89841

  In order to improve power generation characteristics affected by shadows, a solar cell panel may be individually controlled by installing a DC / DC converter in each panel. Although the characteristics are improved by this method, there is a problem that a cost burden is imposed on the DC / DC converter.

Moreover, as described in the above-mentioned patent document, when changing the connection relationship of a plurality of solar cells, it is difficult to determine the connection relationship considering the overall power generation efficiency.
Furthermore, the shadows of buildings and clouds change with time. If the connection is frequently changed in accordance with this change, the power consumption for changing the connection increases, and the consumption of components such as the changeover switch may be accelerated.

  In particular, when there is a building near the solar cell panel, a shadow of the building may be regularly projected onto the solar cell panel depending on the position of the sun. If the solar cell panel can be controlled in consideration of the influence of the shadow that can be predicted in this way, it can be expected to reduce the power consumption for the connection change.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a photovoltaic power generation system for efficiently generating power using a plurality of photovoltaic power generation units that generate power using sunlight. Is to provide.

  In the solar power generation system that solves the above problems, a plurality of solar power generation units are connected, and a sensor unit that detects and outputs an output value for power generation in each of the solar power generation units, and each of the solar power generation units The solar power generation system includes a switch unit that controls output in the control unit and a control unit that acquires an output value detected by the sensor unit, wherein the control unit generates partial shadows due to sunlight obstacles. And the switch unit of each photovoltaic power generation unit is controlled based on the output value detected by the sensor unit and the prediction of the occurrence state of the partial shadow.

  According to the solar power generation system, the control unit records the output value in each solar power generation unit in the actual measurement information recording unit in association with the measurement time, and outputs the output value recorded in the actual measurement information recording unit. It is preferable to predict the occurrence state of the partial shadow at the time corresponding to the measurement time associated with the output value.

According to the solar power generation system, it is preferable that the control unit is connected to an external sensor and predicts the occurrence state of the partial shadow based on information acquired from the external sensor.
According to the solar power generation system, it is preferable that the control unit obtains weather information and predicts the occurrence state of the partial shadow based on the weather information.

  According to the solar power generation system, the control unit acquires weather information, determines an evaluation cycle based on the weather information, and controls the switch unit of each solar power generation unit in the evaluation cycle. It is preferable to control the switch unit of each solar power generation unit when it is determined to change the control of the switch unit of each solar power generation unit by executing a determination process of whether to change.

  According to the solar power generation system, based on the prediction of the occurrence of the partial shadow, the reference power that can be generated in the solar power generation unit is predicted, and the reference power and the output value of each solar power generation unit It is preferable to specify the state of each photovoltaic power generation unit based on the comparison result of comparing the above and output information on this state.

  According to the present invention, efficient power generation can be realized in a solar power generation system including a plurality of solar power generation units that generate power using sunlight.

The block diagram of the solar energy power generation system of 1st Embodiment. Explanatory drawing of the solar cell module of 1st Embodiment. Explanatory drawing of the processing flow of 1st Embodiment. Explanatory drawing of the processing flow of 1st Embodiment. Explanatory drawing of the processing flow of 1st Embodiment. The block diagram of the solar energy power generation system of 2nd Embodiment. Explanatory drawing of the solar cell module of 2nd Embodiment. Explanatory drawing of the transition of the solar cell module used as the master of 2nd Embodiment. Explanatory drawing of the transition of the solar cell module used as the master of 2nd Embodiment. Explanatory drawing of the processing flow of 2nd Embodiment. Explanatory drawing of the processing flow in the example of a change. Explanatory drawing of the electric power generation characteristic of a solar cell.

(First embodiment)
Hereinafter, an embodiment of a photovoltaic power generation system will be described with reference to FIGS. This embodiment demonstrates as a photovoltaic power generation system which controls the connection state of each photovoltaic cell in the photovoltaic power generation system to which the several photovoltaic cell was connected.

  In this embodiment, as shown in FIG. 1, the solar power generation device A1 includes a plurality of solar cell modules 10 (solar power generation units). Here, it is assumed that eight solar cell modules 10 are used and four upper solar cell modules 10 and lower solar cell modules 10 are connected in series. In addition, the number and connection form of the solar cell module 10 are not limited to this.

  As shown in FIG. 2, each solar cell module 10 includes a solar cell SC, a control unit 11, and a power sensor 12. The control unit 11 of each solar cell module 10 is connected to the integrated control unit 20 by a signal line.

  The solar battery cell SC is a semiconductor element that converts incident solar energy into electric power. Furthermore, the electric power generated by the solar battery cell SC is output to the outside through an output line via the switches 131 and 132. The external output line is provided with a switch 133 for bypassing this line. Each switch 131,132,133 is controlled based on the signal from the control part 11, and functions as a switch part which controls the output of the electric power in the photovoltaic cell SC. When using the solar cell SC, the switches 131 and 132 are turned on and the switch 133 is turned off. On the other hand, when the solar cell SC is not used, the switches 131 and 132 are turned off and the switch 133 is turned on.

The power sensor 12 is a sensor unit that measures an output value (voltage and current) of power generated by the solar battery cell SC. Then, the power sensor 12 supplies the measured value (output value of the solar battery cell SC) to the control unit 11.
The control unit 11 includes a transmission unit 111, acquires a measurement value from the power sensor 12, and transmits the measurement value to the integrated control unit 20.

  As shown in FIG. 1, the integrated control unit 20 is a computer that controls the solar cell module 10. The integrated control unit 20 includes an evaluation support unit 210, a measurement unit 211, a determination unit 212, an instruction unit 213, and a measurement value storage unit 22. In addition, the integrated control unit 20 stores the current number of measurement cycles.

  The evaluation support unit 210 generates a partial shadow pattern and executes processing for determining an evaluation cycle based on weather information. The evaluation support unit 210 holds a cycle determination table associated with the evaluation reference count for determining the timing for performing the evaluation in correspondence with the weather information. This evaluation reference number is the number of cycles for determining the evaluation time with respect to the number of measurements. In the cycle determination table, the number of evaluation references is set so that the measurement cycle is longer in the case of a forecast with little weather change than in the case of a forecast with weather change.

Further, the evaluation support unit 210 includes a partial shadow pattern storage unit. In this partial shadow pattern storage unit, a partial shadow pattern is recorded in association with the application time range and the shadow occurrence time. Here, the application time range is a period (for example, month and day) in which this partial shadow pattern can be applied. The shadow occurrence time is a time zone in which a shadow pattern appears. In this embodiment, this time slot | zone is specified by the time of every 0.5 hour in 1 day, for example. In addition, a module identifier that identifies a shadow area module (a solar cell module 10 whose voltage value is expected to decrease in advance due to a shadow of a building or the like) is recorded as a partial shadow pattern.
Further, the evaluation support unit 210 stores a partial shadow pattern to be applied on the control day.

  The measurement unit 211 executes a process of acquiring a measurement value from the control unit 11 of each solar cell module 10 and recording it in the measurement value storage unit 22.

The determination unit 212 determines whether or not the control unit 11 needs to be controlled based on the measurement value acquired from each solar cell module 10. The determination unit 212 holds a switch control pattern (cell pattern) for specifying the current usage state of each solar cell module 10.
The instruction unit 213 transmits a control signal for the control unit 11 to each solar cell module 10 based on the determination result in the determination unit 212.

  The measured value storage unit 22 functions as an actual measurement information recording unit, and stores a measured value record related to the output in the solar cell module 10. This measurement value record is recorded when a measurement value is acquired from each solar cell module 10. In this measurement value record, data relating to measurement time, module identifier, and measurement value are recorded.

In the measurement time data area, data related to the time when the measurement value is acquired from each solar cell module 10 is recorded.
In the module identifier data area, data relating to an identifier for specifying the solar cell module 10 from which the measurement value is acquired is recorded.
In the measured value data area, data relating to measured values (voltage value and current value) acquired from the solar cell module 10 is recorded.

Next, partial shadow registration processing will be described with reference to FIG.
In this partial shadow registration process, partial shadow generation (electric power generation unevenness) due to a building is patterned at each shadow generation time according to the measurement value record (actual measurement information) recorded in the measurement value storage unit 22. This process is performed every predetermined registration period (for example, one year).

  Here, the integrated control unit 20 executes a partial shadow pattern generation process based on the power generation amount (step S101). Specifically, the evaluation support unit 210 of the integrated control unit 20 acquires a measurement value record for the registration period from the measurement value storage unit 22. And the evaluation assistance part 210 calculates the output information (standardized output value) which excluded the influence of the weather etc. for every day. Here, the evaluation support unit 210 specifies the maximum output value (maximum voltage value) of the solar cell module 10 at the same time. Next, the evaluation support unit 210 normalizes the output value by dividing the output value of each solar cell module 10 at this time by the maximum output value. Then, the evaluation support unit 210 searches each solar cell module 10 for a time zone in which the normalized output value periodically decreases in a predetermined application time range (for example, each month). If there is such a time zone, the integrated control unit 20 determines that a partial shadow has occurred. Next, the evaluation support unit 210 summarizes the module identifiers of the solar cell modules 10 whose normalized output values are periodically reduced (become shadow region modules) in the time period in which it is determined that a partial shadow has occurred. A partial shadow pattern is generated. In addition, periodically, when there is no time zone in which the output value decreases in the same solar cell module 10, it is determined that there is no partial shadow, and the process ends.

  Next, the integrated control unit 20 executes a partial shadow pattern registration process in association with the shadow occurrence time (step S102). Specifically, the evaluation support unit 210 of the integrated control unit 20 specifies the time zone in which the partial shadow pattern is generated as the shadow occurrence time. Further, the evaluation support unit 210 records a partial shadow pattern (a module identifier of the shadow area module) in the partial shadow pattern storage unit in association with the application time range and the shadow generation time.

Next, date and time processing will be described with reference to FIG.
In this date and time processing, the occurrence of a partial shadow due to a building is predicted based on the current date. This process is performed every day before the start of power generation.

  First, the integrated control unit 20 executes partial shadow pattern acquisition processing based on the current date (step S201). Specifically, the evaluation support unit 210 of the integrated control unit 20 acquires the current date in the system timer. Then, the evaluation support unit 210 searches the partial shadow pattern storage unit for a partial shadow pattern whose current date is included in the applicable time range. In this case, if the partial shadow pattern whose current date is included in the application time range is not recorded in the partial shadow pattern storage unit, the integrated control unit 20 does not store the partial shadow pattern to be applied on the control day. The date / time processing is terminated.

  Next, the integrated control unit 20 executes a process of recording a partial shadow pattern to be applied (step S202). Specifically, the evaluation support unit 210 of the integrated control unit 20 applies the shadow generation time of the partial shadow pattern acquired from the partial shadow pattern storage unit and the module identifier as the partial shadow pattern on the control day. Store as a pattern.

Next, the control processing of the solar power generation device A1 will be described using FIG.
Here, first, the integrated control unit 20 executes a weather information acquisition process (step S301). Specifically, the evaluation support unit 210 of the integrated control unit 20 acquires weather information on the current day via the Internet or the like.

  Next, the integrated control unit 20 executes an evaluation timing determination process based on the weather information (step S302). Specifically, the evaluation support unit 210 of the integrated control unit 20 determines the number of evaluation criteria corresponding to the weather information using the cycle determination table.

  Next, the integrated control unit 20 executes a power measurement process for each cell (step S303). Specifically, the measurement unit 211 of the integrated control unit 20 specifies the current time using a system timer, and determines whether this current time is the measurement time in the measurement cycle. And the measurement part 211 transmits the measurement instruction | indication of electric power with respect to each solar cell module 10, when arrival of measurement time is detected. In this case, the control unit 11 of each solar cell module 10 detects the output value (current value, voltage value) of the solar cell SC by the power sensor 12. Then, the transmission unit 111 of the control unit 11 transmits data regarding the detected power to the integrated control unit 20. And the measurement part 211 of the integrated control part 20 acquires the output value of the electric power in the solar cell module 10. FIG.

  Next, the integrated control unit 20 executes each cell power recording process (step S304). Specifically, the measurement unit 211 of the integrated control unit 20 stores the measured output value in association with the current time and the module identifier of the solar cell module 10 by using the output value (current value, voltage value) of the acquired power as a measurement value. Record in part 22.

  Next, the integrated control unit 20 executes a determination process as to whether or not it is the evaluation time (step S305). Specifically, the determination unit 212 of the integrated control unit 20 counts the number of measurement cycles from the previous evaluation time. Then, the number of measurement cycles is compared with the number of evaluation criteria. Here, if the number of measurement cycles is less than the number of evaluation criteria, it is determined that the evaluation time is not reached, and if the number of measurement cycles is equal to or greater than the number of evaluation criteria, it is determined that the time is evaluated.

  When it is determined that it is not the evaluation time (in the case of “NO” in step S305), the integrated control unit 20 adds “1” to the current number of measurement cycles, and repeats the processing after step S303.

  On the other hand, when it is determined that the evaluation time is reached (in the case of “YES” in step S305), the integrated control unit 20 executes a process for specifying the state of each cell (step S306). Specifically, the determination unit 212 of the integrated control unit 20 obtains, from the measurement value storage unit 22, the measurement values after the previous evaluation time (number of measurement values corresponding to the number of measurement cycles) for each solar cell module 10. get. Here, the voltage value of the solar cell SC at each measurement time is acquired.

  Next, the integrated control unit 20 performs a determination process as to whether or not there is a pattern shift (step S307). Specifically, the determination unit 212 of the integrated control unit 20 compares the voltage value of the solar cell module 10 with the threshold voltage. And about each solar cell module 10, the map (pattern which combined the present state) which identified the comparison result of a voltage value and a threshold value is created. Next, the determination part 212 compares the map of the solar cell module 10 below the threshold value and the solar cell module 10 exceeding the threshold value with the cell pattern applied at that time. Then, the determination unit 212 determines that there is a pattern shift when the map and the cell pattern are different. For example, when the voltage value of the solar cell module 10 in the on state in the cell pattern is equal to or lower than the threshold value, or when the voltage value of the solar cell module 10 in the off state exceeds the threshold value, there is a pattern shift. become.

  If it is determined that there is no pattern deviation (in the case of “NO” in step S307), the integrated control unit 20 resets the number of measurement cycles to “0” and repeats the processing from step S303 onward.

  On the other hand, when it is determined that there is a pattern shift (in the case of “YES” in step S307), the integrated control unit 20 executes a cell pattern creation process (step S308). Specifically, the determination unit 212 of the integrated control unit 20 generates a cell pattern candidate that is switched on / off of a solar cell (deteriorated cell) whose measurement voltage is lower than a threshold value. For example, when a plurality of deteriorated cells are detected, cell pattern candidates are generated when each deteriorated cell is sequentially switched off. Here, if there are n degraded cells, [2 ^ (n-1)] cell pattern candidates are generated.

  Here, if the partial shadow pattern to be applied on the day of control is stored, the integrated control unit 20 compares the system timer and the shadow occurrence time of the partial shadow pattern, and specifies the shadow area module at the current time. . And the integrated control part 20 searches the cell pattern candidate which the solar cell module 10 of a shadow area module turns on from the produced | generated cell pattern candidate, and excludes this cell pattern candidate from the following process targets. Thereby, the cell pattern candidates to be processed are narrowed down.

  Next, the integrated control unit 20 executes a power calculation process for each cell pattern (step S309). Specifically, the determination unit 212 of the integrated control unit 20 uses each measurement value (current value, voltage value) recorded in the measurement value storage unit 22 to select each solar cell module for each cell pattern candidate narrowed down. A predicted power value when 10 on / off switching control is performed is calculated. In this case, the determination unit 212 calculates a predicted power value using the measurement values of each of the plurality of measurement cycles recorded in the measurement value storage unit 22. Then, the determination unit 212 temporarily stores the calculated predicted power value in association with the cell pattern candidate.

  Next, the integrated control unit 20 executes a determination process as to whether or not evaluation of all cell patterns has been completed (step S310). Here, the integrated control unit 20 determines that the evaluation of all the cell pattern candidates is completed when the predicted power values of all the cell patterns are calculated.

  If it is determined that the evaluation of all the cell patterns has not been completed (in the case of “NO” in step S310), the integrated control unit 20 specifies another cell pattern candidate for which the power predicted value has not yet been calculated. And the integrated control part 20 repeats the process after the electric power calculation process (step S309) of each cell pattern about the specified cell pattern candidate.

  On the other hand, when it is determined that the evaluation of all the cell patterns has been completed (in the case of “YES” in step S310), the integrated control unit 20 executes a maximum power cell pattern determination process (step S311). Specifically, the determination unit 212 of the integrated control unit 20 specifies the largest cell pattern candidate among the temporarily stored power prediction values. The determination unit 212 holds the specified cell pattern candidate as a switch control pattern for specifying the usage state of the solar cell module 10. Then, the determination unit 212 supplies the held switch control pattern to the instruction unit 213.

  Next, the integrated control unit 20 performs a switching signal transmission process for each cell (step S312). Specifically, the instruction unit 213 of the integrated control unit 20 specifies the on / off state of each solar cell module 10 based on the switch control pattern acquired from the determination unit 212. And the instruction | indication part 213 transmits the switching signal (cell pattern) which designated this state to each solar cell module 10. FIG.

Next, each solar cell module 10 performs a switch switching process (step S313). Specifically, the control unit 11 of each solar cell module 10 switches the switches 131 to 133 based on the switching signal acquired from the integrated control unit 20. Here, when the off signal is received, the control unit 11 turns off the switches 131 and 132 and turns on the switch 133. On the other hand, when receiving the ON signal, the control unit 11 turns on the switches 131 and 132 and turns off the switch 133.
Thereafter, the integrated control unit 20 resets the number of measurement cycles to “0”, and repeats the processing after step S101.

According to the photovoltaic power generation system of the above embodiment, the following effects can be obtained.
(1) In the above embodiment, the integrated control unit 20 executes the partial shadow registration process and date / time process. In the control process of the photovoltaic power generation apparatus A1, the integrated control unit 20 narrows down the cell pattern candidates from the generated cell pattern candidates according to the partial shadow pattern applied on the current date. Thereby, the switch can be efficiently switched in consideration of the solar cell module 10 in which the voltage drop is expected due to the shadow of the building.

  (2) In the above embodiment, the integrated control unit 20 executes the weather information acquisition process (step S301) and the evaluation timing determination process (step S302) based on the weather information. Thereby, a cell pattern can be evaluated efficiently according to the weather. For example, when the weather changes drastically and the state of clouds or sunlight is likely to change, the shadow may change accordingly. In this case, by reducing the number of evaluation criteria and shortening the evaluation interval, it is possible to efficiently generate power by applying a cell pattern according to the situation. On the other hand, when the change in weather is small and the change in shadow due to clouds or the like is small, the power consumption can be suppressed by increasing the evaluation interval and increasing the evaluation interval.

  (3) In the above embodiment, the integrated control unit 20 executes the power measurement process (step S303) of each cell, each cell power recording process (step S304), and the determination process (step S305) as to whether it is the evaluation time. . Thereby, while measuring a measured value for every predetermined time, the necessity of evaluation can be judged based on a measurement result of a plurality of times. Therefore, efficient solar power generation can be performed while suppressing power consumption of the control unit 11 and the integrated control unit 20.

  (4) In the above embodiment, when the number of measurement cycles exceeds the evaluation reference number and it is determined as the evaluation time (in the case of “YES” in step S305), the integrated control unit 20 performs the process of specifying the state of each cell. Is executed (step S306). When it is determined that there is a pattern deviation (in the case of “NO” in step S307), the integrated control unit 20 executes a cell pattern creation process (step 308) and a switching signal transmission process (step S312) for each cell. To do. Thereby, for example, when a problematic solar battery cell is detected, the entire power generation state is taken into account even when the power generation amount of some solar power generation units is reduced by generating a cell pattern. Control can be performed.

  (5) In the embodiment described above, the integrated control unit 20 executes the power calculation process for each cell pattern (step S309). If it is determined that all the cell patterns have been evaluated (“YES” in step S310), the integrated control unit 20 executes a maximum power cell pattern determination process (step S311). Thereby, even when the electric power generation amount of some solar cell modules 10 falls, various cell patterns can be assumed. Therefore, it is possible to determine whether or not the solar cell module 10 needs to be detached in consideration of the overall situation.

  In addition, a cell pattern that can output the maximum power can be specified based on the measurement results of a plurality of times. Therefore, even when the shadow changes rapidly, an appropriate cell pattern can be specified based on the measurement values in each measurement cycle from the previous evaluation time.

  (6) In the above embodiment, the integrated control unit 20 executes a switching signal transmission process for each cell (step S312), and each solar cell module 10 executes a switch switching process (step S313). Thereby, using the integrated control unit 20, efficient power generation can be realized through the entire photovoltaic power generation apparatus A1.

(Second Embodiment)
Next, 2nd Embodiment of a solar power generation system is described according to FIGS. In addition, since 2nd Embodiment is a structure which only changed the integrated control part 20 of 1st Embodiment, the detailed description is abbreviate | omitted about the same part. In this embodiment, the function of the integrated control part 20 is implement | achieved in the control part 11 of each solar cell module.

  As shown in FIG. 6, the solar power generation device A2 includes solar cell modules 10a to 10h. And the control part 11 of one solar cell module functions as a master among the solar cell modules 10a-10h, and the control part 11 of another solar cell module functions as a slave. And the control part 11 as a master functions as the integrated control part 20 of the said 1st Embodiment, and transmits a control signal with respect to the other control part 11 which functions as a slave.

  As shown in FIG. 7, each control unit 11 includes a transmission unit 111 and an evaluation support unit 210, a measurement unit 211, a determination unit 212, and the like, as well as the first embodiment. An instruction unit 213 and a measurement value storage unit 22 are provided.

  Further, the control unit 11 includes a master management unit 214. This master management part 214 communicates with another solar cell module, and determines the control part 11 used as a master. The master management unit 214 holds data related to the order of becoming a master among the solar cell modules 10a to 10h. For example, data for specifying an order such as “10a → 10b →... → 10h” is held. In this case, after the last solar cell module 10h becomes the master, the next master becomes the first solar cell module 10a.

And each control part 11 hold | maintains the data for identifying either a master or a slave.
As shown in FIG.8 and FIG.9, the control part 11 of the solar cell module 10 which functions as a master shall switch in order.

Moreover, as shown in FIG. 9, when a solar cell module with a problem (for example, solar cell module 10f) is detected, this solar cell module 10f is avoided, and other solar cell modules 10a-10e, 10g, Any one of 10h functions as a master.
Furthermore, each control unit 11 stores a continuation reference count indicating whether or not it is time to take over the master. Each control unit 11 stores the current number of continuous cycles.

  Next, master-slave takeover processing will be described with reference to FIG. Here, it is assumed that the master is taken over from the preceding solar cell module 10d to the solar cell module 10e, and this solar cell module 10e is taken over to the subsequent solar cell module 10g.

  First, the control part 11 of the solar cell module 10e performs a master succession process (step S401). Specifically, the master management unit 214 of the control unit 11 receives an instruction to become a master from the control unit 11 of the solar cell module 10d. In this case, the master management unit 214 resets the number of continuous cycles to “0”.

  Next, the control part 11 of the solar cell module 10e performs the control process as a master (step S402). Specifically, the measurement unit 211 to the instruction unit 213 of the control unit 11 execute the control process shown in FIG.

  Next, the control part 11 of the solar cell module 10e performs the determination process about whether it is a takeover time (step S403). Specifically, the control unit 11 counts the number of continuous cycles in the control process. Then, the master management unit 214 of the control unit 11 compares the number of continuous cycles with the number of continuous reference times. If the continuous cycle number is less than the continuous reference number, it is determined that it is not the takeover time. If the continuous cycle number is equal to or greater than the continuous reference number, it is determined that the takeover time has come.

  When it is determined that it is not the takeover time (in the case of “NO” in step S403), the control unit 11 of the solar cell module 10e adds “1” to the current cycle number and performs control processing as a master (step S402). Continue on.

  On the other hand, when it is determined that the handover time has arrived (in the case of “YES” in step S403), the control unit 11 of the solar cell module 10e executes a specific process of another module capable of communication (step S404). Specifically, the master management unit 214 of the control unit 11 specifies another solar cell module 10 that has transmitted the output value of the solar cell SC in accordance with the power measurement instruction. For example, when there is no transmission from the solar cell module 10f, the solar cell modules 10a to 10d, 10g, and 10h are specified.

  The control unit 11 of the solar cell module 10e executes a master takeover process to the next module (step S405). Specifically, the master management unit 214 of the control unit 11 identifies other solar cell modules 10a to 10d, 10g, and 10h that can communicate, and identifies the solar cell module of the next rank as the next master module. To do. Here, the control part 11 of the solar cell module 10e skips the solar cell module 10f which has not transmitted the measured value, and specifies the solar cell module 10g. Then, the master management unit 214 of the control unit 11 transmits a master takeover instruction to the subsequent solar cell module 10g.

  Next, similarly to the preceding solar cell module 10, the control unit 11 of the solar cell module 10g executes a master takeover process (step S401) to a master takeover process (step S405).

Therefore, according to the second embodiment, the following effects can be obtained in addition to the effects similar to the effects described in (1) to (6) of the first embodiment.
(7) In 2nd Embodiment, the control part 11 of one solar cell module functions as a master among several solar cell modules 10a-10h, and the control part 11 of another solar cell module functions as a slave. . Thereby, the solar cell module 10 of the master which integrates and manages the other solar cell module 10 can be replaced regularly. Therefore, each solar cell module 10 can be controlled even when a failure occurs in some of the solar cell modules 10.

Moreover, you may change the said embodiment as follows.
-In each above-mentioned embodiment, a solar cell module was assumed as a solar power generation part, and control processing was performed in solar power generation device A1 and A2 which collected this solar cell module. The configuration is not limited to the above as long as the plurality of photovoltaic power generation units are controlled in consideration of the entire state. For example, in a solar battery module composed of a plurality of solar battery cells, each solar battery cell may be switched. A string in which a plurality of modules are arranged in series and connected in series, or an array in which strings are connected in parallel may be controlled in consideration of the state of the entire system.

  In the first embodiment, the integrated control unit 20 performs a weather information acquisition process (step S301). Here, weather information is acquired via the Internet. The method for acquiring weather information is not limited to this. In addition to weather information that can be acquired from the Internet, external sensor information (for example, the amount of light detected by a photosensor) can be used.

  In the first embodiment, the integrated control unit 20 executes weather information acquisition processing (step S301) and evaluation timing determination processing (step S302) based on the weather information. Here, as the weather information, information (weather, wind direction, wind speed, temperature) acquired via the network or information (light quantity, wind speed) acquired by a sensor can be used. For example, on a mild weather day, a large number of evaluation reference numbers are set so that the measurement cycle becomes long because changes are unlikely to occur. Thereby, a cell pattern can be evaluated efficiently according to the weather.

  In the first embodiment, the integrated control unit 20 executes weather information acquisition processing (step S301) and evaluation timing determination processing (step S302) based on the weather information. It may replace with this and may use for the performance evaluation of a photovoltaic cell based on weather information. In this case, for example, as weather information, a light amount may be detected by a photosensor, and performance such as aging deterioration of the solar battery cell may be evaluated using this light amount as a reference. Specifically, a photosensor provided around the solar cell module 10 is connected to the integrated control unit 20. This photo sensor is installed in a place where a shadow such as a building is not generated. The integrated control unit 20 holds information for specifying the connected solar cell module 10. Furthermore, an administrator terminal is connected to the integrated control unit 20 via a network. This administrator terminal is a computer terminal used by an administrator who manages the solar cell module 10.

Next, solar cell evaluation processing will be described with reference to FIG. This evaluation process is periodically executed at different times of the day.
Specifically, the integrated control unit 20 executes photo sensor information acquisition processing (step S501). Specifically, the evaluation support unit 210 of the integrated control unit 20 acquires information on the electromotive force (voltage value) in the photosensor.

  Next, the integrated control unit 20 performs a reference electromotive force calculation process based on the photosensor information (step S502). Specifically, the evaluation support unit 210 of the integrated control unit 20 acquires the output value of each solar cell module 10. Then, the evaluation support unit 210 compares the electromotive force of the photosensor and the voltage value of each solar cell module 10 to calculate each voltage comparison value. In this embodiment, a value obtained by dividing the voltage value of the solar cell module 10 by the electromotive force of the photosensor is used as the voltage comparison value.

  Next, the integrated control unit 20 executes output processing of the degradation diagnosis result (step S503). Specifically, the evaluation support unit 210 of the integrated control unit 20 uses the partial shadow pattern to identify the solar cell module 10 that is predicted not to be affected by the shadow (the output value does not decrease). And the evaluation assistance part 210 confirms whether the voltage comparison value of the specified solar cell module 10 is below a reference value. In the case of the reference value or less, it is determined that there is some problem in the solar cell module 10.

  Here, when the problematic solar cell module 10 is detected, the evaluation support unit 210 of the integrated control unit 20 transmits a caution message to the administrator terminal. This caution message includes information for identifying the solar cell module 10, information on the deterioration of the solar cell, and the like. Thereby, the deterioration diagnosis of the solar cell module 10 can be performed easily.

  In the first embodiment, the integrated control unit 20 executes a partial shadow pattern generation process in the partial shadow registration process (step S101). In this case, the evaluation support unit 210 of the integrated control unit 20 generates a partial shadow pattern using the actual measurement information. In addition to this, the occurrence of partial shadows may be predicted based on weather information. For example, a partial shadow pattern is applied when the sunlight is strong and the influence of a partial shadow is likely to occur, such as on a sunny day. On the other hand, the partial shadow pattern is not applied when the sunlight is weak and the influence of the partial shadow is small, such as a cloudy day. Thus, efficient power generation can be performed in consideration of the influence of partial shadows according to the weather.

  In the first embodiment, the integrated control unit 20 performs a power measurement process for each cell (step S303). Here, the measurement time in the measurement cycle is specified using a timer. When the arrival of the measurement time is detected, the output value of power in each solar cell module 10 is measured. You may make it change the length of this measurement cycle according to a condition. For example, you may change with time zones.

  In the first embodiment, the integrated control unit 20 performs a maximum power cell pattern determination process (step S311). Specifically, the determination unit 212 of the integrated control unit 20 identifies the largest cell pattern among the temporarily stored power predicted values. Here, the cell pattern can also be determined based on the statistical value. For example, an average value (statistical value) of output values between measurement cycles is calculated for the cell pattern. Then, the cell pattern having the largest statistical value is determined.

  Further, when a plurality of cell patterns having the maximum power can be specified, a cell pattern with less on / off switching may be determined with respect to the current cell pattern. As a result, the cell pattern can be changed to an efficient cell pattern with few switches.

  Furthermore, the output predicted value of each cell pattern candidate may be compared for each specific cycle, and the cell pattern candidate having the largest number of times that the output predicted value becomes the largest may be determined as the cell pattern. Thereby, the cell pattern with the largest output predicted value can be specified using the latest output value.

  -In the said 2nd Embodiment, when it determines with the control part 11 of a solar cell module having arrived at the time of taking over (in the case of "YES" in step S403), it performs the master takeover process to the next module ( Step S405). In this process, the control unit 11 specifies another module that can communicate and the next-order solar cell module 10 as the next master module. Next, the identification of the module to be the master is not limited to a predetermined order. Moreover, the replacement of the master may not be regular. For example, the solar cell module 10 having the highest output value may be the master. Specifically, the control unit 11 uses the measurement value to determine whether or not there is a solar cell module 10 that is another communicable module and has a higher output (voltage value) than the current master module. . Here, when the solar cell module 10 which is the current master has the highest voltage value, the control unit 11 of the solar cell module 10 continues the control process (step S402) as a master as it is. On the other hand, when a solar cell module 10 which is another module capable of communication and is higher than the voltage value of the current solar cell module 10 is detected, a master takeover instruction is transmitted to this solar cell module 10. To do. Thereby, it is possible to manage each solar cell module 10 by taking over the master to the control unit 11 of the solar cell module 10 having a large amount of power generation and utilizing this power.

  A1, A2 ... photovoltaic power generation device, SC ... solar cell, 10 ... solar cell module, 11 ... control unit, 12 ... power sensor, 20 ... integrated control unit, 22 ... measured value storage unit, 111 ... transmission unit, 131 , 132, 133 ... switch, 210 ... evaluation support unit, 211 ... measurement unit, 212 ... determination unit, 213 ... instruction unit, 214 ... master management unit.

Claims (6)

Multiple solar power generation units are connected,
A sensor unit that detects and outputs an output value for power generation in each of the solar power generation units;
A switch unit for controlling the output in each of the solar power generation units;
A solar power generation system including a control unit that acquires an output value detected by the sensor unit,
The control unit is
Predict the occurrence of partial shadows due to sunlight obstacles,
The solar power generation system, wherein the switch unit of each solar power generation unit is controlled based on the output value detected by the sensor unit and the prediction of the occurrence state of the partial shadow. The control unit records the output value in each photovoltaic power generation unit in the actual measurement information recording unit in association with the measurement time,
The occurrence state of the partial shadow at a time corresponding to a measurement time associated with the output value is predicted using an output value recorded in the actual measurement information recording unit. Solar power system. The control unit is connected to an external sensor,
The photovoltaic power generation system according to claim 1 or 2, wherein the occurrence state of the partial shadow is predicted based on information acquired from the external sensor. The control unit acquires weather information,
The photovoltaic power generation system according to any one of claims 1 to 3, wherein an occurrence state of the partial shadow is predicted based on the weather information. The control unit acquires weather information,
Based on the weather information, determine an evaluation cycle;
In the evaluation cycle, to determine whether to change the control of the switch unit of each photovoltaic power generation unit,
5. The sun according to claim 1, wherein when it is determined that the control of the switch unit of each solar power generation unit is to be changed, the switch unit of each solar power generation unit is controlled. Photovoltaic system. Based on the prediction of the occurrence of the partial shadow, predicting the reference power that can be generated in the solar power generation unit,
6. The state of each photovoltaic power generation unit is specified based on a comparison result obtained by comparing the reference power and the output value of each photovoltaic power generation unit, and information on this state is output. The solar power generation system as described in any one of.

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