JP5505191B2 - Photovoltaic power generation amount prediction method and distribution system control system - Google Patents

Description

  The present invention relates to a solar power generation amount prediction method for predicting the total power generation amount of a plurality of solar power generators linked to an arbitrary power distribution section, and a power distribution system control system using the method.

  Introduction of photovoltaic generators that generate power by converting inexhaustible solar energy into electrical energy is being promoted. Due to a decrease in the price of introducing solar power generators, an increase in environmental conservation awareness, and demand for conversion to alternative energy due to fluctuations in oil prices, solar power generators are now becoming popular in ordinary homes.

  In general, solar power generators installed in general households are connected to the transmission lines (distribution system) of electric power companies, and the surplus of the power generation amount of the solar power generator is folded back to the connected distribution system. (Reverse current) and sold to a predetermined electric utility. The amount of electricity sold is recorded in a power sale meter installed in each household.

  In the section where the photovoltaic generators are connected, if a power failure occurs due to an accident, the power conditioner also stops the power generation by the photovoltaic generator. This is to prevent an electric shock from a worker who is recovering from a power outage due to the electric power returned from the solar power generator to the distribution system. The stopped solar generator cannot resume power generation immediately after recovering from a power failure, and is connected to the distribution system again after a delay of several minutes.

  From the above, when initially recovering from a power outage, the electric power (substation) sends the entire area load (actual load) that is usually covered by the power generated by the solar power generator to the distribution system. Must be covered by However, from the electric power company, only the transmitted power sent to the distribution system can be grasped, and the power provided by the power generation of the solar power generator cannot be grasped. For this reason, there is concern that it will be overloaded at the moment of recovery from a power outage and linked to a secondary power outage accident.

Therefore, conventionally, when recovering from a power outage as described above, an electric power company uses the total rated power generation capacity (module surface temperature) of a plurality of solar power generators connected to the power distribution system as the output power sent from the power distribution system. Operation of distribution system (switching distribution lines, etc.) by adding the total amount of power generation (JIS standard JIS C 8914)) at 25 degrees, spectral distribution AM (air mass) 1.5, and irradiance 1000 W / m ² I was going. In addition, assuming power to be sent to the power distribution system at this time, a power distribution facility sufficient to flow the power has been constructed.

  On the other hand, the solar power generator can actually generate power at about 70% to 80% of the rated power generation capacity. Moreover, since the amount of power generated by the solar power generator depends on the amount of solar radiation, the amount of power provided by the solar power generator increases or decreases depending on the time of day, the weather, and the like. Therefore, simply adding the total rated power generation capacity as described above has secured excessive power to prevent overload.

  In the future, it is expected that the number of photovoltaic generators will increase further. Therefore, the distribution system will be able to accurately grasp the total load and the actual load, and operate the distribution system without waste. Desired. As a technique for predicting the power generation amount of a solar power generator, for example, in Patent Document 1, the power generation amount of a solar power generator to be installed in the future, its design information, design information of the neighboring solar power generator, and the power generation amount The technique which estimates using the solar radiation amount computed from this is disclosed.

Japanese Patent Application Laid-Open No. 2004-47875

  As described above, in order to operate the power distribution system without waste, it is necessary to accurately grasp the actual load by extending the total power generation amount of a plurality of solar power generators connected to an arbitrary power distribution section. Of course, many systems have been proposed in the past that calculate or measure the amount of solar radiation and predict the amount of power generation in consideration of the power generation efficiency of the solar power generator. However, when the technology for predicting the power generation amount of each individual solar power generator as in Patent Document 1 is applied, the power generation amount of the solar power generator connected to the distribution section is predicted and integrated one by one. Therefore, it is extremely troublesome. In addition, there is a problem that sufficient accuracy cannot be ensured because errors of predicted values of individual solar power generators are superimposed.

  The present invention has been made in view of such a problem, and is capable of predicting the total power generation amount of a plurality of solar power generators connected to an arbitrary power distribution section without taking time and effort with high accuracy. An object is to provide a power generation amount prediction method and a distribution system control system to which the method is applied.

  In order to solve the above problems, the present inventors have intensively studied, focused on the amount of solar radiation proportional to the amount of power generated by the solar power generator, and further studied a method for predicting the amount of power generated more easily and with high accuracy. As a result of repeated research, for the time zone in which the actual load (sum of the tidal current and total power generation) is considered constant, the remainder of subtracting the tidal current from the actual load can be considered as the total power generation. The relationship between the amount of solar radiation and the total amount of power generation can be derived as the power generation coefficient from the fluctuation of the solar radiation and the amount of solar radiation, and it has been found that this power generation coefficient can be applied to other time zones, and the present invention has been completed. It was.

  That is, the typical configuration of the photovoltaic power generation amount prediction method according to the present invention is provided in the distribution section as a target, and the section power flow measured by the sensor built-in automatic switch provided in the distribution section and the distribution section. An information acquisition step of acquiring the amount of solar radiation measured by the pyrrometer every predetermined time and storing it in the data table, and reading out the section current and amount of solar radiation in the time zone in which the actual load of the distribution section can be regarded as almost constant, from the data table, A power generation coefficient calculation step that calculates the power generation coefficient by regression analysis based on the following formula: “section power flow = power generation coefficient x solar radiation amount + auxiliary coefficient”, and by multiplying the solar radiation amount at the time of prediction by the power generation coefficient, power distribution in that time zone A total power generation amount prediction step for predicting the total power generation amount of a plurality of solar power generators linked to the section.

  If the actual load is constant, there is a relationship between the tidal current and the total power generation amount of a plurality of photovoltaic generators linked to the distribution system, where one increases and the other decreases. According to the above configuration, a regression analysis is performed using the section tidal current and the amount of solar radiation proportional to the total amount of power generated by a plurality of solar power generators, and the relationship between the total amount of power generated by the plurality of solar power generators and the amount of solar radiation is obtained. The power generation coefficient shown can be determined. Since this power generation coefficient can be applied to other time zones and does not depend on the weather, the predicted value of the total power generation amount of the solar power generator in that time zone should be calculated from the amount of solar radiation at the time of the forecast. Can do.

  In this method, the power generation amount of the solar power generator connected to the distribution section is not considered as individual, but as the total power generation amount of the plurality of solar power generators as a whole. Therefore, information (rated power generation capacity, installation conditions, etc.) of individual solar power generators is not required, and the total power generation amount of a plurality of solar power generators can be predicted with high accuracy.

  The time period during which the actual load in the distribution section can be considered to be almost constant based on whether the amount of solar radiation measured by the pyranometer is increasing or decreasing at a constant rate with respect to the increase or decrease in the section power flow measured by the sensor built-in automatic switch It is good to decide. Thereby, the time slot | zone which can consider that the real load of a power distribution area is substantially constant can be determined appropriately.

  A plurality of pyranometers are provided in the power distribution section, and in the information acquisition step, the amount of solar radiation obtained by averaging the measurement values of the plural pyranometers may be acquired. By averaging the amount of solar radiation measured at a plurality of points, it is possible to mitigate the effect of clouds passing locally through the solar radiation amount acquisition point. Therefore, a more appropriate (accurate) value can be adopted as the amount of solar radiation in the distribution section, and the total power generation amount of a plurality of solar power generators can be predicted with higher accuracy.

  The representative configuration of the distribution system control system according to the present invention is that the current flow measured by the sensor built-in automatic switch provided in the power distribution section and the pyranometer provided in the power distribution section are measured. An information acquisition unit that acquires the amount of solar radiation obtained every predetermined time, a storage unit that has a data table that stores the acquired section current and amount of solar radiation, and the amount of solar radiation increases and decreases at a constant rate A time zone determination unit that determines that the actual load of the power distribution section is a substantially constant time zone, and a section current and solar radiation amount of the time zone in which the actual load is determined to be substantially constant are read from the data table, A power generation coefficient calculation unit that calculates the power generation coefficient by regression analysis based on the following formula: “Section tidal current = Power generation coefficient x Solar radiation amount + Auxiliary coefficient”, and Multiplying the solar radiation amount at the time of prediction by the power generation coefficient Operating the distribution system based on the total power generation prediction unit that predicts the total power generation amount of a plurality of photovoltaic generators connected to the distribution section in that time zone, and the total power generation amount predicted by the total power generation prediction unit And a switching control unit for performing the above.

  According to the above configuration, it is possible to accurately grasp (predict) the total power generation amount of a plurality of solar power generators linked to the power distribution section, and to operate the power distribution system without waste. In addition, the component corresponding to the technical idea in the photovoltaic power generation amount prediction method mentioned above and its description are applicable also to the said distribution system control system.

  According to the present invention, a solar power generation amount prediction method capable of predicting the total power generation amount of a plurality of solar power generators linked to an arbitrary power distribution section without taking time and effort with high accuracy, and power distribution using the same A system control system can be provided.

It is a figure which shows the power distribution system with which the power distribution system control system concerning embodiment of this invention is applied. It is a block diagram which shows schematic structure of the power distribution system control system shown in FIG. It is a flowchart explaining operation | movement of the power distribution system control system shown in FIG. It is a figure which shows the relationship between the total electric power generation amount and solar radiation amount of the solar power generator linked to a power distribution area in the time slot | zone which can consider that an actual load is substantially constant. It is a figure which illustrates the fluctuation | variation of the real load of the distribution section of the weekday which is a fine day.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

[Distribution system]
FIG. 1 is a diagram illustrating a power distribution system 120 to which a power distribution system control system 100 according to an embodiment of the present invention is applied. As shown in FIG. 1, the electric power sent from the substations 124 a and 124 b is supplied to a plurality of general households 128 a to 128 c by the power distribution system 120. The general households 128b and 128c are provided with solar power generators 130a and 130b, and are connected to the power distribution system 120. Here, the solar generators 132a and 132b which can measure the amount of solar radiation are provided adjacent to the solar power generators 130a and 130b.

  The power distribution system 120 includes a plurality of sensor built-in automatic switches 126 a to 126 h controlled by the power distribution system control system 100. The sensor built-in automatic switches 126a to 126h are section switches that open and close (ON / OFF) the distribution line, and have a sensor function that measures section current (current). In FIG. 1, sensor built-in automatic switches 126a to 126f illustrated by triangles are section automatic switches, and sensor built-in automatic switches 126g and 126h illustrated by squares are interconnected automatic switches 126g and 126h. It is.

  For example, when an accident occurs in the power distribution section 122, the sensor built-in automatic switch 126e and the sensor built-in automatic switch 126f in the vicinity thereof are closed and the power supply is stopped. If power is supplied from the substation 124a before the accident occurs, the power supply downstream of the sensor built-in automatic switch 126f is also stopped. The power supply to the downstream side of the sensor built-in automatic switch 126f can be restored early by switching the sensor built-in automatic switch 126h and performing reverse power transmission from the other substation 124b.

  The load (apparent load) in the distribution section 122 is transmitted by subtracting the measured value of the section power flow of the sensor built-in automatic switch 126f on the downstream side from the measured value of the section power flow of the sensor built-in automatic switch 126e on the upstream side. Can be obtained by multiplying the voltage. However, since a plurality of solar power generators 130a and 130b are connected to the power distribution section 122, a true load (actual load) cannot be obtained by such a simple calculation.

  Therefore, in the power distribution system control system 100, the total power generation amount of the plurality of solar power generators 130a and 130b connected to the power distribution section 122 is predicted, and the actual load is grasped by adding this to the apparent load. And based on this actual load, the sensor built-in automatic switches 126a to 126h are controlled to operate the distribution system 120 (switching of distribution lines, etc.).

[Distribution system control system]
FIG. 2 is a block diagram illustrating a schematic configuration of the power distribution system control system 100. FIG. 3 is a flowchart for explaining the operation of the power distribution system control system 100. As shown in FIG. 2, the power distribution system control system 100 is a computer system that includes a system control unit 102 and a storage unit 104.

  The system control unit 102 is a semiconductor integrated circuit including a central processing unit (CPU) and manages and controls the entire power distribution system control system 100. The storage unit 104 includes a ROM, RAM, EEPROM, nonvolatile RAM, flash memory, HDD, and the like, and stores programs and various data used in the system. In the data table 104a provided in the storage unit 104, the section tide measured by the sensor built-in automatic switches 126a to 126h and the amount of solar radiation measured by the solar meters 132a and 132b in the power distribution section 122 are set every predetermined time (for example, 1 Every minute).

  In addition, the power distribution system control system 100 includes an input unit 106 and an output unit 108. The input unit 106 takes in predetermined information from the outside to the system by a keyboard, a mouse, a touch panel, a file input / output device, data communication through a network, or the like. The output unit 108 includes a display, a printer, and the like, and displays information to the user and performs printing. It is also possible to save the output content as data in a recording medium, or to perform data communication or web display over a network.

  Hereinafter, the information acquisition unit 110, the time zone determination unit 112, the power generation coefficient calculation unit 114, the total power generation amount prediction unit 116, and the switching control unit 118 of the power distribution system control system 100 will be described with reference to the flowchart of FIG. As shown in FIG. 3, the power distribution system control system 100 uses the information acquisition step 134, the time zone determination step 136, and the power generation coefficient calculation step 138 to operate the power distribution system 120 (power distribution system operation step 142). The total power generation amount of the solar power generators 130a and 130b connected to the power generator is predicted (total power generation amount prediction step 140).

  In the information acquisition step 134, the information acquisition unit 110 acquires the interval tide measured by the sensor built-in automatic switches 126a to 126h and the amount of solar radiation measured by the pyranometers 132a and 132b every predetermined time, and the time (time Associated with the band) and stored in the data table 104a. That is, the transition of the section power flow and the amount of solar radiation of the target distribution section 122 every predetermined time is stored.

  In the present embodiment, the information acquisition unit 110 averages the measured values of the plurality of pyranometers 132a and 132b provided in the power distribution section 122, and stores the averaged solar radiation amount in the data table 104a. By averaging the amount of solar radiation measured at a plurality of points, it is possible to mitigate the effect of clouds passing locally through the solar radiation amount acquisition point. Therefore, a more appropriate (accurate) value can be adopted as the amount of solar radiation in the power distribution section 122.

  In the time zone determination step 136, the time zone determination unit 112 reads the section tide and the amount of solar radiation for each predetermined time stored in the data table 104a. Then, a time zone in which the amount of solar radiation increases and decreases at a constant rate with respect to the increase and decrease in the section tide is found, and a time zone in which the actual load in the power distribution section 122 is substantially constant is determined (determined).

  FIG. 4 is a diagram illustrating a relationship between the total power generation amount and solar radiation amount of the solar power generators 130a and 130b connected to the power distribution section 122 in a time zone in which the actual load can be regarded as substantially constant. As shown in FIG. 4, in a time zone where the actual load is almost constant, the section tide and the amount of solar radiation are in an inversely proportional relationship. This is because, when the actual load is constant, the section tidal current increases or decreases to compensate for the total power generation amount of the solar power generators 130a and 130b that is proportional to the solar radiation amount.

  In FIG. 4, the section tide and the amount of solar radiation of “13:00 to 15:00” of “weekdays” that are “sunny days” are plotted. FIG. 5 is a diagram exemplifying fluctuations in the actual load in the distribution section 122 on weekdays that are sunny days. As illustrated in FIG. 5, the actual load from 13:00 to 15:00 on weekdays, which is a sunny day, is actually substantially constant.

Returning to the flowchart of FIG. 3, in the power generation coefficient calculation step 138, the power generation coefficient calculation unit 114 reads, from the data table 104a, the section power flow and the amount of solar radiation in the time zone in which the actual load in the power distribution section 122 can be regarded as substantially constant. Here, as shown in Expression 1, the actual load can be considered as the sum of the section power flow and the total power generation amount of the solar power generators 130a and 130b.
Actual load = section tidal current + total amount of power generated by solar power generator (Formula 1)

On the other hand, since the total power generation amount of the solar power generators 130a and 130b increases and decreases depending on the solar radiation amount, it can be expressed as Equation 2.
Total amount of power generated by photovoltaic generators = unknown coefficient x amount of solar radiation (Formula 2)

Expression 2 is substituted into Expression 1, and a constant actual load is defined as a constant, and a constant including the actual load is expressed as an auxiliary coefficient. In addition, the unknown coefficient is reversed in sign to obtain a power generation coefficient. Then, it can be expressed as Equation 3 below. Then, based on Equation 3, the power generation coefficient and the auxiliary coefficient are calculated by regression analysis. That is, a first-order approximate expression (see FIG. 4) showing the relationship between the section tide and the amount of solar radiation is derived.
Sectional tide = power generation coefficient x solar radiation + auxiliary coefficient (Equation 3)

  At this time, the power generation coefficient calculation unit 114 is a day closest to the prediction date for predicting the total power generation amount of the solar power generators 130a and 130b linked to the power distribution section 122, and the time zone determination unit 112 determines the actual load. It is preferable to read out the tidal current and the amount of solar radiation in the time zone determined to be almost constant. This is to improve the accuracy by using the tidal current and the amount of solar radiation on the nearest day as much as possible. If the number of plots (the number of data) is sufficient, only the current and the amount of solar radiation in that time zone for a certain day is needed. If the number of plots (the number of data) is not enough, the current in the time zone of that time zone for multiple days And use solar radiation.

  In addition, without providing the time zone determination unit 112, for example, “13:00 to 15:00” of “weekdays” that are “sunny days” is assumed (determined) that the actual load is almost constant, and the power generation coefficient calculation unit 114 may be configured to read the section tide and the amount of solar radiation that satisfy these conditions. In such a case, weather information (whether clear or not) and calendar information (weekdays, holiday information) are input to the system from the input unit 106, and the current time and the amount of current in the tidal current and solar radiation accumulated in the data table 104a are displayed. In addition to (time zone), weather and calendar are also stored in association with each other.

  In the total power generation amount prediction step 140, the total power generation amount prediction unit 116 multiplies the solar radiation amount at the time of the prediction by the power generation coefficient obtained above, and a plurality of solar power generators linked to the power distribution section 122 in that time zone. The total power generation amount of 130a and 130b is predicted (predicted value is calculated). The amount of solar radiation to be predicted can be, for example, the amount of solar radiation acquired by the information acquisition unit 110 from the solar meters 132a and 132b at a time point (arbitrary time point) designated by the administrator from the input unit 106. Since the power generation coefficient indicates how much the solar power generators 130a and 130b generate electricity with respect to the amount of solar radiation at that time, the power generation coefficient can be used without depending on the time zone or the weather.

  Thus, by calculating | requiring the total power generation amount of the several solar power generators 130a and 130b linked to the power distribution area 122, total power generation amount can be estimated with very high precision. This is because the power generation amount of the solar power generators 130a and 130b connected to the power distribution section 122 is not regarded as individual, but as the total power generation amount of the plurality of solar power generators 130a and 130b. Moreover, it is also because the average value of the measured values of the plurality of pyranometers 132a and 132b is adopted as the amount of solar radiation to reduce errors. As described above, the information (rated power generation capacity, installation conditions, etc.) of the individual solar power generators 130a, 130b is not required, and labor (collection of necessary information, etc.) and calculation required to calculate the predicted value are also possible. It is reduced.

  On the left side of Table 1, the power generation coefficient is calculated from the tidal current and the amount of solar radiation from “13:00 to 15:00” on “weekdays” on “sunny days” where the actual load can be regarded as almost constant, and the total power generation is calculated. The prediction accuracy is shown. The right side of Table 1 shows the prediction accuracy when the power generation coefficient is calculated based on the tidal current and solar radiation from 6 o'clock to 18 o'clock in a year and the total power generation amount is obtained. As shown in Table 1, by predicting the total power generation amount of the solar power generators 130a and 130b connected to the power distribution section 122 using the section power flow and the amount of solar radiation in a time zone in which the actual load can be regarded as almost constant, The prediction accuracy is greatly improved as compared with the case where the total power generation amount is obtained by using the tidal current and the amount of solar radiation from 6 o'clock to 18 o'clock in the year (taking the average value for the year).

  In the distribution system operation step 142, the switching control unit 118 calculates the actual load based on the predicted value of the total power generation amount of the solar power generators 130a and 130b calculated with high accuracy. Then, the automatic switches 126a to 126h with built-in sensors are controlled to operate the power distribution system 120 without waste based on the actual load.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. According to the above configuration, it is possible to predict the total power generation amount of the plurality of solar power generators 130a and 130b connected to an arbitrary power distribution section 122 without taking time and effort with high accuracy. Needless to say, the present invention is not limited to the examples described above. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  INDUSTRIAL APPLICABILITY The present invention can be used as a solar power generation amount prediction method for predicting the total power generation amount of a plurality of solar power generators linked to an arbitrary power distribution section, and a distribution system control system using the method.

DESCRIPTION OF SYMBOLS 100 ... Distribution system control system, 102 ... System control part, 104 ... Memory | storage part, 104a ... Data table, 106 ... Input part, 108 ... Output part, 110 ... Information acquisition part, 112 ... Time zone determination part, 114 ... Power generation coefficient Calculation unit 116 ... Total power generation amount prediction unit 118 ... Switching control unit 120 ... Distribution system 122 ... Distribution section 124a, 124b Substation 126a-126h Automatic sensor built-in switch 128a-128c General household , 130a, 130b ... solar generator, 132a, 132b ... pyranometer, 134 ... information acquisition step, 136 ... time zone determination step, 138 ... power generation coefficient calculation step, 140 ... total power generation amount prediction step, 142 ... distribution system operation Step

Claims (4)

In the target power distribution section, the section current measured by the sensor built-in automatic switch provided in the power distribution section and the amount of solar radiation measured by the pyranometer provided in the power distribution section are acquired every predetermined time and stored in the data table. An information acquisition step to be stored;
The section current and the amount of solar radiation in the time zone in which the actual load of the distribution section can be regarded as almost constant are read from the data table, and the power generation coefficient is regressively analyzed based on the following formula: "section power flow = power generation coefficient x solar radiation amount + auxiliary coefficient" A power generation coefficient calculation step calculated by:
A total power generation amount prediction step of predicting the total power generation amount of a plurality of solar power generators linked to the power distribution section in that time zone by multiplying the solar radiation amount at the time of prediction by the power generation coefficient;
A method for predicting the amount of photovoltaic power generation, comprising:   Based on whether or not the amount of solar radiation measured by the pyranometer is increasing or decreasing at a constant rate with respect to the increase or decrease of the section power flow measured by the sensor built-in automatic switch, the actual load of the distribution section can be regarded as almost constant. The method for predicting the amount of photovoltaic power generation according to claim 1, wherein a time zone is determined.   The solar power meter according to claim 1 or 2, wherein a plurality of pyranometers are provided in the power distribution section, and in the information acquisition step, a solar radiation amount obtained by averaging measured values of the plural pyranometers is acquired. Solar power generation forecasting method. An information acquisition unit that acquires a current flow measured by a sensor built-in automatic switch provided in the power distribution section and a solar radiation amount measured by a pyranometer provided in the power distribution section at a predetermined time in a target power distribution section; ,
A storage unit having a data table in which the acquired section tide and solar radiation are stored;
A time zone determination unit that determines a time zone in which the amount of solar radiation is increasing or decreasing at a constant rate with respect to an increase or decrease in the zone power flow as a time zone in which the actual load of the power distribution zone is substantially constant;
The section power flow and the solar radiation amount in the time zone in which the actual load is determined to be substantially constant are read from the data table, and the power generation coefficient is calculated by regression analysis based on the following equation “section power flow = power generation coefficient × sun radiation amount + auxiliary coefficient”. A power generation coefficient calculation unit to calculate,
A total power generation amount prediction unit that predicts the total power generation amount of a plurality of solar power generators linked to the power distribution section of the time zone by multiplying the solar radiation amount at the time of prediction by the power generation coefficient;
Based on the total power generation amount predicted by the total power generation amount prediction unit, a switching control unit that operates the distribution system,
A distribution system control system comprising:

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