JP2008182017A - Control method of photovoltaic power generation system and power generation predicting apparatus of photovoltaic power generation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems in operation life and price of electrical power storage part in the photovoltaic power generation system in which a stabilizer is connected to a power system. <P>SOLUTION: The photovoltaic power generating apparatus is divided into a part for regulation operation and a part for backup operation. A control part stores a previously generated peak curve of power generation until the power generation end time from the power generation start time of the photovoltaic power generation apparatus and an operation planning table of charge to the power storage part. During a charging operation until the power generation end time from the power generation start time, an extra power is charged when power generation output is larger than the value in the charging operation planning table and a solar cell group for backup operation is connected to the power system when the power generation output is smaller than the scheduled charging value. Moreover, during a non-charging operation, discharging is conducted along the peak curve. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control method for a solar power generation system and a power generation amount prediction apparatus for the solar power generation system.

  While energy conservation is screamed as a measure against global warming, the use of renewable energy has been reviewed in the field of electrical energy, and distributed generation of natural energy such as solar power generation, wind power generation, fuel cells, or biomass power generation is becoming popular. is there. Such a power system using natural energy is known from Non-Patent Document 1 and the like. For the full-scale introduction of renewable energy such as natural energy, voltage fluctuations in the distribution system and frequency of the system are known. It is necessary to mitigate the effects of fluctuations on the power system.

  Since electricity cannot be stored, if the balance between demand and supply does not match instantaneously and instantaneously, stable supply cannot be achieved. It is required to achieve the same amount of supply. For example, in the conventional system, the same amount within a fluctuation range of 3% of the transmission service contract power is required every 30 minutes. In recent years, the fluctuation range has been made elastic, and a short supply charge (imbalance charge) is set for each stage according to the degree of fluctuation up to 10%, while being basically 3% for 30 minutes.

  In addition, operators who use the power transmission network are also required to perform operations that contribute to the system by load leveling and power quality improvement as cooperation with the power system. For load leveling, peak shave (shaping of power waveform, suppression of power flow fluctuation) operation, peak cut (conversion of power peak amount to another energy) operation, peak shift (shift of power peak time) operation Therefore, it is to perform an appropriate operation according to the situation individually or in combination.

  FIG. 12 shows an example of a network diagram of distributed power using a renewable energy power source. A, B, and C are distributed power systems, each having a network of a plurality of renewable energy power sources and power loads to form one power supply system. In FIG. 12, the distributed power system A is connected to the power company system, and the other distributed power systems B and C are connected to the distributed power system A. When a solar power generation system is used as a renewable energy power source, a power storage device (capacitor or storage battery) or a generator with a tracking capability (gas generator) is combined to control tidal current fluctuation, Constant output control is realized. This is to achieve leveling by outputting or absorbing power fluctuations to these distributed power sources with high fluctuation tracking. Such a technique is known from Non-Patent Document 1.

  FIG. 13 is a schematic diagram of a supply and demand control method. As control, control according to an operation plan, load follow-up control, and local follow-up control are executed. As the control according to the operation plan, there are short-time operation plan change based on the plan change due to the shortage of standby power generation and operation pattern control based on the operation plan data. The load follow-up control controls the difference between supply and demand balance, and the local follow-up control performs follow-up control by charging / discharging from the power storage device to load fluctuations of high frequency components.

In the solar power generation system, the natural energy introduction ratio is improved by dynamically performing an operation plan based on climate prediction and making effective use of a variable-tracking power source such as a power storage device prepared for independent operation. Yes. In addition, the distributed power supply system eliminates a time mismatch between supply and demand, and makes it possible to stabilize intermittent energy.
Funahashi et al., “Examination of optimal generator operation in small-scale power grid (microgrid)”, Journal of EICA, Vol. 127-133, 2006

  These distributed power sources, particularly power storage devices, are expensive, which is an obstacle to the spread of large-scale photovoltaic power generation. Also, in the case of photovoltaic power generation for home use, if photovoltaic power generation devices of a certain size or more are concentrated in the same area, the power flow of the system will be adversely affected. There is a plan to plan. At this time, the current situation is that the price of the power storage device has become a harmful effect and has become a hindrance to its spread.

  At the same time, fluctuations in photovoltaic power generation due to weather changes are large, and even with a leveling method using a distributed power source with high fluctuation tracking characteristics, it is difficult to follow fluctuations in power generation due to weather changes in photovoltaic power generation. As an example of current output fluctuation mitigation control, the wind power plant output is calculated as a one-minute average value. During normal times, wind power generation equipment combined output after frequency fluctuation countermeasures (average for one minute) Value) of “maximum power minus minimum power” is 10% or less of the total rated output of the wind power generator. When strict restrictions such as “are applied to photovoltaic power generation, it is difficult to satisfy the conditions.

  FIG. 14 shows the output characteristics of photovoltaic power generation. The dotted line is the peak curve of photovoltaic power generation, and the solid line is the output curve, which varies greatly with changes in solar radiation intensity due to the influence of clouds. When the power storage device is used as the generator used for the fluctuation follow-up operation, management of the remaining capacity of the power storage device becomes a problem. Depending on the type of power storage device, the remaining capacity may be determined from the DC voltage, but in other cases, it is necessary to calculate the remaining capacity by integrating the current (Ah). When the upper and lower limits of the remaining capacity management value are reached, either charging or discharging cannot be performed. Therefore, the operation pattern of the power generation output according to the operation plan is corrected so that the remaining capacity falls within a fixed or set range. There is no problem if a power storage device with a capacity equivalent to that of solar power generation (5 hours or more) can be prepared and an appropriate operation planning program can be prepared, but depending on the capacity of the power storage device, charging and discharging cannot be further performed. A scene that can be created appears and it is difficult to continue driving.

  In addition, when connecting a photovoltaic power generation system to a commercial system, there is a difference between the peak power generation time of solar power (around 0:00) and the time when the load on the commercial system is maximized (around 1:00). The lack of conformance is a problem.

  The present invention distributes a plurality of photovoltaic power generation devices over a wide area, and uses the diversity to help reduce fluctuations in photovoltaic power generation. The purpose is to predict the amount of power generation in the near future based on the components and to provide an optimal number control method and apparatus for photovoltaic power generation devices.

A first aspect of the present invention is to connect a photovoltaic power generation device including a solar cell group, a stabilization device having a power storage unit and a power conversion unit to the power system, and to the power conversion unit via a control unit of the stabilization device. In a photovoltaic power generation system configured to perform control and charge / discharge control to the power storage unit,
The solar power generation device is divided into a normal operation and a standby one, and the control unit includes a peak curve of power generation amount from a power generation start time to a power generation end time of the solar power generation device created in advance and the power storage unit. The charging / discharging operation plan curve is stored, the surplus when the power generation output amount is larger than the charge value based on the charging operation plan curve during charging from the power generation start time to the power generation end time, When the power is smaller than the planned charge value, the spare solar power generation device is connected to the power system, and when the power storage unit reaches a predetermined value charge amount, the mode is switched to the discharge mode, and the power generation start time to the power generation end time When the battery is not charged at the time of non-charging, control is performed from the power generation start time to the power generation end time. Be repeated at is obtained by it said.

  According to a second aspect of the present invention, the peak curve of the power generation amount is calculated by averaging the deviation at each arbitrary time of the peak of fluctuation up to the time point with respect to the solar radiation intensity curve at the time of clear, The solar radiation intensity curve is multiplied by the solar radiation intensity peak curve, and the solar radiation efficiency peak curve is multiplied by the solar cell efficiency to obtain the peak curve of the day.

  According to a third aspect of the present invention, the predetermined value charge amount is a charge amount that ensures a charge amount satisfying a required amount of power from a full charge of the power storage unit to a power generation end time. It is a thing.

  4th of this invention, the said operation plan curve of the said charge / discharge creates the operation plan curve only at the time of discharge with the value based on the operation plan at the time of charge, the plan value based on each plan curve creates in steps, This is characterized in that a time interval capable of peak shifting is provided at the junction at the end of charging and at the start of discharging.

  According to a fifth aspect of the present invention, when the power storage unit is in a non-charged state and the power generation amount is larger than the power generation output value based on the operation plan curve, the solar power generation device is partially disconnected from the power system. It is characterized by doing.

  A sixth aspect of the present invention is characterized in that the disconnection control from the power system of the photovoltaic power generation device is based on a signal obtained by subtracting the amount of power by load prediction from the predicted output amount of the photovoltaic power generation device. Is.

  According to a seventh aspect of the present invention, the solar cell group is configured by division units divided by a mesh, and connection control with a system and disconnection switching control are performed for output prediction of power generation amount in an arbitrary unit time, and this output. It is characterized in that it is performed for each division unit when the power generation changes with respect to the prediction.

  In the eighth aspect of the present invention, the output prediction of the power generation amount is to measure the power generation amount with a short period measurement width obtained by further subdividing the arbitrary unit time, and the efficiency and area of each solar cell, The solar radiation intensity is calculated from the short cycle measurement time, and the two data are obtained by repeating the short cycle measurement time unit n times while shifting the past data by one mesh in the x-axis and y-axis directions at the center of the mesh. The maximum correlation function is calculated, the wind direction and the wind force are determined from the distance between the maximum correlation function and the mesh, the solar radiation fluctuation component is extracted from the measurement result of the short period, and the amount of solar radiation for the unit time is obtained. The predicted amount of power generation is obtained by multiplying the solar radiation amount by the power generation efficiency and area of each mesh.

  A ninth aspect of the present invention is characterized in that the amount of solar radiation for the unit time is obtained by being repeatedly accumulated sequentially from the windward side.

10th of this invention connects the solar power generation device which consists of a solar cell group, and the stabilization apparatus which has an electric power storage part and a power conversion part to an electric power system, and with respect to a power conversion part via the control part of a stabilization apparatus. It is a photovoltaic power generation system configured to execute control and charge / discharge control to the power storage unit, and divide the solar cell group by an arbitrary mesh into division units, and for each division unit at an arbitrary time In the output prediction of the power generation amount, when the power generation amount is larger than the value of the operation plan curve created in advance based on the output prediction value, the solar power generation device is disconnected from the power system.
Measuring means for measuring the power generation amount of each photovoltaic power generation device in a short cycle that subdivides the unit time, solar cell efficiency and area in each photovoltaic power generation device, and calculating the solar radiation intensity from the short cycle measurement time And a maximum correlation between calculating the maximum correlation coefficient of the two data by repeating the shift of the past data of the solar radiation intensity n times for each mesh in the x-axis and y-axis directions. The number calculation means, the maximum correlation coefficient, the solar radiation fluctuation calculation means for determining the solar radiation fluctuation by determining the wind direction and the wind power from the distance between the meshes, and the mesh can be obtained repeatedly from the windward side to the leeward in the unit time. A solar radiation amount calculating means for calculating the solar radiation amount for the unit time from the integrated solar radiation fluctuation amount, and a predicted value calculation for calculating a predicted power generation amount by multiplying the obtained solar radiation amount by the power generation efficiency and area of the mesh Is obtained is characterized in that a stage.

As described above, according to the present invention, when the power storage unit is used for fluctuation component removal (leveling) control or constant power flow operation of the photovoltaic power generation device, the number of charge switching can be limited to once a day, which is expensive. Deterioration of the power storage unit can be prevented. Also, when the charge / discharge cycle must be changed to absorb large power fluctuations, select the solar power generation device (solar cell group) closest to the amount of power to absorb the expected fluctuations, and disconnect or connect When controlling the number of units to be operated, it is possible to reduce the burden on the power storage unit and prevent deterioration, and if an electric double layer capacitor is used in the power storage unit, the capacity can be reduced. It becomes possible.
In addition, the level of power generation of photovoltaic power generation systems due to the diversity of solar radiation intensity due to the wide area is achieved, and at the same time, fluctuation absorption is provided with the on / off function of multiple solar cell groups, so that the reliability of the system is trusted. Realize improvements in productivity, quality and economy.

FIG. 1 shows a configuration example of a photovoltaic power generation system in which the present invention is implemented. 1 and 2 are solar cells each composed of a plurality of panels, and 1 (1a, 1b... 1n) of them is mainly used in the first solar cell group. 2 (2a...) Is mainly used as a spare in the second solar cell group. Reference numerals 3 and 4 denote power conditioners which have a DC / DC conversion or DC / AC conversion function and a control circuit for controlling them, and are connected to the solar cells 1 and 2, respectively, to constitute a photovoltaic power generation apparatus. ,
A predetermined amount of electric power is output from this solar power generation device. 5 and 6 are transformers, 7 is a substation of a photovoltaic power generation system, 8 is a bus of the substation, and 9 is a substation of an electric power company.

Reference numeral 10 denotes a stabilization device having a power storage unit, and a plurality (here, 10a, 10b) are connected to the bus 8 of the substation. Stabilizers 10a and 10b include power storage units 11a and 11b, power conversion units 12a and 12b having a DC-AC conversion function to perform charging and discharging, and interconnection transformers 13a and 13b. Yes. Reference numeral 14 denotes a control unit that inputs the charge state detection signals A and B in the power storage unit 11, the output voltage and current detection signals of the stabilizing device 10, and based on these input signals and preset setting signals. Then, a control signal for the power converter 12 is generated. As an electrical storage part used for the electric power storage part 11, it can use without being restrict | limited about the kind, such as an electric double layer capacitor and a lithium ion storage battery. Reference numeral 15 denotes a central control station that performs desired control by exchanging signals with the control circuit of the power conditioners 3 and 4 and the control unit 14 of the stabilization device 10 according to the state of the power system.
In FIG. 1, the load connected to the bus 8 and other fluctuation following generators such as a gas generator are omitted.

  The stabilization device 10 during the interconnection operation between the substation 7 of the photovoltaic power generation system and the substation 9 of the electric power company obtains the fluctuation amount of the power flow at the interconnection point and compensates the fluctuation amount via the power conversion unit 12. Perform output control like this.

In general, in the photovoltaic power generation system configured as described above, when leveling (variation component removal) control is performed using the stabilization device 10, an output target value is provided at the center of the variation component, and the target value is set to this target value. On the other hand, when the power generation amount exceeds, the amount is charged, and when the power generation amount is insufficient, the amount is discharged and smoothed. FIG. 11 is a graph showing the relationship between the amount of power generated by photovoltaic power generation and the time. Line A is an output curve during clear weather when the amount of photovoltaic power generated is not affected by clouds, and line A is an operation plan curve ( Value), line U is the output curve of the solar power generation device on that day, and the power generation output changes due to the change of solar radiation intensity due to the influence of clouds. In the control method according to the set operation plan curve (i), charging / discharging of the power storage unit (11) is repeated each time the output curve (c) of the photovoltaic power generation device on the day fluctuates.

  This is not a problem with devices that do not involve chemical reactions, such as electric double layer capacitors and capacitors, but in general storage batteries, the number of charge / discharge cycles affects the life and increases running costs. Therefore, a specific example for limiting the number of times of charge switching for the power storage unit 11 to prevent deterioration of the power storage unit 11 and reducing the necessary capacity of the power storage unit 11 including the case of an electric double layer capacitor or a capacitor. An embodiment of the present invention for means will be described below.

FIG. 2 is a flowchart showing an embodiment of the present invention when the power storage unit 11 is used for fluctuation component removal based on the operation plan. In step S1, one-day operation is started. In step S2, a peak curve indicated by line A ′ shown in FIG. 3 is created.
As a method of calculating the peak curve a of the amount of photovoltaic power generation, the deviation at each time of the peak of fluctuation up to this point is compared to the solar radiation intensity curve when there is no cloud (sunny) as in FIG. Is calculated and averaged. The deviation is applied to the solar radiation intensity curve at the time of fine weather, and the solar radiation intensity peak curve a after that day is created. Multiply the efficiency of solar power generation (calculated from the calculated solar radiation intensity and the actual value of the power generation amount) to obtain the peak curve of the solar power generation amount on that day (S3). The peak curve a ′ of the day is the operation plan value for the charge of the power storage unit 11 until the peak value t2 at the time t1, or the expected peak curve of the photovoltaic power generation amount on the day. Than the lower limit, and
From t2 to t3 is the operation plan value for the discharge of the power storage unit 11, which is set to an upper limit than the peak curve C of the photovoltaic power generation amount on that day. In S4, the solar cell group is divided into normal operation 1a, 1b,... And preliminary operation 2a, and these data and plan values are stored in the control unit 14.

  In step S5, after the time when the solar cell starts power generation as at time t1 (time t1 + n in FIG. 3) is set in the control unit 14 as the charging start time, and when the charging start time t1 + n is reached, the control unit 14 converts the power. The following control command is issued to the unit 12. Charging is repeated at regular intervals from time t1 + n to, for example, time t3 near sunset. In step S6, it is determined whether or not charging end time t3 has been reached, and if not time t3, charging is performed in S7. It is determined whether it is medium or not. In the case of charging, in S8, a comparison is made between the operation plan value set in S3 and the detected power generation output amount of the current solar cell, and when the power generation output is large, the surplus is charged in S9. Execute control. When the power generation output is small, the circuit breaker CB2 is turned on in S10 to connect the second solar cell group to the system. In step S11, it is determined whether or not the power storage device is fully charged. After full charge is secured, the mode is switched to the discharge mode in S12, and when full charge is not secured, the process directly proceeds to S6. .

  On the other hand, if the battery is not being charged in S7, the battery discharges along the peak curve created in S2 in S13, and the discharge discharges the insufficient power output along the peak curve until the entire discharge. In S14, it is determined whether all the discharges have been made. Since the leveling control of the photovoltaic power generation cannot be performed when all the discharges are made, in that case, the circuit breaker CB1 is opened in S15, the first solar cell group is disconnected from the system connection, and the process proceeds to S6. To do.

The above-described steps S7 to S15 are charged from the total power generation amount of solar power generation until the charge amount satisfying the power amount necessary for leveling can be secured from sunrise to sunset. For that purpose, the values of season, date and time, position, weather forecast, temperature, humidity, wind direction, wind force, etc. are used as parameters, as necessary, and calculated from the derived sunshine intensity curve, sunshine amount and change width. In addition, measures such as reinforcing the calculation using a neuro-network technology or chaos technology using past data are taken. When the discharge is determined at S14, the time t3 shown in FIG. 3 is reached, and if there is a storage capacity even at sunset, the surplus is fully discharged at a constant output at S16, or is left as it is for the control of the next day. To.
In S17, the operation of the day ends.

  Here, the operation plan curve a ′ created in step S3 is a charging time that satisfies either the full charge or the electric energy required for leveling at time t2, and from time t2 to sunset t3. Discharges along the peak curve. At that time, if the battery is rapidly charged at time t2 and discharge is started after time t2, there is a concern that the system will be adversely affected. Therefore, in this embodiment, the charging control based on the charging operation plan curve until time t2 is an operation plan in which the fluctuation range is suppressed, so that power leveling control can be performed without adversely affecting the power system. It will be.

It should be noted that according to the operation plan in which the fluctuation range at time t2 is suppressed, all of the power generation output that is large is charged (step S9), and the fluctuation that is insufficient for the power generation output is supplemented by a spare solar power generation device (step S10). ). However, since the portion that is still insufficient is discharged in S12, the number of times of charging / discharging increases by that amount. However, the switching operation does not occur for all fluctuations. In FIG. Only the shortage of power generation at that time.
Moreover, since the discharge amount at the time of discharge after time t2 is a difference after the backup solar power generation device compensates, the discharge depth with respect to the power storage unit 10 can be reduced, and the power storage unit 10 The impact on life can be reduced.

FIG. 4 is a flowchart showing an embodiment of the present invention in which the power storage device of FIG. 1 is used for constant power flow control of the solar power generation device.
In recent years, distributed power systems are required to have a constant power output that keeps the output constant for a certain period of time when selling power to a PPS or power company. As these conditions, for example,
(1) Calculate the 1-minute average value of the power plant output. During normal times, the “maximum power minus minimum power” of the combined output of power generation facilities (average value for 1 minute) after frequency fluctuation countermeasures will be generated within an arbitrary period of time. Must be 10% or less of the total rated output of the machine.
(2) In the designated time zone, make the total electric equipment combined output after frequency fluctuation countermeasure constant without being discharged to the power system, or disconnect the generator.
It is. Here, “constant output” applies to the expression that the deviation between the average value for one minute and the constant control target value is 2% or less of the total rated output value. For that purpose, it is necessary to have a technique for controlling a constant output within a certain time while suppressing variations at intervals of 1 minute, and the embodiment of FIG. 5 can be applied to a distributed power system including a solar power generation device. Is.

  4 differs from FIG. 2 in that the operation plan curve created in step S3 is created stepwise as shown in FIG. 5, and the functions of S20 to S24 are substituted for steps S13 to S15. It is provided. Therefore, the same or corresponding parts as those in FIG.

  If charging is not being performed in step S7, it is determined in S20 whether or not the power generation output is greater than the operation plan value created in advance in S3. When it is large, discharge (S21) is performed according to the operation curve, and when it is small, the solar power generation device corresponding to the surplus is disconnected from the system in S22. This disconnection command is output from the central control station 15 to the switch means of the power conditioner 3 to execute partial disconnection of the photovoltaic power generation apparatus. Then, in S23, it is determined whether or not all the discharges are made. If all the discharges are made, the leveling control of the photovoltaic power generation cannot be performed. In that case, the circuit breaker CB1 is opened in S24 and the first solar cell group is changed. Disconnect from the system connection and proceed to S6. In addition, when not completely discharged in S23, the process proceeds to S6, and steps S7 to S12 and S20 to S24 are repeated at regular intervals from sunrise to sunset.

FIG. 5 is an output curve for constant tidal current control created in steps S2 and S3, which satisfies either the full charge from time t11 to time t12 or the amount of power required for constant tidal control operation until sunset. The operation time for only charging that is set up until time t12 to the time t13 is the planned operation time for only discharging until the entire discharge, and the time width is set slightly larger than the stepwise interval between charging and discharging before and after time t12. Shift is possible. Further, in the hatched portion between line A and line A, the charging amount is from time t11 to t12, and the discharging amount is from t12 to t13.
The control unit 14 performs the daily charge / discharge control along the preset power generation prediction curve. That is, charging is performed along a power generation prediction curve set in stages until time t12, and after time t12, the difference obtained by subtracting the output value of the photovoltaic power generation device from the planned value for constant power flow control is the discharge amount. Become.

The second embodiment also has the same effect as the first embodiment. In addition, the whisker of the power waveform generated up to the interval portion in the height direction between the solar peak curve a and the operation plan curve a just before time t12. The portion performs bearding by partially disconnecting (at S22) the photovoltaic power generation apparatus having an output corresponding to the output (the size of the whiskers) from the power system. For this reason, the capacity | capacitance of an electric power storage part can be made small by that much.
Moreover, when the whisker of the output by the solar power generation device exceeding the set peak value is generated due to the time width around time t12 being set slightly larger, the solar battery group is partially disconnected. As a result, the range of shaving can be expanded, and it is possible to eliminate the time mismatch between supply and demand and to stabilize intermittent energy.

This embodiment is for supporting the optimum operation of the distributed power supply system having a plurality of photovoltaic power generation devices as shown in FIG. 1, and selects the solar cell group closest to the control target in the first and second embodiments. This provides a unit operation control method that enables optimized operation.
The power generation output plan in the constant power flow control shown in FIG. 5 is based on a line during a clear day, but the power generation amount on a corresponding day other than the clear day has a power waveform that fluctuates across the plan curve. A beard occurs. In order to perform the unit operation control with higher accuracy in this shaving, it is necessary to accurately predict the power generation amount. The prediction method will be described below.

  In the following description, for convenience, the solar cell groups 1 and 2 are provided with solar panels in a wide area such as a mega solar (solar farm, solar park), and connected to the grid in units divided by a mesh of a predetermined area. The case where a model that can be / disconnected (on / off) is adopted will be described. However, the present invention does not depend on the control unit in the range divided into meshes or the type of solar panel, and is also applied to centralized management of a plurality of small-scale photovoltaic power generation devices such as urban areas to stabilize the system. Of course you can.

FIGS. 6 and 7 show examples of the solar cell groups 1 and 2 divided into meshes, and are given as initial data based on the area and type of the photovoltaic power generation panel in the mesh. This initial data is the power generation capacity of the solar cells in the mesh (can be calculated from the panel area and conversion efficiency) and can be easily calculated from the sunshine intensity and amount of sunshine of each mesh. Using the calculated value, the change in illuminance can be used for estimating the amount of sunlight.
In addition, for photovoltaic power generation devices that have panels that span two or more sections in the mesh section, even when the area is relatively large and deviates physically from the mesh section, when converting to sunlight intensity and amount of sunlight Since it is divided by the panel area, there is no effect on the calculated value, so it can be solved by forcibly excluding it into one mesh section.

In many cases, the photovoltaic power installed in urban houses is used to satisfy the demand of the house. In this case, if the load and power generation are measured separately, the implementation shown below Application of the example technique is possible.
The prediction of power generation amount uses the measurement result of solar power generation, and the power generation amount of each device used for device selection at the time of on / off control of multiple solar power generation devices is deducted from the load prediction power amount Use things. The load prediction of each house can be calculated using the neuro network technology and chaos technology using the parameters of weather, day of the week, and date / time on the past accumulated data. This will be specifically described below.

For solar cell groups 1 and 2, the following procedure is followed on the premise of power generation units separated by a mesh.
(1) Predict the power generation amount in the mesh after unit time.
(2) Create an optimal operation plan for the power storage device and the plurality of photovoltaic power generation devices.
(3) Control each device according to the operation plan.
(4) Repeat (1) to (3) above.
Each is expanded as follows.

About the electric power generation amount in the mesh after the unit time of (1), it estimates as follows.
a, further divide the unit time and have a short period measurement width.
b. Measure the power generation amount of each solar cell in a short cycle time unit.
c. The solar radiation intensity is calculated from the panel efficiency and area of each solar cell and the short period measurement time.
d, as shown in FIG. 8, the past data is shifted by one mesh in the x and y directions at the center of the mesh, and this is repeated n times for the short period time unit set by a. e, two data ( The maximum correlation function of M1 and M2) in FIG. 9 is calculated.
f, As shown in FIG. 9, the wind direction and the wind force are determined from the maximum correlation coefficient and the distance between the meshes, that is, the distance moved from M1 to M2. At this time, in Japan, 40km / h is generally the west-facing wind that affects the clouds, so if you search for correlation data based on this, you can speed up the search. The wind speed and wind direction derived from this correlation are accumulated as data, and if the correlation data search is applied based on the trend and accumulated data, applying the neural network technology or chaos technology, the subsequent search can be speeded up.

However, the processing from b to f uses the weather forecast from the media and the observation data (observed values of anemometer, anemometer, thermometer, hygrometer, illuminometer) from the meteorological observation equipment. It can be replaced by means of recalculating the wind speed.
g. Extract solar radiation fluctuation component from the difference result of short cycle measurement. This component is a differential component.
h, Since the movement of the cloud directly affects the solar radiation intensity of each mesh, the time and direction in which the same cloud affects the next adjacent mesh is calculated. When the windward mesh is disconnected and sunshine data cannot be obtained, the sunshine data further upstream is used. When there is downstream data, the two values are compared and the intermediate value is adopted.
As shown in FIG. 10, the results of i, g, and h are repeatedly accumulated from the windward side as shown in FIG. 10 to obtain the maximum solar radiation intensity and the maximum solar radiation fluctuation range from the minimum solar radiation intensity. Get solar radiation.
j, FIG. 10 shows an aspect of wind moving time for each mesh, and the solar radiation amount cannot be calculated for the upper two steps of the most upwind mesh row (the portion without the arrow display). Use the previous value. It is also possible to calculate by linear approximation from the measured fluctuation component. In general, when the weather is stable, it is more effective to calculate from the approximate expression, so it is possible to calculate from the approximate expression when the weather is fine, and use the previous value otherwise. This can be replaced by obtaining it with high accuracy from weather prediction using a fish-eye camera or laser light observation.
k, the amount of solar radiation is multiplied by the power generation efficiency and area of the solar power generation device in each mesh, and a predicted value of the power generation amount and the maximum power generation fluctuation range is obtained. The predicted value calculated based on the actual power generation from the windward can be expected to be highly accurate.

  The optimum operation plan for the power storage device (2) and the plurality of photovoltaic power generation devices is created as follows.

<About the target function>
(A) The tidal current fluctuation width per unit time is set to a% or less of the total rated output of all photovoltaic power generation devices (which may be all generators of a distributed power system).
(B) The average tidal current fluctuation width over a plurality of unit times is set to be not more than b% of the total rated output of all photovoltaic power generation devices (which may be all generators of a distributed power system).
(C) Select the best operation economically.
(D) Make the best choice for stable operation.
(E) Select the best operation for the system.
Is given as a condition, and each function is given a weight according to the priority, and finally expressed by a linear inequality.

<About input parameters>
As input parameters at this time,
(F) Prediction of power generation amount and maximum power generation fluctuation range for the next unit time (for example, 1 minute) for each mesh, and predicted fluctuation width (maximum windward and decreases with leeward. Will change ... Minimum in fine weather, followed by rainy weather, fine weather, and cloudy weather)
(G) Average total output power target value across multiple unit times (eg, 20 minutes, 30 minutes, 1 hour) (h) Remaining battery capacity (remaining battery capacity)
There is.

<About constraints>
As a constraint condition,
(I) Power cost of solar power generation equipment (power selling cost, power purchasing cost)
(J) Penalty for driving deviation (cost conversion)
(K) Remaining power storage unit charge / discharge cycle cost (charge / discharge cycle period, depth for charge / discharge count, and charge / discharge cycle life)
(L) Setting of charge / discharge limit value considering operation strategy / preliminary part of power storage unit ... This includes system shutdown when the upper and lower limit values are exceeded, such as stopping all systems and repeating charge / discharge cycles from the beginning. Also determine the behavior.
Charge / discharge switching policy: Number of times, charge / discharge depth to which the number of times of switching is added, and reset timing.
・ Follow the target tide with full power / stop after following the allowable tide.
From the above target function, input parameters, and constraint conditions, the amount of charge / discharge of the power storage unit for the subsequent unit time (eg, 1 minute), the disconnection / connection of the solar cell group (solar power generation device) are obtained, Create an operation plan.

According to this embodiment, solar cell groups (photovoltaic power generation devices) are dispersed in a plurality of units and arranged in a wide area, and a reserve capacity for control against fluctuations is secured, thereby diversifying solar radiation intensity due to wide area. At the same time as the level of power generation of the coming solar power generation system, it is possible to improve the reliability, quality, and economic efficiency of the system by providing on / off function of multiple solar cell groups for fluctuation absorption .
Moreover, the output prediction of unit time (example: 1 minute unit) is performed, and the short-term fluctuation is not limited to other generators, but by the partial disconnection (OFF) of the photovoltaic power generator, Therefore, it is possible to perform optimum large-capacity control in a short time.

Furthermore, it is possible to calculate wind direction and wind power values necessary for short-term prediction of photovoltaic power generation without expensive weather observation equipment, and the predicted values calculated based on actual power generation from the windward are highly accurate. Can be expected.
Photovoltaic power generation devices have various characteristics depending on the type of panel, but they are possible control methods even if they are mixed. In addition, the power storage unit has various characteristics and there is no optimal operation model, but it is possible to provide an optimal operation model for various types of power storage devices by only rewriting the constraint conditions according to the third embodiment. The required capacity of the expensive power storage unit can be reduced.

  In the above embodiment, the creation of the operation plan curve has been described for the charge / discharge cycle once a day. This is intended to extend the life of the expensive power storage unit by suppressing the number of switching as much as possible. Of course, when the power storage unit is, for example, an electric double layer capacitor, a plurality of cycles may be used. Further, even when the power storage unit is configured by an electric double layer capacitor, the capacity can be reduced by adopting the present invention.

The block diagram of the solar energy power generation system which shows embodiment of this invention. The flowchart of the charging / discharging control by this invention. Operation relationship diagram of power generation amount-power storage amount for explanation. The flowchart of other charging / discharging control by this invention. Charge / discharge operation plan diagram for explanation. Explanatory drawing of a solar cell group. Explanatory drawing of a solar cell group. The mesh explanatory drawing of the solar cell used at the time of electric power generation amount prediction. The mesh explanatory drawing of the solar cell used at the time of electric power generation amount prediction. The mesh explanatory drawing of the solar cell used at the time of electric power generation amount prediction. Operation relationship diagram of power generation amount-power storage amount for explanation. The block diagram of a solar power generation system. Schematic explanatory drawing of supply and demand control. The characteristic figure of the electric power generation amount.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... 1st solar cell group 2 ... 2nd solar cell group 3 ... 1st power conditioner 4 ... 2nd power conditioner 5 ... Transformer 6 ... Transformer 7 ... Solar power generation system substation 8 ... Bus 9 Power company substation 10 Stabilization device 11 Power storage unit 12 Power conversion unit 13 Interconnection transformer 14 Control unit

Claims (10)

A photovoltaic power generation device composed of a group of solar cells and a stabilization device having a power storage unit and a power conversion unit are connected to the power system, and control is performed on the power conversion unit via the control unit of the stabilization device to store power. In the photovoltaic power generation system configured to perform charge / discharge control to the unit,
The solar power generation device is divided into a normal operation and a standby one, and the control unit includes a peak curve of power generation amount from a power generation start time to a power generation end time of the solar power generation device created in advance and the power storage unit. The charging / discharging operation plan curve is stored, the surplus when the power generation output amount is larger than the charge value based on the charging operation plan curve during charging from the power generation start time to the power generation end time, When the power is smaller than the planned charge value, the spare solar power generation device is connected to the power system, and when the power storage unit reaches a predetermined value charge amount, the mode is switched to the discharge mode, and the power generation start time to the power generation end time When the battery is not charged at the time of non-charging, control is performed from the power generation start time to the power generation end time. Repetition control method for a photovoltaic power generation system characterized by performing in. The calculation of the peak curve of the amount of power generation is performed by averaging the deviation calculated at each arbitrary time of the peak of fluctuation up to the time point with respect to the solar radiation intensity curve during clear weather, and the deviation and the solar radiation intensity curve during clear weather. The solar power generation system control method according to claim 1, wherein the solar radiation intensity peak curve is multiplied to obtain a peak curve of the day by multiplying the solar radiation intensity peak curve and solar cell efficiency. The said predetermined value charge amount is a quantity which ensures the charge amount which satisfy | fills the amount of electric power required from the time of full charge of the said power storage part to a power generation completion time from a full charge time, or Claim 1 characterized by the above-mentioned. The control method of the solar power generation system of 2. The charging / discharging operation plan curve creates an operation plan curve only at the time of discharging together with a value based on the operation plan at the time of charging, and creates plan values based on each planning curve in stages, at the end of charging and at the start of discharging. 4. The method for controlling a photovoltaic power generation system according to claim 1, wherein a time interval capable of peak shifting is provided at the joint portion of the solar power generation system. The power storage unit is partly disconnected from the power system when the power storage unit is in a non-charged state and the power generation amount is larger than a power generation output value based on an operation plan curve. The control method of the solar power generation system of claim | item 1 thru | or 4. 6. The disconnection control from the power system of the photovoltaic power generation apparatus is based on a signal obtained by subtracting the amount of power by load prediction from the predicted output amount of the photovoltaic power generation apparatus. The solar power generation system control method described. The solar cell group is composed of division units separated by a mesh, and connection control to the grid and disconnection switching control are performed for output prediction of the amount of power generation in an arbitrary unit time, and each division at the time of power generation fluctuation with respect to this output prediction. 5. The method for controlling a solar power generation system according to claim 1, wherein the control method is performed for each unit. The output prediction of the power generation amount is to measure the power generation amount with a short period measurement width obtained by further subdividing the arbitrary unit time, and to calculate solar radiation from the efficiency and area of each solar cell and the short cycle measurement time. Intensity is calculated, and the maximum correlation function of the two data is calculated by repeating the short time measurement time unit n times while shifting the past data by 1 mesh in the x-axis and y-axis directions at the center of the mesh. The wind direction and the wind force are determined from the maximum correlation function and the distance between the meshes, and the solar radiation fluctuation component is extracted from the measurement result of the short period to obtain the solar radiation amount for the unit time. 6. The method for controlling a solar power generation system according to claim 5, wherein the predicted value of the power generation amount is obtained by multiplying the power generation efficiency and area of the solar power generation system. The solar light generation system control method according to claim 6, wherein the amount of solar radiation for the unit time is obtained by sequentially and repeatedly integrating from the windward side. A photovoltaic power generation device composed of a group of solar cells and a stabilization device having a power storage unit and a power conversion unit are connected to the power system, and control is performed on the power conversion unit via the control unit of the stabilization device to store power. A photovoltaic power generation system configured to perform charge / discharge control to a unit, wherein the solar cell group is divided into arbitrary units by an arbitrary mesh, and an output of power generation is predicted at an arbitrary time for each divided unit In the case where the photovoltaic power generation device is disconnected from the power system when the power generation amount is larger than the value of the operation plan curve created in advance based on the output predicted value,
Measuring means for measuring the power generation amount of each photovoltaic power generation device in a short cycle that subdivides the unit time, solar cell efficiency and area in each photovoltaic power generation device, and calculating the solar radiation intensity from the short cycle measurement time And a maximum correlation between calculating the maximum correlation coefficient of the two data by repeating the shift of the past data of the solar radiation intensity n times for each mesh in the x-axis and y-axis directions. The number calculation means, the maximum correlation coefficient, the solar radiation fluctuation calculation means for determining the solar radiation fluctuation by determining the wind direction and the wind power from the distance between the meshes, and the mesh can be obtained repeatedly from the windward side to the leeward in the unit time. A solar radiation amount calculating means for calculating the solar radiation amount for the unit time from the integrated solar radiation fluctuation amount, and a predicted value calculation for calculating a predicted power generation amount by multiplying the obtained solar radiation amount by the power generation efficiency and area of the mesh Power generation amount prediction apparatus of photovoltaic power generation system characterized by including a stage.

Images