JP4992134B2 - Control method and apparatus of photovoltaic power generation system - Google Patents

Description

  The present invention relates to a control method and apparatus for a photovoltaic 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. 11 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. 11, 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. 12 is a schematic diagram of the supply and demand control method. As control, control according to the operation plan, load following control, and local following 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. 13 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 grasped 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 the same capacity as the solar power generation capacity (5 hours or more) can be prepared and an appropriate operation planning program can be prepared. However, 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.

  The present invention provides a control method and a device for a solar power generation system capable of supplying stable power by performing on / off control of a plurality of solar power generation unit units as needed without depending on a power storage device. is there.

Claim 1 of the present invention comprises a plurality of photovoltaic power generation unit units to constitute a photovoltaic power generation system, and performs supply and demand control of the photovoltaic power generation system via a control device.
Create a total power generation peak curve for each solar power generation unit for each weather, consisting of multiple output waveform patterns corresponding to the weather including sunny and cloudy, and create the total of the solar power generation units for each weather created A plurality of time zones are set along the power generation amount peak curve to determine the target value of the output of each time zone corresponding to each weather and store it in the control device,
In the control device, the power generation amount of each solar power generation unit is collected, and the power generation amount of each solar power generation unit is repeatedly predicted in each time period, and the output total value of the power generation amount is calculated based on the predicted value. The connection / disconnection control of the photovoltaic power generation unit to the photovoltaic power generation system is performed so as to be close to the target value corresponding to the weather.

  According to claim 2 of the present invention, an on / off determination for performing connection / disconnection control of the photovoltaic power generation unit to the photovoltaic power generation system includes an index unique to the photovoltaic power generation unit, and an index of the index. Arrange in advance in descending order of the estimated output value of the photovoltaic power generation unit, and perform connection control to the photovoltaic power generation system in descending order of the estimated output value, and the total output of the connected photovoltaic power generation unit units sets the target value When it exceeds, the last one is selected so that the sum is close to the target value.

  A third aspect of the present invention is characterized in that the target value is classified into at least four with reference to weather.

  According to a fourth aspect of the present invention, a power storage device is provided in the solar power generation system, and the power storage device is subjected to charge mode control, discharge mode control, and stop control via the control device.

Claim 5 of the present invention comprises a plurality of photovoltaic power generation unit units to constitute a photovoltaic power generation system, and performs supply and demand control of the photovoltaic power generation system via a control device.
In the control device, a total power generation amount peak curve of the solar power generation unit unit in each weather composed of a plurality of output waveform patterns corresponding to the weather including sunny and cloudy is created in advance, and the generated sunlight in each weather is created A target value determination unit that sets a plurality of time zones along the total power generation amount peak curve of the power generation unit and determines a target value of output in each time zone corresponding to each weather ;
An iterative control unit that outputs a timing signal at a time interval sufficiently shorter than the plurality of time zones;
A measurement value collection unit that collects the power generation amount of each photovoltaic power generation unit based on this timing signal,
A short-term prediction unit that predicts the power generation output of each photovoltaic power generation unit based on the collected measurement values;
An on / off determination unit that performs connection / disconnection determination to the photovoltaic power generation system of each photovoltaic power generation unit so that the total of the power generation output approaches the target value, and performs on / off control via the control instruction unit It is characterized by having.

  A sixth aspect of the present invention is characterized in that the output of the on / off control signal from the collection of the measurement values is executed a plurality of times for each time period.

  According to a seventh aspect of the present invention, a power storage device is provided in the photovoltaic power generation system, and a charge / discharge amount determining unit is provided in the control device, and charging is performed based on the target value and the short-term prediction signal in the charge / discharge amount determining unit. It is characterized by determining power and discharge power.

  As described above, according to the present invention, in the supply and demand control in the photovoltaic power generation system, by turning on / off the photovoltaic power generation unit in a short cycle, only the power necessary for the supply and demand is output, and the excess is cut off. As a result, a stable power output can be output to the system or power system. For this reason, it is possible to supply stable power without a power storage device, and it is possible to construct a system without introducing an expensive power storage device into the photovoltaic power generation system. In addition, even if a power storage device is introduced, a smaller capacity is required, and an operation that extends the life is possible.

In the present invention, a photovoltaic power generation system in which a plurality of photovoltaic power generation unit units (hereinafter referred to as units) are arranged in a distributed manner, a target value of power generation output that can be sufficiently generated by this photovoltaic power generation system is set for each time zone, If the total power output exceeds the target value by measuring the power output of each unit at any time (with a cycle of 1 to several seconds), some units are temporarily disconnected, and the entire photovoltaic power generation system generates power almost as targeted. It is controlled by output.
Here, the time zone is set to one hour zone, for example, every 30 minutes or every hour, and the target value of the power generation output for each time zone is set by performing power generation output prediction in advance.

  FIG. 2 shows an image to which the present invention is applied. In an urban area composed of houses, schools, buildings, etc., an area where dozens or more units of photovoltaic power generation systems are installed, mega solar (solar farm, On / off control is performed by a system in which solar panels are regularly arranged in a wide area such as (Solar Park). This will be specifically described below.

  FIG. 1 is a system configuration diagram showing an embodiment of the present invention. 1 (1a, 1b,..., 1n) is a photovoltaic power generation unit, and each unit has a solar cell 10, a power conditioner 11, a power meter 12, and a circuit breaker 13, and one or several units are grouped together. It is connected to the bus of the photovoltaic power generation system substation 6 through a circuit breaker and a transformer. Here, the photovoltaic power generation system substation 6 is connected to the power grid of the electric power company via a bus. Reference numeral 2 denotes a control device that executes an on / off command to the circuit breaker 13 of each unit 1 and sampling of generated power. 3 is a power storage device using an electric double layer capacitor or the like, 4 is a generator, and a generator other than a solar power generator such as a gas engine generator or a fuel cell, and 5 is a load. The system configuration is changed depending on the arrangement of units and the scale of the entire system.

FIG. 3 shows a configuration diagram of the control device 2. In this embodiment, only the on / off control of the unit 1 is shown, and the power storage device 3, the generator 4, and the load 5 are handled as not included in the control.
In FIG. 3, reference numeral 20 denotes a target value determining unit. The target value determining unit 20 divides a day into several time zones, and sets a target value of power generation output that can sufficiently generate power in the system. Here, the time zone is described as an example in which one hour from every hour is one time zone, but each time zone does not necessarily have the same length and is set as appropriate. Note that because of the nature of solar power generation, there is no need for a night time zone, so control of the time zone can be omitted.

  The target value signal for each time period set in the target value determination unit 20 is output to the on / off determination unit 24 that calculates and determines whether the circuit breaker 13 is turned on or off. Reference numeral 21 denotes an iterative control unit. The iterative control unit 21 generates a periodic timing signal of 1 to several seconds during a time period, and a measurement value collecting unit 22, a short-term prediction unit 23, an on / off determination unit 24, and a control instruction unit 25 respectively. The measurement value collection unit 22 collects output measurement values of the power of each unit with the applied timing signal. The short-term prediction unit 23 collects each unit 1 after Δt for each timing signal based on the collected output measurement value. The short-term prediction calculation of the power generation output is executed. The on / off determination unit 24 selects the connection / disconnection (on / off) of the unit to the photovoltaic power generation system for each timing signal. For this purpose, the on / off determination unit 24 uses the set target value and the predicted power generation output. The combination of on / off control of the unit is calculated and determined so that the total output of the photovoltaic system is sufficiently close to the target value, and is output to the control instruction unit 25. The control instruction unit 25 outputs an on or off signal to the circuit breaker 13 for the selected unit after Δt from the measurement, and executes disconnection or connection control from the power system of the unit.

  FIG. 4 shows an example of the operation timing of the control device 2, where time t is the timing at which the measurement value collecting unit 22 collects power from the unit 1, Δt is a preset calculation processing time, and t + Δt Is the timing at which a single control command is output from the control instruction unit 25 during the time period. This calculation output is repeated and output a plurality of times for each time period. Note that the time Δt is determined within an appropriate range depending on the relationship between the processing time and the prediction accuracy. Further, if the repetition period (timing period) is longer than Δt, each part of 22 to 25 can be configured by one sequence process as shown in FIGS. 4A and 4C, but if the repetition time is shorter than Δt, As shown by 4 (b), part of the processing is parallelized and pipeline processing is performed.

  FIG. 5 is an explanatory diagram of target value determination for each time zone. In order to execute the control according to the present invention, it is sufficient that the target value is determined before the start of the time period, but in the power sales contract, it is up to the previous day or up to two hours before the corresponding time period of the day. Is often requested. In consideration of this restriction, the target value is determined with reference to the weather forecast using the fact that the output waveform of the photovoltaic power generation is roughly classified according to the weather. That is, the line A is a peak curve of the power generation amount when “sunny”, and the target value for each time zone at that time is determined as the line a. The peak curve of the power generation amount in the case of “sunny, cloudy” is B, and the target value for each time zone at that time is determined as shown by the line b. Similarly, the lines C and c are determined in the case of “cloudy”, and the lines D and d are determined in the case of “rain and snow”. In this way, the weather is classified into four ways, and the target value for each time zone is determined from the output waveform patterns (a to d) prepared in advance in the peak curves (A to D) of the power generation amount in each weather. Set the target value below the lower limit of the output waveform pattern predicted for all units.

FIG. 6 shows one cycle of the control processing flow for each time zone in the control device 2. In step S1, the target value is determined by the target value determination unit 20, and the output target value of the photovoltaic power generation system in the time zone is determined based on FIG. In step S2, it is determined whether or not it is repeated at any time during the time period. If it is during the time period, the power generation output value of each unit accumulated by the wattmeter 12 is collected in S3. In step S4, short-term prediction of output is performed in the short-term prediction unit 23, and the output of each unit at time t + Δt is predicted. In S5, the ON / OFF determination unit 24 performs an operation for determining ON / OFF for each unit, and ON / OFF is determined so that the total output at time t + Δt is close to the target value. In S6, the control instruction unit 25 outputs an on / off control command to each unit at time t + Δt.
On the other hand, if it is determined in step S2 that the repetition is completed at any time, the control for a certain time period is ended.

FIG. 7 shows a flowchart for executing the selection control so that the total output value of the unit is closest to the target value.
In the prediction estimation of output, the output of each unit at time t or the output measurement value before that is also used to predict and estimate the output of the unit at time t + Δt, but here the output at time t is simply The measured value is the estimated output value at time t + Δt.
In the ON / OFF determination of each unit, an ON / OFF combination of units in which the total output of the units that are ON is sufficiently close to the target value is determined using the output estimation value of each unit at time t + Δt. Here, the units are first sorted in descending order by the estimated output value, then the units are selected in order from the largest estimated output value, and when the total output of the selected units exceeds the target value, the last one is selected. Select the sum so that the sum is closest to the target value. The generated power exceeding the target value is discarded as it is. Thereby, the superimposition of the generated power on the power system is prevented, and the system can be stabilized.

  In FIG. 7, in step S10, the number of units (unit [0] to unit [n-1]) of the unit unit having the ID (unique number) of the unit 1 and the estimated output value val at the time t + Δt. Prepare an array of Also, on / off is determined with the target value of the total output sum of each unit as the target. In S11, units are arranged in descending order with respect to unit [i] .val (i = 0 to n-1). In S12, sum and the work number i are set, and in S13, it is determined whether i <n. In the case of no, in step S14, n units are set to k units, k units (unit [0] to unit [k−1]) are turned on in advance and connected to the power system, and the remaining units are connected. N−k units (unit [k] to unit [n−1]) are turned off to be disconnected from the system.

  If the comparison in step S13 is yes, the sum of the total output sum of the unit and the estimated output value val of the i-th unit is rewritten as a new total output sum in S15, and the target value target of the sum and sum is changed in S16. Perform a size comparison of. As a result, if sum ≦ target, i is incremented by 1 in S18, and the process returns to S13. In the case of no, in S17, the unit number i is rewritten to k which is turned on, and in S19, the error e1 is set as sum-target, unit [i] .val is pulled back from sum, and i is set to +1. To do. In S20, i <n is compared. If no, the target-sum difference calculation is performed in S21 to obtain the error e2, and the magnitude comparison between this e2 and e1 obtained in step S19 is performed in S22. When e2 <e1, up to k units from the beginning are turned on, and the remaining n−k units are turned off. If no in S22, unit [k] and unit [i-1] are exchanged in S23, k is incremented by 1 in S24, k units are turned on, and the remaining nk units are replaced. Decide off.

  On the other hand, if “yes” in step S20, the operation of sum ← sum + unit [i] .val is executed in S25, and the obtained sum and target are compared in size. If the result of comparison is sum> target, the process returns to S19. If no, the difference calculation of target-sum is performed in S27 to obtain e2, and the magnitude comparison between e2 and e1 obtained in step S19 is performed in S28. . If no in S28, unit [k] and unit [i-1] are exchanged in S23, and if yes, unit [k] and unit [i] are exchanged in S29. Thereafter, in step S24, k is incremented by 1 and the k units are turned on, and the remaining n−k units are turned off. That is, the last one unit selection is executed in steps S19 to S24.

In the prediction estimation of the output of this embodiment, the calculated value P [t] at time t in each unit and the calculated value P [s] at time s one cycle before are used, and at time t + Δt by linear extrapolation. It is also possible to calculate the estimated output value P [t + Δt]. The formula in this case is
P [t + Δt] = P [t] + Δt (P [t] −P [s]) / (ts)
It becomes.

FIG. 8 is a flow chart for on / off control showing the second embodiment.
In this embodiment, in determining ON / OFF of each unit, the units are selected in the predetermined order by omitting the arrangement of the units, and when the total output exceeds the target value, the final one is set as the target. Unit selection is performed so as to be closest. In this embodiment, the deviation from the output target value is slightly larger than that in the first embodiment shown in FIG. 7, but the calculation time is about 1/4. Even if the deviation from the output target value is a little larger, it is sufficient for current and near future requirements, and is effective when the calculation performance of the controller is low and the demand for output accuracy is not particularly strict. It is.

  In FIG. 8, in step S30, an array of n units (unit [0] to unit [n-1]) of unit units having the unit ID and the estimated output value val at the time t + Δt is prepared. To do. The target value of the total output sum of each unit is assumed to be target. In S31, the total output sum and the initial value of the number of units are set, and in S32, i <n is compared. In the case of no, the number of units n is set to k in S33, k units (unit [0] to unit [k-1]) from the top are turned on, and the remaining n−k units (unit [k] ] To unit [n-1]) are turned off. If yes in S32, an operation of sum ← sum + unit [i] .val is executed in S34, and a comparison operation of sum ≦ target is executed in S35. As a result, if yes, the process returns to S32. If no, i ← k, i ← m, e1 ← sum-target, sum ← sum-unit [i] .val, and i ← i + 1 in S37. Perform the operation.

  In step S38, i <n is compared. If yes, sum + unit [i] .val is calculated in S39, and the calculated value s2 is compared with target in S40. If s2 ≦ target, the difference calculation of target-s2 is executed in S41, and if no, the difference calculation of s2-target is executed in S42. In S43, the obtained e2 and e1 are compared and determined. If e2 <e1, m ← i and e1 ← e2 are rewritten in S44, and after i + 1 is calculated in S45, the process returns to S38.

  On the other hand, in the case of no in S38, a target-sum difference calculation is executed in S46, and a comparison is made in S47 as to whether or not e2 <e1 between the obtained e2 and e1. As a result, in the case of yes, k units (unit [0] to unit [k-1]) from the head are turned on, and the remaining nk units (unit [k] to unit [n-1]) ) Off. If no, unit [k] and unit [m-1] are exchanged in S48, k is incremented by 1 in S49, and k units are turned on, and the remaining n-k units are controlled. Turn off. In this embodiment, the last unit is selected in steps S38 to S49.

  Table 1 shows the result of simulating the error between the target value and the actual measurement value in Example 1 and Example 2.

When collecting measurement values and giving control instructions to each unit, a transmission delay can be considered. In addition, it takes time to calculate the estimated output value and the on / off determination of each unit.
Δt is for considering these times. Table 1 shows the results of a simulation carried out under the conditions of 65 units of 5 to 25 kW based on the actually generated power measurement data per second of the photovoltaic power generation apparatus in order to examine the difference in accuracy due to Δt. As a result, even when Δt = 10 seconds, it is sufficiently smaller than the required level required for generated power in the present and near future, for example, within 3% for 30 minutes integration, 10% for 1 minute integration, It can be seen that if Δt <5 seconds, stable power can be supplied up to about 10% even with a maximum error of 1 second.
In addition, since the computation time is about 1 millisecond in the current personal computer performance, if the transmission line is not extremely slow, Δt ≦ 1 second is sufficiently possible, and it is confirmed that stable power supply is possible with the present invention. did it.

  Note that the on / off determination of each unit belongs to a problem generally called an optimization problem. On the other hand, the method used in the first and second embodiments is an algorithm generally called a greedy method, and produces relatively good results at high speed. However, there are many other methods for solving the combinatorial optimization problem. The branch and bound method takes time, but the optimal solution in the strict sense, that is, the on / off of the unit that obtains the output closest to the target value. Combinations can be calculated.

  FIG. 9 shows a configuration diagram of a control device in a case where a power storage device is installed in the solar power generation system and charging / discharging of the power storage device is controlled. The difference from the configuration diagram of the control device shown in FIG. 3 is that a charge / discharge amount determination unit 26 is added. The charge / discharge amount determination unit 26 receives the target value determined by the target value determination unit 20 and the short-term prediction signal calculated by the short-term prediction unit 23, and the charge / discharge amount determination unit 26 controls the control instruction unit 25. The charge / discharge command determined for is output. Therefore, the control device 2 ′ outputs a charge / discharge command for the power storage device 3 in addition to the unit on / off control.

FIG. 10 shows a control flowchart for one day of the control device for the power storage device. The power storage device takes the following operation pattern.
(1) The amount of power stored in the power storage device is almost empty at the time of the morning, and charging is performed using the generated power exceeding the target value until full charge or the required amount of charge is completed.
(2) Discharge until the power storage device is almost empty and supply electric power that is less than the target value.
(3) When the power storage device becomes almost empty, the operation of the power storage device on that day is terminated.
The control device 2 'performs target value determination and on / off control for each time zone as shown in FIG. 10 according to the three stages (1) to (3).

  In the first stage (1), the power storage device is set to the charging operation mode in step S50, and the charging mode control is executed in S51. In the charging mode control, as shown in the charging mode control in the subroutine, the target value is determined in S60. The target value is determined in the same manner as in the first embodiment. However, on / off control is not performed and all units are turned on, and the power exceeding the target value is calculated by the charge / discharge amount determination unit 26 and stored. Charge the device. In order to execute the control, in S61, it is determined whether or not it is repeated at any time during the time period. If it is during the time zone, the power generation output value of each unit accumulated by the power meter 12 is collected in S62. In step S63, short-term prediction of output is performed in the short-term prediction unit 23, and the output of each unit at time t + Δt is predicted. In S64, the charge / discharge amount determination unit 26 determines the output total-target value at time t + Δt as the charge power, and outputs it to the power storage device via the control instruction unit 25, and returns to S61. If the time period ends in S61, the charging mode control ends.

In step S52, it is determined whether or not the charging is finished. After the charging is finished, the second stage (2) is executed. In the target value determination in the discharge operation, a target value is set to be equal to or higher than the upper limit of the predicted output waveform pattern, and electric power that is less than the target value is calculated by the charge / discharge amount determination unit and discharged from the power storage device. The on / off control is performed in the same manner as in the first embodiment, and when there is an output exceeding the prediction, the off control is performed. That is, the power storage device is set to the discharge mode in S53, and the discharge mode control is executed in S54. In the discharge mode control, as shown in the charging mode control in the subroutine, the target value is determined in S70 and is determined to be equal to or more than the upper limit of the expected output waveform pattern. In S71, it is determined whether or not it is repeated at any time during the time period. If it is during the time period, the power generation output value of each unit accumulated by the wattmeter 12 in S72 is collected. In step S73, the short-term prediction of the output based on the collected measurement values is performed by the short-term prediction unit 23, and the output of each unit at time t + Δt is predicted.
In step S74, the on / off determination unit 24 performs an operation for determining on / off for each unit, generates an on / off signal such that the total output at time t + Δt is close to the target value, and the control instruction unit 25, an on / off control command to each unit at time t + Δt is output (S75).
At the same time, the short-term prediction signal is also output to the charge / discharge amount determination unit 26, and the discharge power is determined in S76. At that time, the total output at target value−time t + Δt is determined as the discharge power, and is output to the power storage device via the control instruction unit 25 as the discharge power command value (S77).

In the third stage (3), it is determined in step S55 whether or not the discharge has been completed. If the discharge is being performed, the discharge control is continued. If the discharge is completed, the power storage device is stopped in S56, and this is executed for each time period (S57). Then, the control for one day is ended by determining that one day of S58 is ended.
When performing the notification operation for 2 hours in advance for selling electric power, the stage is switched by predicting the charging state and remaining amount of the power storage device in advance.

In addition, when a generator is installed in the solar power generation system as shown in FIG. 1, the generated power of the generator may be operated at full power as it is constant, or it is always operated at a low output, A generator may be used to raise the bottom when the power generation amount prediction for determining the target value is not selected, and is appropriately selected.
Further, when a load is included in the solar power generation system, the predicted load is subtracted from the power generation amount in the power generation amount prediction for target determination. In the on / off control, an off control is performed for an amount in which the output obtained by subtracting the load from the total unit output exceeds the target value.

The block diagram of the solar energy power generation system which shows embodiment of this invention Illustration of the image of the solar power generation system Configuration diagram of control device of the present invention Control calculation time chart Illustration of target value determination in time zone Control flowchart for each time zone Flow chart at ON / OFF decision Flowchart for determining on / off according to another embodiment Configuration diagram of another control device of the present invention Flow chart of daily control when power storage device is installed Configuration diagram of solar power generation system Schematic diagram of supply and demand control Output characteristics diagram of photovoltaic power generation

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 (1a, 1b ... 1n) ... Photovoltaic power generation unit 2 ... Control device 3 ... Power storage device 4 ... Generator 5 ... Load 6 ... Photovoltaic power generation system substation 10 ... Solar cell 11 ... Power conditioner 12 ... Wattmeter 13 … Circuit breaker

Claims (7)

In what constitutes a solar power generation system with a plurality of solar power generation unit units, and performs supply and demand control of the solar power generation system via the control device,
Create a total power generation peak curve for each solar power generation unit for each weather, consisting of multiple output waveform patterns corresponding to the weather including sunny and cloudy, and create the total of the solar power generation units for each weather created A plurality of time zones are set along the power generation amount peak curve to determine the target value of the output of each time zone corresponding to each weather and store it in the control device,
In the control device, the power generation amount of each solar power generation unit is collected, and the power generation amount of each solar power generation unit is repeatedly predicted in each time period, and the output total value of the power generation amount is calculated based on the predicted value. A control method for a photovoltaic power generation system, wherein connection / disconnection control of the photovoltaic power generation unit to the photovoltaic power generation system is performed so as to be close to the target value corresponding to the weather. The on / off determination for connection / disconnection control of the photovoltaic power generation unit to the photovoltaic power generation system includes an index unique to the photovoltaic power generation unit and an output estimation of the photovoltaic power generation unit of the index. Arrange in advance in descending order of the values, perform connection control to the photovoltaic power generation system in descending order of the estimated output value, and when the total output of the connected photovoltaic power generation unit exceeds the target value, the last one 2. The method for controlling a photovoltaic power generation system according to claim 1, wherein the total is selected so that the sum is close to a target value. 3. The control method for a photovoltaic power generation system according to claim 1, wherein the target value is classified into at least four with reference to weather. 4. The solar power generation system according to claim 1, wherein a power storage device is provided in the solar power generation system, and charge mode control, discharge mode control, and stop control are performed on the power storage device via the control device. Control method. In what constitutes a solar power generation system with a plurality of solar power generation unit units, and performs supply and demand control of the solar power generation system via the control device,
In the control device, a total power generation amount peak curve of the solar power generation unit unit in each weather composed of a plurality of output waveform patterns corresponding to the weather including sunny and cloudy is created in advance, and the generated sunlight in each weather is created A target value determination unit that sets a plurality of time zones along the total power generation amount peak curve of the power generation unit and determines a target value of output in each time zone corresponding to each weather ;
An iterative control unit that outputs a timing signal at a time interval sufficiently shorter than the plurality of time zones;
A measurement value collection unit that collects the power generation amount of each photovoltaic power generation unit based on this timing signal,
A short-term prediction unit that predicts the power generation output of each photovoltaic power generation unit based on the collected measurement values;
An on / off determination unit that performs connection / disconnection determination to the photovoltaic power generation system of each photovoltaic power generation unit so that the total of the power generation output approaches the target value, and performs on / off control via the control instruction unit A control device for a photovoltaic power generation system, comprising: 6. The control device for a photovoltaic power generation system according to claim 5, wherein the output of the on / off control signal from the collection of the measurement values is executed a plurality of times for each time period. A power storage device is provided in the photovoltaic power generation system, and a charge / discharge amount determination unit is provided in the control device, and the charge / discharge amount determination unit determines charging power and discharge power based on the target value and a short-term prediction signal. The control apparatus of the solar power generation system of Claim 5 or 6 characterized by these.

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