JP7147166B2 - Control system, control method and computer program - Google Patents

Description

The present invention relates to control systems, control methods, and computer programs.

2. Description of the Related Art In recent years, power generators using renewable energy have been attracting attention as one of the countermeasures against global warming. Under such circumstances, the wind power generator is one of the power generators using renewable energy that has been introduced the most in the world.

The power generated by the power generation system including the wind power generator is sold to the power company. At that time, various constraint conditions for grid interconnection are determined in advance.

In order to continue operating the power generation system while satisfying the constraints for grid connection, a power generation plan is drawn up based on weather forecast information provided by a predetermined organization, and the power generation system is controlled so as to satisfy the power generation plan. has been conventionally performed (see, for example, Patent Document 1).

JP 2015-80359 A

However, although the accuracy of weather forecast information has improved in recent years, it is difficult to accurately forecast the amount of power generated by wind power generation, and the forecast accuracy is said to be about 30%. Therefore, it is difficult to continue operating the power generation system while satisfying the constraints for grid interconnection.

The present invention has been made in view of such circumstances, and a control system, a control method, and a computer program for continuing to operate a power generation system having a wind power generator while satisfying the constraints for grid interconnection. intended to provide

(1) In order to achieve the above object, a control system according to one embodiment of the present invention is a control system for controlling a power generation system including a wind power generator and a storage battery, wherein the output of the wind power generator is value, information indicating the relationship between the minimum necessary storage battery remaining amount and the combined output for the combined output of the power generation system to satisfy the following first and second constraints. and a synthetic output target value calculation unit that calculates a synthetic output target value, which is a target value of the synthetic output, from the remaining battery level of the storage battery.
First Constraint: Constraints for connecting the power generation system to the grid Second Constraints: Constraints for operating the storage battery

(8) A control method according to another embodiment of the present invention is a control method for controlling a power generation system including a wind power generator and a storage battery, wherein when the output of the wind power generator is a predetermined value, , the storage battery of the storage battery using information indicating the relationship between the minimum required storage battery remaining capacity and the synthesized output so that the synthesized output of the power generation system satisfies the following first and second constraints: A combined output target value calculating step of calculating a combined output target value, which is a target value of the combined output, from the remaining amount.
First Constraint: Constraints for connecting the power generation system to the grid Second Constraints: Constraints for operating the storage battery

(9) A computer program according to another embodiment of the present invention is a computer program for causing a computer to function as a control system that controls a power generation system including a wind power generator and a storage battery, When the output of the wind power generator is a predetermined value, the minimum necessary storage battery remaining amount for the combined output of the power generation system to satisfy the following first and second constraints, and the combined output using the information indicating the relationship between the above, and functions as a target synthetic output value calculation unit that calculates a target synthetic output value, which is the target value of the synthetic output, from the remaining battery level of the storage battery.
First Constraint: Constraints for connecting the power generation system to the grid Second Constraints: Constraints for operating the storage battery

ADVANTAGE OF THE INVENTION According to this invention, the power generation system provided with a wind power generator can be continuously operated, satisfying the constraint conditions for grid connection.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows the structure of the electric power system which concerns on embodiment of this invention. It is a block diagram which shows the structure of the management apparatus which concerns on embodiment of this invention. FIG. 5 is a diagram for explaining a constraint condition (condition a) for short-period output fluctuation mitigation measures; FIG. 5 is a diagram for explaining a constraint condition (condition b) for long-period output fluctuation mitigation measures; It is a figure which shows the time transition of the output of each apparatus, and a storage battery remaining amount. FIG. 10 is a diagram for explaining calculation processing of a target composite output value; 1 is a block diagram showing the configuration of a PCS according to an embodiment of the present invention; FIG. 7 is a flow chart showing a flow of calculation processing of a synthetic output target value by a management device; It is a flow chart which shows a flow of storage battery control processing by PCS. It is another figure which shows the time transition of the output of each apparatus, and a storage battery remaining amount. FIG. 4 is a diagram showing the relationship between the rated capacity of a storage battery and the power generation suppression rate of a wind power generator;

[Overview of Embodiments of the Present Invention]
First, an overview of the embodiments of the present invention will be listed and explained.
(1) A control system according to an embodiment of the present invention is a control system that controls a power generation system including a wind power generator and a storage battery, and when the output of the wind power generator is a predetermined value, Using the information indicating the relationship between the minimum necessary storage battery remaining capacity for the combined output of the power generation system to satisfy the following first and second constraints and the combined output, the storage battery remaining capacity of the storage battery is satisfied. A synthetic output target value calculation unit for calculating a synthetic output target value, which is a target value of the synthetic output, from the amount.
First Constraint: Constraints for connecting the power generation system to the grid Second Constraints: Constraints for operating the storage battery

According to this configuration, when the output of the wind power generator is a predetermined value, it is possible to calculate the combined output target value of the power generation system for satisfying the first constraint and the second constraint. That is, even if the output of the wind power generator is equal to or less than the predetermined value, it is possible to calculate the combined output target value necessary to satisfy the first constraint and the second constraint. By setting the predetermined value to a small value, an appropriate combined output target value can be calculated even when the output of the wind power generator is small depending on the weather conditions. As a result, the control system can continue to operate the power generation system including the wind power generator while satisfying the constraints for grid interconnection.

(2) Preferably, the predetermined value is zero.

According to this configuration, even if the output of the wind power generator is 0, it is possible to calculate the combined output target value for satisfying the first constraint and the second constraint. As a result, even if the wind power generator cannot generate power, it is possible to continue operating the power generation system while satisfying the constraints for grid interconnection.

(3) Further, the control system described above further includes a combined output calculation section that calculates the combined output that satisfies the first constraint based on the combined output target value calculated by the combined output target value calculation section. and a storage battery output calculation unit that calculates the output of the storage battery based on the combined output calculated by the combined output calculation unit and the output of the wind power generator.

According to this configuration, when the combined output target value does not satisfy the first constraint, a combined output that satisfies the first constraint can be calculated based on the combined output target value. When the combined output is calculated, the output of the storage battery can be calculated by subtracting the output of the wind power generator from the combined output. Thereby, the output of the storage battery can be controlled so as to satisfy the first constraint.

(4) Further, the first constraint may include a constraint on the amount of change in the combined output per unit time.

According to this configuration, the power generation system can be controlled such that the combined output satisfies the constraint on the amount of change in the combined output per unit time. As a result, for example, it is possible to prevent a sudden change in the combined output and reverse flow of unstable power to the power system.

(5) Further, the first constraint may include a constraint on the direction of change of the synthesized output in a predetermined time period.

According to this configuration, the power generation system can be controlled such that the combined output satisfies the constraint on the direction of change of the combined output in a predetermined time period. As a result, for example, it is possible to supply power to the power system in accordance with fluctuations in power demand.

(6) Further, the first constraint may include a constraint that the power generation system does not receive power from the power system.

According to this configuration, it is possible to calculate the optimum combined output target value under the constraint that the storage battery is not charged with electric power greater than that generated by the wind power generator.

(7) Further, the second constraint may include a constraint on the remaining capacity of the storage battery.

According to this configuration, it is possible to calculate a combined output target value that allows the power generation system to continue operating while maintaining the remaining battery capacity of the storage battery at or above a certain level.

(8) A control method according to another embodiment of the present invention is a control method for controlling a power generation system including a wind power generator and a storage battery, wherein the output of the wind power generator is a predetermined value. , the storage battery of the storage battery using information indicating the relationship between the minimum required storage battery remaining capacity and the synthesized output so that the synthesized output of the power generation system satisfies the following first and second constraints: A combined output target value calculating step of calculating a combined output target value, which is a target value of the combined output, from the remaining amount.
First Constraint: Constraints for connecting the power generation system to the grid Second Constraints: Constraints for operating the storage battery

This configuration includes steps corresponding to the control system components described above. Therefore, the same actions and effects as those of the control system described above can be obtained.

(9) A computer program according to another embodiment of the present invention is a computer program for causing a computer to function as a control system for controlling a power generation system including a wind power generator and a storage battery, When the output of the wind power generator is a predetermined value, the minimum necessary storage battery remaining amount for the combined output of the power generation system to satisfy the following first and second constraints, and the combined output using the information indicating the relationship between the above, and functions as a target synthetic output value calculation unit that calculates a target synthetic output value, which is the target value of the synthetic output, from the remaining battery level of the storage battery.
First Constraint: Constraints for connecting the power generation system to the grid Second Constraints: Constraints for operating the storage battery

According to this configuration, the computer can function as the control system described above. Therefore, the same actions and effects as those of the control system described above can be obtained.

[Details of the embodiment of the present invention]
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that each of the embodiments described below is a preferred specific example of the present invention. Numerical values, shapes, components, arrangement positions and connection forms of components, steps, order of steps, and the like shown in the following embodiments are examples and are not intended to limit the present invention. The invention is defined by the claims. Therefore, among the constituent elements in the following embodiments, the constituent elements not described in the independent claims representing the top concept of the present invention are not necessarily required to achieve the object of the present invention, but are more It is described as constituting a preferred form.

<Overall configuration of power system>
FIG. 1 is a block diagram showing the configuration of a power system according to an embodiment of the invention.
As shown in FIG. 1, the power system includes three wind power generators 2, a power conditioning system (hereinafter referred to as "PCS") 3, a storage battery 4, a PCS 5, and a management device 6. .

Here, the three wind power generators 2 and the storage battery 4 constitute a power generation system, and the PCS 3, PCS 5 and management device 6 constitute a control system.

The wind power generator 2, for example, rotates wings called blades by wind energy, and transmits the rotation to the power generator through a power transmission shaft, thereby generating and outputting DC power with the power generator. The output of each wind power generator 2 is, for example, 660 kW. Note that the number of wind power generators 2 is not limited to three.

The PCS 3 is a unidirectional DC (direct current)/AC (alternating current) converter that converts the DC power generated by the three wind power generators 2 into AC power and reversely flows the power to the power system. The PCS 3 has a function of limiting the output of the wind power generator 2, and can limit the output of an arbitrary amount of electric power. In other words, the PCS 3 can also limit all of the output of the wind power generator 2 .

The storage battery 4 is a device that stores DC power, and includes, for example, a secondary battery such as a lithium ion battery, a redox flow battery, a molten salt battery, and a lead storage battery. The rated capacity of the storage battery 4 is, for example, 1.6 MW×1.5 hours, and the charging/discharging efficiency (ratio of discharged energy to charged energy) of the storage battery 4 is 100%. It is also assumed that the SOC (State of Charge) range of the storage battery 4 is maintained at 10% to 90%.

The PCS 5 is a bidirectional DC/AC converter that converts the AC power output from the PCS 3 into DC power to charge the storage battery 4, converts the DC power discharged from the storage battery 4 into AC power, Reverse power flow to the power system.

It is assumed that the interconnection capacity of the power reversely flowed from the PCS 3 and 5 to the power system is 3.6 MW.

The management device 6 is connected to the PCS 3 and 5, and based on the power generation amount (output) of the wind power generator 2, the remaining amount of storage battery 4 and the charge/discharge amount (output) of the storage battery 4, etc. A combined output target value, which is the output target value, is calculated. At that time, the management device 6 calculates the combined output target value so as to satisfy the following first and second constraint conditions.
1st Constraint: Constraints for connecting the power generation system to the grid 2nd Constraints: Constraints for operating the storage battery

The second constraint is a constraint for limiting the SOC of the storage battery 4 described above to a certain range. Details of the first constraint will be described later.

The PCS 5 calculates the output of the storage battery 4 based on the combined output target value calculated by the management device 6 and the total output of the three wind power generators 2 . When the output of the storage battery 4 is positive, the output indicates the amount of discharge of the storage battery 4 , and when the output is negative, the absolute value of the output indicates the amount of charge of the storage battery 4 . PCS5 controls charging/discharging of the storage battery 4 so that it may become the calculated output.

<Configuration of management device 6>
FIG. 2 is a block diagram showing the configuration of the management device according to the embodiment of the invention.
As shown in FIG. 2, the management device 6 includes a communication unit 61, a wind power generator output acquisition unit 62, a storage battery output acquisition unit 63, a storage battery remaining amount acquisition unit 64, a combined output target value calculation unit 65, and a storage device 66 .

The communication unit 61 includes a communication interface for communicating with the PCS 3 and 5 by wire or wirelessly.

The wind power generator output acquisition unit 62 acquires information on the output of the wind power generator 2 from the PCS 3 . That is, the wind power generator output acquisition unit 62 acquires the power generation amount of each wind power generator 2 from the PCS 3 at predetermined time intervals.

The storage battery output acquisition unit 63 acquires information on the output of the storage battery 4 from the PCS 5 . That is, the storage battery output acquisition unit 63 acquires the amount of charge or the amount of discharge of the storage battery 4 from the PCS 5 at predetermined time intervals.

The storage battery remaining amount acquisition unit 64 acquires information about the storage battery remaining amount of the storage battery 4 from the PCS 5 at predetermined time intervals.

The combined output target value calculation unit 65 determines that the combined output of the power generation system satisfies the first constraint and the second constraint when the total output of the three wind power generators 2 is a predetermined value (for example, 0). Synthetic output target value, which is the target value of the synthetic output, is calculated from the remaining battery capacity of the storage battery 4 using information indicating the relationship between the minimum required remaining battery capacity and the synthesized output (function g, which will be described later). calculate. The communication unit 61 transmits the combined output target value calculated by the combined output target value calculation unit 65 to the PCS 5 . The calculation processing of the composite output target value by the composite output target value calculation unit 65 will be described later.

The storage device 66 stores various information in addition to the first constraint and the second constraint. The storage device 66 is configured by, for example, a magnetic disk device such as a HDD (Hard Disk Drive), a nonvolatile memory, a volatile memory, or the like.

<Regarding the first constraint>
Here, the first constraint, which is a constraint that must be observed with the electric power company when connecting the power generation system to the grid, will be described.
The first constraint includes, for example, the following three constraints.

(Condition a) Constraints for mitigating short-period output fluctuations At all times, the rate of change in the combined output of the power generation system shall be "1% or less/minute of the rated output of the power generation system". That is, the rate of change of the combined output of the three wind power generators 2 and the storage battery 4 is set to 36 kW/min or less.

FIG. 3 is a diagram for explaining a constraint condition (condition a) for short-cycle output fluctuation mitigation measures.

In FIG. 3, the horizontal axis indicates time and the vertical axis indicates the combined output of the power generation system. According to the condition a, the rate of change in the combined output of the power generation system is corrected to be "1% or less of the rated output of the power generation system/minute". As a result, while the graph before the output fluctuation mitigation shows a large fluctuation in the synthesized output, the short-term fluctuation of the synthesized output is suppressed in the graph after the output fluctuation mitigation according to the condition a.

(Condition b) Constraint conditions for long-period output fluctuation mitigation measures In the following specified time period, the fluctuation direction of the combined output of the power generation system is restricted.
・ 7:00 to 10:00: Do not decrease the combined output of the power generation system ・ 11:30 to 13:30: Do not increase or decrease the combined output of the power generation system ・ 16:00 to 19:00: Decrease the combined output of the power generation system・20:00 to 23:00: Do not increase the combined output of the power generation system

FIG. 4 is a diagram for explaining a constraint condition (condition b) for mitigating long-period output fluctuations.

In FIG. 4, the horizontal axis indicates time and the vertical axis indicates power. As can be seen from the graph of the total demand for electricity in FIG. 4, the total demand for electricity greatly increases in the two time slots from 7:00 to 10:00 and from 16:00 to 19:00. For this reason, condition b does not reduce the combined output of the power generation system during this period. This prevents the power flowing in the power system from decreasing.

Also, from 11:30 to 13:30, fluctuations in the total demand for electricity are large. Therefore, under condition b, the combined output of the power generation system during this period is not increased or decreased. This suppresses fluctuations in the power flowing through the power system.

Furthermore, from 20:00 to 23:00, the total demand for electric power is greatly reduced. Therefore, under condition b, the combined output of the power generation system during this period is not increased. This prevents an increase in power flowing into the power system.

Below the graph in FIG. 4, the combined output of the power generation system before output fluctuation mitigation is indicated by a broken line, and the combined output of the power generation system after output fluctuation mitigation under condition b is indicated by a solid line. Before output fluctuation mitigation, output fluctuations of the composite output occurred in the four time periods described above, but after output fluctuation mitigation according to condition b, long-term output fluctuations occurred in the four time periods. suppressed.

(Condition c) Restriction on Charging of Storage Battery When the storage battery 4 is used to reduce fluctuations in the combined output of the power generation system, the storage battery 4 is not charged from the power system. That is, the storage battery 4 is not charged beyond the total output of the wind power generator 2 .

It is assumed that the above constraints a-c must be met at a granularity of 1 minute.

<Regarding the calculation process of the synthetic output target value>
Next, the calculation processing of the synthetic output target value by the synthetic output target value calculation unit 65 will be described in detail.

FIG. 5 is a diagram showing the temporal transition of the output of each device and the remaining capacity of the storage battery. The horizontal axis indicates time (minutes), the left vertical axis indicates the output (kW) of each device, and the right vertical axis indicates the remaining capacity of the storage battery.

The combined output target value calculation unit 65 calculates a combined output target value, which is the target value of the output (combined output) of the power generation system, under the constraint conditions shown in Equations 1 to 12 below.

Here, the total output of the three wind power generators 2 at time t (hereinafter referred to as "wind power generator output") is Wp(t). Also, let Bp(t) be the output of the storage battery 4 at time t (hereinafter referred to as "storage battery output"). Let Sp(t) be the combined output of the power generation system at time t (hereinafter referred to as "combined output"). Also, let TSp(t) be the combined output target value at time t. Also, let Soc(t) be the remaining amount of storage battery 4 at time t.

Equations 1 and 2 below show the initial conditions. In the example shown in FIG. 5 , the remaining battery capacity Soc(0) at time t=0 is 1200 kWh, which is 50% of the rated capacity of the battery 4 . Also, Equations 3 and 4 indicate stationary conditions. Moreover, Formula 5 shows the condition a of the first constraint conditions. Formulas 6 to 9 show condition b of the first constraint. Equation 10 shows condition c of the first constraint. Furthermore, Equations 11 and 12 represent a second constraint.
Initial conditions:
Bp(0)=0 (Formula 1)
Soc(0)=25%, 50% or 75% of the rated capacity (1.6 MW×1.5 h=2400 kWh) of the storage battery 4 (Formula 2)

Stationary conditions:
0≦t<1440 (Formula 3)
Sp(t)=Wp(t)+Bp(t) (Formula 4)

First Constraint:
|Sp(t+1)−Sp(t)|≦1% of the rated output of the power generation system (36 kW) (Formula 5)
Sp(t+1)≧Sp(t) (420≦t<600) (Formula 6)
Sp(t+1)=Sp(t) (690≦t<810) (Formula 7)
Sp(t+1)≧Sp(t) (960≦t<1140) (Formula 8)
Sp(t+1)≦Sp(t) (1200≦t<1380) (Formula 9)
Sp(t)≧0 (Formula 10)

Second Constraint:
Soc(t)≦90% (2160 kWh) of the rated capacity (2400 kWh) of the storage battery 4 (Equation 11)
Soc(t)≧10% (240 kWh) of the rated capacity (2400 kWh) of the storage battery 4 (Equation 12)

The combined output target value calculation unit 65 calculates the rated output and the number of the wind power generators 2 shown in FIG. 1, the rated capacity and charge/discharge efficiency of the storage battery 4, The combined output target value TSp(t) is calculated so as to satisfy system configuration constraints such as the power interconnection capacity to the power system.

FIG. 6 is a diagram for explaining the calculation processing of the combined output target value. The horizontal axis indicates time [h], and the vertical axis indicates output [kW].

Let Sp(t) be the synthesized output at time t. It is also assumed that the wind power generator output Wp(t) becomes 0 after time t. When Wp(t)=0, Sp(t)=Bp(t) according to Equation 4, so the remaining battery capacity Soc(t) is consumed most. At this time, the transition over time of the synthesized output Sp(t) that satisfies the first constraint conditions shown in Equations 5 and 9 and the second constraint conditions shown in Equations 11 and 12 is as shown in FIG. That is, based on Equation 12, until the remaining amount of storage battery Soc(t) reaches 240 kWh, the combined output Sp(t) is reduced so as to satisfy Equations 5 to 9, resulting in the combined output Sp shown in FIG. It is the temporal transition of (t). The point in time when the combined output Sp(t) becomes 0 is the point in time when the remaining amount Soc(t) of the storage battery reaches 240 kWh.

The cumulative value of the combined output Sp(t) after time t (the area of the hatched region in FIG. 6) is the minimum required remaining battery capacity Soc(t) for the storage battery 4 . In other words, the relationship between the combined output Sp(t) at time t and the minimum remaining battery capacity Soc(t) required to comply with the first and second constraints can be expressed by Equation 13 below. can.
Soc(t)=g(t, Sp(t)) (Formula 13)

If the interval of time t is sufficiently small, Soc(t+1) can be substituted with Soc(t). Also, Soc(t+1) can be calculated by first-order approximation of Soc(t). Therefore, when the inverse function of the function g shown in Equation 13 is the function g ^-1 , the combined output target value calculation unit 65 uses Soc(t+1) derived from the remaining battery capacity Soc(t) at time t. , the combined output Sp(t+1) at time (t+1) is calculated (equation 14).
Sp(t+1)=g ⁻¹ (t+1, Soc(t+1)) (Formula 14)

The synthetic output target value calculation unit 65 sets Sp(t+1) as the synthetic output target value TSp(t+1).
In FIG. 5, the combined output target value TSp(t) is indicated by a dashed line.

The PCS 5 controls the output of the storage battery 4 within a range not exceeding the combined output target value TSp(t). A method of controlling the storage battery output by the PCS 5 will be described later.

<Configuration of PCS5>
FIG. 7 is a block diagram showing the configuration of the PCS according to the embodiment of the invention.
As shown in FIG. 7, the PCS 5 includes a communication unit 51, a combined output target value acquisition unit 52, a combined output calculation unit 53, a wind power generator output acquisition unit 54, a storage battery output calculation unit 55, and a storage device 56. and a storage battery control unit 57 .

The communication unit 51 includes a communication interface for performing wired or wireless communication with the management device 6 .

The combined output target value acquisition unit 52 acquires the combined output target value TSp(t) of the power generation system calculated by the management device 6 from the management device 6 via the communication unit 51 . For example, the synthetic output target value acquisition unit 52 transmits a request signal for the synthetic output target value to the management device 6 at intervals of one minute, and the management device 6 responds to the request signal by obtaining information on the synthetic output target value. may be sent. Alternatively, the management device 6 may transmit the information on the combined output target value to the PCS 5 in a push-type manner at intervals of one minute.

Based on the target synthetic output value TSp(t) acquired by the target synthetic output value acquiring unit 52, the synthetic output calculation unit 53 calculates the synthetic output that satisfies the above-described first constraint within a range that does not exceed the target synthetic output value. Calculate Sp(t). Note that the time for which the synthesized output Sp(t) is calculated is the same as the time t corresponding to the synthesized output target value TSp(t).

In other words, the time transition of the combined output target value TSp(t) may not satisfy the first constraint. Therefore, the synthesized output calculator 53 calculates the synthesized output Sp(t) so as to be closest to the synthesized output target value TSp(t) within the range that satisfies the first constraint. Note that when the synthetic output target value TSp(t) satisfies the first constraint, the synthetic output target value TSp(t) and the synthetic output Sp(t) are the same value.

The wind power generator output acquisition unit 54 acquires information on the total output (wind power generator output) Wp(t) of the three wind power generators 2 from the management device 6 via the communication unit 51 . For example, the combined output calculation unit 53 transmits a wind power generator output request signal to the management device 6 at intervals of one minute, and the management device 6 responds to the request signal by calculating the wind power generator output Wp(t) information may be transmitted. Also, the management device 6 may transmit information on the wind power generator output Wp(t) to the PCS 5 in a push-type manner at intervals of one minute.

The storage battery output calculation unit 55 calculates the storage battery output Bp ( t) is calculated. That is, the storage battery output calculation unit 55 calculates the storage battery output Bp(t) by subtracting the wind power generator output Wp(t) from the combined output Sp(t) according to Equation 15 below.
Bp(t)=Sp(t)-Wp(t) (Formula 15)
Equation 15 is derived from Equation 4.

The storage device 56 stores various information such as the rated capacity of the storage battery 4 . The storage device 56 is configured by, for example, a magnetic disk device such as an HDD, a nonvolatile memory, a volatile memory, or the like.

The storage battery control unit 57 controls charging and discharging of the storage battery 4 based on the storage battery output Bp(t) calculated by the storage battery output calculation unit 55 so that the output is realized. That is, the storage battery control unit 57 discharges the power of the storage battery output Bp(t) from the storage battery 4 when the storage battery output Bp(t) is positive, and discharges the power of the storage battery 4 when the storage battery output Bp(t) is negative. The storage battery 4 is charged with the power of the absolute value of the output Bp(t). All the power stored in the storage battery 4 is power generated by the wind power generator 2 .

<Processing Flow of Management Device 6>
FIG. 8 is a flow chart showing a flow of calculation processing of a synthetic output target value by the management device.

Referring to FIGS. 8 and 2, synthetic output target value calculation unit 65 acquires information on the constraint conditions for calculating the synthetic output target value stored in storage device 66 by reading from storage device 66. (S1). That is, the combined output target value calculation unit 65 calculates the above-described initial conditions (formulas 1 and 2), stationary conditions (formulas 3 and 4), first constraint conditions (formulas 5 to 10), and second constraint conditions ( Equations 11 and 12) and information such as constraints on the system configuration shown in FIG. 1 are acquired.

The wind power generator output acquisition unit 62 acquires the wind power generator output Wp(t) at the current time t from the PCS 3 (S2).

The storage battery output acquisition unit 63 acquires the storage battery output Bp(t) at the current time t from the PCS 5 (S3).

The combined output target value calculation unit 65 calculates a combined output Sp(t) of the wind power generator output Wp(t) and the storage battery output Bp(t) obtained in steps S2 and S3 (S4). That is, the combined output target value calculation unit 65 calculates the combined output Sp(t) by adding the wind power generator output Wp(t) and the storage battery output Bp(t) according to Equation 4 above.

The storage battery remaining amount acquisition unit 64 acquires the storage battery remaining amount Soc(t) at the current time t from the PCS 5 (S5).

The synthetic output target value calculation unit 65 calculates the synthetic output target value TSp(t+1) at the next time (t+1) under the constraint conditions shown in Equations 1 to 12 (S6). Details of the calculation processing of the combined output target value are as described above. Therefore, detailed description thereof will not be repeated.

The management device 6 determines whether or not a predetermined termination condition is satisfied (S7). For example, the management device 6 may determine that the termination condition is met when a predetermined period for calculating the target total output value has expired, or the user has instructed to stop the calculation process for the target total output value. In this case, it may be determined that the termination condition is satisfied.

If the termination condition is not satisfied (NO in S7), the processes after step S2 are repeatedly executed. If the termination condition is satisfied (YES in S7), the management device 6 terminates the composite output target value calculation process.

<Processing flow of PCS5>
FIG. 9 is a flowchart showing the flow of storage battery control processing by the PCS.
9 and 7, synthetic output target value acquisition unit 52 acquires synthetic output target value TSp(t) at current time t of the power generation system from management device 6 (S11).

Based on the target synthetic output value TSp(t) acquired by the target synthetic output value acquiring unit 52, the synthetic output calculation unit 53 calculates the synthetic output that satisfies the above-described first constraint within a range that does not exceed the target synthetic output value. Sp(t) is calculated (S12).

The wind power generator output acquisition unit 54 acquires the wind power generator output Wp(t) from the management device 6 (S13).

The storage battery output calculation unit 55 calculates the storage battery output Bp(t) based on the combined output Sp(t) calculated in step S12 and the wind power generator output Wp(t) obtained in step S13 ( S14). That is, the storage battery output calculation unit 55 calculates the storage battery output Bp(t) by subtracting the wind power generator output Wp(t) from the combined output Sp(t) according to Equation 15 described above.

Based on the battery output Bp(t) calculated by the battery output calculator 55, the battery controller 57 controls charging and discharging of the battery 4 so as to achieve the output (S15).

The PCS 5 determines whether or not a predetermined termination condition is satisfied (S16). For example, the PCS 5 may determine that the termination condition is satisfied when a preset control target period of the storage battery 4 expires, or may determine that the termination condition is satisfied when the storage battery 4 stops.

If the termination condition is not satisfied (NO in S16), the processes after step S11 are repeatedly executed. If the termination condition is satisfied (YES in S16), the PCS 5 terminates the control process for the storage battery 4. FIG.

<Regarding power generation suppression of the wind power generator 2>
FIG. 10 is another diagram showing the temporal transition of the output of each device and the remaining capacity of the storage battery. The view of FIG. 10 is the same as that of FIG.

As described above, the synthetic output Sp(t) is determined within a range not exceeding the synthetic output target value TSp(t), and the storage battery output Bp(t) is controlled. However, in the example shown in FIG. 10, the wind power generator output Wp(t) is large and the remaining battery capacity Soc(t) is also large during the daytime hours. In such a situation, if the storage battery 4 is charged with the wind power generator output Wp(t), the second constraint shown in the above equation 12 may not be satisfied. In such a case, an instruction to suppress wind power generation is transmitted from the management device 6 to the PCS 3 . The PCS 3 implements power generation suppression processing of the wind power generator 2 in response to the suppression instruction.

FIG. 11 is a diagram showing the relationship between the rated capacity of the storage battery and the power generation suppression rate of the wind power generator. The horizontal axis indicates the rated capacity of the storage battery 4 and the vertical axis indicates the power generation suppression rate of the wind power generator 2 .

The power generation suppression rate represents the suppression rate of wind power generation when the power generation of the wind power generator 2 is suppressed so as to satisfy the second constraint shown in Equation 12, and can be calculated by Equation 16 below.

Power generation suppression rate [%] = (total suppression power [kWh]/total wind power generator output [kWh]) x 100 (Equation 16)

Here, the wind power generator output total is the cumulative value of the wind power generator output Wp(t) when the power generation of the wind power generator 2 is not suppressed. The total suppressed power is the cumulative value of the power generated by the wind power generator 2 that is suppressed.

As shown in FIG. 11, the power generation suppression rate is about 0.19% when the rated capacity of the storage battery 4 is 2400 kWh. Therefore, it can be seen that a rated capacity of about 2400 kWh is sufficient for the storage battery 4 . By calculating the power generation suppression rate in this manner, the optimum rated capacity of the storage battery 4 can be obtained.

<Effects of the embodiment, etc.>
As described above, according to the embodiment of the present invention, when the wind power generator output Wp(t) is 0 as shown in FIG. It is possible to calculate the combined output target value TSp(t) of the power generation system for satisfying the two constraints. That is, even if the wind power generator output Wp(t) is 0, it is possible to calculate the combined output target value TSp(t) necessary to satisfy the first constraint and the second constraint. By setting the wind power generator output Wp(t) to 0, an appropriate combined output target value TSp(t) can be calculated even when there is no wind power generator output depending on weather conditions. As a result, the control system can continue to operate the power generation system including the wind power generator 2 while satisfying the constraints for grid interconnection. Although the wind power generator output Wp(t) was assumed to be 0 when calculating the combined output target value TSp(t), the wind power generator output Wp(t) may be assumed to be a predetermined positive value. .

Further, when the target synthesized output value TSp(t) does not satisfy the first constraint, the PCS 5 determines the synthesized output Sp(t) that satisfies the first constraint based on the target synthesized output value TSp(t). can be calculated. After the combined output Sp(t) is calculated, the storage battery output Bp(t) can be calculated by subtracting the wind power generator output Wp(t) from the combined output Sp(t). Thereby, PCS5 can control the output of the storage battery 4 so that a 1st constraint condition may be satisfy|filled.

Note that the first constraint includes a constraint on the amount of change in the combined output Sp(t) per unit time as shown in Equation 5. Therefore, the management device 6 can control the power generation system such that the combined output Sp(t) satisfies the constraint on the amount of change in the combined output Sp(t) per unit time. As a result, for example, it is possible to prevent a sudden change in the combined output Sp(t) and a reverse flow of unstable power to the power system.

In addition, the first constraint includes constraints on the direction of change of the combined output Sp(t) in a predetermined time period as shown in Equations 6-9. Therefore, the management device 6 can control the power generation system so that the combined output SP(t) satisfies the constraints on the direction of change of the combined output Sp(t) in a predetermined time period. As a result, for example, it is possible to supply power to the power system in accordance with fluctuations in power demand.

Also, the first constraint condition includes a constraint that the power generation system as shown in Equation 10 does not receive power from the power grid. Therefore, the management device 6 can calculate the optimum combined output target value TSp(t) under the constraint that the storage battery 4 is not charged with power greater than that generated by the wind power generator 2 .

In addition, the second constraint includes constraints on the remaining capacity of the storage battery 4 as shown in Equations 11 and 12. Therefore, the management device 6 can calculate the combined output target value TSp(t) that allows the power generation system to continue operating while maintaining the remaining battery capacity Soc(t) within a certain range.

<Appendix>
Although the power system 1 according to the embodiment of the present invention has been described above, the present invention is not limited to this embodiment.

For example, in the above embodiment, the management device 6 calculates the synthetic output target value TSp(t), and the PCS 5 calculates the storage battery output Bp(t) based on the synthetic output target value TSp(t). , the management device 6 may calculate the storage battery output Bp(t). The calculated storage battery output Bp(t) is provided from the management device 6 to the PCS 5, and the PCS 5 controls charging and discharging of the storage battery 4 based on the provided storage battery output Bp(t).

Further, each of the devices described above may be specifically configured as a computer including a microprocessor, ROM (Read Only Memory), RAM (Random Access Memory), HDD (Hard Disk Drive), and the like. A computer program is stored in the ROM, RAM or HDD. Each device achieves its function by the microprocessor operating according to the computer program.

Furthermore, part or all of the components constituting each device described above may be configured from one system LSI. A system LSI is an ultra-multifunctional LSI manufactured by integrating multiple components on a single chip. Specifically, it is a computer system that includes a microprocessor, ROM, RAM, etc. . A computer program is stored in the RAM. The system LSI achieves its functions by the microprocessor operating according to the computer program.

Further, the present invention may be the method shown above. Also, the present invention may be a computer program that implements these methods by a computer.

Further, according to the present invention, the computer program may be recorded in a non-transitory computer-readable recording medium such as an HDD, a CD-ROM, a semiconductor memory, or the like. The computer program may be transmitted via an electric communication line, a wireless or wired communication line, a network represented by the Internet, data broadcasting, or the like.
Also, each of the devices described above may be realized by a plurality of computers.

Also, part or all of the functions of the above devices may be provided by cloud computing. That is, part or all of the functions of each device may be realized by the cloud server.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the meaning described above, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

1 Power system 2 Wind power generator 4 Storage battery 6 Management device 51 Communication unit 52 Combined output target value acquisition unit 53 Combined output calculation unit 54 Wind power generator output acquisition unit 55 Storage battery output calculation unit 56 Storage device 57 Storage battery control unit 61 Communication unit 62 Wind power generator output acquisition unit 63 Storage battery output acquisition unit 64 Storage battery remaining amount acquisition unit 65 Synthetic output target value calculation unit 66 Storage device

Claims (7)

A control system for controlling a power generation system including a wind power generator and a storage battery,
When the output of the wind power generator is a predetermined value, the minimum necessary storage battery remaining amount for the combined output of the power generation system to satisfy the following first and second constraints, and the combined output A synthetic output target value calculation unit that calculates a synthetic output target value that is a target value of the synthetic output from the remaining battery level of the storage battery using information indicating the relationship between
First Constraint: Constraints for connecting the power generation system to the grid Second Constraints: Constraints for operating the storage battery
The first constraint conditions include a constraint indicating that the combined output is not to be reduced in a predetermined first time period when power demand increases, and a constraint indicating that the combined output is not reduced in a predetermined second time period when power demand fluctuates. including at least one of a constraint indicating that it should be constant and a constraint indicating that the combined output should not be increased in a predetermined third time period during which power demand decreases;
The control system, wherein the second constraint condition includes a constraint for limiting the remaining battery capacity of the storage battery to a certain range defined by an upper limit value and a lower limit value smaller than the upper limit value. 2. The control system of claim 1, wherein said predetermined value is zero. moreover,
a composite output calculation unit that calculates the composite output that satisfies the first constraint based on the composite output target value calculated by the composite output target value calculation unit;
3. The control according to claim 1, further comprising a storage battery output calculation unit that calculates the output of the storage battery based on the combined output calculated by the combined output calculation unit and the output of the wind power generator. system. 4. The control system according to any one of claims 1 to 3, wherein said first constraint includes a constraint on the amount of change in said combined output per unit time. The control system according to any one of claims 1 to 4 , wherein the first constraint includes a constraint that the power generation system does not receive power from a power system. A control method for controlling a power generation system including a wind power generator and a storage battery,
When the output of the wind power generator is a predetermined value, the minimum necessary storage battery remaining amount for the combined output of the power generation system to satisfy the following first and second constraints, and the combined output a synthetic output target value calculation step of calculating a synthetic output target value, which is a target value of the synthetic output, from the remaining battery level of the storage battery using information indicating the relationship between
First Constraint: Constraints for connecting the power generation system to the grid Second Constraints: Constraints for operating the storage battery
The first constraint conditions include a constraint indicating that the combined output is not to be reduced in a predetermined first time period when power demand increases, and a constraint indicating that the combined output is not reduced in a predetermined second time period when power demand fluctuates. including at least one of a constraint indicating that it should be constant and a constraint indicating that the combined output should not be increased in a predetermined third time period during which power demand decreases;
The control method, wherein the second constraint condition includes a constraint for limiting the remaining battery capacity of the storage battery to a certain range defined by an upper limit value and a lower limit value smaller than the upper limit value. A computer program for causing a computer to function as a control system for controlling a power generation system including a wind power generator and a storage battery,
said computer,
When the output of the wind power generator is a predetermined value, the minimum necessary storage battery remaining amount for the combined output of the power generation system to satisfy the following first and second constraints, and the combined output Using information indicating the relationship between, functioning as a synthetic output target value calculation unit that calculates a synthetic output target value that is the target value of the synthetic output from the remaining battery level of the storage battery,
First Constraint: Constraints for connecting the power generation system to the grid Second Constraints: Constraints for operating the storage battery
The first constraint conditions include a constraint indicating that the combined output is not to be reduced in a predetermined first time period when power demand increases, and a constraint indicating that the combined output is not reduced in a predetermined second time period when power demand fluctuates. including at least one of a constraint indicating that it should be constant and a constraint indicating that the combined output should not be increased in a predetermined third time period during which power demand decreases;
The computer program, wherein the second constraint condition includes a constraint for limiting the remaining battery capacity of the storage battery to a certain range defined by an upper limit value and a lower limit value smaller than the upper limit value.

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