JP7537484B2 - Control system and control method - Google Patents

Description

This disclosure relates to technology for controlling a power storage system connected to a power grid.

For example, selling electricity generated by power generation systems such as solar power generation or wind power generation has been proposed. Patent Document 1 discloses a technology for creating an electricity sales plan to maximize profits from electricity sales.

JP 2015-87886 A

By using a power storage system, it is possible to carry out transactions that include both power purchases and sales. When considering the use of a power storage system, it is important to generate plans for both power purchase and sales transactions. In consideration of the above circumstances, one aspect of the present disclosure aims to efficiently control power purchases and sales using a power storage system.

In order to solve the above problems, a control system according to one embodiment of the present disclosure is a control system that controls a power storage system connected to a power grid, and includes a price acquisition unit that acquires price transitions that represent a time series of predicted electricity market prices, a plan acquisition unit that acquires a trading plan for buying and selling electricity using the power storage system, a revenue analysis unit that calculates revenue when electricity is traded according to the trading plan under the price transitions, and an operation control unit that controls charging and discharging by the power storage system in accordance with the trading plan.

A control method according to one aspect of the present disclosure is a method for controlling a power storage system connected to a power grid, which obtains a price transition representing a time series of predicted electricity market prices, obtains a trading plan for buying and selling electricity using the power storage system, calculates the profit when electricity is traded according to the trading plan under the price transition, and controls charging and discharging by the power storage system according to the trading plan.

FIG. 1 is a block diagram illustrating a configuration of an energy trading system according to a first embodiment. FIG. 2 is a block diagram illustrating a configuration of a control system. FIG. 2 is a block diagram illustrating a functional configuration of the control system. FIG. 13 is a schematic diagram of price transitions. FIG. 1 is a schematic diagram of a trading plan. FIG. 11 is an explanatory diagram of the operation of a profit analysis unit. FIG. 2 is a schematic diagram of an analysis image. 13 is a flowchart of a control process. FIG. 13 is a schematic diagram of price transition in the third embodiment. FIG. 13 is a schematic diagram of a trading plan in the third embodiment. FIG. 13 is a schematic diagram of an analysis image in the third embodiment.

A description of a form for implementing the present disclosure will be given with reference to the drawings. Note that the form described below is an exemplary form that may be envisaged for implementing the present disclosure. Therefore, the scope of the present disclosure is not limited to the form exemplified below.

A: First embodiment Fig. 1 is a block diagram of an energy trading system 100 according to the first embodiment. The energy trading system 100 of the first embodiment is a system that transfers AC power to and from a power grid 200. The power grid 200 is a power distribution system for supplying power generated by a power generation facility (not shown) to consumers such as business facilities or general households.

As illustrated in FIG. 1, the energy trading system 100 includes a power storage system 10 and a control system 20. The power storage system 10 and the control system 20 can communicate with each other via a communication network (not shown), such as a dedicated line.

The energy storage system 10 is connected to the power grid 200. The energy storage system 10 includes an energy storage device 11 that can be charged and discharged. The energy storage device 11 is a storage battery that is charged with power supplied from the power grid 200 and supplies the power generated by discharging to the power grid 200. The control system 20 is a computer system for controlling the energy storage system 10. Specifically, the control system 20 instructs the energy storage system 10 to discharge and charge.

FIG. 2 is a block diagram illustrating an example of the configuration of the control system 20. As illustrated in FIG. 2, the control system 20 includes a control device 21, a storage device 22, a communication device 23, an operation device 24, and a display device 25. The control system 20 may be realized by a single device, or may be realized by multiple devices configured separately from each other. A part or all of the control system 20 may be mounted on the power storage system 10.

The control device 21 is composed of one or more processors that control each element of the control system 20. Specifically, the control device 21 is composed of one or more types of processors, such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or an ASIC (Application Specific Integrated Circuit).

The storage device 22 is a single or multiple memories that store the programs executed by the control device 21 and the data used by the control device 21. The storage device 22 is configured with a known recording medium, such as a magnetic recording medium or a semiconductor recording medium. The storage device 22 may be configured with a combination of multiple types of recording media. A portable recording medium that can be attached to and detached from the control system 20 may be used as the storage device 22.

The communication device 23 communicates with an external device via a wired or wireless connection. Specifically, the communication device 23 communicates with the power storage system 10. For example, the communication device 23 transmits a charge or discharge command to the power storage system 10. Note that the communication device 23, which is separate from the control system 20, may be connected to the control system 20 via a wired or wireless connection.

The operation device 24 is, for example, an input device that accepts instructions from a user of the control system 20. The operation device 24 is, for example, an operator operated by the user, or a touch panel that detects contact by the user. The display device 25 displays images under the control of the control device 21. The display device 25 is, for example, a display panel such as a liquid crystal display panel or an organic EL (Electroluminescence) panel. Note that the operation device 24 or the display device 25, which are separate from the control system 20, may be connected to the control system 20 by wire or wirelessly.

Figure 3 is a block diagram illustrating the functional configuration of the control system 20. The control device 21 executes a program stored in the storage device 22 to realize multiple functions (price acquisition unit 31, plan acquisition unit 32, revenue analysis unit 33, display control unit 34, and operation control unit 35) for controlling the energy storage system 10.

The price acquisition unit 31 acquires multiple price transitions P. FIG. 4 is a schematic diagram of the price transitions P (P1, P2, ...). Each price transition P is data representing a time series of predicted prices of the electricity market price. The predicted price is a predicted value of the price for buying and selling electricity. As illustrated in FIG. 4, the price transition P is a time series of predicted prices for each time. Specifically, the price transition P includes predicted prices for a total of 48 times that divide a day (0:00-24:00) into 30-minute intervals. The predicted price at each time is set individually for each price transition P. Therefore, the predicted price at one time in multiple price transitions P (P1, P2, ...) may differ. However, the predicted price may be partially common between multiple price transitions P.

The price acquisition unit 31 of the first embodiment receives the price transition P distributed from a price prediction system (not shown) by the communication device 23. The price prediction system is a computer system that predicts the electricity market price using various information such as meteorological information or calendar information. The price acquisition unit 31 itself may generate the price transition P by predicting the electricity market price. The price acquisition unit 31 may also accept input of the price transition P from a user to the operation device 24. The price acquisition unit 31 may acquire the price transition P by reading data stored in the storage device 22. As can be understood from the above explanation, "acquisition" of the price transition P includes various operations such as receiving, generating, accepting and reading the price transition P.

The plan acquisition unit 32 in FIG. 3 acquires multiple trading plans Q. FIG. 5 is a schematic diagram of the trading plans Q (Q1, Q2, ...). Each trading plan Q is data representing a plan for buying and selling electricity using the energy storage system 10. As illustrated in FIG. 5, the trading plan Q specifies the time of buying and selling electricity using the energy storage system 10. Specifically, buying or selling electricity is specified for one of multiple times at which the expected price is set in the price transition P. The time of buying or selling electricity is set individually for each trading plan Q. Therefore, the time of buying or selling electricity may differ for each trading plan Q. However, the time of either buying or selling electricity may be common between multiple trading plans Q (Q1, Q2, ...).

The plan acquisition unit 32 of the first embodiment generates a trading plan Q for all combinations of times for selecting each of the times for buying and selling electricity from, for example, multiple times in a day. The plan acquisition unit 32 may receive input of the trading plan Q from the operation device 24 from the user. For example, the plan acquisition unit 32 receives designation of each of the times for buying and selling electricity from the user. The plan acquisition unit 32 may receive the trading plan Q distributed from an external system via the communication device 23. The plan acquisition unit 32 may acquire the trading plan Q by reading data stored in the storage device 22. As can be understood from the above explanation, "acquisition" of the trading plan Q includes various operations such as generating, accepting, receiving, and reading the trading plan Q.

The revenue analysis unit 33 in FIG. 3 calculates revenue R using each price transition P acquired by the price acquisition unit 31 and each trading plan Q acquired by the plan acquisition unit 32. FIG. 6 is an explanatory diagram of the operation of the revenue analysis unit 33. Revenue R is the amount of profit when trading electricity according to trading plan Q under price transition P. Specifically, revenue R is the difference between the electricity selling price X and the electricity purchasing price Y (R=X-Y). The electricity selling price X is the predicted price at the time of electricity selling specified in trading plan Q, among the multiple predicted prices specified in price transition P. On the other hand, the electricity purchasing price Y is the predicted price at the time of electricity purchasing specified in trading plan Q, among the multiple predicted prices specified in price transition P.

The revenue analysis unit 33 in the first embodiment calculates revenue R for each combination of multiple price transitions P (P1, P2, ...) and multiple trading plans Q (Q1, Q2, ...). Specifically, the revenue analysis unit 33 calculates revenue R for all combinations of multiple price transitions P (P1, P2, ...) and multiple trading plans Q (Q1, Q2, ...). In other words, multiple revenues R corresponding to different combinations of price transitions P and trading plans Q are calculated by the revenue analysis unit 33.

The display control unit 34 in FIG. 3 displays an image (hereinafter referred to as "analysis image G") showing the results of the analysis by the revenue analysis unit 33 on the display device 25. FIG. 7 is a schematic diagram of the analysis image G. As illustrated in FIG. 7, the analysis image G is an image (scatter plot) showing the correlation between the power purchase time and the revenue R. Note that, in practice, the revenue R is calculated for each different combination of the power selling time and the power purchasing time, but in the analysis image G in FIG. 7, the revenue R in each of multiple cases in which the power purchasing time is changed under a specific power selling time is illustrated for convenience.

As shown in FIG. 7, in the analysis image G, for each of the multiple power purchase times represented on the horizontal axis, a point image Gp corresponding to multiple revenues R corresponding to different price transitions P is drawn. The maximum value Rmax, average value Rave, and minimum value Rmin of the multiple revenues R are calculated for each power purchase time.

The display control unit 34 displays the maximum value curve Cmax, the average value curve Cave, and the minimum value curve Cmin on the display device 25. The maximum value curve Cmax is a curve that approximates the time series of maximum values Rmax across multiple power purchase times. The average value curve Cave is a curve that approximates the time series of average values Rave across multiple power purchase times. The minimum value curve Cmin is a curve that approximates the time series of minimum values Rmin across multiple power purchase times.

As can be understood from the above explanation, by visually checking the analysis image G, the user can visually grasp the trend of increase or decrease in revenue R relative to the power purchase time. For example, the user can grasp the power purchase time at which the maximum value Rmax or the average value Rave is at its maximum, or the power purchase time at which the minimum value Rmin of revenue R is a positive number.

In the above explanation, an analysis image G showing the revenue R in each case where the power purchase time is changed under a specific power sale time is exemplified, but the analysis image G showing the revenue R in each case where the power sale time is changed under a specific power purchase time is also displayed on the display device 25.

The revenue analysis unit 33 in the first embodiment selects one of a plurality of trading plans Q (hereinafter referred to as the "optimal plan Q") according to the results of analyzing the revenue R. Specifically, the revenue analysis unit 33 selects the trading plan Q that satisfies a predetermined condition (hereinafter referred to as the "extraction condition") as the optimal plan Q.

The extraction conditions are set, for example, in response to an instruction from a user to the operation device 24. For example, one or more of the multiple extraction conditions stored in the storage device 22 are selected in response to an instruction from the user. Specifically, one or more of the multiple extraction conditions, such as a trading plan Q with a maximum value Rmax of the profit R, a trading plan Q with a maximum average value Rave of the profit R, or a trading plan Q with a positive minimum value Rmin, are applied to the selection of the optimal plan Q.

The operation control unit 35 in FIG. 3 controls charging and discharging by the energy storage system 10 according to the transaction plan Q. The operation control unit 35 in the first embodiment controls the energy storage system 10 according to the optimal plan Q selected by the revenue analysis unit 33. Specifically, the operation control unit 35 transmits a charging command from the communication device 23 to the energy storage system 10 at the power purchase time specified in the optimal plan Q. The energy storage system 10 that receives a charging command from the control system 20 charges the energy storage device 11 with power supplied from the power grid 200. In addition, the operation control unit 35 transmits a discharging command from the communication device 23 to the energy storage system 10 at the power selling time specified in the optimal plan Q. The energy storage system 10 that receives a discharging command from the control system 20 supplies power to the power grid 200 by discharging the energy storage device 11.

Figure 8 is a flowchart of the process (hereinafter referred to as "control process") executed by the control device 21. For example, the control process is started in response to an instruction from a user via the operation device 24. The control process is an example of a "control method."

When the control process is started, the control device 21 (price acquisition unit 31) acquires multiple price transitions P (S1). In addition, the control device 21 (plan acquisition unit 32) acquires multiple trading plans Q (S2). Note that the order of acquiring the price transitions P (S1) and acquiring the trading plans Q (S2) may be reversed.

The control device 21 (profit analysis unit 33) calculates multiple profits R for different combinations of price transition P and trading plan Q (S3). The control device 21 (display control unit 34) displays the analysis image G of FIG. 7, which represents the results of analyzing the multiple profits R, on the display device 25 (S4). The control device 21 (profit analysis unit 33) also selects an optimal plan Q from the multiple trading plans Q according to the results of analyzing the profit R (S5). The control device 21 (operation control unit 35) controls the energy storage system 10 according to the optimal plan Q (S6). Note that the selection of the optimal plan Q (S5) may be performed before the display of the analysis image G (S4).

As described above, in the first embodiment, the profit R is calculated when electricity is purchased and sold according to the trading plan Q under the price transition P. Therefore, while analyzing the profit R from electricity purchases (charging) and electricity sales (discharging) using the energy storage system 10, it is possible to effectively control electricity purchases and sales using the energy storage system 10. In particular, in the first embodiment, the profit R is calculated for each combination of each of the multiple price transitions P and each of the multiple trading plans Q, so that it is possible to compare the profit R for multiple cases in which the price transition P or trading plan Q is different.

In addition, in the first embodiment, one of the multiple trading plans Q is selected according to the multiple profits R, so the user does not need to manually select the trading plan Q (optimal plan Q). This reduces the burden on the user. However, the user who has checked the analysis image G may select one of the multiple trading plans Q as the optimal plan Q by operating the operation device 24. In other words, the profit analysis unit 33 accepts the selection of the optimal plan Q by the user.

B: Second embodiment A second embodiment of the present disclosure will be described. Note that, for elements having the same functions as those in the first embodiment in each of the following exemplary aspects, the same reference numerals as those in the first embodiment will be used, and detailed descriptions of each will be omitted as appropriate.

The revenue analysis unit 33 of the second embodiment, like the first embodiment, calculates revenue R for each combination of price transition P and trading plan Q. For each of the multiple trading plans Q, revenue R is calculated for each price transition P. In other words, multiple revenues R corresponding to different price transitions P are calculated for each trading plan Q.

The profit analysis unit 33 of the second embodiment calculates an index (hereinafter referred to as an “evaluation index”) Z for selecting an optimal plan Q from a plurality of trading plans Q for each trading plan Q. The evaluation index Z is expressed by the following formula (1).
Z = a μ - b σ (1)

The symbol μ in formula (1) is the average value of multiple profits R corresponding to one trading plan Q. On the other hand, the symbol σ in formula (1) is the dispersion indicating the degree of dispersion of multiple profits R corresponding to one trading plan Q. Specifically, the standard deviation or variance of multiple profits R is calculated as the dispersion σ. The constants a and b in formula (1) are predetermined positive numbers that are set in advance.

As can be understood from the above explanation, the revenue analysis unit 33 of the second embodiment calculates, for each of the multiple trading plans Q, an evaluation index Z according to the average value μ of the multiple revenues R corresponding to the trading plan Q and the dispersion degree σ of the multiple revenues R.

The average value μ corresponding to a trading plan Q means the expected value (return) of the profit R in the trading plan Q. The larger the average value μ (i.e., the larger the return), the larger the evaluation index Z. On the other hand, the dispersion σ in formula (1) corresponds to the risk in the trading plan Q. The larger the dispersion σ (i.e., the larger the risk), the smaller the evaluation index Z. Taking the above tendencies into consideration, the profit analysis unit 33 of the second embodiment selects one trading plan Q with the maximum evaluation index Z from among multiple trading plans Q as the optimal plan Q. In other words, the trading plan Q with the large expected value of profit R while reducing risk is selected as the optimal plan Q.

In the second embodiment, the same effect as in the first embodiment is achieved. In addition, in the second embodiment, an optimal plan Q is selected using an evaluation index Z according to the average value μ and dispersion σ of multiple profits R. That is, a trading plan Q is selected taking into account not only the average value μ (expected value = return) of profits R but also the dispersion σ (risk) of profits R. Therefore, effective trading that takes into account return and risk is possible.

C: Third embodiment In the first embodiment, one electricity market is assumed, but in reality, a plurality of electricity markets exist. The third embodiment is a form assuming electricity trading in a plurality of electricity markets.

The multiple electricity markets include, for example, a supply and demand adjustment market and a wholesale electricity market. The supply and demand adjustment market is a market for trading adjustment power that balances the demand and supply of electricity, and includes, for example, a tertiary adjustment power (1) market and a tertiary adjustment power (2) market. On the other hand, the wholesale electricity market is a market for the wholesale of electricity, and includes, for example, a spot market and an hour-ahead market.

The trading conditions differ for each electricity market. The trading conditions are, for example, the electricity market price, the presence or absence of power purchase, or the timing (cycle) of the agreement. For example, in the tertiary adjustment capacity (1) market of the supply and demand adjustment market, electricity transactions are agreed every Tuesday for every 30 minutes from Saturday to Friday of the following week. In the tertiary adjustment capacity (2) market of the supply and demand adjustment market, electricity transactions are agreed every 30 minutes for the following day at 14:00 every day. In the spot market of the wholesale electricity market, electricity transactions are agreed every 30 minutes for the following day at 10:00 every day. In the time-ahead market of the wholesale electricity market, electricity transactions for the next 30 minutes are agreed every hour. As described above, the timing of agreement for the trading period differs for each electricity market. Therefore, in the third embodiment, the control process is executed at the earliest agreement time among the multiple electricity markets (specifically, before the agreement in the tertiary adjustment capacity (1) market).

The price acquisition unit 31 of the third embodiment acquires multiple price transitions P for each electricity market (S1). FIG. 9 is a schematic diagram of the price transitions P for each electricity market. In FIG. 9, price transitions P are illustrated for the supply and demand adjustment market (tertiary adjustment capacity (1) market, tertiary adjustment capacity (2) market) and the wholesale electricity market (spot market, hour-ahead market). Note that while only one price transition P is illustrated for each electricity market in FIG. 9 for convenience, the price acquisition unit 31 of the third embodiment acquires multiple price transitions P (P1, P2, ...) for each electricity market, in which the predicted prices for each time differ.

As illustrated in FIG. 9, the price transition P in the supply and demand adjustment market (the tertiary adjustment capacity (1) market, the tertiary adjustment capacity (2) market) includes a time series of predicted prices for each of the capacity price (kW) and the energy price (kWh). The capacity price is the price of electricity steadily secured as electricity dedicated to the adjustment capacity, and is specified in units of power value (kW). On the other hand, the energy price is the price of the adjustment capacity requested by commands that are generated sequentially in parallel with the actual electricity transactions, and is specified in units of energy (kWh). The predicted price in the supply and demand adjustment market is the sum of the capacity price and the energy price. As can be understood from the above explanation, the price transition P in the supply and demand adjustment market represents a time series of predicted prices according to the capacity price and the energy price.

The plan acquisition unit 32 of the third embodiment acquires multiple trading plans Q (Q1, Q2, ...) in the same manner as in the first embodiment (S2). FIG. 10 is a schematic diagram of multiple trading plans Q (Q1, Q2, ...) acquired by the plan acquisition unit 32 of the third embodiment. As illustrated in FIG. 10, the trading plan Q of the third embodiment specifies one of multiple electricity markets as the trading market for each of the power purchase and the power sale. That is, the trading plan Q specifies the transaction content (power purchase/power sale) and the trading market for each time.

Among the multiple electricity markets, there are some where only electricity buying or selling is permitted. For example, in the supply and demand adjustment markets (tertiary adjustment capacity (1) market, tertiary adjustment capacity (2) market), only electricity selling is permitted and electricity buying does not occur. Therefore, for the supply and demand adjustment market, only electricity selling is specified in the trading plan Q. In other words, the supply and demand adjustment market is not specified as a trading market for electricity buying in the trading plan Q. As can be understood from the above explanation, the plan acquisition unit 32 acquires the trading plan Q within the range of the trading conditions for each electricity market.

The revenue analysis unit 33 calculates revenue R for each combination of each of the multiple price transitions P for each electricity market and each of the multiple trading plans Q (S3). Revenue R is a numerical value obtained by summing the differences between the electricity selling price X and the electricity purchasing price Y across the multiple electricity markets (R = Σ(X-Y)). The electricity selling price X at a time when electricity selling in a specific electricity market is specified in the trading plan Q is the predicted price specified for that time in the price transition P of that electricity market. On the other hand, the electricity purchasing price Y at a time when electricity purchasing in a specific electricity market is specified in the trading plan Q is the predicted price specified for that time in the price transition P of that electricity market. However, since electricity purchases do not occur in the supply and demand adjustment market, the electricity purchasing price Y is calculated only for the wholesale electricity market.

The profit analysis unit 33 selects the trading plan Q with the maximum profit R from among the multiple trading plans Q as the optimal plan Q (S5). That is, the profit analysis unit 33 in the third embodiment selects the optimal plan Q from the multiple trading plans Q with the extraction condition that the profit R is maximized. However, the extraction condition for the optimal plan Q is not limited to the above example. For example, as in the first embodiment, one or more of the multiple extraction conditions such as the trading plan Q with the maximum value Rmax of the profit R, the trading plan Q with the maximum average value Rave of the profit R, or the trading plan Q with the minimum value Rmin being a positive number may be applied to the selection of the optimal plan Q.

The operation (S6) in which the operation control unit 35 controls the energy storage system 10 according to the optimal plan Q selected by the revenue analysis unit 33 is the same as in the first embodiment. That is, the operation control unit 35 transmits a charging command from the communication device 23 to the energy storage system 10 at the power purchase time specified in the optimal plan Q, and transmits a discharging command from the communication device 23 to the energy storage system 10 at the power sale time specified in the optimal plan Q.

The display control unit 34 displays an analysis image G showing the results of the analysis by the profit analysis unit 33 on the display device 25 (S4). FIG. 11 is a schematic diagram of the analysis image G in the third embodiment. As illustrated in FIG. 11, the analysis image G is an image (scatter plot) showing the correlation between the power selling time and the profit r. The profit R described above is the total profit when power trading is carried out in multiple power markets under the trading plan Q, while the profit r is the profit for each power market. In other words, the profit r is calculated for each combination of the power selling time, the power buying time, and the power market. However, in FIG. 11, the profit r in each of multiple cases in which the power selling time is changed while the power buying time is fixed in a specific power market is illustrated for convenience.

As illustrated in FIG. 11, for each of the multiple electricity selling times represented on the horizontal axis, a dot image Gp corresponding to multiple profits r corresponding to different price transitions P is displayed in a different display mode for each electricity market. That is, a dot image Gp corresponding to multiple profits r corresponding to different price transitions P in one electricity market is displayed in a different display mode for each electricity market. As can be understood from the above explanation, the display control unit 34 of the third embodiment displays the profits r when trading according to the trading plan Q in each of the multiple electricity markets on the display device 25 in a different display mode for each electricity market.

The "display mode" of the dot image Gp refers to the characteristics of the image that can be visually distinguished by the user. For example, the display color, pattern (design), size, or shape of the dot image Gp are all included in the concept of the "display mode." The display color is defined by the hue (tone), saturation, or brightness (gradation).

By visually checking the analysis image G described above, users can confirm the temporal changes in the revenue r for each electricity market. For example, depending on the vertical position of the multiple dot images Gp displayed at a specific selling time for one electricity market, users can grasp the level of revenue r (return) when selling electricity at that time in that electricity market. In addition, depending on the range in the vertical axis direction of the multiple dot images Gp displayed at a specific selling time for one electricity market, users can grasp the variance (risk) of revenue r when selling electricity at that time in that electricity market.

The third embodiment achieves the same effect as the first embodiment. Moreover, in the third embodiment, the price transition P is obtained for each electricity market, and the trading plan Q includes the designation of the electricity market for each transaction (electricity purchase/electricity sale). Therefore, it is possible to control the electricity purchase and sale using the energy storage system 10 while analyzing the profits from electricity purchase and sale in multiple electricity markets. In particular, in the third embodiment, the profit r for each electricity market is displayed in a different display mode, so that the user can visually and intuitively grasp the profit r for each electricity market.

In addition, in the third embodiment, the revenue R is calculated taking into account both the capacity price (kW) and the power price (kWh) in the supply and demand adjustment market. Therefore, the energy storage system 10 can be controlled so as to realize effective revenue according to the actual situation in the supply and demand adjustment market.

D: Fourth embodiment In the third embodiment, the predicted price at the price transition P in the supply and demand adjustment market is exemplified as the total value of the capacity price and the energy price. However, power trading based on the energy price occurs depending on the degree of tightness of supply and demand in the power system 200. Therefore, there are cases where power trading based on the energy price does not actually occur. In other words, the predicted price in the supply and demand adjustment market can fluctuate between the price of only the capacity price and the total price of the capacity price and the energy price.

In consideration of the above circumstances, the price acquisition unit 31 in the fourth embodiment calculates the predicted price E in the supply and demand adjustment market by the following formula (2) that applies the capacity price e (kW) and the energy price e (kWh). The predicted price E is calculated for each hour.
E = e1 + ρ · e2 ... (2)

The coefficient ρ in formula (2) is an index of the possibility that an energy transaction based on the energy price e2 will occur, and is set to a positive number equal to or less than 1. The coefficient ρ is set experimentally or statistically, for example, according to the past performance of energy transactions based on the energy price. Specifically, the coefficient ρ is set according to the probability that an energy transaction based on the energy price will occur. That is, when the probability of an energy transaction based on the energy price occurring is high, the coefficient ρ is set to a value close to 1, and when the probability of an energy transaction based on the energy price occurring is low, the coefficient ρ is set to a value close to 0. Note that since the frequency of an energy transaction based on the energy price occurring varies depending on the time period, the coefficient ρ may be set separately for each time period.

The fourth embodiment also achieves the same effects as the first and third embodiments. In addition, in the fourth embodiment, the optimal plan Q can be appropriately selected, taking into account the possibility that electricity trading based on the energy price does not occur.

E: Modifications Specific modifications to the above-mentioned embodiments are illustrated below. Two or more embodiments selected from the following examples may be combined as appropriate within the scope of not being mutually contradictory.

(1) In each of the above embodiments, the price acquisition unit 31 acquires multiple price transitions P, but a configuration in which the price acquisition unit 31 acquires only one price transition P is also envisioned. In addition, in each of the above embodiments, the plan acquisition unit 32 acquires multiple trading plans Q, but a configuration in which the plan acquisition unit 32 acquires only one trading plan Q is also envisioned.

(2) In each of the above-described embodiments, the control system 20 includes the display control unit 34, but the display control unit 34 may be omitted. In other words, the display of the analysis image G illustrated in FIG. 7 or FIG. 11 may be omitted.

(3) In each of the above embodiments, the operation control unit 35 transmits a command to charge or discharge according to the trading plan Q to the energy storage system 10, but the method in which the operation control unit 35 controls the operation of the energy storage system 10 is not limited to the above examples. For example, the operation control unit 35 may transmit the trading plan Q to the energy storage system 10 from the communication device 23. The energy storage system 10 executes charging and discharging of the energy storage device 11 according to the trading plan Q. Note that a user who has learned the results of the analysis by the revenue analysis unit 33 (optimal plan Q) may manually operate the energy storage system 10. In other words, the operation control unit 35 may be omitted.

(4) In the third embodiment assuming multiple electricity markets, after the initial optimal plan Q is selected by the control process, the optimal plan Q may be updated as needed. For example, among the multiple electricity markets illustrated in the third embodiment, the tertiary adjustment capacity (1) market is the first to be contracted for actual electricity trading. Therefore, the optimal plan Q may be re-set by the control device 21 executing a control process targeting other electricity markets at an appropriate time between when the optimal plan Q is set by the initial control process before the contract in the tertiary adjustment capacity (1) market and before the start of actual electricity trading.

(5) As described above, the functions of the control system 20 according to each of the above embodiments are realized by the cooperation of one or more processors constituting the control device 21 and the program stored in the storage device 22. The above-mentioned programs can be provided in a form stored in a computer-readable recording medium and installed in the computer. The recording medium is, for example, a non-transitory recording medium, and a good example is an optical recording medium (optical disk) such as a CD-ROM, but also includes any known type of recording medium such as a semiconductor recording medium or a magnetic recording medium. Note that a non-transitory recording medium includes any recording medium except for a transient, propagating signal, and does not exclude volatile recording media. In addition, in a configuration in which a distribution device distributes a program via a communication network, the recording medium that stores the program in the distribution device corresponds to the non-transitory recording medium described above.

F: Supplementary Note From the above-described exemplary embodiments, the following configurations, for example, can be understood.

A control system according to one aspect (aspect 1) of the present disclosure is a control system for controlling a power storage system connected to a power grid, and includes a price acquisition unit that acquires price transitions representing a time series of predicted electricity market prices, a plan acquisition unit that acquires a trading plan for buying and selling electricity using the power storage system, a profit analysis unit that calculates profits when electricity is traded according to the trading plan under the price transitions, and an operation control unit that controls charging and discharging by the power storage system according to the trading plan. According to the above aspect, it is possible to effectively control buying and selling of electricity using the power storage system while analyzing profits from buying (charging) and selling (discharging) electricity using the power storage system.

In a specific example (Aspect 2) of Aspect 1, the price acquisition unit acquires a plurality of price transitions, the plan acquisition unit acquires a plurality of trading plans, and the profit analysis unit calculates profit for each combination of each of the plurality of price transitions and each of the plurality of trading plans. According to the above embodiment, profit is calculated for each combination of each of the plurality of price transitions and each of the plurality of trading plans, so that profits can be compared for multiple cases where price transitions or trading plans are different.

In a specific example (Aspect 3) of Aspect 2, the profit analysis unit calculates multiple profits corresponding to different combinations of the price transition and the trading plan, and selects one of the multiple trading plans according to the multiple profits, and the operation control unit controls the energy storage system according to the selected trading plan. According to the above embodiment, one of the multiple trading plans is selected according to the multiple profits, so that the user does not need to manually select a trading plan. Therefore, the burden on the user can be reduced.

In a specific example (Aspect 4) of Aspect 3, the profit analysis unit, in selecting the trading plan, calculates an evaluation index for each of a plurality of trading plans according to the average value of a plurality of profits corresponding to the trading plan and the dispersion of the plurality of profits, and selects the trading plan according to the evaluation index. In the above embodiment, a trading plan is selected taking into account not only the average value of profits (expected value = return) but also the dispersion of profits (risk), enabling effective trading that takes into account return and risk.

In a specific example (Aspect 5) of any of Aspects 1 to 4, the price acquisition unit acquires the price transition for each of a plurality of electricity markets, and the trading plan includes a designation of one of the plurality of electricity markets for the electricity purchase and the electricity sale. In the above embodiment, the electricity purchase and sale using the electricity storage system can be controlled while analyzing the profits from the electricity purchase and sale in a plurality of electricity markets.

In a specific example (Aspect 6) of Aspect 5, the multiple electricity markets include a balancing market, and the price transition in the balancing market represents a time series of predicted prices according to the capacity price and the energy price. In the above embodiment, the revenue is calculated taking into account both the capacity price (kW) and the energy price (kWh) in the balancing market. Therefore, the energy storage system can be controlled to realize effective revenue according to the actual situation of the balancing market.

In a specific example (aspect 7) of aspect 5 or aspect 6, a display control unit is provided that displays on a display device the profits generated when trading is performed according to the trading plan in each of the multiple electricity markets in a display mode that differs for each electricity market. According to the above aspect, a user can visually and intuitively grasp the profits for each electricity market.

A control method according to one aspect (aspect 8) of the present disclosure is a method for controlling a power storage system connected to a power grid, which obtains a price transition representing a time series of predicted electricity market prices, obtains a trading plan for buying and selling electricity using the power storage system, calculates the profit when electricity is traded according to the trading plan under the price transition, and controls charging and discharging by the power storage system according to the trading plan.

100...Electricity trading system, 200...Power system, 10...Energy storage system, 11...Energy storage device, 20...Control system, 21...Control device, 22...Storage device, 23...Communication device, 24...Operation device, 25...Display device, 31...Price acquisition unit, 32...Plan acquisition unit, 33...Revenue analysis unit, 34...Display control unit, 35...Operation control unit, P...Price transition, Q...Trading plan, G...Analysis image.

Claims (5)

A control system for controlling a power storage system connected to a power grid,
a price acquisition unit for acquiring a plurality of price transitions representing a time series of predicted electricity market prices;
a plan acquisition unit that acquires a plurality of trading plans for power purchases and sales using the power storage system;
a profit analysis unit that calculates a plurality of profits when trading electricity according to a trading plan under each of the plurality of price transitions for different combinations of the plurality of price transitions and the plurality of trading plans, and selects one of the plurality of trading plans according to the plurality of profits ;
an operation control unit that controls charging and discharging by the power storage system in accordance with a trading plan selected by the profit analysis unit ;
The profit analysis unit, in selecting the trading plan,
For each of the plurality of trading plans, an evaluation index is calculated according to an average value of a plurality of profits corresponding to the trading plan and a dispersion degree of the plurality of profits, and the trading plan is selected according to the evaluation index.
Control system. A control system for controlling a power storage system connected to a power grid,
a price acquisition unit that acquires a plurality of price transitions representing a time series of predicted electricity market prices for each electricity market ;
a plan acquisition unit that acquires a plurality of trading plans for the power purchase and sale using the power storage system for each of the power markets ;
a profit analysis unit that calculates , for each of the electricity markets, a plurality of profits when trading electricity according to the trading plan under each of the price transitions for different combinations of the plurality of price transitions and the plurality of trading plans;
an operation control unit that controls charging and discharging by the power storage system in accordance with the trading plan ;
a display control unit that displays a time series of maximum values, average values, and minimum values of the plurality of revenues calculated for each of the electricity markets on a display device in a display mode that differs for each of the electricity markets;
A control system comprising: The electricity market includes a balancing market;
The control system of claim 2 , wherein the price transition in the balancing market represents a time series of predicted prices according to a capacity price and an energy price. A method for controlling a power storage system connected to a power grid, comprising:
Obtaining a plurality of price transitions representing a time series of forecasted electricity market prices;
acquiring a plurality of trading plans for buying and selling electricity using the electricity storage system;
calculating a plurality of profits when trading electricity according to the trading plan under each of the plurality of price transitions for different combinations of the plurality of price transitions and the plurality of trading plans, and selecting one of the plurality of trading plans according to the plurality of profits ;
Controlling charging and discharging of the energy storage system in accordance with the selected trading plan ;
In selecting the trading plan,
For each of the plurality of trading plans, an evaluation index is calculated according to an average value of a plurality of profits corresponding to the trading plan and a dispersion degree of the plurality of profits, and the trading plan is selected according to the evaluation index.
A control method implemented by a computer system. A method for controlling a power storage system connected to a power grid, comprising:
Obtaining multiple price transitions representing a time series of predicted electricity market prices for each electricity market ;
acquiring a plurality of trading plans for the purchase and sale of electricity using the energy storage system for each of the electricity markets ;
calculating , for each of the electricity markets, a plurality of revenues in a case where electricity is traded according to the trading plan under each of the price transitions for each different combination of the plurality of price transitions and each of the plurality of trading plans;
Controlling charging and discharging of the power storage system in accordance with the trading plan ;
A time series of the maximum, average and minimum values of the plurality of profits calculated for each of the electricity markets is displayed on a display device in a display mode different for each of the electricity markets.
A control method implemented by a computer system.

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