Control method, control system, and program for power storage device

Abstract

Make effective use of the power storage device. [Solution] The control system 30 includes an information acquisition unit 51 that acquires the health H(t) of the storage device at a target time within the operation period, and an arithmetic processing unit 52 that calculates a second value in accordance with the health H(t) of the storage device so that the capacity degradation of the storage device expected at the end of the operation period does not exceed an allowable value when the number of operation cycles of the storage device increases from a first value to a second value at the target time.

Description

[Technical Field]

[0001] The present disclosure relates to a technique for controlling a power storage device. [Background technology]

[0002] Technologies for transferring power between a power grid and a power storage device by discharging and charging have been proposed. For example, Patent Document 1 discloses a configuration for controlling the power discharged and charged by each storage battery system so that deterioration is uniform across multiple storage battery systems. Patent Document 2 discloses a configuration for calculating an integrated capacity based on data on the capacity maintenance rate until the end of the storage battery's life and the rated capacity of the storage battery, and determining a charge control voltage based on the integrated capacity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 186659 [Patent Document 2] International Publication No. 2019 / 016998 Summary of the Invention [Problem to be solved by the invention]

[0004] The state of health (SOH) of a power storage device deteriorates over time during operation. When designing a power storage device, it is assumed that the power storage device will be operated so that the SOH reaches a predetermined allowable value at the end of a predetermined operation period. However, for example, the number of operation cycles may be reduced in order to ensure a margin in the state of health of the power storage device, and as a result, the operation period may actually end with the state of health still sufficiently close to the allowable value. If the power storage device can be utilized more effectively during the operation period, there is a possibility that further revenue can be expected from the exchange of power with the power grid. Taking the above circumstances into consideration, one aspect of the present disclosure aims to effectively utilize a power storage device. [Means for solving the problem]

[0005] In order to solve the above problems, a control method for a storage device according to one embodiment of the present disclosure includes a control system that obtains the health of the storage device at a target time point within an operation period, and calculates the second value according to the health of the storage device so that when the number of operation cycles of the storage device increases from a first value to a second value at the target time point, the capacity degradation of the storage device expected at the end of the operation period does not exceed an allowable value.

[0006] A control system according to one embodiment of the present disclosure includes an information acquisition unit that acquires the health of a storage device at a target time within an operation period, and an arithmetic processing unit that calculates the second value based on the health of the storage device so that when the number of operation cycles of the storage device increases from a first value to a second value at the target time, the capacity degradation of the storage device expected at the end of the operation period does not exceed an allowable value.

[0007] A program according to one embodiment of the present disclosure causes a computer system to function as an information acquisition unit that acquires the health of a storage device at a target time point within an operation period, and an arithmetic processing unit that calculates the second value based on the health of the storage device so that the capacity degradation of the storage device expected at the end of the operation period does not exceed an allowable value when the number of operation cycles of the storage device increases from a first value to a second value at the target time point. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram illustrating a configuration of a power system according to a first embodiment. [Figure 2] FIG. 1 is a block diagram illustrating a configuration of a control system. [Figure 3] This shows the change over time in the state of health (SOH) of the storage battery device. [Figure 4] FIG. 10 is an explanatory diagram regarding the time variation of the total number of cycles M and the state of charge (SOC). [Figure 5]FIG. 2 is a block diagram illustrating an example of the functional configuration of the control system. [Figure 6] FIG. 10 is a schematic diagram of a reference image G1. [Figure 7] 10 is a flowchart of a management process. [Figure 8] 10 is a graph showing the relationship between the number of operation cycles N and the ratio α(N) in the second embodiment. [Figure 9] 10 is a flowchart of a management process in the second embodiment. [Figure 10] 10 is a flowchart of a management process according to a third embodiment. [Figure 11] FIG. 10 is a schematic diagram of a reference image G2. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The following description of an embodiment of the present disclosure will be given with reference to the accompanying drawings. The embodiment described below is an exemplary embodiment that may be implemented in the present disclosure. Therefore, the scope of the present disclosure is not limited to the embodiment described below.

[0010] 1. First embodiment 1 is a block diagram illustrating the configuration of a power system 100 according to a first embodiment of the present disclosure. The power system 100 is a system that exchanges electric power (AC power) with a power grid 10. The power grid 10 is, for example, a distribution system or a transmission system that supplies electric power generated by a power generation facility (not shown) such as a thermal power plant or a nuclear power plant to consumers such as business facilities or ordinary households.

[0011] 1 , the power system 100 includes a power storage system 20 and a control system 30. The power storage system 20 is a power facility that is capable of discharging (i.e., supplying power to the power grid 10) and charging (receiving power from the power grid 10). The power system 100 may include multiple power storage systems 20. In a configuration in which the power system 100 includes multiple power storage systems 20, the following exemplary configuration and operation are adopted for each power storage system 20.

[0012] The power storage system 20 includes a power storage device 21, an adjustment device 22, and a transformer device 23. The power storage device 21 is a system storage battery that discharges and charges DC power. Any type of power storage device 21 may be used, but examples of the power storage device 21 include secondary batteries such as lithium-ion batteries or sodium-sulfur batteries. Note that the power storage device 21 may be composed of multiple storage batteries.

[0013] The adjusting device 22 is a PCS (Power Conditioning System) that controls discharging and charging of the power storage device 21. Specifically, the adjusting device 22 is a power conversion device that converts between DC power discharged or charged by the power storage device 21 and AC power transformed by the transformer device 23. The transformer device 23 converts the voltage of the AC voltage.

[0014] The control system 30 is a computer system (PMS: Power Management System) that controls the power storage system 20 (power storage device 21). Specifically, the control system 30 commands the power storage system 20 to set a power value (hereinafter referred to as "individual command value B") of power to be discharged or charged by the power storage device 21. The adjustment device 22 of the power storage system 20 causes the power storage device 21 to discharge or charge DC power corresponding to the individual command value B. As described above, the control system 30 controls the power storage device 21 (power storage system 20).

[0015] Fig. 2 is a block diagram illustrating the configuration of the control system 30. As illustrated in Fig. 2, the control system 30 includes a control device 31, a storage device 32, a display device 33, and a communication device 34. The control system 30 may be realized by a single device, or may be realized by multiple devices configured separately from each other.

[0016] The control device 31 is composed of one or more processors that control each element of the control system 30. Specifically, the control device 31 is composed of one or more types of processors, such as a programmable logic device (PLD), a central processing unit (CPU), a digital signal processor (DSP), a field programmable gate array (FPGA), or an application specific integrated circuit (ASIC).

[0017] The storage device 32 is one or more memories that store programs executed by the control device 31 and data used by the control device 31. The storage device 32 is configured with a known storage medium such as a magnetic storage medium or a semiconductor storage medium. The storage device 32 may be configured with a combination of multiple types of storage medium. A portable storage medium that can be attached to and detached from the control system 30 may be used as the storage device 32.

[0018] The display device 33 displays various images under the control of the control device 31. The display device 33 is configured with a display panel such as a liquid crystal panel or an organic EL (Electroluminescence) panel.

[0019] The communication device 34 transmits and receives signals to and from external devices via wired or wireless communication. For example, the communication device 34 communicates with the management system 40 of FIG. 1 . The management system 40 is a computer system (EMS: Energy Management System) that manages electricity transactions in various electricity markets, such as a wholesale electricity market or a supply-demand balancing market. The communication device 34 receives a power command value A transmitted from the management system 40. The power command value A is the total value of power to be exchanged with the power grid 10. The control system 30 calculates an individual command value B corresponding to the power command value A and transmits the individual command value B to the power storage system 20. The management system 40 may be interpreted as an element of the power system 100.

[0020] The communication device 34 communicates with the power storage system 20 (specifically, the adjustment device 22) via a communication network (not shown), such as a dedicated line. Specifically, the communication device 34 transmits an individual command value B to the power storage system 20. The communication device 34 also receives the health H(t) of the power storage device 21 from the power storage system 20. The health H(t) is the ratio of the power capacity at any time t to the initial power capacity of the power storage device 21. The health H(t) is measured, for example, by a charge / discharge test during maintenance work (e.g., repair or replacement) of the power storage device 21, and is transmitted from the power storage system 20 to the control system 30. The health H(t) is measured for each maintenance work performed, for example, on an annual basis. In a configuration in which the health H(t) measured by the charge / discharge test is stored in the storage device 32, the control device 31 may acquire the health H(t) from the storage device 32.

[0021] FIG. 3 shows the change over time in the health H(t) of the power storage device 21. The operation period P in FIG. 3 is the period during which the power storage device 21 is expected to be used. Specifically, the operation period P is a predetermined length (for example, 20 years) from the operation start point t0 on the time axis to the expiration point T. The operation start point t0 is the time when the operation of the power storage device 21 begins. The expiration point T is the time when the operation period P expires. When the expiration point T arrives (i.e., the expiration of the operation period P), the power storage device 21 is replaced, for example.

[0022] As illustrated in FIG. 3, the health level H(t) of the power storage device 21 decreases over time during operation, with the numerical value H(t0) at the operation start point t0 of the operation period P being the maximum value Hmax. The maximum value Hmax is, for example, 100%. When designing the power storage device 21, it is assumed that the health level H(t) changes over time, as illustrated in FIG. 3 as a hypothetical time change Vref, so that the health level H(t) reaches a minimum value Hmin (H(T)=Hmin) at the expiration time T of the operation period P. The minimum value Hmin of the health level H(t) is, for example, 70%.

[0023] However, the actual time change V of the health H(t) is affected by various factors, such as the operation method or installation environment of the power storage device 21. Therefore, the actual time change V of the health H(t) differs from the designed time change Vref. Specifically, as illustrated in FIG. 3 , the health H(t) may exceed the minimum value Hmin at the expiration time T of the operation period P (H(T)>Hmin). In other words, the operation period P may expire with the health H(t) still having a sufficient margin up to the minimum value Hmin. If the power storage device 21 can be utilized more effectively during the operation period P, it may be possible to expect further profits from the exchange of power with the power grid 10.

[0024] Taking the above circumstances into consideration, the control system 30 of the first embodiment increases the number of operation cycles N of the storage device 21 at a point in the operation period P when it is expected that the health H(t) will not reach the minimum value Hmin at the expiration time T of the operation period P, thereby bringing the time change V of the health H(t) closer to the designed time change Vref.

[0025] The number of operation cycles N is the upper limit of the number of cycles of discharging and charging the power storage device 21 within a unit period (for example, one day). That is, the number of operation cycles N means the upper limit of the number of times a set of discharging and charging is repeated within a unit period. Specifically, the number of operation cycles N is an equivalent or virtual number (equivalent number of cycles) obtained by converting discharge and charging (depth of charge) in a part of the section from the minimum to the maximum value of the state of charge (SOC), with one cycle consisting of a set of charging from the minimum to the maximum value of the state of charge and discharging from the maximum to the minimum value of the state of charge.

[0026] FIG. 4 is an explanatory diagram of the time variation of the total number of cycles M and the state of charge (SOC). The total number of cycles M is the total number of cycles in the course of operation of the power storage device 21. FIG. 4 illustrates the time variation of the total number of cycles M and the state of charge when the number of operation cycles N is set to a value N1, and the time variation of the total number of cycles M and the state of charge when the number of operation cycles N is set to a value N2. The value N2 of the number of operation cycles N is greater than the value N1. For example, the value N1 is set to "1" and the value N2 is set to "1.2."

[0027] 4, the total number of cycles M when the number of operation cycles N is set to the value N2 exceeds the total number of cycles M when the number of operation cycles N is set to the value N1. Furthermore, the number of SOC fluctuations when the number of operation cycles N is set to the value N2 exceeds the number of SOC fluctuations when the number of operation cycles N is set to the value N1. Therefore, the profit that the manager (e.g., the electricity seller) can obtain from the energy trading using the energy storage device 21 whose number of operation cycles N is set to the value N2 exceeds the profit that can be obtained when the number of operation cycles N is set to the value N1. In other words, by increasing the number of operation cycles N within the operation period P, it is possible to increase the manager's profit.

[0028] 5 is a block diagram illustrating an example of the functional configuration of the control system 30. The control device 31 executes a program stored in the storage device 32 to realize a plurality of functions (an information acquisition unit 51, an arithmetic processing unit 52, and a display control unit 53) for controlling the power storage system 20.

[0029] The information acquisition unit 51 acquires the health H(X) of the power storage device 21 at a specific time point t (hereinafter referred to as the "target time point X") within the operation period P. Specifically, the information acquisition unit 51 receives the health H(X) transmitted from the power storage system 20 via the communication device 34. The information acquisition unit 51 may calculate the health H(X) using the information received from the power storage system 20. In addition, in a configuration in which the health H(t) measured by a charge / discharge test during maintenance work is stored in the storage device 32, the information acquisition unit 51 may acquire the health H(X) at the target time point X from the storage device 32 when performing a management process (FIG. 7) described below. As illustrated above, the acquisition of the health H(X) by the information acquisition unit 51 includes, in addition to receiving the health H(X) via the communication device 34, for example, calculating the health H(X) and reading the health H(X) from the storage device 32.

[0030] The calculation processing unit 52 calculates a numerical value N2 of the number of operation cycles N according to the health level H(X) of the power storage device 21 acquired by the information acquisition unit 51. The numerical value N2 is the numerical value of the number of operation cycles N that should be applied to the operation of the power storage device 21 after the target time point X within the operation period P. That is, the number of operation cycles N of the power storage device 21 is updated from a predetermined numerical value N1 to a numerical value N2 at the target time point X. The calculation of the numerical value N2 by the calculation processing unit 52 will be described in detail below.

[0031] 3 is the amount of capacity degradation in the power storage device 21. Specifically, the capacity degradation D(t) is the difference between the health level H(t0) (=Hmax) at the operation start point t0 of the operation period P and the health level H(t) at time t, as expressed by the following formula (1). FIG. 3 illustrates the capacity degradation D(T) at the expiration time T of the operation period P and the capacity degradation D(X) at the target time X.

number

[0032] As illustrated in Fig. 3, capacity degradation D(t) at any time t within operation period P includes cycle degradation Dc(t) and storage degradation Ds(t). Specifically, capacity degradation D(t) is the sum of cycle degradation Dc(t) and storage degradation Ds(t) (D(t) = Dc(t) + Ds(t)). Cycle degradation Dc(t) of power storage device 21 is expressed by the following formula (2), and storage degradation Ds(t) is expressed by the following formula (3).

number

[0033] The symbol α in formula (2) means the ratio of cycle degradation Dc(t) to capacity degradation D(t), and is set to a predetermined value greater than or equal to 0 and less than or equal to 1. Similarly, the symbol (1-α) in formula (3) means the ratio of storage degradation Ds(t) to capacity degradation D(t), and is set to a predetermined value greater than or equal to 0 and less than or equal to 1.

[0034] Cycle degradation Dc(t) of capacity degradation D(t) is a decrease in the health state H(t) that occurs due to repeated charging and discharging of the power storage device 21. In other words, cycle degradation Dc(t) is a deterioration in power capacity that depends on the number of operating cycles N (or the total number of cycles M). Specifically, cycle degradation Dc(t) is proportional to the square root of the total number of cycles M at time t. Therefore, cycle degradation Dc(X) at a target time X within the operating period P is expressed by the following equation (4):

number

[0035] The target time point X is expressed as a numerical value in years. Therefore, the value inside the square root in formula (4) (N1·365·X) means the total number of cycles M when the energy storage device 21 is operated for the number of operation cycles N of the numerical value N1 during the period from the operation start point t0 (t=0) to the target time point X. The symbol C1 in formula (4) is a proportionality coefficient. By modifying formula (4), the following formula (5) expressing the proportionality coefficient C1 is derived.

number

[0036] On the other hand, storage degradation Ds(t) of capacity degradation D(t) is a decrease in the health state H(t) that progresses over time regardless of the discharging and charging of the power storage device 21. In other words, storage degradation Ds(t) is a deterioration in power capacity that does not depend on the number of operation cycles N (or the total number of cycles M). Specifically, storage degradation Ds(t) is proportional to the square root of the operation time (number of storage days) of the power storage device 21. Therefore, storage degradation Ds(X) at a target time point X within the operation period P is expressed by the following equation (6).

number

[0037] The square root (365·X) in equation (6) represents the number of days from the start of operation t0 (t=0) to the target time point X. The symbol C2 in equation (6) is a proportionality coefficient. By transforming equation (6), the following equation (7) is derived, which expresses the proportionality coefficient C2.

number

[0038] As mentioned above, assuming that the number of operating cycles N increases from a value N1 to a value N2 at a target time X of the operating period P, the cycle deterioration Dc(T) at the end time T of the operating period P is expressed by the following equation (8).

number

[0039] As described above, the first term (N1·365·X) inside the square root in formula (8) means the total number of cycles M when the energy storage device 21 is operated for the number of operation cycles N of the value N1 during the period from the operation start point t0 to the target time point X during the operation period P. Furthermore, the second term (N2·365·(TX)) inside the square root in formula (8) means the total number of cycles M when the energy storage device 21 is operated for the number of operation cycles N of the value N2 during the period (length of time: TX) from the target time point X to the expiration time T during the operation period P. In other words, the term inside the square root in formula (8) corresponds to the total number of cycles M throughout the entire operation period P.

[0040] Further, the storage deterioration Ds(T) at the time T at which the operation period P expires is expressed by the following formula (9).

number

[0041] The capacity degradation D(T) at the expiration time T of the operation period P is the amount of decrease in the power capacity of the storage device 21 that is expected at the expiration time T of the operation period P when the number of operation cycles N of the storage device 21 increases from a value N1 to a value N2 at the target time X. As expressed by the following formula (10), the capacity degradation D(T) at the expiration time T must not exceed a predetermined allowable value Dmax.

number

[0042] 3, the tolerance value Dmax means the capacity degradation D(T) at the expiration time T of the design time change Vref of the health level H(t) of the power storage device 21. That is, the tolerance value Dmax is the difference between the health level H(t0) at the operation start point t0 of the operation period P (i.e., the maximum value Hmax) and the health level H(T) at the expiration time T of the design time change Vref (i.e., the minimum value Hmin) (Dmax=Hmax-Hmin).

[0043] From the condition of equation (10) that the capacity degradation D(T), which is the sum of the cycle degradation Dc(T) of equation (8) to which the proportional coefficient C1 of equation (5) is applied and the storage degradation Ds(T) of equation (9) to which the proportional coefficient C2 of equation (7) is applied, does not exceed the allowable value Dmax, the following equation (11) is derived, which represents the condition that the value N2 of the number of operating cycles N after changing it must satisfy.

number

[0044] 5 calculates the maximum value that satisfies Equation (11) as the changed value N2 of the number of operation cycles N. That is, the calculation processing unit 52 calculates the value N2 according to the health level H(X) of the power storage device 21 so that the capacity deterioration D(T) of the power storage device 21 expected at the expiration time T of the operation period P does not exceed the allowable value Dmax when the number of operation cycles N of the power storage device 21 increases from the value N1 to the value N2 at the target time X. Specifically, the calculation processing unit 52 calculates the value N2 of the number of operation cycles N so that the sum of the cycle deterioration Dc(T) at the expiration time T of the operation period P and the storage deterioration Ds(T) at the expiration time T does not exceed the allowable value Dmax.

[0045] As can be seen from equation (11), the smaller the ratio α of cycle degradation Dc(t) to capacity degradation D(t), the more likely it is that the value N2 of the number of operating cycles N after the change can be increased. Also, the closer the target time X is to the expiration time T, the more likely it is that the value N2 of the number of operating cycles N after the change can be increased. Furthermore, the closer the health level H(X) at the target time X is to the health level H(t0) (=Hmax) at the start of operation t0, the more likely it is that the value N2 of the number of operating cycles N after the change can be increased.

[0046] 5, the calculation processing unit 52 notifies the management system 40 of the changed value N2 of the number of operation cycles N. Specifically, the calculation processing unit 52 transmits the value N2 to the management system 40 via the communication device 34. The management system 40 sets the power command value A according to the changed value N2 of the number of operation cycles N. For example, the management system 40 increases the power command value A as the changed value N2 increases.

[0047] The display control unit 53 in Fig. 5 displays an image representing the result of the above-described processing on the display device 33. For example, the display control unit 53 displays the reference image G1 in Fig. 6 on the display device 33. As illustrated in Fig. 6, the reference image G1 is an image representing the time change V1 and the time change V2 of the state of health H(t) (SOH).

[0048] The time change V1 is a curve representing the change over time in the health level H(t) when the power storage device 21 is operated with the number of operation cycles N equal to the numerical value N1 throughout the entire operation period P. On the other hand, the time change V2 is a curve representing the change over time in the health level H(t) when the number of operation cycles N is increased from the numerical value N1 to the numerical value N2 at the target time point X (present) within the operation period P.

[0049] In the reference image G1, the time change V1 and the time change V2 are displayed in a contrastive manner. That is, an administrator viewing the reference image G1 can visually compare the time change V1 and the time change V2. Specifically, the time change V1 and the time change V2 are displayed in parallel on the display device 33.

[0050] As described above, in the first embodiment, for example, a manager of the storage device 21 can intuitively or visually grasp the time change V1 of the health H(t) when the number of operation cycles N is maintained at the value N1 throughout the entire operation period P, and the time change V2 of the health H(t) when the number of operation cycles N is increased to the value N2 at the target time point X.

[0051] 7 is a flowchart of the operation (hereinafter referred to as "management process") of the control system 30 to manage the number of operation cycles N. The management process is executed every time a target time point X arrives in a predetermined cycle (for example, one year). The number of operation cycles N is cumulatively updated every time the management process is executed.

[0052] When the management process is started, the control device 31 (information acquisition unit 51) acquires the health H(X) of the power storage device 21 at the target time point X (Sa1). The control device 31 (arithmetic processing unit 52) calculates the value N2 of the number of operation cycles N by calculating the above-mentioned formula (11) (Sa2). The control device 31 (arithmetic processing unit 52) notifies the management system 40 of the value N2 via the communication device 34 (Sa3). In addition, the control device 31 (display control unit 53) displays the reference image G1 of FIG. 6 on the display device 33 (Sa4). The specific steps of the management process are as described above.

[0053] As described above, in the first embodiment, the value N2 after increasing the number of operation cycles N at the target time point X is calculated so that the capacity degradation D(T) of the power storage device 21 expected at the expiration time point T of the operation period P does not exceed the allowable value Dmax. Therefore, by increasing the number of operation cycles N from the value N1 to the value N2 at the target time point X within the operation period P, the power storage device 21 can be effectively utilized within a range in which the capacity degradation D(T) does not exceed the allowable value Dmax. As a result of utilizing the power storage device 21, it is possible to increase the profit from energy trading using the power storage device 21 compared to operating the power storage device 21 with the number of operation cycles of the value N1 throughout the entire operation period P.

[0054] In particular, in the first embodiment, the value N2 is calculated so that the sum of cycle degradation Dc(T), which is dependent on the number of operation cycles N among the capacity degradation D(T) at the expiration time T, and storage degradation Ds(T), which is independent of the number of operation cycles N among the capacity degradation D(T), does not exceed the allowable value Dmax. Therefore, compared to a configuration in which only one of cycle degradation Dc(t) and storage degradation Ds(t) is taken into account as the capacity degradation D(t) of the storage device 21, the value N2 of the number of operation cycles N can be calculated with high accuracy.

[0055] 2. Second embodiment A second embodiment of the present disclosure will be described. Note that, for elements in the following exemplary aspects that have the same functions as those in the first embodiment, the same reference numerals as those in the first embodiment will be used, and detailed descriptions of each will be omitted as appropriate.

[0056] In the first embodiment, for convenience, a configuration in which the ratio α of cycle degradation Dc(t) to capacity degradation D(t) is set to a predetermined value is illustrated. In reality, the ratio α changes depending on the number of operation cycles N. In consideration of the above circumstances, in the second embodiment, the ratio α(N) is controlled depending on the number of operation cycles N.

[0057] Fig. 8 is a graph showing the relationship between the number of operation cycles N and the ratio α(N). As shown in Fig. 8, the ratio α(N) of cycle deterioration Dc(t) tends to monotonically increase with the number of operation cycles N of the power storage device 21. Specifically, the ratio α(N) is approximately expressed by the following formula (12), which uses the number of operation cycles N as a variable.

number

[0058] The symbol α(1) in formula (12) is the ratio α(N) of cycle deterioration Dc(t) when the power storage device 21 is operated at an operation cycle number N (N=1) of 1 cycle / day. The calculation processing unit 52 calculates the ratio α(N) by calculating formula (12). That is, the calculation processing unit 52 sets the ratio α(N) of cycle deterioration Dc(t) to capacity deterioration D(t) to a numerical value according to the ratio α(1) corresponding to 1 cycle / day and the current operation cycle number N of the power storage device 21.

[0059] 9 is a flowchart of the management process in the second embodiment. As illustrated in FIG. 9, when the health level H(X) at the target time point X is acquired (Sa1) in the management process, the control device 31 (arithmetic processing unit 52) calculates the ratio α(N) by calculating Equation (12) (Sb1). Note that the order of acquiring the health level H(X) (Sa1) and calculating the ratio α(N) (Sb1) may be reversed.

[0060] The control device 31 (arithmetic processing unit 52) calculates the numerical value N2 of the number of operation cycles N by calculating formula (11) to which the ratio α(N) is applied (Sa2). That is, as the ratio α in formula (11), a variable ratio α(N) according to the number of operation cycles N is applied. Notification of the numerical value N2 to the management system 40 (Sa3) and display of the reference image G1 (Sa4) are similar to those in the first embodiment.

[0061] The second embodiment also achieves the same effects as the first embodiment. Furthermore, the second embodiment takes into consideration the relationship that the ratio α(N) of cycle degradation Dc(t) to capacity degradation D(t) in the power storage device 21 depends on the ratio α(1), which corresponds to the number of operation cycles N per cycle / day, and the number of operation cycles N of the power storage device 21. Therefore, the capacity degradation D(T) of the power storage device 21 at the expiration time T of the operation period P can be calculated with high accuracy.

[0062] 3. Third embodiment Fig. 10 is a flowchart of the management process in the third embodiment. As illustrated in Fig. 10, when the value N2 after the change of the number of operation cycles N is calculated (Sa2), the control device 31 (arithmetic processing unit 52) calculates the first predicted profit Y1 and the second predicted profit Y2 (Sc1).

[0063] The first predicted profit Y1 is the profit that the manager can obtain through electricity trading when the power storage device 21 is operated for the number of operation cycles N of the numerical value N1 throughout the entire operation period P. The control device 31 (arithmetic processing unit 52) calculates the first predicted profit Y1 by a predetermined calculation applying the numerical value N1.

[0064] The second predicted profit Y2 is the profit that the manager can obtain from the power trading during the operation period P when the number of operation cycles N is increased from the value N1 to the value N2 at the target time point X. ( The calculation processing unit 52 calculates the second predicted profit Y2 by a predetermined calculation applying the numerical value N1 and the numerical value N2. As can be understood from the explanation of Figure 4, the second predicted profit Y2 exceeds the first predicted profit Y1 (Y2>Y1).

[0065] The control device 31 (display control unit 53) displays the reference image G2 on the display device 33 (Sc2). FIG. 11 is a schematic diagram of the reference image G2. As illustrated in FIG. 11, the reference image G2 includes a first predicted profit Y1 and a second predicted profit Y2. Specifically, the first predicted profit Y1 and the second predicted profit Y2 are displayed in a contrastive manner in the reference image G2. For example, the first predicted profit Y1 and the second predicted profit Y2 are displayed using bar graphs. Therefore, a manager viewing the reference image G2 can visually compare the first predicted profit Y1 and the second predicted profit Y2. The reference image G1 and the reference image G2 are displayed in parallel or sequentially on the display device 33. The reference image G2 also includes an increase rate U of the second predicted profit Y2 relative to the first predicted profit Y1.

[0066] The third embodiment also achieves the same effects as the first embodiment. In the third embodiment, the manager of the power storage device 21 can intuitively or visually grasp the first predicted profit Y1 when the number of operation cycles N is maintained at the value N1 throughout the entire operation period P, and the second predicted profit Y2 when the number of operation cycles N is increased at the target time point X.

[0067] 4. Variations Specific modified embodiments that can be added to each of the embodiments exemplified above are exemplified below. Two or more embodiments arbitrarily selected from the following examples may be appropriately combined within the scope of not being mutually contradictory.

[0068] (1) In the third embodiment, the first predicted profit Y1 and the second predicted profit Y2 for the entire investment period P are displayed on the display device 33, but the period covered by the first predicted profit Y1 and the second predicted profit Y2 is not limited to the entire investment period P. For example, the profit on an annual basis within the investment period P, or the profit for the period from the target time X to the expiration time T within the investment period P, may be calculated as the first predicted profit Y1 or the second predicted profit Y2.

[0069] (2) In the third embodiment, a configuration in which the control system 30 (arithmetic processing unit 52) calculates the first predicted profit Y1 and the second predicted profit Y2 was exemplified, but the entity that calculates the first predicted profit Y1 and the second predicted profit Y2 is not limited to the control system 30 (control device 31). For example, the management system 40 may calculate the first predicted profit Y1 and the second predicted profit Y2 in accordance with the numerical value N2 notified from the control system 30. In other words, the function of calculating the first predicted profit Y1 and the second predicted profit Y2 may be omitted from the control system 30.

[0070] (3) In the third embodiment, both the reference image G1 and the reference image G2 are displayed on the display device 33. However, a configuration in which only the reference image G2 is displayed is also possible. In other words, the display of the reference image G1 may be omitted.

[0071] (4) As described above, the functions of the control system 30 according to each of the above embodiments are realized through cooperation between one or more processors constituting the control device 31 and a program stored in the storage device 32. The programs exemplified above can be provided in a form stored on a computer-readable recording medium and installed on a computer. The recording medium is, for example, a non-transitory recording medium, such as an optical recording medium (optical disk) such as a CD-ROM, but also includes any known form 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 other than a transitory, propagating signal, and does not exclude volatile recording media. Furthermore, in a configuration in which a distribution device distributes a program via a communication network, the recording medium storing the program in the distribution device corresponds to the non-transitory recording medium described above.

[0072] (5) The term "nth" (n is a natural number) in this application is used only as a formal and convenient label to distinguish each element in the description and does not have any substantive meaning. Therefore, there is no room for restrictive interpretation of the position or order of each element based on the term "nth."

[0073] 5. Additional Notes From the above-described exemplary embodiments, the following configurations can be understood, for example.

[0074] In a method for controlling an energy storage device according to one aspect (aspect 1) of the present disclosure, a control system acquires a health level of the energy storage device at a target time point within an operation period, and calculates the second value according to the health level of the energy storage device so that, when the number of operation cycles of the energy storage device increases from a first value to a second value at the target time point, the capacity degradation of the energy storage device expected at the end of the operation period does not exceed an allowable value. In the above aspect, the second value after the increase in the number of operation cycles at the target time point is calculated so that the capacity degradation of the energy storage device expected at the end of the operation period does not exceed an allowable value. Therefore, by increasing the number of operation cycles from the first value to the second value at the target time point within the operation period, the energy storage device can be effectively utilized within a range in which the capacity degradation does not exceed an allowable value. As a result of utilizing the energy storage device, it is possible to increase profits from energy trading using the energy storage device compared to operating the energy storage device with the first value of the number of operation cycles throughout the operation period.

[0075] In a specific example (Aspect 2) of Aspect 1, the control system further displays, on a display device, the change in the health degree over time when the power storage device is operated with the first value of the number of operation cycles throughout the operation period, and the change in the health degree over time when the number of operation cycles is increased from the first value to the second value at the target time point. According to the above aspect, a manager of the power storage device, for example, can intuitively or visually grasp the change in the health degree over time when the number of operation cycles is maintained at the first value throughout the operation period, and the change in the health degree over time when the number of operation cycles is increased at the target time point.

[0076] In a specific example (Aspect 3) of Aspect 2, the control system further calculates a first predicted profit when the power storage device is operated with the first value of the number of operating cycles throughout the entire operating period, and a second predicted profit when the number of operating cycles is increased from the first value to the second value at the target time point, and displays the first predicted profit and the second predicted profit on the display device. According to the above aspect, a manager of the power storage device, for example, can intuitively or visually grasp the first predicted profit when the number of operating cycles is maintained at the first value throughout the operating period, and the second predicted profit when the number of operating cycles is increased at the target time point.

[0077] In a specific example (Aspect 4) of any of Aspects 1 to 3, the second value is calculated so that the sum of the cycle degradation at the expiration time among the capacity degradation and the storage degradation at the expiration time among the capacity degradation does not exceed the allowable value. In the above aspect, the second value is calculated so that the sum of the cycle degradation that depends on the number of operating cycles among the capacity degradation and the storage degradation that does not depend on the number of operating cycles among the capacity degradation does not exceed the allowable value. Therefore, the second value of the number of operating cycles can be calculated with high accuracy compared to a configuration in which only one of cycle degradation and storage degradation is taken into account as capacity degradation of the power storage device.

[0078] In a specific example (Aspect 5) of Aspect 4, in calculating the second value, the ratio of cycle degradation to capacity degradation is set to a numerical value corresponding to the ratio of cycle degradation to capacity degradation when the power storage device is operated at 1 cycle / day and the number of operation cycles. According to the above aspect, the relationship in which the ratio of cycle degradation to capacity degradation in the power storage device depends on the ratio corresponding to the number of operation cycles N of 1 cycle / day and the number of operation cycles of the power storage device is taken into consideration, so that the capacity degradation of the power storage device at the end of the operation period can be calculated with high accuracy.

[0079] A control system according to one aspect (aspect 6) of the present disclosure includes an information acquisition unit that acquires the health of a storage device at a target time point within an operation period, and an arithmetic processing unit that calculates the second value in accordance with the health of the storage device so that the capacity degradation of the storage device expected at the end of the operation period does not exceed an allowable value when the number of operation cycles of the storage device increases from a first value to a second value at the target time point.

[0080] A program according to one aspect (aspect 7) of the present disclosure causes a computer system to function as an information acquisition unit that acquires the health of a storage device at a target time point within an operation period, and an arithmetic processing unit that calculates the second value in accordance with the health of the storage device so that the capacity degradation of the storage device expected at the end of the operation period does not exceed an allowable value when the number of operation cycles of the storage device increases from a first value to a second value at the target time point. [Explanation of symbols]

[0081] 100...power system, 10...power system, 20...energy storage system, 21...energy storage device, 22...adjusting device, 23...transformer, 30...control system, 31...control device, 32...storage device, 33...display device, 34...communication device, 40...management system, 51...information acquisition unit, 52...arithmetic processing unit, 53...display control unit.

Claims

1. The control system Obtain the health status of the energy storage device at a target time during the operation period, calculating the second value according to a health degree of the power storage device so that capacity deterioration of the power storage device expected at the end of the operation period does not exceed an allowable value when it is assumed that the number of operation cycles of the power storage device has increased from a first value to a second value at the target time point; calculating a first predicted profit when the energy storage device is operated with the first value of the number of operation cycles throughout the entire operation period, and a second predicted profit when the number of operation cycles is assumed to be increased from the first value to the second value at the target time point; Displaying the first predicted profit and the second predicted profit on a display device A method for controlling an electricity storage device.

2. The control system Obtain the health status of the energy storage device at a target time during the operation period, The second value is calculated according to the health of the power storage device so that, assuming that the number of operation cycles of the power storage device has increased from a first value to a second value at the target time, the capacity deterioration of the power storage device expected at the time of expiration of the operation period does not exceed an allowable value. A control method for a power storage device, comprising: In calculating the second value, The second value is calculated so that the sum of the cycle deterioration at the expiration time among the capacity deterioration and the storage deterioration at the expiration time among the capacity deterioration does not exceed the allowable value. A method for controlling an electricity storage device.

3. In calculating the second value, The ratio of the cycle deterioration to the capacity deterioration is set to a value corresponding to the ratio of the cycle deterioration to the capacity deterioration when the power storage device is operated at one cycle / day and the number of operation cycles. The control method of claim 2.

4. an information acquisition unit that acquires the health status of the power storage device at a target time point within an operation period; a first calculation processing unit that calculates the second value according to a health degree of the power storage device so that capacity deterioration of the power storage device expected at the end of the operation period does not exceed an allowable value when it is assumed that the number of operation cycles of the power storage device has increased from a first value to a second value at the target time point; a second calculation processing unit that calculates a first predicted profit when the energy storage device is operated with the first value of the number of operation cycles throughout the entire operation period, and a second predicted profit when it is assumed that the number of operation cycles is increased from the first value to the second value at the target time point; a display control unit that displays the first predicted profit and the second predicted profit on a display device; A control system comprising:

5. an information acquisition unit that acquires the health status of the power storage device at a target time point within an operation period; a calculation processing unit that calculates the second value according to a health degree of the power storage device so that capacity deterioration of the power storage device expected at the end of the operation period does not exceed an allowable value when it is assumed that the number of operation cycles of the power storage device has increased from a first value to a second value at the target time point; Equipped with The calculation processing unit calculates the second value so that a sum of cycle deterioration at the time of expiration among the capacity deterioration and storage deterioration at the time of expiration among the capacity deterioration does not exceed the allowable value. Control system.

6. an information acquisition unit that acquires the health status of the power storage device at a target time point within the operation period; a first calculation processing unit that calculates the second value according to a health degree of the power storage device so that capacity deterioration of the power storage device expected at the end of the operation period does not exceed an allowable value when it is assumed that the number of operation cycles of the power storage device has increased from a first value to a second value at the target time point; a second calculation processing unit that calculates a first predicted profit when the energy storage device is operated with the first value of the number of operation cycles throughout the entire operation period, and a second predicted profit when the number of operation cycles is assumed to be increased from the first value to the second value at the target time point; and a display control unit that displays the first predicted profit and the second predicted profit on a display device; A program that makes a computer system function as a

7. an information acquisition unit that acquires the health status of the power storage device at a target time point within the operation period; and a calculation processing unit that calculates the second value according to a health degree of the power storage device so that capacity deterioration of the power storage device expected at the end of the operation period does not exceed an allowable value when it is assumed that the number of operation cycles of the power storage device has increased from a first value to a second value at the target time point; A program that causes a computer system to function as The calculation processing unit calculates the second value so that a sum of cycle deterioration at the time of expiration among the capacity deterioration and storage deterioration at the time of expiration among the capacity deterioration does not exceed the allowable value. program.

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