Planning system and planning method

Abstract

Generate an appropriate operating plan that takes into account the decrease in the charge level of the power storage device. [Solution] The planning system is a planning system that generates an operational plan for charging and discharging a power storage device capable of providing primary adjustment power to a power grid, and comprises: a first calculation unit 51 that calculates a first activation rate k1(i) corresponding to the loss due to charging and discharging of primary adjustment power based on the charging efficiency and discharging efficiency of the power storage device and frequency information relating to the grid frequency in the power grid; a second calculation unit 52 that calculates the average charging and discharging power Pa(i) of the power storage device based on the contracted power of the adjustment power and the first activation rate k1(i); and a planning generation unit 53 that generates an operational plan X of the power storage device based on the average charging and discharging power Pa(i).

Description

[Technical Field]

[0001] This disclosure relates to a technology for generating a plan for charging and discharging power storage devices (hereinafter referred to as the "operation plan"). [Background technology]

[0002] Power storage devices such as energy storage devices are used to provide adjustment capabilities to the power grid. For example, Patent Document 1 discloses a configuration for calculating the amount of charge / discharge power needed to cancel out the difference between the amount of change in the amount of stored energy based on the amount of charge / discharge power of the battery during the first period and the reference amount of change in the amount of stored energy based on the reference value of the charge / discharge power of the battery during the first period. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2023 / 148918 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Regarding adjustment power, particularly primary adjustment power, frequent switching between charging and discharging in power storage devices is required to respond to fluctuations in the frequency of the power system. As a result of frequent switching between charging and discharging, the amount of charge in the power storage device decreases. Therefore, it is difficult to generate an appropriate operating plan for the power storage device. Taking these circumstances into consideration, one aspect of this disclosure aims to generate an appropriate operating plan that takes into account the decrease in the amount of charge in the power storage device. [Means for solving the problem]

[0005] A planning system according to one aspect of the present disclosure is a planning system for generating an operational plan for charging and discharging a power storage device capable of providing primary adjustment power to a power grid, comprising: a first calculation unit that calculates a first activation rate corresponding to the loss due to charging and discharging of the primary adjustment power based on the charging efficiency and discharging efficiency of the power storage device and frequency information relating to the grid frequency in the power grid; a second calculation unit that calculates the average charging and discharging power of the power storage device based on the contracted power of the adjustment power and the first activation rate; and a planning generation unit that generates an operational plan for the power storage device based on the average charging and discharging power.

[0006] A planning method according to one aspect of the present disclosure is a planning method for generating an operational plan for charging and discharging a power storage device capable of providing primary adjustment power to a power grid, the planning system comprising: calculating a first activation rate corresponding to the loss due to charging and discharging of the primary adjustment power based on the charging efficiency and discharging efficiency of the power storage device and frequency information relating to the grid frequency in the power grid; calculating the average charging and discharging power of the power storage device based on the contracted power of the adjustment power and the first activation rate; and generating an operational plan for the power storage device based on the average charging and discharging power. [Brief explanation of the drawing]

[0007] [Figure 1] This is a block diagram illustrating the configuration of a power system according to the first embodiment. [Figure 2] This is an explanatory diagram of systematic frequency and mean absolute deviation. [Figure 3] This is a block diagram illustrating the configuration of the planning system. [Figure 4] This is a block diagram illustrating the functional configuration of the planning system. [Figure 5] This is a block diagram illustrating the functional configuration of the planning system in the second embodiment. [Figure 6] This graph shows the relationship between power offset and calculation coefficients in the third embodiment. [Figure 7] This is an explanatory diagram illustrating the operation of the coefficient setting unit in setting the calculation coefficients. [Figure 8] This is a block diagram illustrating the functional configuration of the planning system in the fourth embodiment. [Modes for carrying out the invention]

[0008] The embodiments for implementing this disclosure will be described with reference to the drawings. The embodiments described below are exemplary embodiments that may be envisioned when implementing this disclosure. Therefore, the scope of this disclosure is not limited to the embodiments described below.

[0009] A: First Embodiment Figure 1 is a block diagram illustrating the configuration of a power system 100 according to the first embodiment of this disclosure. The power system 100 is a system that exchanges AC power with a power grid 10. The power grid 10 is a distribution or transmission system for supplying electricity generated by power generation facilities (not shown), such as a thermal power plant or a nuclear power plant, to business facilities or consumers such as ordinary households.

[0010] As illustrated in Figure 1, the power system 100 comprises a battery storage system 20, a control system 30, and a planning system 40. The battery storage system 20, the control system 30, and the planning system 40 can communicate with each other via a communication network (not shown), such as a dedicated line. Although the power system 100 may include multiple battery storage systems 20, for convenience, the following explanation will focus on a single battery storage system 20.

[0011] The energy storage system 20 is connected to the power grid 10 at the interconnection point 11. The energy storage system 20 is a power facility capable of supplying power to the power grid 10 (i.e., discharging) and receiving power from the power grid 10 (i.e., charging). In other words, the energy storage system 20 adjusts the power at the interconnection point 11 in the power grid 10 (hereinafter referred to as "interconnection point power") by charging and discharging. Specifically, the energy storage system 20 can provide the power grid 10 with adjustment power, including, for example, primary adjustment power. Primary adjustment power is adjustment power that requires instantaneous charging and discharging in order to suppress fluctuations in the frequency of the interconnection point power.

[0012] The energy storage system 20 comprises an energy storage device 21 and a control device 22. The energy storage device 21 is a power equipment (power storage device) that stores electricity. Specifically, the energy storage device 21 is a grid battery that discharges and charges DC power. The type of energy storage device 21 is arbitrary, but for example, a secondary battery such as a lithium-ion battery or a sodium-sulfur battery is exemplified as the energy storage device 21. In Figure 1, the energy storage device 21 is conveniently shown as a single element, but the energy storage device 21 may be composed of multiple batteries.

[0013] The control device 22 is a Power Conditioning System (PCS) that controls the discharge and charging of the energy storage device 21. Specifically, the control device 22 is a power converter that converts between the DC power discharged or charged by the energy storage device 21 and the AC power transmitted by the power grid 10. For convenience, the diagram of the transformer equipment that converts the voltage of the AC power between the energy storage system 20 and the power grid 10 has been omitted. Also, although only one set of the energy storage device 21 and the control device 22 is shown in Figure 1 for convenience, the energy storage system 20 may consist of multiple sets of the energy storage device 21 and the control device 22.

[0014] The planning system 40 is a computer system (EMS: Energy Management System) that generates the operation plan X. The operation plan X is a plan for charging and discharging the energy storage device 21. The operation plan X specifies the planned amount of energy that the energy storage device 21 should charge or discharge for each unit period of a predetermined length. Each unit period is, for example, 30 minutes.

[0015] The planning system 40 receives transaction information Y1 from, for example, a management system (not shown) that manages electricity trading in the supply and demand adjustment market. Transaction information Y1 is information related to electricity trading, such as adjustment capacity. The planning system 40 also receives operational performance Y2 from the control system 30. Operational performance Y2 is the actual amount of electricity exchanged by the energy storage system 20. The planning system 40 generates an operational plan X based on the transaction information Y1 and the operational performance Y2.

[0016] The control system 30 is a computer system (PMS: ​​Power Management System) that controls the energy storage system 20. Specifically, the control system 30 transmits an operation command Z to the energy storage system 20. The operation command Z includes a command value for the power that the energy storage device 21 should charge or discharge.

[0017] The control system 30 receives the operation plan X generated by the planning system 40. The control system 30 also receives the operation record Y2 from the energy storage system 20 (control device 22). The operation record Y2 is transmitted from the control system 30 to the planning system 40.

[0018] The control system 30 receives the adjustment power command value Y3 from the central power dispatch system (central dispatch system). The adjustment power command value Y3 is the command value for the adjustment power that should be dynamically provided in the supply and demand adjustment market according to the relationship between supply and demand. The control system 30 also generates the adjustment power command value Y4 for the primary adjustment power. The control system 30 generates the adjustment power command value Y4 for the primary adjustment power according to the frequency of the interconnection point power.

[0019] The control system 30 generates an operation command Z based on the operation plan X, the actual operation results Y2, the adjustment force command value Y3, and the adjustment force command value Y4. A known method is arbitrarily adopted for generating the operation command Z.

[0020] The operation plan X generated by the planning system 40 will be described in detail. As described above, the operation plan X specifies the planned value W SOC (i) [kWh] of the amount of power that the power storage device 21 should charge or discharge for each unit period. The planned value W SOC (i) is the amount of power in the power storage device 21 at the end of the unit period. Specifically, the planned value W SOC (i) is expressed by the following mathematical formula (1).

Equation

[0021] The symbol i in the mathematical formula (1) is a number for identifying the unit period, and the symbol T is the time length [hour] of the unit period. Also, the symbol Ps(i) in the mathematical formula (1) is the tie-point power [kW]. The tie-point power Ps(i) is expressed with a positive number for the discharge direction and a negative number for the charge direction. That is, a positive number of the tie-point power Ps(i) means the power value that the power storage system 20 should discharge to the power grid 10, and a negative number of the tie-point power Ps(i) means the power value that the power storage system 20 should charge by receiving power from the power grid 10. The first line on the right side of the mathematical formula (1) is the planned value W SOC (i) when the power storage system 20 discharges, and the second line is the planned value W SOC (i) when the power storage system 20 charges.

[0022] The symbol η in the mathematical formula (1) out means the discharge efficiency of the power storage device 21. That is, the discharge efficiency η out means the ratio of the amount of power discharged by the power storage device 21 to the decrease in the amount of charge in the power storage device 21. Therefore, the lower the discharge efficiency η out [[ID=ID=34]], the smaller the amount of power that the power storage device 21 can discharge with respect to the decrease in the amount of charge. Also, the symbol η in the mathematical formula (1) in means the charge efficiency of the power storage device 21. That is, the charge efficiency ηin This represents the ratio of the amount of electricity actually charged by the energy storage device 21 to the amount of electricity supplied to the energy storage device 21. Therefore, the charging efficiency η in The lower the value, the less power the energy storage device 21 can charge relative to the power supply.

[0023] In equation (1), the interconnection point power Ps(i) is equal to the discharge efficiency η out The division operation is performed by dividing the interconnection point power Ps(i) by the discharge efficiency η out This means a process that corrects the power Ps(i) at the connection point by the charging efficiency η. Similarly, in equation (1), the charging efficiency η is added to the power Ps(i) at the connection point. in The operation of multiplying by the interconnection point power Ps(i) by the charging efficiency η in This means a process that corrects the power Ps(i) at the connection point using the discharge efficiency η. As can be understood from equation (1), the power Ps(i) at the connection point is corrected by the discharge efficiency η. out or charging efficiency η in The energy consumption is corrected and converted to the amount of electricity within the unit period, and the converted amount of electricity is the planned value W for the immediately preceding unit period. SOC The planned value W is the difference from (i-1). SOC (i) is calculated.

[0024] For example, the interconnection point power Ps(i) due to adjustment forces such as primary adjustment force is uncertain until the adjustment force command value Y4 is actually issued during the operation of the energy storage system 20. Therefore, in the first embodiment, the interconnection point power Ps(i) is estimated using the expected value of the activation rate k(i) as follows.

[0025] First, the interconnection point power Ps(i) is expressed by the following equation (2).

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[0026] The planned power Pb(i) is the power value planned for each unit period according to the basic plan for the operation of the energy storage device 21. The basic plan that defines the planned power Pb(i) includes, for example, a power generation plan that defines the plan in the discharge direction (power generation direction) and a reference value plan that defines the plan in the charging direction (power consumption direction). As can be understood from the above explanation, the power that the energy storage system 20 exchanges with the power grid 10 is power based on the planned power Pb(i) with adjustment forces such as primary adjustment forces superimposed.

[0027] The average charge / discharge power Pa(i) in equation (2) is expressed by the following equation (3).

number

[0028] Therefore, in actual operation, if the adjustment force command value Y3 is maintained at the minimum value of 0, or if the adjustment force command value Y3 is at the maximum value P ΔkW It is possible that this condition may be maintained. The activation rate k(i) in formula (3) is the maximum value P ΔkW This is the ratio (utilization rate) of the amount of electricity that the energy storage system 20 is expected to consume (or the amount of electricity that the energy storage system 20 actually consumed due to the command) to the amount of electricity [kWh] that the energy storage system 20 will provide, assuming that the command continues.

[0029] For example, contracted power P ΔkWLet's consider a scenario where the available power is 5000kW and the adjustment power is provided for one unit period (30 minutes). If the adjustment power command value Y3 is 0kW in the first half of the unit period (start to 15 minutes) and 2500kW in the second half of the unit period (15 minutes to end), the activation rate k(i) will be 25% calculated as follows.

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[0030] The activation rate k(i) described above is expressed by the following formula (4), which includes the first activation rate k1(i) and the second activation rate k2(i).

number

[0031] The second activation rate k2(i) in equation (4) is equal to the contracted power P ΔkW This is the ratio of the expected value of the adjustment force command value Y3 to the second activation rate k2(i). The second activation rate k2(i) is set in advance to a predetermined value. For example, the average value of past activation rates k(i) is adopted as the second activation rate k2(i). Alternatively, for example, a value predicted using artificial intelligence based on past operational performance, or a value instructed by the administrator of the planning system 40, may be adopted as the second activation rate k2(i).

[0032] Furthermore, since the power frequency of the power system 10 (hereinafter referred to as "system frequency f") fluctuates around a predetermined reference frequency f0, the charge command (negative number) and the discharge command (positive number) switch frequently when primary regulating power is supplied. In other words, the charge command and the discharge command cancel each other out. Therefore, if the regulating power supplied by the energy storage system 20 is only primary regulating power, the second activation rate k2(i) may be set to zero.

[0033] The first activation rate k1(i) is described in detail below. For convenience, the unit period number (i) will be omitted in the following explanation.

[0034] First, we focus on the adjustment force command value P1 of the primary adjustment force corresponding to the deviation Δf of the system frequency f with respect to a predetermined reference frequency f0 (hereinafter referred to as "frequency deviation"). The reference frequency f0 is the reference value of the system frequency (Western Japan: 60 Hz, Eastern Japan: 50 Hz). As illustrated in Figure 2, the system frequency f fluctuates frequently around the reference frequency f0.

[0035] The frequency deviation Δf is at its maximum value (hereinafter referred to as "maximum frequency deviation") Δf max When the agreed power P is reached ΔkW Considering that the provision of is required, the adjustment force command value P1 is expressed by the following formula (5). Note that the maximum frequency deviation Δf max This is a predetermined fixed value (e.g., ±0.3Hz or ±0.2Hz). However, the variable value that changes under predetermined conditions is the maximum frequency deviation Δf. max It may be adopted as such. Note that the maximum frequency deviation Δf max This may also be the upper limit of the control for the frequency deviation Δf when the adjustment force command value P1 is changed based on equation (5).

number

[0036] The frequency deviation Δf is calculated from actual values ​​observed in past operations of the power system 10. For example, the frequency deviation Δf is calculated by statistically processing past data on the system frequency f. The frequency deviation Δf may also be manually entered by the administrator of the planning system 40, for example, by operating the control device 44. Furthermore, if the frequency deviation Δf is a value for each unit period, the frequency deviation Δf for each unit period may be calculated from measured values ​​of the system frequency f in past unit periods with similar conditions to the current unit period. The conditions for the unit period may be, for example, meteorological information such as temperature, humidity, solar radiation, or weather.

[0037] As illustrated in Figure 2, the mean of the absolute value |Δf| of the frequency deviation Δf (hereinafter referred to as the "mean absolute deviation") Δf ave Assume the mean absolute deviation Δf ave Applying this as the frequency deviation Δf in equation (5), we get the average of the absolute values ​​of the adjustment force command value P1 |P1| ave The following equation (6) is derived, which represents the following:

number

[0038] Next, the average value P on the discharge side of the adjustment force command value P1. out_ave and the average value P on the charging side in_ave We will focus on the following: the average value P on the discharge side. out_ave The value P on the charging side is expressed by the following formula (7), and in_ave This can be expressed by the following formula (8).

number

[0039] The symbol max(P1,0) is an operator that selects the adjustment force command value P1 when it is a positive number (in the case of discharge) and selects 0 when it is a negative number. On the other hand, the symbol min(P1,0) is an operator that selects the adjustment force command value P1 when it is a negative number (in the case of charging) and selects 0 when it is a positive number. Therefore, the following equation (9) holds true.

number

[0040] The mean value of the absolute value |P1| of the adjustment force command value P1 in equation (6) |P1| ave This can be expressed by the following equation (10) by applying equations (7) through (9).

number

[0041] Furthermore, since the adjustment force command value P1 of the primary adjustment force fluctuates around 0, we can assume that the average of the adjustment force command value P1 is 0. Therefore, the following equation (11) holds true.

number

[0042] From equations (10) and (11) and the aforementioned equation (6), the following equation (12) is derived.

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[0043] Next, we will examine the charge-discharge losses due to the primary adjustment force. The average value P on the discharge side of the adjustment force command value P1 is... out_ave The decrease in the amount of charge (SOC: State of Charge) ΔW when the energy storage device 21 discharges power equivalent to this amount over a time length Δt is defined as the decrease in the amount of charge (SOC: State of Charge) ΔW when the energy storage device 21 discharges power equivalent to this amount over a time length Δt. SOC_out [kWh] is the discharge efficiency η out This is expressed by the following formula (13) using the following formula.

number

number

[0044] Therefore, the discharge loss ΔW of the energy storage device 21 over a time length Δt loss_out The charging loss ΔW of the energy storage device 21 over a time length Δt is expressed by the following formula (15), and loss_in This can be expressed by the following formula (16).

number

number

[0045] Therefore, charge / discharge loss ΔW loss This can be expressed by the following formula (17).

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[0046] Charge / discharge loss ΔW loss To express this in terms of the activation rate k(i), we use the charge / discharge loss ΔW in equation (17). loss It is necessary to convert this into a command value for the adjustment force. Equation (17) Charge / discharge loss ΔW loss However, assuming that this is power lost due to the discharge of the energy storage device 21, the discharged energy amount ΔW loss ' is expressed by the following formula (18).

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[0047] Discharge power ΔW in equation (18) loss 'Average power P over time length Δt loss When converted, it can be expressed by the following formula (19).

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[0048] Since the first activation rate k1 is obtained by converting the charge and discharge losses into an equivalent activation rate, the following equation (20) holds true.

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[0049] From equations (19) and (20), the following equation (21) is derived, which represents the first activation rate k1. The first activation rate k1 is the charge / discharge loss (P) of the primary regulating power in the energy storage device 21. loss This is a numerical value equivalent to ).

number

[0050] The specific configuration of the planning system 40, which generates the operation plan X using the relationships described above, will be detailed below. Figure 3 is a block diagram illustrating the configuration of the planning system 40. As illustrated in Figure 3, the planning system 40 comprises a control device 41, a storage device 42, a communication device 43, and an operating device 44. The planning system 40 can be implemented as a single device or as a group of devices configured separately from each other.

[0051] The control device 41 consists of one or more processors that control each element of the planning system 40. Specifically, the control device 41 is composed of one or more types of processors, such as a PLD (Programmable Logic Device), a CPU (Central Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or an ASIC (Application Specific Integrated Circuit).

[0052] The storage device 42 is one or more memories that store programs executed by the control device 41 and data used by the control device 41. The storage device 42 is composed of known recording media, such as magnetic recording media or semiconductor recording media. The storage device 42 may be composed of a combination of multiple types of recording media. A portable recording media that is attached to and detached from the planning system 40 may be used as the storage device 42.

[0053] The communication device 43 communicates with external devices. For example, the communication device 43 communicates with the energy storage system 20 (control device 41) and the planning system 40. The operating device 44 is an input device that receives instructions from the administrator of the planning system 40.

[0054] Figure 4 is a block diagram illustrating the functional configuration of the planning system 40. The control device 41 executes a program stored in the storage device 42 to realize multiple functions (first calculation unit 51, second calculation unit 52, plan generation unit 53) for generating the operation plan X.

[0055] The first calculation unit 51 calculates the first activation rate k1(i) by performing the calculation of formula (21). As can be understood from formula (21), the first calculation unit 51 calculates the charging efficiency η of the energy storage device 21. in and discharge efficiency η out Based on the frequency information relating to the system frequency f of the power system 10, the first activation rate k1(i) is calculated. The frequency information in the first embodiment is the mean absolute deviation Δf, which is the average of the absolute values ​​|Δf| of the frequency deviation Δf, as can be understood from equation (21). ave And the maximum frequency deviation Δf in the primary adjustment force. max This includes.

[0056] The second calculation unit 52 calculates the average charge / discharge power Pa(i) of the energy storage device 21 based on the first activation rate k1(i) calculated by the first calculation unit 51. Specifically, the second calculation unit 52 calculates the activation rate k(i) by performing the calculation of formula (4) which applies the first activation rate k1(i), and calculates the average charge / discharge power Pa(i) by performing the calculation of formula (3) which applies the activation rate k(i). As can be understood from formula (3), the second calculation unit 52 calculates the agreed power P of the adjustment force. ΔkW The average charge / discharge power Pa(i) of the energy storage device 21 is calculated based on the first activation rate k1(i).

[0057] The planning generation unit 53 generates an operating plan X for the energy storage device 21 based on the average charge / discharge power Pa(i) calculated by the second calculation unit 52. Specifically, the planning generation unit 53 calculates the interconnection point power Ps(i) by applying formula (2), which is the average charge / discharge power Pa(i) and the planned power Pb(i) other than the adjustment power, and calculates the planned value W of the amount of energy that the energy storage device 21 should charge or discharge by applying formula (1), which is the interconnection point power Ps(i). SOC(i) is calculated. The above process is repeated for each unit period within a predetermined period on the time axis (e.g., 1 day), and the planned value W is calculated for different unit periods. SOC An operational plan X is generated specifying (i).

[0058] As described above, in the first embodiment, in addition to frequency information relating to the grid frequency f, the charging efficiency η of the energy storage device 21 is also included. in and discharge efficiency η out However, this is taken into account in the average charge / discharge power Pa(i) of the energy storage device 21. Therefore, compared to a configuration that generates the operation plan X based only on frequency information, it is possible to generate an appropriate operation plan X that takes into account the decrease in the charge amount of the energy storage device 21.

[0059] Furthermore, the frequency information in the first embodiment is the mean absolute deviation Δf, which is the average of the absolute values ​​|Δf| of the frequency deviation Δf. ave Because it includes the mean absolute deviation Δf ave Compared to a configuration that does not include this element, the operational plan X can be calculated appropriately.

[0060] B: Second Embodiment A second embodiment of this disclosure will now be described. For elements whose function is the same as in the first embodiment in each of the embodiments described below, the same reference numerals as in the first embodiment will be used, and detailed descriptions of each will be omitted as appropriate.

[0061] Figure 5 is a block diagram illustrating the functional configuration of the planning system 40 in the second embodiment. As illustrated in Figure 5, the control device 41 of the second embodiment functions as a coefficient setting unit 54 in addition to the same elements as in the first embodiment (first calculation unit 51, second calculation unit 52, planning generation unit 53).

[0062] The coefficient setting unit 54 sets the calculation coefficient α to be applied to the formula (4) described above. As described above, the calculation coefficient α is a coefficient that represents the degree of influence of the first activation rate k1(i) on the operation plan X. The coefficient setting unit 54 sets the calculation coefficient α according to various factors. For example, the coefficient setting unit 54 sets the calculation coefficient α according to the operation of the control device 44 by the administrator.

[0063] The second calculation unit 52 calculates the average charge / discharge power Pa(i) of the energy storage device 21 based on the first activation rate k1(i), similar to the first embodiment. The calculation coefficient α set by the coefficient setting unit 54 is applied to the calculation of formula (4) in which the second calculation unit 52 calculates the activation rate k(i) according to the first activation rate k1(i). As described above, the second calculation unit 52 of the second embodiment calculates the agreed power P ΔkW Based on the first activation rate k1(i) and the calculation coefficient α set by the coefficient setting unit 54, the average charge / discharge power Pa(i) is calculated. The configuration and operation of the first calculation unit 51 and the planning generation unit 53 are the same as in the first embodiment.

[0064] The same effects as in the first embodiment are achieved in the second embodiment as well. In the second embodiment, the contracted power P ΔkW Based on the first activation rate k1(i) and the calculation coefficient α, the average charge / discharge power Pa(i) is calculated. Therefore, an appropriate operation plan X can be generated according to various conditions, such as the status of power supply by the energy storage device 21.

[0065] C: Third Embodiment The functional configuration of the planning system 40 in the third embodiment is the same as that of the second embodiment illustrated in Figure 5. That is, the coefficient setting unit 54 sets the calculation coefficient α to be variable. The coefficient setting unit 54 in the third embodiment sets the power offset P according to the basic plan for the operation of the energy storage device 21. offset Based on this, the calculation coefficient α is set.

[0066] Power offset P offset This is the power imbalance (DC component) that the energy storage device 21 should charge and discharge. Specifically, it is the power offset P. offset This can be expressed by the following formula (22).

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[0067] As mentioned above, the planned power Pb in equation (22) is the power (other than the adjustment power) planned for each unit period according to the basic plan. As can be understood from equation (22), the coefficient setting unit 54 of the third embodiment sets the planned power Pb(i) defined by the basic plan and the agreed power P of the adjustment power. ΔkW The power offset P is calculated by applying the second activation rate k2(i) to formula (22). offset Calculate the power offset P offset The calculation coefficient α is set accordingly.

[0068] Figure 6 shows the power offset P offset This is a graph showing the relationship between and the calculation coefficient α. Figure 7 is an explanatory diagram of the operation in which the coefficient setting unit 54 of the third embodiment sets the calculation coefficient α. As mentioned above, the adjustment force command value P1 of the primary adjustment force frequently fluctuates around 0. In the third embodiment, it is assumed that the adjustment force command value P1 fluctuates within the range between the minimum value (hereinafter referred to as the "lower adjustment force limit") - ΔP1 and the maximum value (hereinafter referred to as the "upper adjustment force limit") + ΔP1. As illustrated in Figure 7, the interconnection point power Ps(i) frequently fluctuates due to the primary adjustment force. Power offset P offset This power corresponds to the center of fluctuation of the interconnection point power Ps(i).

[0069] Power offset P offset If it is 0, it means that the interconnection point power Ps(i) consists only of primary regulating power, and the planned power Pb is 0. Therefore, the power offset P offset If the value is 0, the coefficient setting unit 54 sets the calculation coefficient to 1 (i.e., the maximum value).

[0070] Power offset P offset If the adjustment force falls below the lower limit -ΔP1, the interconnection point power Ps(i) will only be a negative number indicating charging of the energy storage device 21. On the other hand, the power offset P offset If the adjustment force exceeds the upper limit + ΔP1, the interconnection point power Ps(i) will be only a positive number that indicates the discharge of the energy storage device 21. That is, power offset P offset The absolute value of |P offsetWhen | exceeds the predetermined value ΔP1, the switching between charging and discharging in the power storage device 21 does not occur. Therefore, the power offset P offset When it is less than the adjustment force lower limit value -ΔP1 or exceeds the adjustment force upper limit value +ΔP1, the coefficient setting unit 54 sets the calculation coefficient α to 0. That is, the influence of the first activation rate k1(i) on the operation plan X is ignored.

[0071] On the other hand, the power offset P offset When it is a numerical value between the adjustment force lower limit value -ΔP1 and the adjustment force upper limit value +ΔP1, although the switching frequency in the power storage device 21 decreases according to the power offset P offset the switching between charging and discharging in the power storage device 21 occurs. Therefore, when the power offset P offset is a numerical value between the adjustment force lower limit value -ΔP1 and the adjustment force upper limit value +ΔP1, the coefficient setting unit 54 sets the calculation coefficient α to a variable value according to the power offset P offset That is, the calculation coefficient α is expressed by a function F(P offset ) with P offset as a variable.

[0072] Specifically, when the power offset P offset is a negative number greater than or equal to the adjustment force lower limit value -ΔP1 (-P1 ≤ P offset < 0), the coefficient setting unit 54 sets the calculation coefficient α so that the calculation coefficient α increases (for example, monotonically increases) in conjunction with the increase of the power offset P offset Specifically, the calculation coefficient α changes linearly with respect to the power offset P offset On the other hand, when the power offset P offset is a positive number less than or equal to the adjustment force upper limit value +ΔP1 (0 < P offset ≤ +ΔP1), the coefficient setting unit 54 sets the calculation coefficient α so that the calculation coefficient α decreases (for example, monotonically decreases) in conjunction with the increase of the power offset P offset Specifically, the calculation coefficient α changes linearly with respect to the power offset P offset Note that the relationship of the calculation coefficient α with respect to the power offset P is not limited to the relationship illustrated in FIG. 6. For example, the calculation coefficient α may be the power offset P offset The relationship of the calculation coefficient α with respect to P is not limited to the relationship illustrated in FIG. 6. For example, the calculation coefficient α may be the power offset P offsetIt may also change curvilinearly.

[0073] As can be understood from the above explanation, the calculation coefficient α in the third embodiment is expressed by the following formula (23).

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[0074] The configuration and operation of the first calculation unit 51 and the plan generation unit 53 are the same as in the first embodiment. Therefore, the same effects as in the first embodiment are achieved in the third embodiment as well. In addition, in the third embodiment, the power offset P is determined by the basic plan (power generation plan or reference value plan). offset The calculation coefficient α is set based on this. Therefore, the switching between charging and discharging in the energy storage device 21 is the power offset P offset By considering the tendency for this to become less likely to occur (i.e., the reduction in charge amount due to charge / discharge losses becomes less likely), an appropriate operating plan X can be generated.

[0075] D: Fourth Embodiment Figure 8 is a block diagram illustrating the functional configuration of the planning system 40 in the fourth embodiment. As illustrated in Figure 8, the control device 41 of the second embodiment functions as a third calculation unit 55 in addition to the same elements as in the first embodiment (first calculation unit 51, second calculation unit 52, planning generation unit 53).

[0076] The third calculation unit 55 calculates the third activation rate k3. The third activation rate k3 corresponds to the discharge loss when the energy storage device 21 does not correspond to the command value in the charging direction of the adjustment force command value P1 (i.e., when the energy storage device 21 only performs discharge). Specifically, the average value of the discharge side of the adjustment force command value P1 P out_ave (Equation (12)) and contracted power P ΔkW The following relationship (24) holds between and the third activation rate k3.

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[0077] By using equation (12) to transform equation (24), the following equation (25) is derived. The third calculation unit 55 calculates the third activation rate k3 by performing calculations using equation (25).

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[0078] In the fourth embodiment, the second calculation unit 52 calculates the activation rate k by performing the calculation of the following formula (26), instead of the formula (4) of the first embodiment.

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[0079] In formula (26), the selection coefficients b and c are set to either 0 or 1. The selection coefficients b and c are set complementaryly. That is, when the selection coefficient b is set to 0, the selection coefficient c is set to 1, and when the selection coefficient b is set to 1, the selection coefficient c is set to 0. Therefore, the second calculation unit 52 selects either the first activation rate k1 or the third activation rate k3. Specifically, the second calculation unit 52 selects the first activation rate k1 by setting the selection coefficient b to 1, and selects the third activation rate k3 by setting the selection coefficient c to 1.

[0080] Specifically, if the energy storage device 21 does not perform charging, the second calculation unit 52 selects the third activation rate k3 by setting the selection coefficient b to 0 and the selection coefficient c to 1. On the other hand, if the energy storage device 21 performs both charging and discharging, the second calculation unit 52 selects the first activation rate k1 by setting the selection coefficient b to 1 and the selection coefficient c to 0. The case in which the energy storage device 21 does not perform charging is, for example, a state where the charge rate (SOC) has reached its upper limit and the energy storage device 21 cannot perform further charging.

[0081] The second calculation unit 52 identifies the charge rate of the energy storage device 21 by referring to the operational performance Y2 supplied from the energy storage system 20 via the control system 30, and selects the third activation rate k3 if the charge rate has reached a predetermined upper limit. On the other hand, if the charge rate of the energy storage device 21 has not reached the upper limit (i.e., if the energy storage device 21 is capable of both charging and discharging), the second calculation unit 52 selects the first activation rate k1. The second calculation unit 52 may also select either the first activation rate k1 or the third activation rate k3 in response to an operation on the control device 44 by the administrator of the planning system 40.

[0082] The second calculation unit 52 calculates the activation rate k based on the selected value from the first activation rate k1 and the third activation rate k3 and the second activation rate k2, as shown in formula (26). The second calculation unit 52 also calculates the activation rate k and the contracted power P ΔkW The average charge / discharge power Pa(i) is calculated by the calculation of formula (3) which applies the above. As can be understood from the above explanation, the second calculation unit 52 of the fourth embodiment calculates the agreed power P ΔkW Then, the average charge / discharge power Pa(i) is calculated based on either the first activation rate k1 or the third activation rate k3.

[0083] The same effects as in the first embodiment are achieved in the fourth embodiment. Furthermore, in the fourth embodiment, even when the energy storage device 21 only performs discharge and does not perform charge, the operation plan X of the energy storage device 21 can be appropriately generated. The configuration of the second or third embodiment in which the coefficient setting unit 54 sets the calculation coefficient α may be applied similarly in the fourth embodiment.

[0084] In the above explanation, the example given was when the charge level of the energy storage device 21 has reached its upper limit. However, the examples are not limited to cases where the energy storage device 21 does not perform charging. For example, even if the overall profitability of the power system 100 is greater when the energy storage device 21 does not respond to the charging direction command value among the adjustment force command values ​​P1, there may be operations in which the energy storage device 21 is not allowed to perform charging.

[0085] In the above explanation, the example given was that the energy storage device 21 performs only discharge and does not perform charge. However, the same form applies when the energy storage device 21 performs only charge and does not perform discharge. In the form where the energy storage device 21 performs only charge, the third activation rate k3 corresponds to the charge loss when the energy storage device 21 does not correspond to the command value in the discharge direction of the adjustment force command value P1 (i.e., when the energy storage device 21 performs only charge). As can be understood from the above explanation, the third activation rate k3 is comprehensively expressed as a numerical value that corresponds to the loss (charge loss or discharge loss) when the energy storage device 21 does not correspond to either charge or discharge in the primary adjustment force. The operation of the second calculation unit 52 when the energy storage device 21 does not correspond to the command value in the discharge direction of the adjustment force command value P1 is the same as in the fourth embodiment.

[0086] E: Fifth Embodiment The frequency information that the first calculation unit 51 of the first embodiment applies to the calculation of the first activation rate k1(i) is, as shown in formula (21), the mean absolute deviation Δf ave and maximum frequency deviation Δf max This includes the following. In the fifth embodiment, the content of the frequency information differs from that of the first embodiment.

[0087] The frequency deviation Δf is the deviation of the system frequency f with respect to the reference frequency f0. In the fifth embodiment, the standard deviation Δf of the frequency deviation Δf is σ We will focus on the mean absolute deviation Δf. ave and the standard deviation Δf σ The following relationship (27) holds between them.

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[0088] By substituting equation (27) into equation (21), the following equation (28), which represents the first activation rate k1, is derived.

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[0089] In the fifth embodiment, the first calculation unit 51 calculates the first activation rate k1(i) by calculation of formula (28). As can be understood from formula (28), the first calculation unit 51 calculates the charging efficiency η of the energy storage device 21. in and discharge efficiency η out Based on the frequency information relating to the system frequency f of the power system 10, the first activation rate k1(i) is calculated. The frequency information in the fifth embodiment is the standard deviation Δf of the frequency deviation Δf, as can be understood from equation (28). σ And the maximum frequency deviation Δf in the primary adjustment force. max This includes the following: In other words, the fifth embodiment is the mean absolute deviation Δf in the first embodiment. ave Instead, the standard deviation Δf of the frequency deviation Δf σ The first activation rate k1(i) is calculated using this method.

[0090] The same effects as in the first embodiment are achieved in the fifth embodiment. In addition, the frequency information in the fifth embodiment is the standard deviation Δf of the frequency deviation Δf. σ This includes the mean absolute deviation Δf of the system frequency f. ave Even in situations where the frequency information cannot be obtained, the first activation rate k1(i) can be calculated appropriately. σ The configuration of the fifth embodiment, including the above, may be applied to any of the first to fourth embodiments.

[0091] Mean absolute deviation Δf in the first embodiment ave and the standard deviation Δf in the fifth embodiment σ This is comprehensively expressed as a statistical quantity (dispersion) that represents the degree of dispersion of the frequency deviation Δf of the system frequency f relative to the reference frequency f0. In other words, the frequency information used in calculating the first activation rate k1(i) is the dispersion of the frequency deviation Δf and the maximum frequency deviation Δf max This includes the following. According to the above configuration, the dispersion of the frequency deviation Δf and the maximum frequency deviation Δf max Based on this, the first activation rate k1(i) can be appropriately calculated.

[0092] Furthermore, the notation "the nth" (where n is a natural number) in this application is used solely as a formal and convenient label to distinguish each element in notation, and has no substantive meaning whatsoever. Therefore, there is no room for restrictive interpretation of the position or order of each element based on the notation "the nth".

[0093] G: Note From the forms exemplified above, the following configuration can be understood, for example.

[0094] A planning system according to one aspect of the present disclosure (Aspect 1) is a planning system for generating an operational plan for charging and discharging a power storage device capable of providing primary adjustment power to a power grid, comprising: a first calculation unit that calculates a first activation rate corresponding to the loss due to charging and discharging of the primary adjustment power based on the charging efficiency and discharging efficiency of the power storage device and frequency information relating to the grid frequency in the power grid; a second calculation unit that calculates the average charging and discharging power of the power storage device based on the contracted power of the adjustment power and the first activation rate; and a planning generation unit that generates the operational plan based on the average charging and discharging power. In the above aspect, in addition to frequency information relating to the grid frequency, the charging efficiency and discharging efficiency of the power storage device are taken into account in the average charging and discharging power of the power storage device. Therefore, compared to an aspect in which an operational plan is generated based only on frequency information, it is possible to generate an appropriate operational plan that takes into account the decrease in the amount of charge of the power storage device.

[0095] In a specific example of Embodiment 1 (Embodiment 2), the frequency information includes the dispersion of the deviation of the system frequency with respect to a predetermined reference frequency and the maximum frequency deviation in the primary adjustment force. In the above embodiment, the first activation rate can be appropriately calculated based on the dispersion of the system frequency and the maximum frequency deviation.

[0096] In the specific example of Embodiment 2 (Embodiment 3), the dispersion is the average of the absolute values ​​of the deviations of the system frequency with respect to the reference frequency. In the above embodiments, the first activation rate can be appropriately calculated using the average of the absolute values ​​of the deviations of the system frequency with respect to the reference frequency (mean absolute deviation).

[0097] In the specific example of Embodiment 2 (Embodiment 4), the dispersion is the standard deviation of the deviation of the system frequency with respect to the reference frequency. In the above embodiments, by using the standard deviation of the deviation of the system frequency with respect to the reference frequency, the first activation rate can be appropriately calculated even in situations where the mean absolute deviation of the system frequency cannot be obtained.

[0098] In any specific example of Embodiments 1 to 4 (Embodiment 5), the system further comprises a coefficient setting unit for setting a calculation coefficient that represents the degree of influence of the first activation rate on the operation plan, and the second calculation unit calculates the average charge / discharge power based on the contracted power, the first activation rate, and the calculation coefficient. In the above embodiments, since the average charge / discharge power is calculated based on the contracted power, the first activation rate, and the calculation coefficient, an appropriate operation plan can be generated according to various conditions, such as the status of power supply by the power storage device.

[0099] In a specific example of Embodiment 5 (Embodiment 6), the coefficient setting unit sets the calculation coefficient based on a power offset corresponding to the basic plan for the operation of the power storage device. In the above embodiment, since the calculation coefficient is set based on the power offset according to the basic plan (generation plan or reference value plan), an appropriate operation plan can be generated, taking into account the tendency for switching between charging and discharging in the power storage device to become less likely to occur in accordance with the power offset (meaning that a decrease in the amount of charge due to charge / discharge losses becomes less likely).

[0100] In any specific example of Embodiments 1 to 6 (Embodiment 7), the system further comprises a third calculation unit that calculates a third activation rate corresponding to the loss when the power storage device does not correspond to either charging or discharging in the primary adjustment power, and the second calculation unit calculates the average charge / discharge power based on the contracted power and either the first activation rate or the third activation rate. In the above embodiment, an appropriate operating plan for the power storage device can be generated even when the power storage device performs only one of charging or discharging.

[0101] A planning method according to one aspect of the present disclosure (Aspect 8) is a planning method for generating an operational plan for charging and discharging a power storage device capable of providing primary adjustment power to a power grid, the planning system comprising: calculating a first activation rate corresponding to the loss due to charging and discharging of the primary adjustment power based on the charging efficiency and discharging efficiency of the power storage device and frequency information relating to the grid frequency in the power grid; calculating the average charging and discharging power of the power storage device based on the contracted power of the adjustment power and the first activation rate; and generating the operational plan based on the average charging and discharging power. [Explanation of Symbols]

[0102] 100...Power system, 10...Power grid, 11...Connection point, 20...Energy storage system, 21...Energy storage device, 22...Control device, 30...Control system, 40...Planning system, 41...Control device, 42...Memory device, 43...Communication device, 44...Operating device, 51...First calculation unit, 52...Second calculation unit, 53...Plan generation unit, 54...Coefficient setting unit, 55...Third calculation unit.

Claims

1. A planning system for generating an operational plan for charging and discharging power storage devices capable of providing primary adjustment power to the power grid, A first calculation unit calculates a first activation rate corresponding to the loss due to charging and discharging of the primary regulating power, based on the charging efficiency and discharging efficiency of the power storage device and frequency information relating to the grid frequency in the power grid. A second calculation unit calculates the average charge / discharge power of the power storage device based on the agreed power of the adjustment force and the first activation rate, A planning generation unit that generates the operation plan based on the average charge / discharge power, A planning system equipped with the following features.

2. The aforementioned frequency information is The degree of dispersion of the deviation of the system frequency with respect to a predetermined reference frequency, Includes the maximum frequency deviation in the primary adjustment force. The planning system according to claim 1.

3. The aforementioned spraying degree is, This is the average of the absolute values ​​of the deviations of the system frequency from the reference frequency. The planning system according to claim 2.

4. The aforementioned spraying degree is, This is the standard deviation of the deviation of the system frequency from the reference frequency. The planning system according to claim 2.

5. The system further comprises a coefficient setting unit for setting a calculation coefficient that represents the degree of influence of the first activation rate on the operation plan, The second calculation unit calculates the average charge / discharge power based on the agreed power, the first activation rate, and the calculation coefficient. The planning system according to claim 1.

6. The coefficient setting unit sets the calculation coefficient based on the power offset according to the basic plan for the operation of the power storage device. The planning system according to claim 5.

7. The system further comprises a third calculation unit that calculates a third activation rate corresponding to the loss when the power storage device does not correspond to either the charging or discharging in the primary adjustment power, The second calculation unit calculates the average charge / discharge power based on the agreed power and one of the first activation rate and the third activation rate. The planning system according to claim 1.

8. A planning method for generating an operational plan for charging and discharging a power storage device capable of providing primary adjustment power to a power grid, The planning system Based on the charging efficiency and discharging efficiency of the power storage device and frequency information relating to the grid frequency in the power grid, a first activation rate corresponding to the loss due to charging and discharging of the primary regulating power is calculated. Based on the agreed power of the adjustment force and the first activation rate, the average charge / discharge power of the power storage device is calculated, To generate the operation plan based on the average charge / discharge power mentioned above. A planning method that includes this.

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