Control and Management Systems

Abstract

The allocation of active power to be instructed to a plurality of power storage devices is appropriately calculated. [Solution] The control system 40 is a control system for controlling a storage system that adjusts the active power at a combination point with a power grid using a plurality of storage units including storage devices that discharge and charge DC power, and is equipped with a command calculation unit 51 that calculates a total DC power command value Cp, which is the total value of power to be discharged or charged by the storage devices in the plurality of storage units, by adding power losses including conversion losses due to conversion between DC power and AC power and conversion losses due to conversion between AC power and active power at the combination point to a basic command value C0 for active power, a command distribution unit 52 that calculates an active power allocation value P[m] to be allocated to each of the plurality of storage units from the total DC power command value Cp, and an operation instruction unit 53 that instructs each of the plurality of storage units of the active power allocation value P[m] of that storage unit.

Description

[Technical field]

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

[0002] For example, a technique for controlling a plurality of power storage devices according to a command value for power to be exchanged with a power grid has been proposed. For example, Patent Document 1 discloses a configuration for controlling the charging and discharging of each storage battery according to a command value based on a charging request or a discharging request in a storage battery system having a plurality of banks each composed of an AC / DC converter and a storage battery. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-94363 A Summary of the Invention [Problem to be solved by the invention]

[0004] Various power losses may occur in the paths from each power storage device to the combining point. Therefore, there is room for further improvement in terms of appropriately calculating the distribution of active power instructed to the multiple power storage devices. [Means for solving the problem]

[0005] In order to solve the above problems, a control system according to one embodiment of the present disclosure is a control system for controlling a storage system that adjusts active power at a combination point with a power grid using a plurality of storage units including storage devices that discharge and charge DC power, and includes a command calculation unit that calculates a total DC power command value that is a total value of power to be discharged or charged by the storage devices in the plurality of storage units by adding power losses including conversion losses due to conversion between DC power and AC power and transformation losses due to transformation between the storage system and a substation equipment between the storage system and the combination point to a basic command value of the active power, a command distribution unit that calculates from the total DC power command value an active power allocation value to be allocated to each of the plurality of storage units, and an operation instruction unit that instructs each of the plurality of storage units on the active power allocation value of the storage unit.

[0006] A management system according to one embodiment of the present disclosure includes a storage system that adjusts active power at a combination point with a power grid using a plurality of storage units including storage devices that discharge and charge DC power, and a control system that controls the storage system. The control system includes a command calculation unit that calculates a total DC power command value, which is a total value of power to be discharged or charged by the storage devices in the plurality of storage units, by adding power losses including conversion losses due to conversion between DC power and AC power and transformation losses due to transformation between the storage system and a substation equipment between the storage system and the combination point, to a basic command value of the active power, a command distribution unit that calculates an active power allocation value to be allocated to each of the plurality of storage units from the total DC power command value, and an operation instruction unit that instructs each of the plurality of storage units on the active power allocation value of the storage unit. [Brief description of the drawings]

[0007] [Figure 1] 1 is a block diagram illustrating a configuration of a management system according to a first embodiment. [Diagram 2] FIG. 2 is a block diagram illustrating a configuration of a control system. [Diagram 3] FIG. 2 is a block diagram illustrating a functional configuration of the control system. [Figure 4] FIG. 11 is an equivalent circuit diagram in which a plurality of power storage units are virtually integrated. [Diagram 5] FIG. 4 is an explanatory diagram of the operation of a command calculation unit. [Figure 6] FIG. 4 is an explanatory diagram of the operation of a command calculation unit. [Figure 7] FIG. 2 is a block diagram illustrating a configuration of a command distribution unit. [Figure 8] 13 is a specific example of an operation of the distribution processing unit when a total DC power command value indicates discharging. [Figure 9] FIG. 4 is an explanatory diagram of the relationship between effective power allocation values ​​and combination point power. [Figure 10] 13 is a specific example of an operation of the distribution processing unit when a total DC power command value indicates charging. [Figure 11] FIG. 4 is an explanatory diagram of the relationship between effective power allocation values ​​and combination point power. [Figure 12] 13 is a flowchart of a control process. [Figure 13] FIG. 11 is a block diagram illustrating a configuration of a restriction setting unit in the second embodiment. [Figure 14] 11 is an explanatory diagram of an operation in which a candidate value setting unit sets a candidate value according to a voltage. FIG. [Figure 15] 11 is an explanatory diagram of an operation in which a candidate value setting unit sets a candidate value according to a charging rate. FIG. [Figure 16] 11 is an explanatory diagram of an operation in which a candidate value setting unit sets a candidate value according to temperature. FIG. [Figure 17] 13 shows the relationship between the temperature and the candidate value when the power storage device absorbs heat due to discharging. [Figure 18] 11 is an explanatory diagram of an operation in which a candidate value setting unit sets a candidate value according to a voltage. FIG. [Figure 19] 11 is an explanatory diagram of an operation in which a candidate value setting unit sets a candidate value according to a charging rate. FIG. [Figure 20] 11 is an explanatory diagram of an operation in which a candidate value setting unit sets a candidate value according to temperature. FIG. [Figure 21]13 shows the relationship between the temperature and the candidate value when the power storage device generates heat due to charging. [Figure 22] FIG. 13 is an explanatory diagram of the operation of a coefficient setting unit in the third embodiment. [Diagram 23] FIG. 13 is an explanatory diagram of the operation of a coefficient setting unit in the third embodiment. [Figure 24] FIG. 1 is an explanatory diagram of operating watt-hour capacity. [Diagram 25] FIG. 13 is an explanatory diagram of a first process in the fourth embodiment. [Figure 26] FIG. 13 is an explanatory diagram of a process for calculating a weight value in the fourth embodiment. [Figure 27] 13 is an explanatory diagram of weighted values ​​when a total DC power command value indicates charging. FIG. [Figure 28] FIG. 13 is an explanatory diagram of a process for calculating a weight value in the fourth embodiment. [Figure 29] FIG. 13 is an explanatory diagram of a process for calculating a weight value in the fourth embodiment. [Diagram 30] FIG. 13 is an explanatory diagram of a first process in the fifth embodiment. [Diagram 31] FIG. 13 is an explanatory diagram of a process for calculating a weight value in the fifth embodiment. [Diagram 32] FIG. 13 is an explanatory diagram of a process for calculating a weight value in the fifth embodiment. [Diagram 33] FIG. 13 is an explanatory diagram of a process for calculating a weight value α[m] in the fifth embodiment. [Diagram 34] 13 is an explanatory diagram of weighted values ​​when a total DC power command value indicates charging. FIG. [Diagram 35] FIG. 23 is an explanatory diagram of a first process in the sixth embodiment. [Diagram 36] FIG. 23 is an explanatory diagram of a process for calculating a weight value in the sixth embodiment. [Figure 37] FIG. 23 is an explanatory diagram of a process for calculating a weight value in the sixth embodiment. [Figure 38] FIG. 23 is an explanatory diagram of a first process in the seventh embodiment. [Figure 39] 13 is an explanatory diagram of the operation of a coefficient setting unit in the eighth embodiment. FIG. [Diagram 40] FIG. [Diagram 41] FIG. 11 is an explanatory diagram of a specific configuration for implementing smoothing processing. [Diagram 42] 10 is an explanatory diagram relating to an operation in a case where one power storage unit is additionally started up during discharging by the power storage system. FIG. [Diagram 43] FIG. 11 is an explanatory diagram regarding changes over time in distribution coefficients and distribution values. [Diagram 44] 10 is an explanatory diagram relating to an operation in a case where one power storage unit is additionally started up during charging by the power storage system. FIG. [Diagram 45] FIG. 11 is an explanatory diagram regarding changes over time in distribution coefficients and distribution values. [Figure 46] 11 is an explanatory diagram relating to an operation in a case where one power storage unit is stopped during discharging by the power storage system. FIG. [Figure 47] FIG. 11 is an explanatory diagram regarding changes over time in distribution coefficients and distribution values. [Figure 48] 10 is an explanatory diagram relating to an operation in a case where one power storage unit is stopped during charging by the power storage system. FIG. [Figure 49] FIG. 11 is an explanatory diagram regarding changes over time in distribution coefficients and distribution values. [Figure 50] FIG. 23 is an explanatory diagram of the operation of a command calculation unit in the eleventh embodiment. [Figure 51] FIG. 23 is an explanatory diagram of the operation of the management system in the eleventh embodiment. [Figure 52] FIG. 2 is an explanatory diagram of the operation of the management system in operation case 1 of the first embodiment. [Figure 53] FIG. 2 is an explanatory diagram of the operation of the management system in operation case 1 of the first embodiment. [Figure 54] FIG. 11 is an explanatory diagram of the operation of the management system in an operation case 2 of the first embodiment. [Figure 55] FIG. 11 is an explanatory diagram of the operation of the management system in an operation case 2 of the first embodiment. [Figure 56] FIG. 11 is an explanatory diagram of the operation of the management system in operation case 3 of the first embodiment. [Figure 57] FIG. 11 is an explanatory diagram of the operation of the management system in operation case 3 of the first embodiment. [Figure 58] FIG. 11 is an explanatory diagram of the operation of the management system in operation case 4 of the first embodiment. [Figure 59] FIG. 11 is an explanatory diagram of the operation of the management system in operation case 4 of the first embodiment. [Figure 60] FIG. 23 is a block diagram illustrating a functional configuration of a control system according to a thirteenth embodiment. [Figure 61] FIG. 23 is an explanatory diagram of the operation of a command calculation unit in the thirteenth embodiment. [Figure 62] 5 is an explanatory diagram of an operation of a command distribution unit calculating a reactive power distribution value of each power storage unit. FIG. [Figure 63] FIG. 23 is a block diagram illustrating the configuration of a management system according to a fourteenth embodiment. [Figure 64] FIG. 23 is a block diagram illustrating the configuration of a management system according to a fifteenth embodiment. [Figure 65] FIG. 23 is a block diagram illustrating a configuration of a power storage unit in a sixteenth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] An embodiment for carrying out the present disclosure will be described with reference to the drawings. Note that the embodiment described below is an exemplary embodiment assumed when carrying out the present disclosure. Therefore, the scope of the present disclosure is not limited to the embodiment exemplified below.

[0009] 1. First embodiment FIG. 1 is a block diagram illustrating an example of the configuration of a management system 100 according to a first embodiment. The management system 100 is a system that transfers AC power to and from a power system 10. The power system 10 is, for example, a distribution system or a transmission system for supplying AC power generated by a power generation facility 23 (not shown) such as a thermal power plant or a nuclear power plant to consumers such as business facilities or general households. The management system 100 is connected to the power system 10 at a combination point 11. The combination point 11 is an interconnection point that corresponds to the boundary between the power system 10 and the management system 100.

[0010] 1, the management system 100 includes a substation facility 21, a load facility 22, a power storage system 30, and a control system 40. The power storage system 30 is a power facility that receives and transmits AC power to and from the power grid 10.

[0011] The substation equipment 21 is a power facility that aggregates the outputs of the multiple energy storage units U[m] constituting the energy storage system 30 and the inputs of the load equipment 22, and transforms the voltage of the AC power exchanged between these and the combining point 11 using a transformer. The transformer of the substation equipment 21 may be omitted. The load equipment 22 is various loads (in-station loads) that operate by consuming power supplied from the energy storage system 30 or the power grid 10. For example, the load equipment 22 includes various facilities that supply control power, operation power, or auxiliary power to each element of the management system 100 (the substation equipment 21, the energy storage system 30, or the control system 40). Specifically, examples of the load equipment 22 include a station transformer that transforms the supply voltage from the substation equipment 21, a DC power supply device that supplies a control power source or an operation power source to the substation equipment 21 or the AC / DC converter 322, an uninterruptible power supply (UPS) that supplies power when an abnormality occurs, a power supply device that supplies auxiliary power (for example, driving power required for auxiliary equipment such as air conditioning equipment) or a control power source to the power storage device 31, an oil pump or a cooling fan used in the substation equipment 21 or the AC / DC converter 322, a communication device used for security calls with the power company, lighting equipment or air conditioning equipment installed on a site or building, a measurement system that measures environmental information such as temperature or humidity, and various firefighting equipment (smoke detectors, heat detectors, fire alarms, etc.). Note that the load equipment 22 may be omitted.

[0012] The power storage system 30 of the first embodiment is composed of a plurality of power storage units U[m] (m=1 to 5). In the following description, for convenience, an example in which the power storage system 30 includes five power storage units U[1] to U[5] is shown. However, the number of power storage units U[m] constituting the power storage system 30 can be changed arbitrarily.

[0013] Each of the multiple power storage units U[m] is a power facility capable of charging and discharging power. As illustrated in Fig. 1, each power storage unit U[m] includes a power storage device 31 and a power adjustment device 32. The power storage device 31 is a secondary battery that charges and discharges DC power. The type of the power storage device 31 is arbitrary, but examples of the power storage device 31 include a lithium ion battery or a sodium sulfur battery.

[0014] The power conditioning device 32 is a PCS (Power Conditioning System) that controls discharging and charging of the power storage device 31. Specifically, the power conditioning device 32 includes a transformer 321 and an AC / DC converter 322. The transformer 321 converts the voltage of AC power. The AC / DC converter 322 converts DC power and AC power back and forth. Specifically, the AC / DC converter 322 converts DC power supplied by discharging the power storage device 31 into AC power, and the transformer 321 converts the voltage of the AC power converted by the AC / DC converter 322 and supplies it to the combining point 11. In addition, the transformer 321 converts the voltage of the AC power supplied from the power system 10, converts the AC power transformed by the transformer 321 into DC power and supplies it to the power storage device 31. As described above, the power storage system 30 adjusts the active power at the combining point 11 with the power grid 10 by using a plurality of power storage units U[m] including the power storage device 31. The transformer 321 may be omitted. Also, a single transformer 321 may be shared by a plurality of power storage units U[m].

[0015] The control system 40 is a computer system (PMS: ​​Power Management System) that controls the power storage system 30. Specifically, the control system 40 instructs each power storage unit U[m] of the power storage system 30 of an active power allocation value P[m]. Each power storage unit U[m] causes the power storage device 31 to discharge or charge DC power corresponding to the active power allocation value P[m]. The active power allocation value P[m] is a power value of AC power to be discharged or charged by the power storage unit U[m]. Specifically, a positive value of the active power allocation value P[m] corresponds to a command for discharging (i.e., power supply from the power storage unit U[m] to the combining point 11), and a negative value of the active power allocation value P[m] corresponds to a command for charging (i.e., power reception from the combining point 11 by the power storage unit U[m]). Note that a negative value of the active power allocation value P[m] may correspond to a command for discharging, and a positive value of the active power allocation value P[m] may correspond to a command for charging.

[0016] Fig. 2 is a block diagram illustrating an example of the configuration of the control system 40. As illustrated in Fig. 2, the control system 40 includes a control device 41, a storage device 42, and a transmission / reception device 43. The control system 40 may be realized by a single device, or may be realized by a plurality of devices configured separately from each other.

[0017] The control device 41 is composed of one or more processors that control each element of the control system 40. Specifically, the control device 41 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).

[0018] The storage device 42 is one or more memories that store the programs executed by the control device 41 and the data used by the control device 41. The storage device 42 is configured with a known recording medium such as a magnetic recording medium or a semiconductor recording medium. The storage device 42 may be configured with a combination of multiple types of recording media. A portable recording medium that is detachable from the control system 40 may be used as the storage device 42.

[0019] The transmitting / receiving device 43 transmits and receives signals to and from an external device via a wired or wireless connection. Specifically, the transmitting / receiving device 43 communicates with each power storage unit U[m] (specifically, the power adjustment device 32) via a communication network (not shown) such as a dedicated line. For example, the active power allocation value P[m] is transmitted from the transmitting / receiving device 43 to each power storage unit U[m]. Note that the signals exchanged between the transmitting / receiving device 43 and each power storage unit U[m] (specifically, the power adjustment device 32) may be either digital signals or analog signals.

[0020] 3 is a block diagram illustrating an example of a functional configuration of the control system 40. The control device 41 executes a program stored in the storage device 42 to realize a plurality of functions (a command calculation unit 51, a command distribution unit 52, and an operation instruction unit 53) for controlling a plurality of power storage units U[m].

[0021] 3, a basic command value C0 is input to the control system 40. The basic command value C0 is a command value for active power at a combining point 11 with the power grid 10 (hereinafter referred to as "combining point power"). In other words, the basic command value C0 is a total value of power to be discharged or charged by the entire management system 100. The basic command value C0 indicates the numerical value of the combining point power, and also indicates the direction of power (discharging / charging) to the combining point 11 by a sign. Specifically, power supply from the power storage system 30 to the combining point 11 (i.e., discharging by the power storage unit U[m]) is indicated by a positive number, and power reception from the combining point 11 by the power storage system 30 (i.e., charging by the power storage unit U[m]) is indicated by a negative number.

[0022] The base command value C0 is transmitted to the control system 40 from an external system that manages an electricity market, such as a wholesale electricity market or a supply and demand adjustment market. That is, the base command value C0 is the total value of electricity that the management system 100 should trade in various electricity markets.

[0023] 3 calculates a total DC power command value Cp from the basic command value C0. The total DC power command value Cp is a command value obtained by adding a power loss from the power storage devices 31 of each power storage unit U[m] to the combining point 11 to the basic command value C0. Specifically, the total DC power command value Cp specifies a total value of DC power to be generated by each power storage device 31 so that the combining point power is maintained at the basic command value C0 even when a power loss is accompanied from each power storage device 31 to the combining point 11. In other words, the total DC power command value Cp is a total value of DC power to be discharged or charged by the power storage devices 31 in the multiple power storage units U[m] to realize the basic command value C0.

[0024] Fig. 4 is an equivalent circuit diagram in which a plurality of power storage units U[m] are virtually integrated. As illustrated in Fig. 4, the power storage devices 31 in the plurality of power storage units U[m] are equivalently replaced with one power storage device 31eq, and the power adjustment devices 32 in the plurality of power storage units U[m] are equivalently replaced with one power adjustment device 32eq.

[0025] 4, the total DC power command value Cp calculated by the command calculation unit 51 is the total value of the DC power to be discharged or received by the power storage device 31eq. As can be understood from the above description, the total DC power command value Cp can also be expressed as a numerical value obtained by converting the AC power to be set at the combination point 11 (i.e., the combination point power specified by the basic command value C0) into an equivalent DC power generated by the power storage device 31.

[0026] As illustrated in FIG. 4, in the path from the power storage device 31 of each power storage unit U[m] to the combining point 11, a transformation loss X1, a load loss X2, and a conversion loss X3 occur.

[0027] The transformation loss X1 is a power loss caused by the transformation by the substation equipment 21. That is, the transformation loss X1 is a loss (e.g., load loss and no-load loss) that occurs due to the transformation between the AC voltage between the power storage system 30 and the substation equipment 21 and the voltage at the combination point 11.

[0028] The transformation loss X1 is calculated by adding up a calculated value of copper loss occurring in the transformer of the substation equipment 21 when power corresponding to the basic command value C0 passes through the combining point 11 and back, and an iron loss occurring in the transformer of the substation equipment 21 when a voltage is applied to the substation equipment 21. Stray load loss or dielectric loss of the transformer in the substation equipment 21 may be added to the transformation loss X1. The transformation loss X1 may be calculated from the absolute value of the difference between the power at the combining point 11 corresponding to the basic command value C0 (or a measurement value by a power meter installed at the combining point 11) and a measurement value by a meter installed at the input of the substation equipment 21. Furthermore, a line loss between the energy storage system 30 and the substation equipment 21 may be added to the transformation loss X1.

[0029] The load loss X2 is a power loss caused by the consumption of power by the load equipment 22. That is, the load loss X2 corresponds to the active power consumed by the load equipment 22. The load loss X2 is calculated according to a measurement value measured by a measuring instrument, for example. The load loss X2 may be calculated according to a planned value set in advance for the load equipment 22. Furthermore, a line loss between the energy storage system 30 and the load equipment 22 may be added to the load loss X2.

[0030] The conversion loss X3 is a power loss obtained by totaling, across the multiple power storage units U[m], the conversion losses x[m] caused by the power conversion by the power adjustment device 32 of each power storage unit U[m]. The conversion loss x[m] of each power storage unit U[m] is a loss generated by conversion between DC power between the power storage device 31 and the power adjustment device 32 and AC power between the control system 40 and the substation equipment 21.

[0031] The conversion loss x[m] is the sum of the loss (e.g., load loss and no-load loss) of the transformer 321 in the power storage unit U[m] and the loss of the AC-DC converter 322. A line loss between the transformer 321 and the AC-DC converter 322 may be added to the conversion loss x[m].

[0032] The loss of the transformer 321 is calculated by adding a calculated value of the copper loss of the transformer 321 that occurs when power equivalent to the active power allocation value P[m] passes through the transformer 321 and vice versa, and an iron loss of the transformer 321 that occurs when a voltage is applied to the transformer 321. Stray load loss or dielectric loss of the transformer 321 may be added to the conversion loss x[m]. The loss of the transformer 321 may be calculated by the absolute value of the difference between the power equivalent to the active power allocation value P[m] input to the transformer 321 (or a value measured by a power meter provided at the input of the transformer 321) and a value measured by a power meter provided at the output of the transformer 321.

[0033] The loss of the AC / DC converter 322 is calculated, for example, by the absolute value of the difference between the active power allocation value P[m] (or the measurement value by a power meter installed on the AC side of the AC / DC converter 322) and the measurement value of the DC power.

[0034] 5 and 6 are explanatory diagrams of the operation of the command calculation unit 51. Fig. 5 shows the operation of the command calculation unit 51 when discharge by the power storage system 30 is instructed by the basic command value C0 (C0>0). As illustrated in Fig. 5, the command calculation unit 51 calculates the total DC power command value Cp by adding a power loss (X1+X2+X3) including a transformation loss X1, a load loss X2, and a conversion loss X3 to the basic command value C0. Fig. 5 illustrates a state in which the conversion loss x[m] of each power storage unit U[m] is "1", and therefore the conversion loss X3 is "5".

[0035] Fig. 6 shows the operation of the command calculation unit 51 when charging by the power storage system 30 is instructed by the basic command value C0 (C0<0). The basic command value C0 is a negative number, while the transformation loss X1, the load loss X2, and the conversion loss X3 are positive numbers. When charging by the power storage system 30 is instructed by the basic command value C0, the command calculation unit 51 calculates the total DC power command value Cp by adding the power loss (X1+X2+X3) including the transformation loss X1, the load loss X2, and the conversion loss X3 to the basic command value C0, as in the case of Fig. 5.

[0036] That is, the command calculation unit 51 calculates the total DC power command value Cp by adding the transformation loss X1, the load loss X2, and the conversion loss X3 to the basic command value C0, as expressed by the following formula (1).

number

[0037] 3 calculates an active power command value (hereinafter referred to as "active power allocation value P[m]") to be allocated to each of the multiple energy storage units U[m] from the total DC power command value Cp. The active power allocation value P[m] is a command value for AC power to be discharged (P[m]>0) or charged (P[m]<0) by each energy storage unit U[m].

[0038] The operation instruction unit 53 instructs each of the multiple power storage units U[m] of the active power allocation value P[m] of the power storage unit U[m]. Specifically, the operation instruction unit 53 transmits the active power allocation value P[m] calculated by the command allocation unit 52 to the power storage unit U[m] via the transmission / reception device 43.

[0039] 7 is a block diagram illustrating a specific configuration of the command distribution unit 52. As illustrated in FIG. 7, the command distribution unit 52 includes a coefficient setting unit 521, a limit value setting unit 522, and a distribution processing unit 523.

[0040] The coefficient setting unit 521 sets a distribution coefficient K[m] (K[1] to K[5]) for each of the multiple power storage units U[m]. Each distribution coefficient K[m] is a positive number that indicates the proportion of the power that should be shared by the power storage unit U[m] in the total DC power command value Cp. The coefficient setting unit 521 in the first embodiment sets the distribution coefficient K[m] according to, for example, the specifications or state of each power storage device 31.

[0041] The limit value setting unit 522 sets a limit value L[m] (L[1] to L[5]) for each of the multiple power storage units U[m]. Each limit value L[m] is a numerical value for limiting the active power allocation value P[m] within a predetermined range. The limit value L[m] includes a limit value L[m]_d (d: discharge) related to discharging the power storage device 31 and a limit value L[m]_c (c: charge) related to charging the power storage device 31. The limit value setting unit 522 in the first embodiment sets the limit value L[m] according to, for example, the specifications or state of each power storage device 31.

[0042] The allocation processing unit 523 calculates an active power allocation value P[m] to be allocated to each power storage unit U[m] from the total DC power command value Cp. The allocation processing unit 523 of the first embodiment allocates the total DC power command value Cp to a plurality of active power allocation values ​​P[m] in accordance with an allocation coefficient K[m] set by a coefficient setting unit 521 for each power storage unit U[m] and a limit value L[m] (L[m]_d, L[m]_c) set by a limit value setting unit 522 for each power storage unit U[m].

[0043] 8 to 11 are explanatory diagrams of the operation by the distribution processing unit 523. First, Fig. 8 is a specific example of the operation of the distribution processing unit 523 when the total DC power command value Cp indicates discharging (Cp>0).

[0044] In step Sa1, the allocation processing unit 523 calculates a power allocation value Pa[m] to be allocated to each power storage unit U[m] of the total DC power command value Cp according to an allocation coefficient K[m] of each power storage unit U[m]. Specifically, the allocation processing unit 523 calculates each power allocation value Pa[m] such that each power allocation value Pa[m] has a ratio corresponding to the allocation coefficient K[m]. Note that the power allocation value Pa[m] is an example of a "first power allocation value."

[0045] For example, the allocation processing unit 523 calculates each power allocation value Pa[m] by the calculation of the following formula (2). That is, the allocation processing unit 523 calculates each power allocation value Pa[m] by multiplying the ratio of each allocation coefficient K[m] to the total value ΣK[m] of the multiple allocation coefficients K[m] (K[1] to K[5]) by the total DC power command value Cp of discharge illustrated in Fig. 5. As can be understood from the above description, according to the first embodiment, the total DC power command value Cp can be allocated to each of the multiple power storage units U[m] in accordance with the allocation coefficient K[m] of each power storage unit U[m].

number

[0046] The power allocation value Pa[m] calculated in step Sa1 may exceed the limit value L[m]_d for discharging. When the total DC power command value Cp indicates discharging, the power allocation value Pa[m] exceeds the limit value L[m]_d when the power allocation value Pa[m] exceeds the limit value L[m]_d (Pa[m]>L[m]_d). For example, FIG. 8 illustrates a case where the power allocation value Pa[1] (=50) of the power storage unit U[1] exceeds the limit value L[1]_d (=40) and the power allocation value Pa[2] (=40) of the power storage unit U[2] exceeds the limit value L[2]_d (=30).

[0047] The allocation processing unit 523 allocates a total excess value E1, which is the sum of the excess values ​​(Pa[m]-L[m]_d) for one or more power storage units U[m] among the multiple power storage units U[m] whose power allocation value Pa[m] exceeds the limit value L[m]_d, to each of one or more power storage units U[m] among the multiple power storage units U[m] whose power allocation value Pa[m] does not exceed the limit value L[m]_d (Sa2 to Sa5).

[0048] Specifically, in step Sa2 in Fig. 8, the allocation processing unit 523 calculates a total excess value E1 by summing up the differences (i.e., excess values) between the power allocation value Pa[m] and the limit value L[m]_d for one or more power storage units U[m] among the multiple power storage units U[m] whose power allocation value Pa[m] exceeds the limit value L[m]_d. In the situation in Fig. 8, the total excess value E1 is calculated as "20", which is the sum of "10" which is the excess value (Pa[1]-L[1]_d) of the power storage unit U[1] and "10" which is the excess value (Pa[2]-L[2]_d) of the power storage unit U[2].

[0049] In step Sa3, the allocation processing unit 523 calculates the total available power E2 by summing up the differences (i.e., margin values) between the limit value L[m]_d and the power allocation value Pa[m] for one or more power storage units U[m] among the multiple power storage units U[m] whose power allocation value Pa[m] does not exceed the limit value L[m]_d. In the situation of Fig. 8, the total available power E2 is calculated as "30", which is the sum of "10" which is the margin value (L[4]_d-Pa[4]) of the power storage unit U[4] and "20" which is the margin value (L[5]_d-Pa[5]) of the power storage unit U[5].

[0050] In step Sa4, the allocation processing unit 523 calculates an additional allocation value ΔP[m] for one or more power storage units U[m] whose power allocation value Pa[m] does not exceed the limit value L[m]_d among the multiple power storage units U[m]. Specifically, the allocation processing unit 523 calculates each additional allocation value ΔP[m] by calculating the following formula (3a). That is, the allocation processing unit 523 calculates the additional allocation value ΔP[m] by multiplying the ratio of each margin value (L[m]_d-Pa[m]) to the total available power E2 by the total excess value E1.

number

[0051] In step Sa5, the allocation processing unit 523 calculates a power allocation value Pb[m] for each power storage unit U[m]. That is, each power allocation value Pa[m] is updated to the power allocation value Pb[m]. Specifically, the allocation processing unit 523 sets the limit value L[m]_d as the updated power allocation value Pb[m] for one or more power storage units U[m] whose power allocation value Pa[m] exceeds the limit value L[m]_d among the multiple power storage units U[m]. In addition, the allocation processing unit 523 calculates the updated power allocation value Pb[m] by adding an additional allocation value ΔP[m] to the power allocation value Pa[m] for one or more power storage units U[m] whose power allocation value Pa[m] does not exceed the limit value L[m]_d among the multiple power storage units U[m]. For the power storage units U[m] among the multiple power storage units U[m] whose power allocation value Pa[m] is equal to the limit value L[m]_d, the power allocation value Pa[m] is adopted as the power allocation value Pb[m]. The power allocation value Pb[m] is a command value for the DC power to be discharged by the power storage device 31 of each power storage unit U[m].

[0052] In step Sa6, the allocation processing unit 523 calculates an active power allocation value P[m] by subtracting the conversion loss x[m] in each power storage unit U[m] from the power allocation value Pb[m] calculated for that power storage unit U[m] (P[m]=Pb[m]-x[m]). That is, the active power allocation value P[m] is a command value for the active power to be discharged by the power storage unit U[m], as described above. The operation of the allocation processing unit 523 to calculate the active power allocation value P[m] when the total DC power command value Cp indicates discharge (Cp>0) is as described above.

[0053] As described above, between each energy storage unit U[m] and the combining point 11, a transformation loss X1 due to the substation equipment 21 and a load loss X2 due to the load equipment 22 occur. As illustrated in Fig. 9, the transformation loss X1 and the load loss X2 are offset from the total value ΣP[m] of the active power allocation values ​​P[m] calculated by the above procedure, and as a result, AC power equivalent to the basic command value C0 (=130) is supplied from the management system 100 to the combining point 11.

[0054] FIG. 10 shows a specific example of the operation of the distribution processing unit 523 when the total DC power command value Cp indicates charging (Cp<0).

[0055] In step Sa1, the allocation processing unit 523 calculates a power allocation value Pa[m] to be allocated to each power storage unit U[m] from the total DC power command value Cp according to the allocation coefficient K[m] of each power storage unit U[m]. Specifically, the allocation processing unit 523 calculates each power allocation value Pa[m] so that each power allocation value Pa[m] has a ratio corresponding to the allocation coefficient K[m]. That is, the allocation processing unit 523 calculates each power allocation value Pa[m] by multiplying the total DC power command value Cp of charging illustrated in FIG. 6 by the ratio of each allocation coefficient K[m] to the total value ΣK[m] of the multiple allocation coefficients K[m] (K[1] to K[5]) as shown in the above-mentioned formula (2).

[0056] The power distribution value Pa[m] calculated in step Sa1 may exceed the charging limit value L[m]_c. When the total DC power command value Cp indicates charging, the case where the power distribution value Pa[m] exceeds the limit value L[m]_c means the case where the power distribution value Pa[m] is below the limit value L[m]_c (Pa[m]<L[m]_c). For example, in FIG. 10, the power distribution value Pa[4] (= -40) of the power storage unit U[4] exceeds the limit value L[4]_c (= -30), and the power distribution value Pa[5] (= -50) of the power storage unit U[5] exceeds the limit value L[5]_c (= -40) is illustrated.

[0057] The distribution processing unit 523 distributes the total excess value E1 obtained by summing the excess value (Pa[m] - L[m]_c) to each of one or more power storage units U[m] among the plurality of power storage units U[m] whose power distribution value Pa[m] exceeds the limit value L[m]_c (Sa2 to Sa5).

[0058] Specifically, in step Sa2 of FIG. 10, the distribution processing unit 523 calculates the total excess value E1 by summing the difference between the power distribution value Pa[m] and the limit value L[m]_c (i.e., the excess value) for one or more power storage units U[m] among the plurality of power storage units U[m] whose power distribution value Pa[m] exceeds the limit value L[m]_c. In the situation of FIG. 10, "-20" obtained by summing "-10", which is the excess value (Pa[4] - L[4]_c) of the power storage unit U[4], and "-10", which is the excess value (Pa[5] - L[5]_c) of the power storage unit U[5], is calculated as the total excess value E1.

[0059] In step Sa3, the allocation processing unit 523 calculates the total available power E2 by summing up the differences (i.e., margin values) between the limit value L[m]_c and the power allocation value Pa[m] for one or more of the power storage units U[m] whose power allocation value Pa[m] does not exceed the limit value L[m]_c. In the situation of Fig. 10, the total available power E2 is calculated as "-30", which is the sum of "-20", which is the margin value (L[1]_c-Pa[1]) of the power storage unit U[4], and "-10", which is the margin value (L[2]_c-Pa[2]) of the power storage unit U[2].

[0060] In step Sa4, the allocation processing unit 523 calculates an additional allocation value ΔP[m] for one or more power storage units U[m] whose power allocation value Pa[m] does not exceed the limit value L[m]_c among the multiple power storage units U[m]. Specifically, the allocation processing unit 523 calculates each additional allocation value ΔP[m] by calculating the following formula (3b). That is, the allocation processing unit 523 calculates the additional allocation value ΔP[m] by multiplying the ratio of each margin value (L[m]_c-Pa[m]) to the total available power E2 by the total excess value E1.

number

[0061] In step Sa5, the allocation processing unit 523 calculates a power allocation value Pb[m] for each power storage unit U[m]. That is, each power allocation value Pa[m] is updated to the power allocation value Pb[m]. Specifically, the allocation processing unit 523 sets the limit value L[m]_c as the updated power allocation value Pb[m] for one or more power storage units U[m] whose power allocation value Pa[m] exceeds the limit value L[m]_c among the multiple power storage units U[m]. In addition, the allocation processing unit 523 calculates the updated power allocation value Pb[m] by adding an additional allocation value ΔP[m] to the power allocation value Pa[m] for one or more power storage units U[m] whose power allocation value Pa[m] does not exceed the limit value L[m]_c among the multiple power storage units U[m]. For the power storage units U[m] among the multiple power storage units U[m] whose power allocation value Pa[m] and the limit value L[m]_c are equal, the power allocation value Pa[m] is adopted as the power allocation value Pb[m]. The power allocation value Pb[m] is a command value for the DC power to be charged to the power storage device 31 of each power storage unit U[m].

[0062] In step Sa6, the allocation processing unit 523 calculates an active power allocation value P[m] by subtracting the conversion loss x[m] in each power storage unit U[m] from the power allocation value Pb[m] calculated for that power storage unit U[m] (P[m]=Pb[m]-x[m]). That is, the active power allocation value P[m] is a command value for the active power to be charged by the power storage unit U[m], as described above. The operation of the allocation processing unit 523 to calculate the active power allocation value P[m] when the total DC power command value Cp indicates charging (Cp<0) is as described above.

[0063] As described above, between each energy storage unit U[m] and the combining point 11, a transformation loss X1 due to the substation equipment 21 and a load loss X2 due to the load equipment 22 occur. As illustrated in Fig. 11, the transformation loss X1 and the load loss X2 are offset from the total value ΣP[m] of the active power allocation values ​​P[m] calculated by the above procedure, and as a result, AC power equivalent to the basic command value C0 (=-170) is supplied from the combining point 11 to the management system 100.

[0064] Fig. 12 is a flowchart of the overall operation (hereinafter referred to as "control processing") of the control system 40. For example, the control processing of Fig. 12 is repeated at a predetermined cycle.

[0065] When the control process is started, the control device 41 (command calculation unit 51) acquires a basic command value C0 (S1). The control device 41 (command calculation unit 51) calculates a total DC power command value Cp by adding power losses including a transformation loss X1, a load loss X2, and a conversion loss X3 to the basic command value C0 (S2).

[0066] The control device 41 (command allocation unit 52) ​​calculates an active power allocation value P[m] which is a command value of power to be allocated to each of the plurality of power storage units U[m] from the total DC power command value Cp (S3). A specific example of the process of calculating the active power allocation value P[m] is as described above with reference to Fig. 8 and Fig. 10. The control device 41 (operation instructing unit 53) instructs each of the plurality of power storage units U[m] of the active power allocation value P[m] of the power storage unit U[m] (S4).

[0067] When the power storage system 30 includes a power storage unit U[m] that responds with DC power in response to a command for DC power, the control device 41 (operation instruction unit 53) may instruct the power storage unit U[m] of the power allocation value Pb[m] calculated for the power storage unit U[m]. When the power storage system 30 includes a power storage unit U[m] that responds with active power at a point between the transformer 321 and the AC / DC converter 322 in response to an instruction of active power at the point, the control device 41 (operation instruction unit 53) may instruct the power storage unit U[m] of a numerical value obtained by subtracting a loss of the transformer 321 in the power storage unit U[m] from the power allocation value Pb[m] calculated for the power storage unit U[m].

[0068] As described above, in the first embodiment, the power loss including the conversion loss X3 due to conversion between DC power and AC power discharged or charged by the power storage device 31 and the transformation loss X1 due to mutual transformation between the substation equipment 21 and the power storage system 30 is added to the basic command value C0 to calculate the total DC power command value Cp, and the total DC power command value Cp is allocated to each power storage unit U[m]. Therefore, compared with a form in which the basic command value C0 is allocated to each power storage unit U[m] without considering the transformation loss X1 and the conversion loss X3, the active power allocation value P[m] instructed to each power storage unit U[m] can be calculated appropriately. When the basic command value C0 is small, the influence of the conversion losses (X1 to X3) on the basic command value C0 relatively increases, so the configuration of the first embodiment in which the transformation loss X1 and the conversion loss X3 are added to the basic command value C0 is particularly effective.

[0069] In the first embodiment, a total excess value E1 obtained by adding up the excess values ​​of one or more power storage units U[m] whose power allocation value Pa[m] exceeds the limit value L[m] among the multiple power storage units U[m] is allocated to each of one or more power storage units U[m] whose power allocation value Pa[m] does not exceed the limit value L[m] among the multiple power storage units U[m]. Therefore, the power allocated to each power storage unit U[m] can be suppressed to within the range of the limit value L[m] while maintaining the combination point power at the basic command value C0.

[0070] 2. Second embodiment A second embodiment of the present disclosure will be described. Note that, for elements having the same functions as those in the first embodiment in each of the following exemplary aspects, the same reference numerals as those in the first embodiment will be used, and detailed descriptions of each will be omitted as appropriate.

[0071] In the second embodiment, the configuration and operation of the limit value setting unit 522 differ from those of the first embodiment. The configurations and operations of the elements other than the limit value setting unit 522 are the same as those of the first embodiment. Therefore, the second embodiment also achieves the same effects as the first embodiment.

[0072] FIG. 13 is a block diagram illustrating the configuration of the limit value setting unit 522 in the second embodiment. The transmission / reception device 43 in the second embodiment receives status data D[m] from each power storage unit U[m]. The status data D[m] is data that represents the status of the power storage unit U[m] (particularly the power storage device 31). Specifically, the status data D[m] includes the voltage V[m], charging rate S[m], and temperature T[m] of the power storage device 31. The voltage V[m] is a measured value of a DC voltage (for example, a voltage at an output terminal of the power storage device 31) used for discharging or charging the power storage device 31. The charging rate S[m] is a ratio (SOC: State of Charge) of the current charge amount to the capacity (full charge capacity) of the power storage device 31. The temperature T[m] is a measured value of the temperature of the power storage device 31.

[0073] As illustrated in FIG. 13, the limit value setting unit 522 includes a first setting unit 61 and a second setting unit 62. The first setting unit 61 sets a limit value L[m]_d for discharging for each power storage unit U[m]. Specifically, the first setting unit 61 sets a limit value L[m]_d for each power storage unit U[m] according to status data D[m] acquired from the power storage unit U[m]. Similarly, the second setting unit 62 sets a limit value L[m]_c for charging for each power storage unit U[m]. Specifically, the second setting unit 62 sets a limit value L[m]_c for each power storage unit U[m] according to status data D[m] acquired from the power storage unit U[m].

[0074] [First setting unit 61] The first setting unit 61 includes a candidate value setting unit 611, a candidate value setting unit 612, a candidate value setting unit 613, and a candidate value selection unit 614. The candidate value setting unit 611 sets a candidate value Z1[m]_d according to the voltage V[m] of the power storage device 31. The candidate value setting unit 612 sets a candidate value Z2[m]_d according to the charging rate S[m] of the power storage device 31. The candidate value setting unit 613 sets a candidate value Z3[m]_d according to the temperature T[m] of the power storage device 31. Note that the candidate value Z1[m]_d is an example of a "first candidate value", the candidate value Z2[m]_d is an example of a "second candidate value", and the candidate value Z3[m]_d is an example of a "third candidate value".

[0075] The candidate value selection unit 614 selects the limit value L[m]_d from the multiple candidate values ​​Z[m]_d. The multiple candidate values ​​Z[m]_d include candidate values ​​Z1[m]_d, candidate values ​​Z2[m]_d, and candidate values ​​Z3[m]_d, as well as candidate values ​​Z4[m]_d and Z5[m]_d. The candidate value Z4[m]_d is the capacity of the discharge side at the DC end of the AC / DC converter 24 of the power storage unit U[m]. The candidate value Z5[m]_d is a required value of the discharge side according to the specifications of the power storage device 31 of the power storage unit U[m]. Specifically, the candidate value selection unit 614 selects the minimum value of the multiple candidate values ​​Z[m]_d as the limit value L[m]_d.

[0076] As can be understood from the above description, the limit value setting unit 522 selects the limit value L[m]_d for each of the multiple energy storage units U[m] from multiple candidate values ​​Z[m]_d related to different states of the energy storage unit U[m]. Therefore, the limit value L[m]_d can be appropriately set from multiple perspectives related to the state of the energy storage unit U[m]. The setting of the candidate values ​​Z1[m]_d, Z2[m]_d, and Z3[m]_d will be described in detail below.

[0077] [Setting of candidate value Z1[m]_d by candidate value setting unit 611] Fig. 14 is an explanatory diagram of the operation of the candidate value setting unit 611 to set the candidate value Z1[m]_d according to the voltage V[m]. The relationship between the voltage V[m] and the candidate value Z1[m]_d is illustrated in Fig. 14. Note that each element (R11[m]_d, R12[m]_d, R13[m]_d, V1[m]_d, V2[m]_d, z11[m]_d, z12[m]_d, z13[m]_d) related to the relationship between the voltage V[m] and the candidate value Z1[m]_d may be set individually for each power storage unit U[m], or may be set to a common value for a plurality of power storage units U[m].

[0078] As illustrated in FIG. 14, the range of the voltage V[m] is divided into a first range R11[m]_d, a second range R12[m]_d, and a third range R13[m]_d. The first range R11[m]_d is a range of positive numbers below a predetermined voltage V1[m]_d. The second range R12[m]_d is a range above a predetermined voltage V2[m]_d. The voltage V2[m]_d is above the voltage V1[m]_d. The third range R13[m]_d is a range between the first range R11[m]_d and the second range R12[m]_d. That is, the third range R13[m]_d is a range between the voltage V1[m]_d and the voltage V2[m]_d.

[0079] When the voltage V[m] is a value within the first range R11[m]_d, the candidate value setting unit 611 sets the candidate value Z1[m]_d to the first value z11[m]_d. On the other hand, when the voltage V[m] is a value within the second range R12[m]_d, the candidate value setting unit 611 sets the candidate value Z1[m]_d to the second value z12[m]_d. The first value z11[m]_d is a fixed value that is lower than the second value z12[m]_d. Specifically, the first value z11[m]_d is set to a negative number that is slightly lower than 0. On the other hand, the second value z12[m]_d is a variable value of a positive number that changes according to the voltage V[m]. Specifically, the second value z12[m]_d increases monotonically with respect to the voltage V[m] at a predetermined gradient. 14 is calculated by multiplying the voltage V[m] and the current limit value on the discharge side of the energy storage unit U[m], for example. Therefore, when the voltage V[m] is a value within the second range R12[m]_d, the candidate value Z1[m]_d (and further the limit value L[m]_d) can be set so as not to exceed the current limit value on the discharge side of the energy storage unit U[m].

[0080] When the voltage V[m] is a value within the third range R13[m]_d, the candidate value setting unit 611 sets the candidate value Z1[m]_d to a third value z13[m]_d that changes according to the voltage V[m] between the first value z11[m]_d and the second value z12[m]_d. The third value z13[m]_d increases monotonically with respect to the voltage V[m] at a predetermined gradient. The gradient of the third value z13[m]_d with respect to the voltage V[m] exceeds the gradient of the second value z12[m]_d with respect to the voltage V[m].

[0081] As described above, in the second embodiment, the candidate value Z1[m]_d is set according to the voltage V[m] of the power storage device 31. Therefore, the limit value L[m]_d can be appropriately set in terms of the voltage V[m] of the power storage device 31. Furthermore, when the voltage V[m] is a value within the third range R13[m]_d, the candidate value Z1[m]_d changes between the first value z11[m]_d and the second value z12[m]_d according to the voltage V[m]. Therefore, compared to a form in which the candidate value Z1[m]_d is set alternatively to either the first value z11[m]_d or the second value z12[m]_d, it is possible to suppress abrupt and frequent fluctuations in the limit value L[m]_d according to the voltage V[m] of the power storage device 31. Furthermore, according to a configuration in which candidate value Z1[m]_d (second value z12[m]_d) when voltage V[m] is a numerical value within the second range R12[m]_d is calculated by multiplying voltage V[m] by the discharge side current limit value of the storage unit U[m], candidate value Z1[m]_d (and thus limit value L[m]_d) can be set so as not to exceed the discharge side current limit value of the storage unit U[m].

[0082] The first value z11[m]_d, which is the minimum value of the candidate values ​​Z1[m]_d, is set to a negative number that instructs charging of the power storage device 31. Therefore, when the voltage V[m] of the power storage device 31 falls within the first range R11[m]_d, the power storage device 31 is slightly charged, and as a result, it is possible to increase the voltage V[m] to a specific range.

[0083] [Setting of candidate value Z2[m]_d by candidate value setting unit 612] Fig. 15 is an explanatory diagram of the operation of the candidate value setting unit 612 to set the candidate value Z2[m]_d according to the charging rate S[m]. The relationship between the charging rate S[m] and the candidate value Z2[m]_d is illustrated in Fig. 15. Note that each element (R21[m]_d, R22[m]_d, R23[m]_d, S1[m]_d, S2[m]_d, z21[m]_d, z22[m]_d, z23[m]_d) related to the relationship between the voltage V[m] and the candidate value Z2[m]_d may be set individually for each power storage unit U[m], or may be set to a common value for a plurality of power storage units U[m].

[0084] As illustrated in FIG. 15, the range of the charging rate S[m] is divided into a first range R21[m]_d, a second range R22[m]_d, and a third range R23[m]_d. The first range R21[m]_d is a range below a predetermined charging rate S1[m]_d. The second range R22[m]_d is a range above a predetermined charging rate S2[m]_d. The charging rate S2[m]_d is above the charging rate S1[m]_d. The third range R23[m]_d is a range between the first range R21[m]_d and the second range R22[m]_d. That is, the third range R23[m]_d is a range between the charging rate S1[m]_d and the charging rate S2[m]_d.

[0085] When the charging rate S[m] is a value within the first range R21[m]_d, the candidate value setting unit 612 sets the candidate value Z2[m]_d to the first value z21[m]_d. On the other hand, when the charging rate S[m] is a value within the second range R22[m]_d, the candidate value setting unit 612 sets the candidate value Z2[m]_d to the second value z22[m]_d. The first value z21[m]_d is a fixed value slightly below 0. The second value z22[m]_d is a fixed value that exceeds the first value z21[m]_d.

[0086] When the charging rate S[m] is a value within the third range R23[m]_d, the candidate value setting unit 612 sets the candidate value Z2[m]_d to a third value z23[m]_d that changes depending on the charging rate S[m] between the first value z21[m]_d and the second value z22[m]_d. The third value z23[m]_d increases monotonically with respect to the charging rate S[m] at a predetermined gradient.

[0087] As described above, in the second embodiment, the candidate value Z2[m]_d is set according to the charging rate S[m] of the power storage device 31. Therefore, the limit value L[m]_d can be appropriately set in terms of the charging rate S[m] of the power storage device 31. In addition, when the charging rate S[m] is a value within the third range R23[m]_d, the candidate value Z2[m]_d changes between the first value z21[m]_d and the second value z22[m]_d according to the charging rate S[m]. Therefore, compared to a form in which the candidate value Z2[m]_d is set alternatively to either the first value z21[m]_d or the second value z22[m]_d, it is possible to suppress abrupt and frequent fluctuations in the limit value L[m]_d according to the charging rate S[m] of the power storage device 31.

[0088] The first value z21[m]_d, which is the minimum value of the candidate values ​​Z2[m]_d, is set to a negative number that instructs charging of the power storage device 31. Therefore, when the charging rate S[m] of the power storage device 31 falls within the first range R21[m]_d, the power storage device 31 is slightly charged, and as a result, it is possible to increase the charging rate S[m] to a specific range.

[0089] [Setting of candidate value Z3[m]_d by candidate value setting unit 613] Fig. 16 is an explanatory diagram of the operation of the candidate value setting unit 613 to set the candidate value Z3[m]_d according to the temperature T[m]. The relationship between the temperature T[m] and the candidate value Z3[m]_d is illustrated in Fig. 16. In Fig. 16, the power storage device 31 is assumed to have a characteristic of generating heat by discharging. Each element (R31[m]_d, R32[m]_d, R33[m]_d, T1[m]_d, T2[m]_d, z31[m]_d, z32[m]_d, z33[m]_d) related to the relationship between the voltage V[m] and the candidate value Z3[m]_d may be set individually for each power storage unit U[m], or may be set to a common value for a plurality of power storage units U[m].

[0090] As illustrated in FIG. 16, the range of temperature T[m] is divided into a first range R31[m]_d, a second range R32[m]_d, and a third range R33[m]_d. The first range R31[m]_d is a range above a predetermined temperature T1[m]_d. The second range R32[m]_d is a range below a predetermined temperature T2[m]_d. The temperature T2[m]_d is below the temperature T1[m]_d. The third range R33[m]_d is a range between the first range R31[m]_d and the second range R32[m]_d. That is, the third range R33[m]_d is a range between the temperature T1[m]_d and the temperature T2[m]_d.

[0091] When the temperature T[m] is a value within the first range R31[m]_d, the candidate value setting unit 613 sets the candidate value Z3[m]_d to the first value z31[m]_d. On the other hand, when the temperature T[m] is a value within the second range R32[m]_d, the candidate value setting unit 613 sets the candidate value Z3[m]_d to the second value z32[m]_d. The first value z31[m]_d is a fixed value that is slightly below 0. The second value z32[m]_d is a fixed value that is above the first value z31[m]_d.

[0092] When the temperature T[m] is a value within the third range R33[m]_d, the candidate value setting unit 613 sets the candidate value Z3[m]_d to a third value z33[m]_d that changes according to the temperature T[m] between the first value z31[m]_d and the second value z32[m]_d. The third value z33[m]_d decreases monotonically with respect to the temperature T[m] at a predetermined gradient.

[0093] On the other hand, FIG. 17 shows the relationship between the temperature T[m] and the candidate value Z3[m]_d when the power storage device 31 absorbs heat by discharging. As illustrated in FIG. 17, the range of the temperature T[m] is divided into a first range R31[m]_d, a second range R32[m]_d, and a third range R33[m]_d. The first range R31[m]_d is a range below a predetermined temperature T1[m]_d. The second range R32[m]_d is a range above a predetermined temperature T2[m]_d. The temperature T2[m]_d is above the temperature T1[m]_d. The third range R33[m]_d is a range between the first range R31[m]_d and the second range R32[m]_d. That is, the third range R33[m]_d is a range between the temperature T1[m]_d and the temperature T2[m]_d.

[0094] When the temperature T[m] is a value within the first range R31[m]_d, the candidate value setting unit 613 sets the candidate value Z3[m]_d to the first value z31[m]_d. On the other hand, when the temperature T[m] is a value within the second range R32[m]_d, the candidate value setting unit 613 sets the candidate value Z3[m]_d to the second value z32[m]_d. The first value z31[m]_d is a fixed value that is slightly below 0. The second value z32[m]_d is a fixed value that is above the first value z31[m]_d.

[0095] When the temperature T[m] is a value within the third range R33[m]_d, the candidate value setting unit 613 sets the candidate value Z3[m]_d to a third value z33[m]_d that varies between the first value z31[m]_d and the second value z32[m]_d according to the temperature T[m]. The third value z33[m]_d increases monotonically with respect to the temperature T[m] at a predetermined gradient.

[0096] As described above, in the second embodiment, the candidate value Z3[m]_d is set according to the temperature T[m] of the power storage device 31. Therefore, the limit value L[m]_d can be appropriately set in terms of the temperature T[m] of the power storage device 31. Furthermore, when the temperature T[m] is a numerical value within the third range R33[m]_d, the candidate value Z3[m]_d changes between the first value z31[m]_d and the second value z32[m]_d according to the temperature T[m]. Therefore, compared to a form in which the candidate value Z3[m]_d is alternatively set to either the first value z31[m]_d or the second value z32[m]_d, it is possible to suppress abrupt and frequent fluctuations in the limit value L[m]_d according to the temperature T[m] of the power storage device 31.

[0097] The first value z31[m]_d, which is the minimum value of the candidate values ​​Z3[m]_d, is set to a negative number that instructs charging of the power storage device 31. Therefore, in a state in which the temperature T[m] of the power storage device 31 is within the first range R31[m]_d, slight charging of the power storage device 31 is performed, and as a result, it is possible to return the temperature T[m] to the specific range.

[0098] [Second setting unit 62] The second setting unit 62 in FIG. 13 includes a candidate value setting unit 621, a candidate value setting unit 622, a candidate value setting unit 623, and a candidate value selection unit 624. The candidate value setting unit 621 sets a candidate value Z1[m]_c according to the voltage V[m] of the power storage device 31. The candidate value setting unit 622 sets a candidate value Z2[m]_c according to the charging rate S[m] of the power storage device 31. The candidate value setting unit 623 sets a candidate value Z3[m]_c according to the temperature T[m] of the power storage device 31. Note that the candidate value Z1[m]_c is an example of a "first candidate value", the candidate value Z2[m]_c is an example of a "second candidate value", and the candidate value Z3[m]_c is an example of a "third candidate value".

[0099] The candidate value selection unit 624 selects the limit value L[m]_c from the multiple candidate values ​​Z[m]_c. The multiple candidate values ​​Z[m]_c include candidate values ​​Z1[m]_c, Z2[m]_c, and Z3[m]_c, as well as candidate values ​​Z4[m]_c and Z5[m]_c. The candidate value Z4[m]_c is the capacity of the charging side at the DC end of the AC / DC converter 24 of the power storage unit U[m]. The candidate value Z5[m]_c is a required value of the charging side according to the specifications of the power storage device 31 of the power storage unit U[m]. Specifically, the candidate value selection unit 624 selects the maximum value of the multiple candidate values ​​Z[m]_c as the limit value L[m]_c.

[0100] As can be understood from the above description, the limit value setting unit 522 selects the limit value L[m]_c for each of the multiple energy storage units U[m] from multiple candidate values ​​Z[m]_c related to different states of the energy storage unit U[m]. Therefore, the limit value L[m]_c can be appropriately set from multiple perspectives related to the state of the energy storage unit U[m]. The setting of the candidate values ​​Z1[m]_c, Z2[m]_c, and Z3[m]_c will be described in detail below.

[0101] [Setting of candidate value Z1[m]_c by candidate value setting unit 621] Fig. 18 is an explanatory diagram of the operation of the candidate value setting unit 621 to set the candidate value Z1[m]_c according to the voltage V[m]. The relationship between the voltage V[m] and the candidate value Z1[m]_c is illustrated in Fig. 18. Note that each element (R11[m]_c, R12[m]_c, R13[m]_c, V1[m]_c, V2[m]_c, z11[m]_c, z12[m]_c, z13[m]_c) related to the relationship between the voltage V[m] and the candidate value Z1[m]_c may be set individually for each power storage unit U[m], or may be set to a common value for a plurality of power storage units U[m].

[0102] As illustrated in FIG. 18, the range of the voltage V[m] is divided into a first range R11[m]_c, a second range R12[m]_c, and a third range R13[m]_c. The first range R11[m]_c is a range that exceeds a predetermined voltage V1[m]_c. The second range R12[m]_c is a range that is below a predetermined voltage V2[m]_c. The voltage V2[m]_c is below the voltage V1[m]_c. The third range R13[m]_c is a range between the first range R11[m]_c and the second range R12[m]_c. That is, the third range R13[m]_c is a range between the voltage V1[m]_c and the voltage V2[m]_c.

[0103] When the voltage V[m] is a value within the first range R11[m]_c, the candidate value setting unit 621 sets the candidate value Z1[m]_c to the first value z11[m]_c. On the other hand, when the voltage V[m] is a value within the second range R12[m]_c, the candidate value setting unit 621 sets the candidate value Z1[m]_c to the second value z12[m]_c. The first value z11[m]_c is a fixed value that exceeds the second value z12[m]_c. Specifically, the first value z11[m]_c is set to a positive number that is slightly greater than 0. On the other hand, the second value z12[m]_c is a variable negative value that changes according to the voltage V[m]. Specifically, the second value z12[m]_c monotonically decreases with respect to the voltage V[m] at a predetermined gradient. 18 is calculated by multiplying the voltage V[m] by the current limit value on the charging side of the energy storage unit U[m], for example. Therefore, when the voltage V[m] is a value within the second range R12[m]_c, the candidate value Z1[m]_c (and further the limit value L[m]_c) can be set so as not to exceed the current limit value on the charging side of the energy storage unit U[m].

[0104] When the voltage V[m] is a value within the third range R13[m]_c, the candidate value setting unit 621 sets the candidate value Z1[m]_c to a third value z13[m]_c that changes according to the voltage V[m] between the first value z11[m]_c and the second value z12[m]_c. The third value z13[m]_c increases monotonically with respect to the voltage V[m] at a predetermined gradient. The gradient of the third value z13[m]_c with respect to the voltage V[m] exceeds the gradient of the second value z12[m]_c with respect to the voltage V[m].

[0105] As described above, in the second embodiment, the candidate value Z1[m]_c is set according to the voltage V[m] of the power storage device 31. Therefore, the limit value L[m]_c can be appropriately set in terms of the voltage V[m] of the power storage device 31. Furthermore, when the voltage V[m] is a value within the third range R13[m]_c, the candidate value Z1[m]_c changes between the first value z11[m]_c and the second value z12[m]_c according to the voltage V[m]. Therefore, compared to a form in which the candidate value Z1[m]_c is set alternatively to either the first value z11[m]_c or the second value z12[m]_c, it is possible to suppress abrupt and frequent fluctuations in the limit value L[m]_c according to the voltage V[m] of the power storage device 31. Furthermore, according to a configuration in which candidate value Z1[m]_c (second value z12[m]_c) when voltage V[m] is a numerical value within the second range R12[m]_c is calculated by multiplying voltage V[m] by the current limit value on the charging side of the storage unit U[m], candidate value Z1[m]_c (and thus limit value L[m]_c) can be set so as not to exceed the current limit value on the charging side of the storage unit U[m].

[0106] The first value z11[m]_c, which is the maximum value of the candidate values ​​Z1[m]_c, is set to a positive number that instructs discharging of the power storage device 31. Therefore, when the voltage V[m] of the power storage device 31 has risen to within the first range R11[m]_c, a small amount of discharging of the power storage device 31 is performed, and as a result, it is possible to reduce the voltage V[m] to a specific range.

[0107] [Setting of candidate value Z2[m]_c by candidate value setting unit 622] Fig. 19 is an explanatory diagram of the operation of the candidate value setting unit 622 to set the candidate value Z2[m]_c according to the charging rate S[m]. The relationship between the charging rate S[m] and the candidate value Z2[m]_c is illustrated in Fig. 19. Note that each element (R21[m]_c, R22[m]_c, R23[m]_c, S1[m]_c, S2[m]_c, z21[m]_c, z22[m]_c, z23[m]_c) related to the relationship between the voltage V[m] and the candidate value Z2[m]_c may be set individually for each power storage unit U[m], or may be set to a common value for a plurality of power storage units U[m].

[0108] As illustrated in FIG. 19, the range of the charging rate S[m] is divided into a first range R21[m]_c, a second range R22[m]_c, and a third range R23[m]_c. The first range R21[m]_c is a range that exceeds a predetermined charging rate S1[m]_c. The second range R22[m]_c is a range that falls below a predetermined charging rate S2[m]_c. The charging rate S2[m]_c falls below the charging rate S1[m]_c. The third range R23[m]_c is a range between the first range R21[m]_c and the second range R22[m]_c. That is, the third range R23[m]_c is a range between the charging rate S1[m]_c and the charging rate S2[m]_c.

[0109] When the charging rate S[m] is a value within the first range R21[m]_c, the candidate value setting unit 622 sets the candidate value Z2[m]_c to the first value z21[m]_c. On the other hand, when the charging rate S[m] is a value within the second range R22[m]_c, the candidate value setting unit 622 sets the candidate value Z2[m]_c to the second value z22[m]_c. The first value z21[m]_c is a fixed value slightly above 0. The second value z22[m]_c is a fixed value below the first value z21[m]_c.

[0110] When the charging rate S[m] is within the third range R23[m]_c, the candidate value setting unit 622 sets the candidate value Z2[m]_c to a third value z23[m]_c that varies between the first value z21[m]_c and the second value z22[m]_c according to the charging rate S[m]. The third value z23[m]_c increases monotonically with respect to the charging rate S[m] at a predetermined gradient.

[0111] As described above, in the second embodiment, the candidate value Z2[m]_c is set according to the charging rate S[m] of the power storage device 31. Therefore, the limit value L[m]_c can be appropriately set in terms of the charging rate S[m] of the power storage device 31. In addition, when the charging rate S[m] is a value within the third range R23[m]_c, the candidate value Z2[m]_c changes between the first value z21[m]_c and the second value z22[m]_c according to the charging rate S[m]. Therefore, compared to a form in which the candidate value Z2[m]_c is set alternatively to either the first value z21[m]_c or the second value z22[m]_c, it is possible to suppress abrupt and frequent fluctuations in the limit value L[m]_c according to the charging rate S[m] of the power storage device 31.

[0112] The first value z21[m]_c, which is the maximum value of the candidate value Z2[m]_c, is set to a positive number that instructs discharging of the power storage device 31. Therefore, when the voltage V[m] of the power storage device 31 has risen to within the first range R21[m]_c, a small amount of discharging of the power storage device 31 is performed, and as a result, it is possible to reduce the voltage V[m] to a specific range.

[0113] [Setting of candidate value Z3[m]_c by candidate value setting unit 623] Fig. 20 is an explanatory diagram of the operation of the candidate value setting unit 623 to set the candidate value Z3[m]_c according to the temperature T[m]. The relationship between the temperature T[m] and the candidate value Z3[m]_c is illustrated in Fig. 20. Note that each element (R31[m]_c, R32[m]_c, R33[m]_c, T1[m]_c, T2[m]_c, z31[m]_c, z32[m]_c, z33[m]_c) related to the relationship between the voltage V[m] and the candidate value Z3[m]_c may be set individually for each power storage unit U[m], or may be set to a common value for a plurality of power storage units U[m]. Also, in Fig. 20, a power storage device 31 having a characteristic of absorbing heat by charging is assumed.

[0114] As illustrated in FIG. 20, the range of temperature T[m] is divided into a first range R31[m]_c, a second range R32[m]_c, and a third range R33[m]_c. The first range R31[m]_c is a range below a predetermined temperature T1[m]_c. The second range R32[m]_c is a range above a predetermined temperature T2[m]_c. The temperature T2[m]_c is above the temperature T1[m]_c. The third range R33[m]_c is a range between the first range R31[m]_c and the second range R32[m]_c. That is, the third range R33[m]_c is a range between the temperature T1[m]_c and the temperature T2[m]_c.

[0115] When the temperature T[m] is a value within the first range R31[m]_c, the candidate value setting unit 623 sets the candidate value Z3[m]_c to the first value z31[m]_c. On the other hand, when the temperature T[m] is a value within the second range R32[m]_c, the candidate value setting unit 623 sets the candidate value Z3[m]_c to the second value z32[m]_c. The first value z31[m]_c is a fixed value slightly above 0. The second value z32[m]_c is a fixed value below the first value z31[m]_c.

[0116] When the temperature T[m] is a value within the third range R33[m]_c, the candidate value setting unit 623 sets the candidate value Z3[m]_c to a third value z33[m]_c that varies depending on the temperature T[m] between the first value z31[m]_c and the second value z32[m]_c. The third value z33[m]_c decreases monotonically with respect to the temperature T[m] at a predetermined gradient.

[0117] FIG. 21 shows the relationship between the temperature T[m] and the candidate value Z3[m]_c when the power storage device 31 generates heat due to charging. As shown in FIG. 21, the range of the temperature T[m] is divided into a first range R31[m]_c, a second range R32[m]_c, and a third range R33[m]_c. The first range R31[m]_c is a range above a predetermined temperature T1[m]_c. The second range R32[m]_c is a range below a predetermined temperature T2[m]_c. The temperature T2[m]_c is below the temperature T1[m]_c. The third range R33[m]_c is a range between the first range R31[m]_c and the second range R32[m]_c. That is, the third range R33[m]_c is a range between the temperature T1[m]_c and the temperature T2[m]_c.

[0118] When the temperature T[m] is a value within the first range R31[m]_c, the candidate value setting unit 623 sets the candidate value Z3[m]_c to the first value z31[m]_c. On the other hand, when the temperature T[m] is a value within the second range R32[m]_c, the candidate value setting unit 623 sets the candidate value Z3[m]_c to the second value z32[m]_c. The first value z31[m]_c is a fixed value slightly above 0. The second value z32[m]_c is a fixed value below the first value z31[m]_c.

[0119] When the temperature T[m] is a value within the third range R33[m]_c, the candidate value setting unit 623 sets the candidate value Z3[m]_c to a third value z33[m]_c that varies depending on the temperature T[m] between the first value z31[m]_c and the second value z32[m]_c. The third value z33[m]c increases monotonically with respect to the temperature T[m] at a predetermined gradient.

[0120] As described above, in the second embodiment, the candidate value Z3[m]_c is set according to the temperature T[m] of the power storage device 31. Therefore, the limit value L[m]_c can be appropriately set in terms of the temperature T[m] of the power storage device 31. Furthermore, when the temperature T[m] is a value within the third range R33[m]_c, the candidate value Z3[m]_c changes between the first value z31[m]_c and the second value z32[m]_c according to the temperature T[m]. Therefore, compared to a form in which the candidate value Z3[m]_c is set alternatively to either the first value z31[m]_c or the second value z32[m]_c, it is possible to suppress abrupt and frequent fluctuations in the limit value L[m]_c according to the temperature T[m] of the power storage device 31.

[0121] The first value z31[m]_c, which is the maximum value of the candidate values ​​Z3[m]_c, is set to a positive number that instructs discharging of the power storage device 31. Therefore, when the temperature T[m] of the power storage device 31 is within the first range R31[m]_c, a small amount of discharging of the power storage device 31 is performed, and as a result, it is possible to return the temperature T[m] to the specific range.

[0122] The relationship between each element of the status data D[m] (voltage V[m], charging rate S[m], or temperature T[m]) and the candidate value Z[m] is not limited to the relationships illustrated in Figures 14 to 21. For example, a relationship may be established in which the candidate value Z[m] changes in a curved manner with respect to each element of the status data D[m].

[0123] 3. Third embodiment In the third embodiment, the operation of a coefficient setting unit 521 that sets the distribution coefficient K[m] is different from that of the first embodiment. The configurations and operations of the elements other than the coefficient setting unit 521 are the same as those of the first embodiment. Therefore, the third embodiment also achieves the same effects as the first embodiment.

[0124] 22 and 23 are explanatory diagrams of the operation of the coefficient setting unit 521 in the third embodiment. The coefficient setting unit 521 in the third embodiment sets the distribution coefficient K[m] of each power storage unit U[m] by executing a first process Sb1, a second process Sb2, and a third process Sb3.

[0125] The first process Sb1 is a process for setting a weight value α[m] for each of the plurality of power storage units U[m]. The weight value α[m] is a reference value that is the basis of the distribution coefficient K[m]. In the third embodiment, it is assumed that each weight value α[m] is set to a common positive number. However, each weight value α[m] may be different.

[0126] The second process Sb2 is a process for setting a correction value β[m] corresponding to an operating watt-hour capacity B[m] of each of the plurality of power storage units U[m]. Specifically, the second process Sb2 includes a process Sb21 and a process Sb22.

[0127] Process Sb21 is a process for calculating an operating watt-hour capacity B[m] of each power storage unit U[m]. The operating watt-hour capacity B[m] is an amount of power (Wh) corresponding to the capacity of the power storage device 31 in the power storage unit U[m]. As illustrated in FIG. 23, the operating watt-hour capacity B[m] may differ for each power storage unit U[m].

[0128] Fig. 24 is an explanatory diagram of the operating watt-hour capacity B[m]. Fig. 24 illustrates the total watt-hour capacity B_all[m] of the power storage unit U[m]. The total watt-hour capacity B_all[m] is the total capacity that is logically available in the power storage unit U[m]. Specifically, the total watt-hour capacity B_all[m] is calculated from the initial watt-hour capacity B0[m] and the health H[m] of the power storage device 31 in the power storage unit U[m].

[0129] The initial watt-hour capacity B0[m] is the initial watt-hour capacity of the power storage device 31 (i.e., the maximum watt-hour capacity expected for the undegraded power storage device 31). The health H[m] is the ratio (SOH: State of Health) of the current watt-hour capacity to the initial watt-hour capacity B0[m]. The coefficient setting unit 521 calculates the total watt-hour capacity B_all[m] by, for example, multiplying the health H[m] by the initial watt-hour capacity B0[m] (B_all[m]=H[m]×B0[m]).

[0130] The storage device 31 is operated with a charging rate S[m] within a predetermined range (hereinafter referred to as "operating charging rate range Rs[m]"). That is, the operating charging rate range Rs[m] is a range of the charging rate S[m] according to the specifications in which the storage device 31 can be used. Specifically, the operating charging rate range Rs[m] is a range between the minimum value Smin[m] and the maximum value Smax[m] of the charging rate S[m]. As illustrated in FIG. 24, the operating watt-hour capacity B[m] corresponds to the operating charging rate range Rs[m] of the charging rate S[m]. In the process Sb21 of the second process Sb2, the coefficient setting unit 521 calculates the operating watt-hour capacity B[m] by the calculation of the following formula (4).

number

[0131] 22 and 23, the process Sb22 of the second process Sb2 is a process for calculating a correction value β[m] for each of the plurality of power storage units U[m] according to the operating watt-hour capacity B[m] of the power storage unit U[m]. Specifically, the coefficient setting unit 521 calculates the ratio of the operating watt-hour capacity B[m] to the total value ΣB[m] of the operating watt-hour capacity B[m] across the plurality of power storage units U[m] as the correction value β[m] (β[m]=B[m] / ΣB[m]). However, the method for calculating the correction value β[m] is not limited to the above example.

[0132] The third process Sb3 is a process of calculating the distribution coefficient K[m] according to the weight value α[m] and the correction value β[m] for each of the multiple storage units U[m]. Specifically, the multiplication value of the weight value α[m] and the correction value β[m] is calculated as the distribution coefficient K[m] (K[m]=α[m]×β[m]). However, the method of calculating the distribution coefficient K[m] is not limited to the above example. For example, a configuration in which the weighted sum of the weight value α[m] and the correction value β[m] is calculated as the distribution coefficient K[m], or a configuration in which the distribution coefficient K[m] is calculated by a predetermined calculation including the weight value α[m] and the correction value β[m] may be assumed. In addition, the use of the correction value β[m] may be omitted. For example, the distribution coefficient K[m] may be calculated by a predetermined calculation to which only the weight value α[m] is applied.

[0133] As described above, the coefficient setting unit 521 of the third embodiment sets the allocation coefficient K[m] according to the operating watt-hour capacity B[m] of each power storage unit U[m]. For example, the larger the operating watt-hour capacity B[m], the larger the allocation coefficient K[m] is set to. As can be understood from the description of the first embodiment, roughly speaking, the larger the allocation coefficient K[m], the larger the active power allocation value P[m] of each power storage unit U[m] becomes.

[0134] In a configuration in which the allocation coefficient K[m] does not depend on the operating watt-hour capacity B[m] of each power storage unit U[m] (hereinafter referred to as the "comparative embodiment"), for example, the allocation coefficient K[m] of a power storage device 31 having a small operating watt-hour capacity B[m] may be set to a large value. Therefore, in the comparative embodiment, the time required for discharging or charging according to the active power allocation value P[m] or the charging rate of the power storage device 31 may differ significantly for each power storage unit U[m]. As described above, when the conditions for discharging or charging the power storage device 31 differ significantly between the power storage units U[m], there is a problem that the degree of progress of characteristic deterioration of the power storage device 31 differs for each power storage unit U[m].

[0135] In the third embodiment, as described above, the distribution coefficient K[m] is set according to the operating watt-hour capacity B[m] of each power storage unit U[m]. Therefore, the variation in the discharge or charge time or the charge rate of the power storage device 31 between the power storage units U[m] is suppressed. Therefore, according to the third embodiment, it is possible to suppress the variation in the progress of characteristic deterioration of the power storage device 31 between the power storage units U[m], as compared to the comparative example.

[0136] 4. Fourth embodiment In the third embodiment, for convenience, the case where each weight value α[m] is set to a common positive number is illustrated. The fourth embodiment is a specific example of the first process Sb1 in which the coefficient setting unit 521 sets the weight value α[m] in the third embodiment.

[0137] FIG. 25 is an explanatory diagram of the first process Sb1 in the fourth embodiment. FIG. 25 illustrates the above-mentioned operational charging rate range Rs[m]. As described above, the operational charging rate range Rs[m] is a range between the minimum value Smin[m] and the maximum value Smax[m] of the charging rate S[m]. As illustrated in FIG. 25, the first process Sb1 in the fourth embodiment includes a normalization process Sb11, a deviation calculation process Sb12, and a weight setting process Sb13.

[0138] The operational charging rate range Rs[m] of the power storage device 31 may differ for each power storage unit U[m]. Specifically, one or both of the minimum value Smin[m] and the maximum value Smax[m] may differ for each power storage unit U[m]. The normalization process Sb11 is a process for normalizing the charging rate S[m] of the power storage device 31 of each power storage unit U[m] to a charging rate Sn[m] within a predetermined numerical range (hereinafter referred to as the "standard range Rs_n").

[0139] The standard range Rs_n is a numerical range common to a plurality of energy storage units U[m]. Specifically, the standard range Rs_n is a range from a minimum value of 0 to a maximum value of 1. In other words, the normalized charging rate Sn[m] is a numerical value within the standard range Rs_n from a minimum value of 0 to a maximum value of 1, regardless of the operational charging rate range Rs[m] of each energy storage unit U[m].

[0140] Specifically, in the normalization process Sb11, the coefficient setting unit 521 calculates the normalized charging rate Sn[m] by the calculation of the following formula (5).

number

[0141] The deviation calculation process Sb12 is a process for calculating the deviation ΔS[m] between the charging rate Sn[m] after normalization by the normalization process Sb11 and a reference value Sref (ΔS[m]=Sn[m]-Sref). The reference value Sref is, for example, a representative value of the charging rate Sn[m] across multiple power storage units U[m]. Specifically, the average value (e.g., simple average) of the charging rate Sn[m] is used as the reference value Sref to calculate the deviation ΔS[m]. The deviation ΔS[m] is an example of the "first deviation."

[0142] The weight setting process Sb13 is a process for setting a weight α[m] in accordance with the deviation ΔS[m] calculated in the deviation calculation process Sb12.

[0143] The larger the deviation ΔS[m] of the power storage unit U[m], the higher the charging rate Sn[m] is compared to the other power storage units U[m]. Therefore, when the total DC power command value Cp indicates discharging (Cp>0), the larger the deviation ΔS[m] of the power storage unit U[m], the higher the priority should be given to allocating the power storage unit U[m] for discharging. On the other hand, the larger the allocation coefficient K[m] (the larger the weight value α[m]), the larger the active power allocation value P[m] of each power storage unit U[m] becomes. Taking the above into consideration, the coefficient setting unit 521 of the fourth embodiment sets the weight value α[m] to a larger value as the deviation ΔS[m] increases.

[0144] On the other hand, when the total DC power command value Cp indicates charging (Cp<0), the smaller the deviation ΔS[m] of the power storage unit U[m], the higher the priority should be in allocating it to charging. On the other hand, the larger the allocation coefficient K[m] (the larger the weight value α[m]), the larger the active power allocation value P[m] of each power storage unit U[m] becomes. Taking the above into consideration, the coefficient setting unit 521 of the fourth embodiment sets the weight value α[m] to a larger value as the deviation ΔS[m] becomes smaller.

[0145] As described above, in the fourth embodiment, the weight value α[m] (and hence the distribution coefficient K[m]) is set according to the charging rate S[m] of the power storage device 31 in each power storage unit U[m], so that each distribution coefficient K[m] can be set so that the charging rates S[m] of the power storage devices 31 approach each other. This reduces the possibility that the output of each power storage unit U[m] is limited due to the charging rate S[m] of the power storage device 31. In other words, the storage capacity of the entire power storage system 30 can be effectively used.

[0146] As a method for the coefficient setting unit 521 to calculate the weight value α[m] in accordance with the deviation ΔS[m], in the fourth embodiment, the following exemplary modes 4A and 4B can be adopted.

[0147] [Aspect 4A] 26 and 27 are explanatory diagrams of the process in which the coefficient setting unit 521 calculates the weight value α[m] in the aspect 4A of the fourth embodiment. Specifically, the relationship between the deviation ΔS[m] of the charging rate S[m] and the weight value α[m] is shown in FIG. 26 and FIG.

[0148] FIG. 26 is an explanatory diagram of the weight value α[m] when the total DC power command value Cp indicates discharging (Cp>0). As illustrated in FIG. 26, when the total DC power command value Cp indicates discharging, the coefficient setting unit 521 roughly sets the weight value α[m] to the function value Fa(ΔS). The function value Fa(ΔS) is a variable value according to the deviation ΔS[m]. The larger the deviation ΔS[m], the larger the function value Fa(ΔS) is set to. Note that the function value Fa(ΔS) is an example of a "second value".

[0149] In FIG. 26, threshold values Y1 and Y2 are illustrated. The threshold values Y1 and Y2 are positive numbers. The threshold value Y1 is greater than the threshold value Y2 (Y1>Y2). When the deviation ΔS[m] increases from a value less than the threshold value Y1 to a value greater than the threshold value Y1, the coefficient setting unit 521 sets the weighting value α[m] from the function value Fa(ΔS) to the maximum value 1 (the first value). With the above configuration, each effective power distribution value P[m] is set so that the power storage unit U[m] with a large deviation ΔS[m] among the plurality of power storage units U[m] preferentially executes discharging. On the other hand, when the deviation ΔS[m] decreases from a value greater than the threshold value Y2 to a value less than the numerical value Y2, the coefficient setting unit 521 sets the weighting value α[m] to the function value Fa(ΔS).

[0150] Also, in FIG. 26, threshold values Y3 and Y4 are illustrated. The threshold values Y3 and Y4 are negative numbers. The threshold value Y3 is less than the threshold value Y4 (Y3<Y4). When the deviation ΔS[m] decreases from a value greater than the threshold value Y3 to a value less than the threshold value Y3, the coefficient setting unit 521 sets the weighting value α[m] from the function value Fa(ΔS) to the minimum value 0 (the second value). With the above configuration, each effective power distribution value P[m] is set so that discharging of the power storage unit U[m] with a small deviation ΔS[m] among the plurality of power storage units U[m] is preferentially avoided. Also, when the deviation ΔS[m] increases from a value less than the threshold value Y4 to a value greater than the numerical value Y4, the coefficient setting unit 521 sets the weighting value α[m] to the function value Fa(ΔS).

[0151] FIG. 27 is an explanatory diagram of the weighting value α[m] when the total DC power command value Cp indicates charging (Cp<0). As illustrated in FIG. 27, when the total DC power command value Cp indicates charging, the coefficient setting unit 521 generally sets the weighting value α[m] to the function value Fa(ΔS). The function value Fa(ΔS) is a variable value according to the deviation ΔS[m]. The larger the deviation ΔS[m], the smaller the function value Fa(ΔS) is set.

[0152] When the deviation ΔS[m] increases from a value below the threshold Y1 to a value above the threshold Y1, the coefficient setting unit 521 sets the weight value α[m] from the function value Fa(ΔS) to the minimum value 0 (first value). With the above configuration, each active power allocation value P[m] is set so that charging of the power storage unit U[m] having a large deviation ΔS[m] among the multiple power storage units U[m] is avoided preferentially. Furthermore, when the deviation ΔS[m] decreases from a value above the threshold Y2 to a value below the value Y2, the coefficient setting unit 521 sets the weight value α[m] to the function value Fa(ΔS).

[0153] When the deviation ΔS[m] decreases from a value exceeding the threshold Y3 to a value below the threshold Y3, the coefficient setting unit 521 sets the weight value α[m] from the function value Fa(ΔS) to the maximum value 1 (second value). With the above configuration, each active power allocation value P[m] is set so that the power storage unit U[m] having the smallest deviation ΔS[m] among the multiple power storage units U[m] is preferentially charged. Furthermore, when the deviation ΔS[m] increases from a value below the threshold Y4 to a value above the value Y4, the coefficient setting unit 521 sets the weight value α[m] to the function value Fa(ΔS).

[0154] As described above, in the embodiment 4A, the relationship between the deviation ΔS[m] and the weight value α[m] exhibits a hysteresis characteristic. Therefore, even if the deviation ΔS[m] fluctuates near each threshold value (Y1, Y2, Y3, Y4), excessively frequent fluctuations in the weight value α[m] can be suppressed. Note that each threshold value (Y1, Y2, Y3, Y4) related to the deviation ΔS[m] may be set individually for each power storage unit U[m], or may be set to a common value for multiple power storage units U[m].

[0155] [Aspect 4B] 28 and 29 are explanatory diagrams of the process in which the coefficient setting unit 521 calculates the weight value α[m] in the aspect 4B of the fourth embodiment. Specifically, the relationship Fb(ΔS) between the deviation ΔS[m] of the charging rate S[m] and the weight value α[m] is shown in FIG.

[0156] Fig. 28 is an explanatory diagram of the weight value α[m] when the total DC power command value Cp indicates discharging (Cp>0). As illustrated in Fig. 28, the relationship Fb(ΔS) is expressed by a straight line passing through a point corresponding to a predetermined positive number s1 of the deviation ΔS[m] and the maximum value 1 of the weight value α[m]. The coefficient setting unit 521 sets a numerical value in the relationship Fb(ΔS) for the deviation ΔS[m] as the weight value α[m].

[0157] Furthermore, the coefficient setting unit 521 determines the relationship Fb(ΔS) according to the total DC power command value Cp. Specifically, the coefficient setting unit 521 changes the gradient of the relationship Fb(ΔS) according to the absolute value |Cp| of the total DC power command value Cp. For example, the gradient of the relationship Fb(ΔS) decreases as the absolute value |Cp| increases. Specifically, the relationship Fb(ΔS) changes between the relationship F1 and the relationship F2 according to the absolute value |Cp|.

[0158] When the relationship Fb(ΔS) is set to the relationship F1, the weighting value α[m] is set to a positive number for the energy storage units U[m] whose deviation ΔS[m] is within a wide range from a negative number s2 to a positive number s1. By setting the weighting value α[m] to a positive number, the allocation coefficient K[m] is also set to a positive number, and therefore each active power allocation value P[m] is set so that a large number of energy storage units U[m] execute discharge. The positive number s1 and the negative number s2 are arbitrary numerical values.

[0159] In a state in which the relationship Fb(ΔS) is set to the relationship F2, the weighting value α[m] is set to a positive number for the energy storage units U[m] whose deviation ΔS[m] is in the range of positive numbers. On the other hand, the weighting value α[m] is set to 0 for the energy storage units U[m] whose deviation ΔS[m] is in the range of negative numbers, and therefore the allocation coefficient K[m] is also set to 0. In other words, each active power allocation value P[m] is set so that some of the energy storage units U[m] whose deviation ΔS[m] is in the range of positive numbers are preferentially discharged.

[0160] Fig. 29 is an explanatory diagram of the weight value α[m] when the total DC power command value Cp indicates charging (Cp<0). As illustrated in Fig. 29, the relationship Fb(ΔS) is expressed by a straight line passing through a point corresponding to a predetermined negative number s2 of the deviation ΔS[m] and the maximum value 1 of the weight value α[m]. The coefficient setting unit 521 sets a numerical value in the relationship Fb(ΔS) for the deviation ΔS[m] as the weight value α[m].

[0161] The coefficient setting unit 521 determines the relationship Fb(ΔS) according to the total DC power command value Cp. Specifically, the coefficient setting unit 521 changes the gradient of the relationship Fb(ΔS) according to the absolute value |Cp| of the total DC power command value Cp. For example, the gradient of the relationship Fb(ΔS) decreases as the absolute value |Cp| increases. Specifically, the relationship Fb(ΔS) changes between the relationship F1 and the relationship F2 according to the absolute value |Cp|.

[0162] In a state in which the relationship Fb(ΔS) is set to the relationship F1, the weighting value α[m] is set to a positive number for the energy storage units U[m] whose deviation ΔS[m] is within a wide range from a negative number s2 to a positive number s1. Since the weighting value α[m] is set to a positive number, the allocation coefficient K[m] is also set to a positive number, and each active power allocation value P[m] is set so that a large number of energy storage units U[m] execute charging.

[0163] In a state in which the relationship Fb(ΔS) is set to the relationship F2, the weighting value α[m] is set to a positive number for the energy storage units U[m] whose deviation ΔS[m] is in the range of negative numbers. On the other hand, the weighting value α[m] is set to 0 for the energy storage units U[m] whose deviation ΔS[m] is in the range of positive numbers, and therefore the allocation coefficient K[m] is also set to 0. In other words, each active power allocation value P[m] is set so that some of the energy storage units U[m] whose deviation ΔS[m] is in the range of negative numbers are given priority in performing charging.

[0164] As described above, according to the embodiment 4B, the relationship Fb(ΔS) between the deviation ΔS[m] and the weight value α[m] is determined according to the total DC power command value Cp. Therefore, compared to the embodiment in which the relationship between the deviation ΔS[m] and the weight value α[m] is fixed, the total DC power command value Cp can be appropriately allocated to the multiple power storage units U[m]. Note that the configuration for changing the relationship Fb(ΔS) according to the total DC power command value Cp may be omitted. That is, the relationship Fb(ΔS) may be a fixed relationship between the relationship F1 and the relationship F2, for example.

[0165] 5. Fifth embodiment In the third embodiment, for convenience, the case where each weight value α[m] is set to a common positive number is illustrated. As in the fourth embodiment, the fifth embodiment is a specific example of the first process Sb1 in which the coefficient setting unit 521 sets the weight value α[m] in the third embodiment.

[0166] Fig. 30 is an explanatory diagram of the first process Sb1 in the fifth embodiment. As illustrated in Fig. 30, the first process Sb1 in the fifth embodiment includes a normalization process Sb11, a deviation calculation process Sb12, and a weight setting process Sb13, similar to the fourth embodiment.

[0167] 30 illustrates an example of an operating temperature range Rt[m] of the power storage device 31. The operating temperature range Rt[m] is a specified range of temperatures T[m] at which the power storage device 31 can be used. Specifically, the operating temperature range Rt[m] is a range between a minimum value Tmin[m] and a maximum value Tmax[m] of the temperature T[m].

[0168] The operating temperature range Rt[m] of the power storage device 31 may differ for each power storage unit U[m]. Specifically, one or both of the minimum value Tmin[m] and the maximum value Tmax[m] may differ for each power storage unit U[m]. The normalization process Sb11 is a process for normalizing the temperature T[m] of the power storage device 31 of each power storage unit U[m] to a temperature Tn[m] within a predetermined numerical range (hereinafter referred to as the "standard range Rt_n").

[0169] The standard range Rt_n is a numerical range common to a plurality of power storage units U[m], similar to the standard range Rs_n in the fourth embodiment. In the normalization process Sb11, the coefficient setting unit 521 calculates the normalized temperature Tn[m] by the calculation of the following formula (6).

number

[0170] The deviation calculation process Sb12 is a process for calculating the deviation ΔT[m] between the temperature Tn[m] after normalization by the normalization process Sb11 and a reference value Tref (ΔT[m]=Tn[m]-Tref). The reference value Tref is, for example, a representative value (for example, an average value) of the temperatures Tn[m] across multiple power storage units U[m]. The deviation ΔT[m] is an example of the "second deviation."

[0171] The weight setting process Sb13 is a process for setting a weight α[m] according to the deviation ΔT[m] calculated by the deviation calculation process Sb12. In the following description, it is assumed that the power storage device 31 of each power storage unit U[m] absorbs heat by discharging and releases heat by charging. That is, the temperature T[m] of the power storage device 31 decreases by discharging and increases by charging.

[0172] The larger the deviation ΔT[m] of the power storage unit U[m], the higher the temperature Tn[m] is compared to the other power storage units U[m]. Therefore, when the total DC power command value Cp indicates discharging (Cp>0), the larger the deviation ΔT[m] of the power storage unit U[m], the higher the priority should be given to allocating the power storage unit U[m] for discharging, thereby lowering the temperature T[m]. In consideration of the above, the coefficient setting unit 521 of the fifth embodiment sets the weight value α[m] to a larger value as the deviation ΔT[m] increases.

[0173] On the other hand, when the total DC power command value Cp indicates charging (Cp<0), the smaller the deviation ΔT[m] of the power storage unit U[m], the higher the priority should be in allocating it to charging, thereby increasing the temperature T[m]. In consideration of the above, the coefficient setting unit 521 of the fifth embodiment sets the weight value α[m] to a larger value as the deviation ΔT[m] is smaller.

[0174] As described above, in the fifth embodiment, the weight value α[m] (and hence the distribution coefficient K[m]) is set according to the temperature T[m] of the power storage device 31 in each power storage unit U[m], so that the distribution coefficients K[m] can be set so that the temperatures T[m] of the power storage devices 31 approach each other. This reduces the possibility that the output of each power storage unit U[m] is limited due to variations in the temperatures T[m] of the power storage devices 31. In other words, the storage capacity of the entire power storage system 30 can be effectively utilized.

[0175] As a method for the coefficient setting unit 521 to calculate the weight value α[m] according to the deviation ΔT[m], in the fifth embodiment, the following exemplary aspects 5A and 5B can be adopted.

[0176] [Aspect 5A] 31 and 32 are explanatory diagrams of the process in which the coefficient setting unit 521 calculates the weight value α[m] in aspect 5A of the fifth embodiment. Specifically, the relationship between the deviation ΔT[m] of the temperature T[m] and the weight value α[m] is shown in FIG.

[0177] Fig. 31 is an explanatory diagram of the weight value α[m] when the total DC power command value Cp indicates discharging (Cp>0). As illustrated in Fig. 31, when the total DC power command value Cp indicates discharging, the coefficient setting unit 521 roughly sets the weight value α[m] to the function value Fa(ΔT). The function value Fa(ΔT) is a variable value according to the deviation ΔT[m]. The larger the deviation ΔT[m], the larger the value of the function value Fa(ΔT) is set to. Note that the function value Fa(ΔT) is an example of a "second value".

[0178] When the deviation ΔT[m] increases from a value below the threshold Y1 to a value above the threshold Y1, the coefficient setting unit 521 sets the weight value α[m] from the function value Fa(ΔT) to the maximum value 1 (first value). With the above configuration, each active power allocation value P[m] is set so that the power storage unit U[m] having the larger deviation ΔT[m] among the multiple power storage units U[m] is preferentially discharged. On the other hand, when the deviation ΔT[m] decreases from a value above the threshold Y2 to a value below the value Y2, the coefficient setting unit 521 sets the weight value α[m] to the function value Fa(ΔT).

[0179] When the deviation ΔT[m] decreases from a value exceeding the threshold Y3 to a value below the threshold Y3, the coefficient setting unit 521 sets the weight value α[m] from the function value Fa(ΔT) to the minimum value 0 (second value). With the above configuration, each active power allocation value P[m] is set so that discharge of the power storage unit U[m] having a small deviation ΔT[m] among the multiple power storage units U[m] is avoided preferentially. Furthermore, when the deviation ΔT[m] increases from a value below the threshold Y4 to a value above the value Y4, the coefficient setting unit 521 sets the weight value α[m] to the function value Fa(ΔT).

[0180] Fig. 32 is an explanatory diagram of the weight value α[m] when the total DC power command value Cp indicates charging (Cp<0). As illustrated in Fig. 32, when the total DC power command value Cp indicates charging, the coefficient setting unit 521 roughly sets the weight value α[m] to the function value Fa(ΔT). The function value Fa(ΔT) is a variable value according to the deviation ΔT[m]. The larger the deviation ΔT[m], the smaller the value at which the function value Fa(ΔT) is set.

[0181] When the deviation ΔT[m] increases from a value below the threshold Y1 to a value above the threshold Y1, the coefficient setting unit 521 sets the weight value α[m] from the function value Fa(ΔT) to the minimum value 0 (first value). With the above configuration, each active power allocation value P[m] is set so that charging of the power storage unit U[m] having a large deviation ΔT[m] among the multiple power storage units U[m] is avoided preferentially. On the other hand, when the deviation ΔT[m] decreases from a value above the threshold Y2 to a value below the value Y2, the coefficient setting unit 521 sets the weight value α[m] to the function value Fa(ΔT).

[0182] Furthermore, when the deviation ΔT[m] decreases from a value exceeding the threshold Y3 to a value below the threshold Y3, the coefficient setting unit 521 sets the weight value α[m] from the function value Fa(ΔT) to the maximum value 1 (second value). With the above configuration, each active power allocation value P[m] is set so that the power storage unit U[m] having the smallest deviation ΔT[m] among the multiple power storage units U[m] is preferentially charged. On the other hand, when the deviation ΔT[m] increases from a value below the threshold Y4 to a value above the value Y4, the coefficient setting unit 521 sets the weight value α[m] to the function value Fa(ΔT).

[0183] As described above, in the embodiment 5A, the relationship between the deviation ΔT[m] and the weight value α[m] exhibits a hysteresis characteristic. Therefore, even if the deviation ΔT[m] fluctuates near each threshold value (Y1, Y2, Y3, Y4), excessively frequent fluctuations in the weight value α[m] can be suppressed. Note that each threshold value (Y1, Y2, Y3, Y4) related to the deviation ΔT[m] may be set individually for each power storage unit U[m], or may be set to a common value for multiple power storage units U[m].

[0184] [Aspect 5B] 33 and 34 are explanatory diagrams of the process in which the coefficient setting unit 521 calculates the weight value α[m] in aspect 5B of the fifth embodiment. Specifically, the relationship Fb(ΔT) between the deviation ΔT[m] of the temperature T[m] and the weight value α[m] is shown in FIG.

[0185] Fig. 33 is an explanatory diagram of the weight value α[m] when the total DC power command value Cp indicates discharging (Cp>0). As illustrated in Fig. 33, the relationship Fb(ΔT) is expressed by a straight line passing through a point corresponding to a predetermined positive number s1 of the deviation ΔT[m] and the maximum value 1 of the weight value α[m]. The coefficient setting unit 521 sets a numerical value in the relationship Fb(ΔT) for the deviation ΔT[m] as the weight value α[m].

[0186] Furthermore, the coefficient setting unit 521 determines the relationship Fb(ΔT) according to the total DC power command value Cp. Specifically, the coefficient setting unit 521 decreases the gradient of the relationship Fb(ΔT) as the absolute value |Cp| increases. Specifically, the relationship Fb(ΔT) changes between the relationship F1 and the relationship F2 according to the absolute value |Cp|.

[0187] In a state where the relationship Fb(ΔT) is set to the relationship F1, the weight value α[m] is set to a positive number for the energy storage units U[m] whose deviation ΔT[m] is within a wide range from a negative number s2 to a positive number s1. Thus, each active power allocation value P[m] is set so that many energy storage units U[m] execute discharge. On the other hand, in a state where the relationship Fb(ΔT) is set to the relationship F2, the weight value α[m] is set to a positive number for the energy storage units U[m] whose deviation ΔT[m] is within a positive number range, while the weight value α[m] is set to 0 for the energy storage units U[m] whose deviation ΔT[m] is within a negative number range. Thus, each active power allocation value P[m] is set so that some energy storage units U[m] whose deviation ΔT[m] is within a positive number range execute discharge preferentially.

[0188] Fig. 34 is an explanatory diagram of the weight value α[m] when the total DC power command value Cp indicates charging (Cp<0). As illustrated in Fig. 34, the relationship Fb(ΔT) is expressed by a straight line passing through a point corresponding to the negative value s2 of the deviation ΔT[m] and the maximum value 1 of the weight value α[m]. The coefficient setting unit 521 sets a numerical value in the relationship Fb(ΔT) for the deviation ΔT[m] as the weight value α[m].

[0189] Furthermore, the coefficient setting unit 521 determines the relationship Fb(ΔT) according to the total DC power command value Cp. Specifically, the coefficient setting unit 521 decreases the gradient of the relationship Fb(ΔT) as the absolute value |Cp| increases. Specifically, the relationship Fb(ΔT) changes between the relationship F1 and the relationship F2 according to the absolute value |Cp|.

[0190] In a state where the relationship Fb(ΔT) is set to the relationship F1, the weight value α[m] is set to a positive number for the power storage units U[m] whose deviation ΔT[m] is within a wide range from a negative number s2 to a positive number s1. Thus, each active power allocation value P[m] is set so that many power storage units U[m] perform charging. On the other hand, in a state where the relationship Fb(ΔT) is set to the relationship F2, the weight value α[m] is set to a positive number for the power storage units U[m] whose deviation ΔT[m] is within a negative number range, while the weight value α[m] is set to 0 for the power storage units U[m] whose deviation ΔT[m] is within a positive number range. Thus, each active power allocation value P[m] is set so that some power storage units U[m] whose deviation ΔT[m] is within a negative number range perform charging preferentially.

[0191] As described above, according to the aspect 5B, the relationship Fb(ΔT) between the deviation ΔT[m] and the weight value α[m] is determined according to the total DC power command value Cp. Therefore, compared to the aspect in which the relationship between the deviation ΔT[m] and the weight value α[m] is fixed, the total DC power command value Cp can be appropriately allocated to the multiple power storage units U[m]. Note that the configuration for changing the relationship Fb(ΔT) according to the total DC power command value Cp may be omitted. That is, the relationship Fb(ΔT) may be a fixed relationship between the relationship F1 and the relationship F2, for example.

[0192] In the above description, it is assumed that the power storage device 31 of each power storage unit U[m] absorbs heat by discharging and dissipates heat by charging. However, depending on the type of the power storage device 31, it is also assumed that the power storage device 31 dissipates heat by discharging and absorbs heat by charging. In a configuration in which the power storage device 31 having the characteristic of dissipating heat by discharging and absorbing heat by charging is installed in each power storage unit U[m], the relationship between the deviation ΔT[m] and the weight value α[m] in the above-mentioned configuration 5A and configuration 5B is inverted around the vertical axis. In a configuration in which the power storage device 31 having the characteristic of dissipating heat by both discharging and charging is installed in each power storage unit U[m], the characteristic in FIG. 32 is applied in the configuration 5A regardless of the polarity of the total DC power command value Cp, and the characteristic in FIG. 34 is applied in the configuration 5B regardless of the polarity of the total DC power command value Cp.

[0193] 6. Sixth embodiment In the third embodiment, for convenience, the case where each weight value α[m] is set to a common positive number is illustrated. As in the fourth embodiment, the sixth embodiment is a specific example of the first process Sb1 in which the coefficient setting unit 521 sets the weight value α[m] in the third embodiment.

[0194] Fig. 35 is an explanatory diagram of the first process Sb1 in the sixth embodiment. As illustrated in Fig. 35, the first process Sb1 in the sixth embodiment includes a normalization process Sb11, a deviation calculation process Sb12, and a weight setting process Sb13, similar to the fourth embodiment.

[0195] In the sixth embodiment, attention is focused on the number of times N[m] that the power storage device 31 in each power storage unit U[m] is charged and discharged. The number of times N[m] that the power storage device 31 is charged and discharged is the number of times (the number of cycles) that a set of charging and discharging is repeated. Specifically, the number of times N[m] that the power storage device 31 is charged and discharged is the number of times that a set of charging from the minimum value Smin[m] to the maximum value Smax[m] of the charging rate S[m] and discharging from the maximum value Smax[m] to the minimum value Smin[m] is repeated. The number of times N[m] that the power storage device 31 is charged and discharged is included in the status data D[m] transmitted from each power storage unit U[m] to the control system 40.

[0196] The number of charge / discharge cycles N[m] may be measured by the control system 40. The sum of an integrated amount of power obtained by integrating the DC power in the charging direction between the power storage device 31 and the power regulating device 32 and an integrated amount of power obtained by integrating the DC power in the discharging direction (integrated charge / discharge power amount) may be used as the number of charge / discharge cycles N[m].

[0197] The maximum number Nmax[m] in Fig. 35 is the maximum value of the number of charge / discharge cycles N[m] during operation of the energy storage unit U[m] (i.e., the life of the energy storage device 31). In a form in which the above-mentioned integrated charge / discharge power amount is applied as the number of charge / discharge cycles N[m], the maximum number Nmax[m] is the maximum value of the integrated charge / discharge power amount during operation of the energy storage unit U[m]. The normalization process Sb11 is a process for normalizing the number of charge / discharge cycles N[m] of the energy storage device 31 of each energy storage unit U[m] to the number of charge / discharge cycles Nn[m] within a predetermined numerical range (hereinafter referred to as "standard range Rn_n").

[0198] The standard range Rn_n is a numerical range common to a plurality of power storage units U[m], similar to the standard range Rs_n in the fourth embodiment. In the normalization process Sb11, the coefficient setting unit 521 calculates the normalized charge / discharge count Nn[m] by the calculation of the following formula (7).

number

[0199] The deviation calculation process Sb12 is a process for calculating the deviation ΔN[m] between the number of charge / discharge operations Nn[m] after normalization by the normalization process Sb11 and a reference value Nref (ΔN[m]=Nn[m]-Nref). The reference value Nref is, for example, a representative value (for example, an average value) of the number of charge / discharge operations Nn[m] across multiple energy storage units U[m]. The deviation ΔN[m] is an example of a "third deviation."

[0200] The weight setting process Sb13 is a process for setting a weight α[m] according to the deviation ΔN[m] calculated by the deviation calculation process Sb12. The larger the deviation ΔN[m] of the power storage unit U[m], the higher the number of charge / discharge cycles Nn[m] compared to other power storage units U[m]. Therefore, the coefficient setting unit 521 should preferentially allocate the power storage unit U[m] with a smaller deviation ΔN[m] to discharge or charge. In consideration of the above circumstances, the coefficient setting unit 521 of the sixth embodiment sets the weight α[m] to a larger value as the deviation ΔN[m] is smaller.

[0201] As described above, in the sixth embodiment, the weight value α[m] (and hence the distribution coefficient K[m]) is set according to the number of times N[m] of charging and discharging of the power storage device 31 in each power storage unit U[m], so that each distribution coefficient K[m] can be set so that the number of times N[m] of charging and discharging of each power storage device 31 approaches each other. This reduces the possibility that the output of each power storage unit U[m] is limited due to variations in the number of times N[m] of charging and discharging of the power storage device 31. In other words, the storage capacity of the entire power storage system 30 can be effectively used.

[0202] As a method for the coefficient setting unit 521 to calculate the weight value α[m] according to the deviation ΔN[m], in the sixth embodiment, the following exemplary aspects 6A and 6B can be adopted.

[0203] [Aspect 6A] Fig. 36 is an explanatory diagram of the process in which the coefficient setting unit 521 calculates the weight value α[m] in aspect 6A of the sixth embodiment. Specifically, Fig. 36 illustrates the relationship between the deviation ΔN[m] of the number of charging and discharging times N[m] and the weight value α[m]. The relationship between the deviation ΔN[m] and the weight value α[m] is the same regardless of whether the total DC power command value Cp indicates discharging or charging.

[0204] As illustrated in Fig. 36, the coefficient setting unit 521 roughly sets the weight value α[m] to the function value Fa(ΔN). The function value Fa(ΔN) is a variable value according to the deviation ΔN[m]. The larger the deviation ΔN[m], the smaller the function value Fa(ΔN) is set to. The function value Fa(ΔN) is an example of a "second value".

[0205] When the deviation ΔN[m] increases from a value below the threshold Y1 to a value above the threshold Y1, the coefficient setting unit 521 sets the weight value α[m] from the function value Fa(ΔN) to the minimum value 0 (first value). With the above configuration, each active power allocation value P[m] is set so that discharging and charging of the power storage unit U[m] having a large deviation ΔN[m] among the multiple power storage units U[m] is avoided preferentially. On the other hand, when the deviation ΔN[m] decreases from a value above the threshold Y2 to a value below the value Y2, the coefficient setting unit 521 sets the weight value α[m] to the function value Fa(ΔN).

[0206] Furthermore, when the deviation ΔN[m] decreases from a value exceeding the threshold Y3 to a value below the threshold Y3, the coefficient setting unit 521 sets the weight value α[m] from the function value Fa(ΔN) to the maximum value 1 (second value). With the above configuration, each active power allocation value P[m] is set so that the power storage unit U[m] having the smallest deviation ΔN[m] among the multiple power storage units U[m] is preferentially discharged and charged. On the other hand, when the deviation ΔN[m] increases from a value below the threshold Y4 to a value above the value Y4, the coefficient setting unit 521 sets the weight value α[m] to the function value Fa(ΔN).

[0207] As described above, in the embodiment 6A, the relationship between the deviation ΔN[m] and the weight value α[m] exhibits a hysteresis characteristic. Therefore, even if the deviation ΔN[m] fluctuates near each threshold value (Y1, Y2, Y3, Y4), excessively frequent fluctuations in the weight value α[m] can be suppressed. Note that each threshold value (Y1, Y2, Y3, Y4) related to the deviation ΔN[m] may be set individually for each power storage unit U[m], or may be set to a common value for multiple power storage units U[m].

[0208] [Aspect 6B] Fig. 37 is an explanatory diagram of a process in which the coefficient setting unit 521 calculates the weight value α[m] in aspect 6B of the sixth embodiment. Specifically, Fig. 37 illustrates the relationship Fb(ΔN) between the deviation ΔN[m] of the number of charge / discharge cycles N[m] and the weight value α[m].

[0209] 37, the relationship Fb(ΔN) is expressed by a straight line passing through a point corresponding to a predetermined negative number s2 of the deviation ΔN[m] and the maximum value 1 of the weighting value α[m]. The coefficient setting unit 521 sets a numerical value in the relationship Fb(ΔN) for the deviation ΔN[m] as the weighting value α[m].

[0210] Furthermore, the coefficient setting unit 521 determines the relationship Fb(ΔN) according to the total DC power command value Cp. Specifically, the coefficient setting unit 521 decreases the gradient of the relationship Fb(ΔN) as the absolute value |Cp| increases. Specifically, the relationship Fb(ΔN) changes between the relationship F1 and the relationship F2 according to the absolute value |Cp|.

[0211] In a state where the relationship Fb(ΔN) is set to the relationship F1, the weight value α[m] is set to a positive number for the power storage units U[m] whose deviation ΔN[m] is within a wide range from a negative number s2 to a positive number s1. Thus, each active power allocation value P[m] is set so that many power storage units U[m] perform discharging or charging. On the other hand, in a state where the relationship Fb(ΔN) is set to the relationship F2, the weight value α[m] is set to a positive number for the power storage units U[m] whose deviation ΔN[m] is within a negative number range, while the weight value α[m] is set to 0 for the power storage units U[m] whose deviation ΔN[m] is within a positive number range. Thus, each active power allocation value P[m] is set so that some power storage units U[m] whose deviation ΔN[m] is within a positive number range preferentially perform discharging or charging.

[0212] As described above, according to the aspect 6B, the relationship Fb(ΔN) between the deviation ΔN[m] and the weight value α[m] is determined according to the total DC power command value Cp. Therefore, compared to the aspect in which the relationship between the deviation ΔN[m] and the weight value α[m] is fixed, the total DC power command value Cp can be appropriately allocated to the multiple power storage units U[m]. Note that the configuration for changing the relationship Fb(ΔN) according to the total DC power command value Cp may be omitted. That is, the relationship Fb(ΔN) may be a fixed relationship between the relationship F1 and the relationship F2, for example.

[0213] 7. Seventh embodiment Fig. 38 is an explanatory diagram of the first process Sb1 in the seventh embodiment. As illustrated in Fig. 38, the first process Sb1 in the seventh embodiment includes a setting process Sc11, a setting process Sc12, a setting process Sc13, an adjustment process Sc21, an adjustment process Sc22, an adjustment process Sc23, and an addition process Sc3.

[0214] The setting process Sc11 is a process for setting a weight value α1[m] according to the charging rate S[m] of the power storage device 31 in each power storage unit U[m]. The weight value α1[m] corresponds to the weight value α[m] in the fourth embodiment. That is, the setting process Sc11 includes, for example, the normalization process Sb11, the deviation calculation process Sb12, and the weight value setting process Sb13 in the fourth embodiment. The adjustment process Sc21 is a process for adjusting the weight value α1[m] by multiplying the weight value α1[m] by an adjustment value γ1[m]. The adjustment value γ1[m] is set to a predetermined value. The weight value α1[m] is an example of a "first weight value".

[0215] The setting process Sc12 is a process for setting a weight value α2[m] according to the temperature T[m] of the power storage device 31 in each power storage unit U[m]. The weight value α2[m] corresponds to the weight value α[m] in the fifth embodiment. That is, the setting process Sc12 includes, for example, the normalization process Sb11, the deviation calculation process Sb12, and the weight value setting process Sb13 in the fifth embodiment. The adjustment process Sc22 is a process for adjusting the weight value α2[m] by multiplying the weight value α2[m] by an adjustment value γ2[m]. The adjustment value γ2[m] is set to a predetermined value. The weight value α2[m] is an example of a "second weight value".

[0216] The setting process Sc13 is a process for setting a weight value α3[m] according to the number of charge / discharge cycles N[m] of the power storage device 31 in each power storage unit U[m]. The weight value α3[m] corresponds to the weight value α[m] in the sixth embodiment. That is, the setting process Sc13 includes, for example, the normalization process Sb11, the deviation calculation process Sb12, and the weight value setting process Sb13 in the sixth embodiment. The adjustment process Sc23 is a process for adjusting the weight value α3[m] by multiplying the weight value α3[m] by an adjustment value γ3[m]. The adjustment value γ3[m] is set to a predetermined value. The weight value α3[m] is an example of the "third weight value".

[0217] The addition process Sc3 calculates the final weight value α[m] by adding the adjusted values ​​γ1[m]·α1[m] by the adjustment process Sc21, the adjusted values ​​γ2[m]·α2[m] by the adjustment process Sc22, and the adjusted values ​​γ3[m]·α3[m] by the adjustment process Sc23. That is, the coefficient setting unit 521 of the seventh embodiment sets the weight value α[m] by the weighted sum of the weight value α1[m] according to the charging rate S[m], the weight value α2[m] according to the temperature T[m], and the weight value α3[m] according to the number of charge / discharge cycles N[m]. The adjustment values ​​γ1[m], γ2[m], and γ3[m] may be set to different values ​​or may be set to the same value.

[0218] In addition, the adjustment process Sc21, the adjustment process Sc22, and the adjustment process Sc23 may be omitted in part or in whole. For example, the coefficient setting unit 521 may set the weight value α[m] by adding the weight value α1[m], the weight value α2[m], and the weight value α3[m]. As can be understood from the above example, the coefficient setting unit 521 of the seventh embodiment sets the weight value α[m] according to the weight value α1[m], the weight value α2[m], and the weight value α3[m]. In addition, the third process Sb3 that calculates the distribution coefficient K[m] according to the weight value α[m] and the correction value β[m] according to the operating watt-hour capacity B[m] described above is the same as that of the third embodiment (FIG. 22).

[0219] In the seventh embodiment, the weight value α[m] is set according to the charging rate S[m], temperature T[m], and number of charge / discharge cycles N[m] of each power storage unit U[m]. Therefore, compared to a form in which the weight value α[m] is set according to only a specific state of the power storage unit U[m], it is possible to set an appropriate weight value α[m] (and thus the distribution coefficient K[m]) from various perspectives (S[m], T[m], N[m]) related to the state of the power storage device 31.

[0220] 8. Eighth embodiment 39 is an explanatory diagram of the operation of the coefficient setting unit 521 in the eighth embodiment. The coefficient setting unit 521 in the eighth embodiment includes a smoothing process Sd in addition to the same processes (Sb1, Sb2, Sb3) as in the third embodiment. The smoothing process Sd is a process for reducing the speed of temporal fluctuation of the distribution coefficient K[m] calculated by the third process Sb3.

[0221] Fig. 40 is an explanatory diagram of the smoothing process Sd. As illustrated in Fig. 40, the distribution coefficient K[m] immediately after the third process Sb3 may vary discontinuously on the time axis. On the other hand, the distribution coefficient K[m] after the smoothing process Sd varies continuously on the time axis. As explained above, the smoothing process Sd is a low-pass filter process that suppresses high-frequency components in the time series of the distribution coefficient K[m].

[0222] For example, when the allocation coefficient K[1] of the energy storage unit U[1] fluctuates sharply, the active power allocation value P[1] of the energy storage unit U[1] is linked, and the active power allocation values ​​P[m] of the other energy storage units U[2] to U[5] are also linked and fluctuate sharply. However, since there may be variations in the time at which each energy storage unit U[m] receives the active power allocation value P[m], there is a possibility that the power at the combining point fluctuates during the period from when the allocation coefficient K[1] fluctuates to when the fluctuation of the allocation coefficient K[1] is reflected in the active power of all the energy storage units U[m]. According to the eighth embodiment, the speed of temporal fluctuation of the allocation coefficient K[m] is reduced, so that it is possible to reduce the possibility that the power at the combining point fluctuates suddenly due to a sharp fluctuation of the distribution power in each energy storage unit U[m].

[0223] FIG. 41 is an explanatory diagram of a specific configuration for realizing the smoothing process Sd. As illustrated in FIG. 41, the coefficient setting unit 521 is supplied with an allocation target flag f[m] for each power storage unit U[m]. The allocation target flag f[m] is a flag indicating whether the power storage unit U[m] is a target or not a target for allocation of the total DC power command value Cp. Specifically, the allocation target flag f[m] of the power storage unit U[m] that is a target for allocation is set to a valid value (for example, 1), and the allocation target flag f[m] of the power storage unit U[m] that is not a target for allocation is set to an invalid value (for example, 0). For example, the allocation target flag f[m] is set to a valid value for each power storage unit U[m] that is in a normal operating state. On the other hand, for example, the allocation target flag f[m] is set to an invalid value for a power storage unit U[m] that is in a state that cannot respond to an instruction from the control system 40 (for example, a stopped state) or a power storage unit U[m] that is undergoing maintenance work such as repair and inspection.

[0224] 41, the coefficient setting unit 521 includes a switching unit 5212 and a smoothing unit 5213. The allocation target flag f[m] is supplied to the switching unit 5212.

[0225] The smoothing unit 5213 smoothes the temporal fluctuation of the distribution coefficient K[m]. For example, a low-pass filter in which three stages of first-order lag filters are connected in series is exemplified as the smoothing unit 5213. The switching unit 5212 is a switch that switches whether or not to supply the distribution coefficient K[m] calculated by the third process Sb3 to the smoothing unit 5213 according to the distribution target flag f[m].

[0226] In the above configuration, for example, for a power storage unit U[m] that starts operation due to the completion of maintenance work, the allocation target flag f[m] is changed from an invalid value to a valid value. By changing the allocation target flag f[m] to a valid value, supply of the allocation coefficient K[m] to the smoothing unit 5213 is started. Therefore, it is possible to stably start (soft start) the setting and variation of the allocation coefficient K[m] for the power storage unit U[m] that starts operation.

[0227] On the other hand, for a power storage unit U[m] that stops operation to start maintenance work, for example, the allocation target flag f[m] is changed from a valid value to an invalid value, thereby stopping the supply of the allocation coefficient K[m] to the smoothing unit 5213. Therefore, for the power storage unit U[m] that stops operation, it is possible to stably stop (soft stop) the setting and variation of the allocation coefficient K[m].

[0228] 9. Ninth embodiment The ninth embodiment is a form for additionally starting up one or more power storage units U[m] during the operation of the power storage system 30.

[0229] FIG. 42 is an explanatory diagram of an operation in a case where one power storage unit U[1] is additionally started up during the execution of discharging by the four power storage units U[2] to U[5] of the power storage system 30. The conversion loss X3 before the start of the power storage unit U[1] is a numerical value (e.g., 4) obtained by summing up the conversion losses x[m] for the four power storage units U[2] to U[5] that are discharging. As a result of starting up the power storage unit U[1], the conversion loss X3 is changed to a numerical value (e.g., 5) obtained by summing up the conversion losses x[m] for the five power storage units U[1] to U[5]. Therefore, as illustrated in FIG. 42, the total DC power command value Cp calculated by the command calculation unit 51 is changed by the start up of the power storage unit U[1].

[0230] 42, when the power storage unit U[1] is started, the coefficient setting unit 521 increases the distribution coefficient K[1] from the minimum value 0 to the target value, and the limit value setting unit 522 increases the limit value L[1]_d from the reference value 0 to the target value. The target value of the distribution coefficient K[1] is a numerical value calculated, for example, by the third to eighth embodiments, and the target value of the limit value L[1]_d is a numerical value calculated, for example, by the second embodiment.

[0231] As described above, each power allocation value Pa[m] is calculated by multiplying the ratio of each allocation coefficient K[m] to the total value ΣK[m] of the allocation coefficients K[m] by the total DC power command value Cp. Therefore, when the allocation coefficient K[1] increases, as illustrated in FIG. 42, the power allocation value Pa[m] of the power storage unit U[1] to be added increases, while the power allocation values ​​Pa[m] of the existing power storage units U[2] to U[5] decrease.

[0232] 43 is an explanatory diagram regarding the temporal change of the distribution coefficient K[1] and the power distribution value Pa[1]. As illustrated in FIG. 43, the coefficient setting unit 521 increases the distribution coefficient K[1] from the minimum value 0 to the target value 5 over time from the start point to the end point of the period Ta. Therefore, the power distribution value Pa[1] increases over time from the minimum value 0 to the target value 40 from the start point to the end point of the period Ta. The start point of the period Ta is, for example, the time point when the administrator of the management system 100 instructs the power storage unit U[1] to start up and when the power storage unit U[1] becomes capable of responding to an instruction from the control system 40.

[0233] 43 also shows the change over time in the active power allocation value P[1] limited by the limit value L[1]_d. The limit value setting unit 522 increases the limit value L[1]_d from the reference value 0 to the target value 40 over time from the start point to the end point of the period Tb, thereby increasing the active power allocation value P[1] over time from the reference value 0 to the target value 39. Note that the start point of the period Tb is the same point in time as the start point of the period Ta.

[0234] As described above, the allocation coefficient K[1] and the limit value L[1]_d change over time, and as a result, the active power allocation value P[1] of the energy storage unit U[1] increases over time from the initial value 0 to the target value 39 from the start point to the end point of the period Tb. Note that, although the above description has been given of an example in which the length of the period Tb exceeds the length of the period Ta, there are also cases in which the length of the period Tb is shorter than the length of the period Ta.

[0235] Fig. 44 is an explanatory diagram relating to the operation when one energy storage unit U[5] is additionally started up during charging by the four energy storage units U[1] to U[4] of the energy storage system 30. As in the case of Fig. 42, the addition of the energy storage unit U[5] changes the conversion loss X3, and as a result, the total DC power command value Cp calculated by the command calculation unit 51 also changes.

[0236] 44, when the power storage unit U[5] is started, the coefficient setting unit 521 increases the allocation coefficient K[5] from the minimum value 0 to the target value, and the limit value setting unit 522 decreases the limit value L[5]_c from the reference value 0 to the target value. As a result of the changes in the allocation coefficient K[5] and the limit value L[5]_c, the power allocation value Pa[5] of the power storage unit U[5] to be added decreases within the range of negative numbers, while the power allocation values ​​Pa[m] of the existing power storage units U[1] to U[4] increase.

[0237] Fig. 45 is an explanatory diagram regarding the temporal change of the allocation coefficient K[5] and the power allocation value Pa[5]. As illustrated in Fig. 45, the coefficient setting unit 521 increases the allocation coefficient K[5] from the minimum value 0 to the target value 5 over time from the start point to the end point of the period Ta. Therefore, the power allocation value Pa[5] decreases over time from the initial value 0 to the target value -40 from the start point to the end point of the period Ta. The start point of the period Ta is, for example, the time point when the administrator of the management system 100 issues an instruction to start up the power storage unit U[5].

[0238] 45 also shows the change over time in the active power allocation value P[5] limited by the limit value L[5]_c. The limit value setting unit 522 reduces the active power allocation value P[5] over time from the reference value 0 to the target value -41 by reducing the limit value L[5]_c over time from the start point to the end point of the period Tb. Note that the start point of the period Tb is the same point in time as the start point of the period Ta.

[0239] As described above, as a result of the changes in the allocation coefficient K[5] and the limit value L[5]_c over time, the active power allocation value P[5] of the power storage unit U[5] decreases over time from the initial value 0 to the target value -41 from the start point to the end point of the period Tb. Note that, although the above description has been given of an example in which the length of the period Tb exceeds the length of the period Ta, there are also cases in which the length of the period Tb is shorter than the length of the period Ta.

[0240] As described above, in the ninth embodiment, the distribution coefficient K[m] and the limit value L[m] change continuously over the period Ta when the energy storage unit U[m] is started. That is, discontinuous fluctuations in the distribution coefficient K[m] and the limit value L[m] caused by the start-up of the energy storage unit U[m] are suppressed. Therefore, it is possible to reduce the possibility that the combination point power will suddenly fluctuate due to abrupt fluctuations in the distribution coefficient K[m] or the limit value L[m] in each energy storage unit U[m].

[0241] 10. Tenth embodiment In the ninth embodiment, attention is focused on the additional activation of the power storage unit U[m]. The tenth embodiment is a form for stopping one or more power storage units U[m] during the operation of the power storage system 30.

[0242] Fig. 46 is an explanatory diagram relating to an operation in a case where one energy storage unit U[1] is stopped during execution of discharge by five energy storage units U[1] to U[5] of the energy storage system 30. As illustrated in Fig. 46, when the energy storage unit U[1] is stopped, the coefficient setting unit 521 reduces the allocation coefficient K[1] to the minimum value 0, and the limit value setting unit 522 reduces the limit value L[1]_d to the minimum value 1. As a result of the change in the allocation coefficient K[1] and the limit value L[1]_d, the power allocation value Pa[m] of the energy storage unit U[1] to be stopped decreases, while the power allocation value Pa[m] of the energy storage units U[2] to U[5] that continue to operate increases.

[0243] Fig. 47 is an explanatory diagram regarding the change over time of the allocation coefficient K[1] and the power allocation value Pa[1]. As illustrated in Fig. 47, the coefficient setting unit 521 decreases the allocation coefficient K[1] over time from the current value 5 to the minimum value 0 from the start point to the end point of the period Ta. Therefore, the power allocation value Pa[1] decreases over time from the current value 40 to the minimum value 1 from the start point to the end point of the period Ta. The start point of the period Ta is, for example, the time point when the administrator of the management system 100 issues an instruction to stop the power storage unit U[1].

[0244] 47 also shows the change over time in the active power allocation value P[1] limited by the limit value L[1]_d. The limit value setting unit 522 reduces the active power allocation value P[1] over time from the current value 39 to the reference value 0 by reducing the limit value L[1]_d from the current value 40 to the minimum value 1 from the start point to the end point of the period Tb. The start point of the period Tb is the same point in time as the start point of the period Ta.

[0245] As described above, as a result of the distribution coefficient K[1] and the limit value L[1]_d changing over time, the active power distribution value P[1] of the energy storage unit U[1] decreases over time from the current value 39 to the minimum value 0 from the start point to the end point of the period Tb. Note that, although the above description has been given of an example in which the length of the period Tb exceeds the length of the period Ta, there are also cases in which the length of the period Tb is shorter than the length of the period Ta.

[0246] 48, a case is assumed in which one power storage unit U[5] is stopped during the execution of charging by five power storage units U[1] to U[5] of the power storage system 30. As illustrated in FIG. 48, when the power storage unit U[5] is stopped, the coefficient setting unit 521 decreases the allocation coefficient K[5] from the current value 5 to the minimum value 0, and the limit value setting unit 522 increases the limit value L[5]_c from the current value -40 to the reference value 0. As a result of the change in the allocation coefficient K[5] and the limit value L[5]_c, the power allocation value Pa[5] of the power storage unit U[5] to be added increases, while the power allocation value Pa[m] of the power storage units U[1] to U[4] decreases.

[0247] Fig. 49 is an explanatory diagram of temporal changes in the distribution coefficient K[5] and the power distribution value Pa[5]. As illustrated in Fig. 49, the coefficient setting unit 521 increases the distribution coefficient K[5] from the current value 5 to the minimum value 0 over time from the start point to the end point of the period Ta. Therefore, the power distribution value Pa[5] increases over time from the current value -40 to the reference value 0 from the start point to the end point of the period Ta.

[0248] 49 also shows the change over time in the active power allocation value P[5] limited by the limit value L[5]_c. The limit value setting unit 522 increases the limit value L[5]_c from the current value -40 to the reference value 0 over time from the start point to the end point of the period Tb, thereby increasing the active power allocation value P[5] over time from the current value -41 to the reference value 0. Note that the start point of the period Tb is the same point in time as the start point of the period Ta.

[0249] As described above, as a result of the distribution coefficient K[5] and the limit value L[5]_c changing over time, the active power distribution value P[5] of the energy storage unit U[5] increases over time from the current value -41 to the reference value 0 from the start point to the end point of the period Tb. Note that, although the above explanation has been given of an example in which the length of the period Tb exceeds the length of the period Ta, there are also cases in which the length of the period Tb is shorter than the length of the period Ta.

[0250] In the tenth embodiment, similarly to the ninth embodiment, when the energy storage unit U[m] is stopped, the distribution coefficient K[m] and the limit value L[m] change continuously over the period Ta. That is, discontinuous fluctuations in the distribution coefficient K[m] and the limit value L[m] caused by the stop of the energy storage unit U[m] are suppressed. Therefore, similarly to the ninth embodiment, it is possible to reduce the possibility that the combination point power will suddenly change due to abrupt fluctuations in the distribution coefficient K[m] or the limit value L[m] in each energy storage unit U[m].

[0251] 11. Eleventh embodiment In the eleventh embodiment, it is assumed that some of the power storage units U[m] (hereinafter referred to as "maintenance target units U[m]") among the multiple power storage units U[m] of the power storage system 30 are in a maintenance state, such as repair or inspection. The maintenance target units U[m] are excluded from the targets of the allocation of the total DC power command value Cp. In other words, the active power allocation value P[m] is not calculated for the maintenance target units U[m].

[0252] Fig. 50 is an explanatory diagram of the operation of the command calculation unit 51 in the eleventh embodiment. The maintenance power Ga illustrated in Fig. 50 is active power (i.e., power for maintenance) used for maintenance work in the maintenance target unit U[m]. The maintenance power Ga is set to a predetermined value depending on the content of the maintenance work, for example. The maintenance power Ga may be a measured value of the active power of the maintenance target unit U[m]. When the maintenance power Ga is a positive number, it means that charging is performed in the maintenance target unit U[m], and when the maintenance power Ga is a negative number, it means that discharging is performed in the maintenance target unit U[m].

[0253] The command calculation unit 51 of the eleventh embodiment calculates a total DC power command value Cp by adding the transformation loss X1, the load loss X2, the conversion loss X3, and the maintenance power Ga to the basic command value C0. Specifically, the total DC power command value Cp is calculated by adding the transformation loss X1, the load loss X2, the conversion loss X3, and the maintenance power Ga to the basic command value C0, as shown in the following formula (8).

number

[0254] The total DC power command value Cp calculated by Formula (8) is allocated to each power storage unit U[m] other than the maintenance target unit U[m] among the multiple power storage units U[m] of the power storage system 30. As can be understood from the above description, in the eleventh embodiment, each power storage unit U[m] other than the maintenance target unit U[m] operates extra to secure maintenance power Ga for maintenance of the maintenance target unit U[m]. That is, power discharged by each power storage unit U[m] other than the maintenance target unit U[m] is lent for maintenance work on the maintenance target unit U[m].

[0255] Fig. 51 is an explanatory diagram of the operation of the management system 100 in the eleventh embodiment. In Fig. 51, a case is assumed in which the energy storage unit U[4] among the multiple energy storage units U[m] is the maintenance target unit U[4]. The total DC power command value Cp is a numerical value (Cp>0) indicating discharging.

[0256] 51, the active power allocation value P[m] is calculated for the four power storage units U[m] (U[1], U[2], U[3], U[5]) other than the maintenance target unit U[4]. That is, for the maintenance target unit U[4], the setting of the allocation coefficient K[m] and the limit value L[m], the calculation of the power allocation value Pa[m] (Sa1), the calculation of the power allocation value Pb[m] (Sa2 to Sa5), and the calculation of the active power allocation value P[m] are not performed.

[0257] A part of the power of the active power allocation value P[m] generated by each energy storage unit U[m] other than the maintenance target unit U[4] (maintenance power Ga) is supplied to the maintenance target unit U[4] and used for maintenance work. As described above, according to the eleventh embodiment, while maintaining the combination point power at the basic command value C0, the power required for maintenance of the maintenance target unit U[m] can be accommodated by the other energy storage units U[m] in operation.

[0258] 12. Twelfth embodiment There are cases where it is necessary to preferentially discharge or charge a specific power storage unit U[m] among the multiple power storage units U[m] in the power storage system 30. For example, when the power storage unit U[m] to be maintained is in a state where it is sufficiently charged, it may be necessary to start maintenance work after sufficiently lowering the charging rate S[m] by preferentially discharging the power storage unit U[m]. When the power storage unit U[m] to be maintained is in a state where it is not sufficiently charged, it may be necessary to start maintenance work after sufficiently raising the charging rate S[m] of the power storage unit U[m] by preferentially charging the power storage unit U[m].

[0259] Furthermore, in a state where the charging rate S[m] of a power storage unit U[m] newly added to the power storage system 30 or a power storage unit U[m] that has returned from maintenance work is significantly lower than that of the other power storage units U[m], it may be necessary to increase the charging rate S[m] by preferential charging. On the other hand, in a state where the charging rate S[m] of a power storage unit U[m] newly added to the power storage system 30 or a power storage unit U[m] that has returned from maintenance work is significantly higher than that of the other power storage units U[m], it may be necessary to decrease the charging rate S[m] by preferential discharging.

[0260] Taking the above circumstances into consideration, the twelfth embodiment is a form in which a specific energy storage unit U[m] (hereinafter referred to as a "priority unit U[m]") among the multiple energy storage units U[m] of the energy storage system 30 is preferentially discharged or charged.

[0261] In the following description, the power discharged or charged by the priority unit U[m] is referred to as "correction power Gb." The correction power Gb indicates the discharge / charge of the priority unit U[m] by its sign. Specifically, a positive correction power Gb means the power value that the priority unit U[m] should discharge. On the other hand, a negative correction power Gb means the power value that the priority unit U[m] should charge.

[0262] Specifically, the command calculation unit 51 of the twelfth embodiment adds the power losses (X1, X2, X3) to the base command value C0 as in the above-described embodiments, and also calculates the total DC power command value Cp by subtracting the correction power Gb from the base command value C0. That is, the command calculation unit 51 calculates the total DC power command value Cp by the calculation of the following formula (9).

number

[0263] In addition, the allocation processing unit 523 of the 12th embodiment calculates an active power allocation value P[m] from the total DC power command value Cp for each energy storage unit (hereinafter referred to as a "normal unit") U[m] other than the priority unit U[m] among the multiple energy storage units U[m] of the energy storage system 30, and sets the correction power Gb as the active power allocation value P[m] for the priority unit U[m].

[0264] The operation of the twelfth embodiment will be described in detail below. In the following description, the case where the priority unit U[m] is discharged and the case where the priority unit U[m] is powered will be described for each of the cases where the total DC power command value Cp indicates discharging (Cp>0) and charging (Cp<0).

[0265] [Operation Case 1] 52 and 53 are explanatory diagrams of the operation of the management system 100 in operating case 1. Operating case 1 is a case where the total DC power command value Cp indicates discharging (Cp>0) and the priority unit U[m] is discharged (Gb>0). In the following description, it is assumed that the power storage unit U[1] is the priority unit U[1] and the power storage units U[2] to U[5] are normal units U[m].

[0266] As illustrated in FIG. 52, the command calculation unit 51 calculates the total DC power command value Cp by adding the power losses (X1, X2, X3) to the basic command value C0 and subtracting the correction power Gb.

[0267] As illustrated in FIG. 53, the allocation processor 523 sets the limit value L[1]_d of the priority unit U[1] to 0, thereby excluding the priority unit U[1] from the allocation target of the total DC power command value Cp. The allocation processor 523 calculates (Sa1) the power allocation value Pa[m], (Sa2-Sa5) the power allocation value Pb[m], and (Sa6) the active power allocation value P[m] for each normal unit U[m]. That is, the active power allocation value P[m] of each normal unit U[m] is calculated by the same processes (Sa1-Sa6) as those in each of the above-mentioned forms. In addition, the allocation processor 523 sets the active power allocation value P[m] of the priority unit U[1] to a numerical value corresponding to the correction power Gb. Specifically, the power allocation value Pb[1] of the priority unit U[1] is set to the corrected power Gb (=60), and the effective power allocation value P[1] is set to a value (=59) obtained by subtracting the conversion loss x[1] from the power allocation value Pb[1].

[0268] The active power allocation value P[m] calculated by the above procedure is transmitted to each energy storage unit U[m]. Therefore, each normal unit U[m] (U[2] to U[5]) discharges the power of the active power allocation value P[m] to which the total DC power command value Cp is allocated, and the priority unit U[1] discharges the correction power Gb. As a result of the above operation, it is possible to preferentially discharge the priority unit U[1] while maintaining the combination point power at the basic command value C0.

[0269] [Operation Case 2] 54 and 55 are diagrams illustrating the operation of the management system 100 in operating case 2. Operating case 2 is a case where the total DC power command value Cp indicates discharging (Cp>0) and the priority unit U[m] is charged (Gb<0). In the following description, it is assumed that the power storage unit U[5] is the priority unit U[5] and the power storage units U[1] to U[4] are normal units U[m].

[0270] As illustrated in FIG. 54, the command calculation unit 51 calculates the total DC power command value Cp by adding the power losses (X1, X2, X3) to the basic command value C0 and subtracting the correction power Gb.

[0271] As illustrated in FIG. 55, the allocation processor 523 sets the limit value L[1]_d of the priority unit U[5] to 0, thereby excluding the priority unit U[5] from the allocation target of the total DC power command value Cp. The allocation processor 523 calculates an active power allocation value P[m] for each normal unit U[m] by the same process (Sa1 to Sa6) as in the first embodiment. The allocation processor 523 also sets the active power allocation value P[5] of the priority unit U[5] to a numerical value corresponding to the corrected power Gb. Specifically, the power allocation value Pb[5] of the priority unit U[5] is set to the corrected power Gb (-60), and the active power allocation value P[5] is set to a numerical value (-61) obtained by subtracting the conversion loss x[5] from the power allocation value Pb[5].

[0272] The active power allocation value P[m] calculated by the above procedure is transmitted to each storage unit U[m]. Therefore, each normal unit U[m] (U[1] to U[4]) discharges the power of the active power allocation value P[m] to which the total DC power command value Cp is allocated, and the priority unit U[5] charges with the correction power Gb. As a result of the above operation, it is possible to charge the priority unit U[5] preferentially while maintaining the combination point power at the basic command value C0.

[0273] [Operation Case 3] 56 and 57 are explanatory diagrams of the operation of the management system 100 in operation case 3. Operation case 3 is a case where the total DC power command value Cp indicates charging (Cp<0) and the priority unit U[m] is discharged (Gb>0). In the following description, it is assumed that the power storage unit U[1] is the priority unit U[1] and the power storage units U[2] to U[5] are normal units U[m].

[0274] As illustrated in FIG. 56, the command calculation unit 51 calculates the total DC power command value Cp by adding the power losses (X1, X2, X3) to the basic command value C0 and subtracting the correction power Gb.

[0275] As illustrated in FIG. 57, the allocation processor 523 sets the limit value L[1]_c of the priority unit U[1] to 0, thereby excluding the priority unit U[1] from the allocation target of the total DC power command value Cp. The allocation processor 523 calculates an active power allocation value P[m] for each normal unit U[m] by the same process (Sa1 to Sa6) as in each of the above-mentioned forms. In addition, the allocation processor 523 sets the active power allocation value P[m] of the priority unit U[1] to a numerical value corresponding to the correction power Gb. Specifically, the power allocation value Pb[1] of the priority unit U[1] is set to the correction power Gb (=60), and the active power allocation value P[1] is set to a numerical value (=59) obtained by subtracting the conversion loss x[1] from the power allocation value Pb[1].

[0276] The active power allocation value P[m] calculated by the above procedure is transmitted to each storage unit U[m]. Therefore, each normal unit U[m] (U[2] to U[5]) charges with the power of the active power allocation value P[m] to which the total DC power command value Cp is allocated, and the priority unit U[1] discharges the correction power Gb. As a result of the above operation, it is possible to preferentially discharge the priority unit U[1] while maintaining the combination point power at the basic command value C0.

[0277] [Operation Case 4] 58 and 59 are explanatory diagrams of the operation of the management system 100 in operation case 4. Operation case 4 is a case where the total DC power command value Cp indicates charging (Cp<0) and the priority unit U[m] is charged (Gb<0). In the following description, it is assumed that the power storage unit U[5] is the priority unit U[5] and the power storage units U[1] to U[4] are normal units U[m].

[0278] As illustrated in FIG. 58, the command calculation unit 51 calculates the total DC power command value Cp by adding the power losses (X1, X2, X3) to the basic command value C0 and subtracting the correction power Gb.

[0279] As illustrated in FIG. 59, the allocation processor 523 sets the limit value L[1]_c of the priority unit U[5] to 0, thereby excluding the priority unit U[5] from the allocation target of the total DC power command value Cp. The allocation processor 523 calculates an active power allocation value P[m] for each normal unit U[m] by the same process (Sa1 to Sa6) as in each of the above-mentioned forms. The allocation processor 523 also sets the active power allocation value P[5] of the priority unit U[5] to the correction power Gb. Specifically, the power allocation value Pb[5] of the priority unit U[5] is set to the correction power Gb (=-60), and the active power allocation value P[5] is set to a value (=-61) obtained by subtracting the conversion loss x[5] from the power allocation value Pb[5].

[0280] The active power allocation value P[m] calculated by the above procedure is transmitted to each storage unit U[m]. Therefore, each normal unit U[m] (U[1] to U[4]) is charged with the power of the active power allocation value P[m] to which the total DC power command value Cp is allocated, and the priority unit U[5] is charged with the correction power Gb. As a result of the above operation, it is possible to charge the priority unit U[5] preferentially while maintaining the combination point power at the basic command value C0.

[0281] 13. Thirteenth embodiment In each of the above embodiments, attention has been focused on the active power exchanged between the power system 10 and the management system 100. The thirteenth embodiment is a embodiment that focuses on the reactive power exchanged between the power system 10 and the management system 100. In the thirteenth embodiment, the configuration and method for calculating the active power allocation value P[m] of each power storage unit U[m] from the basic command value C0 are similar to those of the above embodiments.

[0282] 60 is a block diagram illustrating a functional configuration of a control system 40 in the 13th embodiment. A control device 41 in the 13th embodiment functions as the same elements (a command calculation unit 51, a command distribution unit 52, and an operation instruction unit 53) as those in the first embodiment.

[0283] The command calculation unit 51 of the thirteenth embodiment calculates a total DC power command value Cp as in the above-mentioned embodiments, and also calculates a total reactive power command value Cq. The total reactive power command value Cq is a total value of reactive power to be generated by a plurality of power storage units U[m]. Note that, regarding reactive power, a direction in which lagging-phase reactive power is generated in the power system 10 (i.e., a direction in which the power storage unit U[m] is capacitive) is expressed by a positive number, and a direction in which leading-phase reactive power from the power system 10 is absorbed (i.e., a direction in which the power storage unit U[m] is inductive) is expressed by a negative number.

[0284] Generally, when active power is supplied to the power system 10, the voltage of the power system 10 rises, and therefore the voltage rise is suppressed by an operation in a direction to absorb leading-phase reactive power from the power system 10. On the other hand, when active power is consumed from the power system 10, the voltage of the power system 10 drops, and therefore the voltage drop is suppressed by an operation in a direction to generate lagging-phase reactive power in the power system 10.

[0285] Fig. 61 is an explanatory diagram of the operation of the command calculation unit 51 in the thirteenth embodiment. As illustrated in Fig. 61, the command calculation unit 51 calculates a reactive power command value Cq0 according to a basic command value C0. For example, the command calculation unit 51 calculates the reactive power command value Cq0 by multiplying the basic command value C0 by a predetermined power factor.

[0286] The command calculation unit 51 calculates the total reactive power command value Cq by correcting the reactive power command value Cq0 with the correction value Xq. The correction value Xq is a total value of reactive power generated in the management system 100 due to factors other than the normal operation of each storage unit U[m]. Specifically, the correction value Xq is calculated by subtracting the lagging reactive power (in the direction in which the load equipment 22 becomes inductive, expressed by a positive number) or the leading reactive power (in the direction in which the load equipment 22 becomes capacitive, expressed by a negative number) consumed by the load equipment 22 from the lagging reactive power (positive number) generated by the storage unit U[m] that is excluded from the distribution target of active power due to, for example, maintenance work among the multiple storage units U[m]. As illustrated in FIG. 61, the command calculation unit 51 calculates the total reactive power command value Cq by, for example, subtracting the correction value Xq from the reactive power command value Cq0 (Cq=Cq0-Xq).

[0287] The command allocation unit 52 in Fig. 60 calculates an active power allocation value P[m] of each power storage unit U[m] from the total DC power command value Cp as in the above-mentioned embodiments, and also calculates a command value of reactive power (hereinafter referred to as "reactive power allocation value Q[m]") to be allocated to each of the plurality of power storage units U[m] from the total reactive power command value Cq. The reactive power allocation value Q[m] is a command value of reactive power to be generated by each power storage unit U[m]. That is, the command allocation unit 52 allocates the total reactive power command value Cq to the plurality of power storage units U[m].

[0288] The operation instruction unit 53 instructs each power storage unit U[m] of an active power allocation value P[m] and a reactive power allocation value Q[m]. Specifically, the operation instruction unit 53 transmits the active power allocation value P[m] and the reactive power allocation value Q[m] calculated by the command allocation unit 52 to the power storage unit U[m] via the transmission / reception device 43. Each power storage unit U[m] (power adjustment device 32) causes the power storage device 31 to discharge or charge DC power equivalent to the active power allocation value P[m], and also generates reactive power equivalent to the reactive power allocation value Q[m].

[0289] Fig. 62 is an explanatory diagram of the operation of the command distribution unit 52 to calculate the reactive power allocation value Q[m] of each power storage unit U[m]. Fig. 62 illustrates the active power allocation value P[m] calculated for each power storage unit U[m] by the configuration and operation exemplified in each of the above-mentioned embodiments.

[0290] In step Se1, the command distribution unit 52 acquires a capacity characteristic A[m] for each of the plurality of power storage units U[m]. The capacity characteristic A[m] is a relationship between active power and reactive power that the power storage unit U[m] can process (e.g., a condition of apparent power). The capacity characteristic A[m] may differ for each power storage unit U[m]. The capacity characteristic A[m] is determined in advance according to, for example, the specifications of each power storage unit U[m]. Note that, for example, the capacity characteristic A[m] may be included in the status data D[m] that the transmission / reception device 43 receives from each power storage unit U[m].

[0291] In step Se2, the command allocator 52 calculates the available reactive power q[m] of each power storage unit U[m] according to the active power allocation value P[m] and the capacity characteristic A[m]. The available reactive power q[m] is the maximum value of reactive power that the power storage unit U[m] can generate. Specifically, the command allocator 52 calculates the reactive power corresponding to the active power allocation value P[m] under the capacity characteristic A[m] as the available reactive power q[m].

[0292] For example, when the basic command value C0 indicates discharging (C0>0), discharging by each energy storage unit U[m] acts in a direction that increases the voltage at the combining point 11. In order to suppress the increase in voltage at the combining point 11, the command distribution unit 52 calculates the leading reactive power as available reactive power q[m]. On the other hand, when the basic command value C0 indicates charging (C0<0), charging by each energy storage unit U[m] acts in a direction that decreases the voltage at the combining point 11. In order to suppress the decrease in voltage at the combining point 11, the command distribution unit 52 calculates the lagging reactive power as available reactive power q[m].

[0293] In step Se3, the command allocator 52 calculates a reactive power allocation value Q[m] of each energy storage unit U[m] according to the total reactive power command value Cq and each available reactive power q[m]. Specifically, the command allocator 52 calculates each reactive power allocation value Q[m] by the calculation of the following formula (10).

number

[0294] As can be seen from the formula (10), the command allocation unit 52 calculates the reactive power allocation value Q[m] of each energy storage unit U[m] by multiplying the total reactive power command value Cq by the ratio of each available reactive power q[m] to the total value Σq[m] of the multiple available reactive powers q[m]. In other words, the total reactive power command value Cq is allocated to each energy storage unit U[m] based on the ratio of each available reactive power q[m].

[0295] As described above, in the thirteenth embodiment, in addition to the generation of active power by each energy storage unit U[m], the generation of reactive power can also be controlled. Therefore, for example, a reactive power compensator (SVC (Static Var Compensator), SVG (Static Var Generator), STATCOM (STATic synchronous COMpensator)) dedicated to controlling the reactive power of each energy storage unit U[m] can be made unnecessary in principle. However, a reactive power compensator may be used in combination in the thirteenth embodiment.

[0296] 14. Fourteenth embodiment Fig. 63 is a block diagram illustrating a configuration of a management system 100 according to the 14th embodiment. As illustrated in Fig. 63, the management system 100 of the 14th embodiment includes a power generation facility 23 in addition to the same elements as those of the first embodiment (Fig. 1) (the substation facility 21, the load facility 22, the power storage system 30, and the control system 40).

[0297] The power generation facility 23 is, for example, a distributed power source that generates power using renewable energy. For example, any type of power generation system that uses renewable energy, such as a solar power generation system that converts solar energy into electric power, a wind power generation system that converts wind energy into electric power, a geothermal power generation system that converts geothermal energy into electric power, a hydroelectric power generation system that converts hydroelectric energy into electric power, or a biomass power generation system that converts biomass energy into electric power, is used as the power generation facility 23. The power generation facility 23 may be configured by a plurality of power generation systems that use different power generation methods.

[0298] The command calculation unit 51 in each of the above-described embodiments calculates the total DC power command value Cp by adding the power loss (X1+X2+X3) including the transformation loss X1, the load loss X2, and the conversion loss X3 to the basic command value C0 as shown in the above-described formula (1). The command calculation unit 51 in the fourteenth embodiment calculates the total DC power command value Cp by adding the active power generated by the power generation facility 23 (hereinafter referred to as the "generated active power value Gc") to the basic command value C0 in addition to the power loss (X1+X2+X3). Specifically, the command calculation unit 51 calculates the total DC power command value Cp by a calculation including the addition of the power loss (X1+X2+X3) to the basic command value C0 and the subtraction of the generated active power value Gc as shown in the following formula (11).

number

[0299] The configuration and operation for calculating the active power allocation value P[m] of each storage unit U[m] from the total DC power command value Cp are the same as those in the above-mentioned embodiments. According to the fourteenth embodiment, even in an environment in which a power generation facility 23 is installed in parallel with a plurality of storage units U[m], the combined point power can be maintained at the basic command value C0 with high accuracy.

[0300] 15. Fifteenth embodiment Fig. 64 is a block diagram illustrating a configuration of a management system 100 according to a fifteenth embodiment. As illustrated in Fig. 64, the power adjustment device 32 in each power storage unit U[m] in the fifteenth embodiment is a DC / DC converter that converts DC power into DC power of a different voltage value. That is, each power storage unit U[m] in the fifteenth embodiment supplies or receives DC power. The conversion loss X3 applied to the calculation of the total DC power command value Cp in the fifteenth embodiment includes a numerical value obtained by totaling the power losses caused by the power conversion by the power adjustment device 32 over the multiple power storage units U[m].

[0301] As illustrated in Fig. 64, an AC / DC converter 24 is installed between the substation equipment 21 and the power storage system 30. The AC / DC converter 24 is an AC / DC converter that converts DC power into AC power and vice versa. AC power is exchanged between the AC / DC converter 24 and the substation equipment 21, and DC power is exchanged between the AC / DC converter 24 and each power storage unit U[m]. In the above configuration, the transformation loss X1 is a power loss caused by the transformation by the substation equipment 21, and the conversion loss x[m] is the sum of the loss of the AC / DC converter 24 and the loss of the power adjustment device 32 (DC / DC converter) of each power storage unit U[m].

[0302] The management system 100 of the fifteenth embodiment includes a load facility 22a and a load facility 22b. The load facility 22a is installed in parallel with the plurality of power storage units U[m], similar to the load facility 22 of the first embodiment. The load facility 22b is connected between the AC / DC converter 24 and the substation facility 21. The load loss X2 of the fifteenth embodiment is the sum of the power loss in the load facility 22a and the power loss in the load facility 22b.

[0303] In the fifteenth embodiment, similarly to the first embodiment, the command calculation unit 51 calculates the total DC power command value Cp by adding the power loss (X1+X2+X3) including the transformation loss X1, the load loss X2, and the conversion loss X3 to the basic command value C0. Note that the power generation facility 23 of the fourteenth embodiment may be added to the fifteenth embodiment.

[0304] 16. Sixteenth embodiment Fig. 65 is a block diagram illustrating a configuration of each power storage unit U[m] in the sixteenth embodiment. As illustrated in Fig. 65, the power storage unit U[m] in the sixteenth embodiment includes load equipment 33 in addition to the same elements as those in the above-described embodiments (power storage device 31, power adjustment device 32). The load equipment 33 is various loads that operate by consuming power supplied from the power adjustment device 32. For example, the load equipment 33 is a power supply device that generates auxiliary power or control power source used in the power storage unit U[m].

[0305] In the sixteenth embodiment, the conversion loss x[m] of each energy storage unit U[m] includes the losses of the transformer 321 and the AC / DC converter 322 (and further the line loss) as well as the active power X31 of the load equipment 33 in the energy storage unit U[m]. That is, the conversion loss X3 in the sixteenth embodiment includes the sum of the active power X31 of the load equipment 33 in the multiple energy storage units U[m]. The active power X31 of the load equipment 33 is measured, for example, by a measuring instrument (not shown) installed in each energy storage unit U[m].

[0306] In the sixteenth embodiment described above, a case is assumed in which one or more energy storage units U[m] are stopped during the operation of the energy storage system 30 as in the tenth embodiment. As in the example of Fig. 47 shown above, the limit value setting unit 522 decreases the limit value L[1]_d over time from the current value 40 to a value -X31 from the start point to the end point of the period Tb. Therefore, the active power allocation value P[1] decreases over time from the current value 39 to a value -X31 from the start point to the end point of the period Tb.

[0307] 17. Variations Specific modified embodiments added to each of the above-mentioned embodiments are exemplified below. Two or more embodiments selected from the following examples may be appropriately combined as long as they are not mutually contradictory.

[0308] (1) Two or more embodiments selected from the above-described embodiments may be arbitrarily combined. The configurations exemplified in each of the above-described embodiments may be implemented without being premised on the configurations of other embodiments.

[0309] (2) The functions of the control system 40 according to the above embodiment are realized by the cooperation of one or more processors constituting the control device 41 and the program stored in the storage device 42, as described above. The above-mentioned programs can be provided in a form stored in a computer-readable recording medium and installed in a computer. The recording medium is, for example, a non-transitory recording medium, and a good example is an optical recording medium (optical disk) such as a CD-ROM, but also includes any known type of recording medium such as a semiconductor recording medium or a magnetic recording medium. Note that the non-transitory recording medium includes any recording medium except for a transient, propagating signal, and does not exclude volatile recording media. In addition, in a configuration in which a distribution device distributes a program via a communication network, the recording medium that stores the program in the distribution device corresponds to the non-transitory recording medium described above.

[0310] (3) 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 substantial meaning. Therefore, there is no room for restrictive interpretation of the position or order of each element based on the term "nth".

[0311] 18. Notes From the above-described exemplary embodiments, the following configurations can be understood, for example.

[0312] A control system according to one embodiment (embodiment 1) of the present disclosure is a control system that controls a storage system that adjusts active power at a combination point with a power grid using a plurality of storage units including storage devices that discharge and charge DC power, and includes a command calculation unit that calculates a total DC power command value, which is the total value of the power to be discharged or charged by the storage devices in the plurality of storage units, by adding power losses including conversion losses due to conversion between DC power and AC power and transformation losses due to transformation between the storage system and a substation equipment between the storage system and the combination point to a basic command value of the active power, a command distribution unit that calculates from the total DC power command value an active power allocation value to be allocated to each of the plurality of storage units, and an operation instruction unit that instructs each of the plurality of storage units on the active power allocation value of that storage unit.

[0313] In the above aspect, a total DC power command value is calculated by adding power losses including a conversion loss due to conversion between DC power and AC power discharged or charged by the power storage device and a transformation loss due to mutual transformation between the substation equipment and the power storage system (i.e., a loss occurring due to mutual transformation between the AC voltage between the power storage system and the substation equipment and the combination point voltage at the combination point) to the basic command value, and the total DC power command value is allocated to each power storage unit. Therefore, compared with a form in which a basic command value is allocated to each power storage unit without considering the conversion loss between DC power and AC power and the transformation loss between the power storage system and the substation equipment, it is possible to properly calculate an active power allocation value instructed to each power storage unit. When the basic command value is small, the influence of the conversion loss and the transformation loss on the basic command value relatively increases, so the configuration of the present disclosure in which the conversion loss and the transformation loss are added to the basic command value is particularly effective.

[0314] In a specific example (Aspect 2) of Aspect 1, the command allocation unit includes a coefficient setting unit that sets an allocation coefficient for each of the plurality of power storage units, and an allocation processing unit that calculates a first power allocation value to be allocated to each of the plurality of power storage units out of the total DC power command value in accordance with the allocation coefficient of each of the power storage units. According to the above aspect, the total DC power command value can be allocated to each of the plurality of power storage units in accordance with the allocation coefficient of each of the power storage units.

[0315] In a specific example (Aspect 3) of Aspect 2, the command allocation unit further includes a limit value setting unit that sets a limit value for each of the plurality of power storage units, and the allocation processing unit allocates a total excess value obtained by adding up the excess values ​​of one or more power storage units among the plurality of power storage units whose first power allocation value exceeds the limit value, to each of one or more power storage units among the plurality of power storage units whose first power allocation value does not exceed the limit value. In the above aspect, the power allocated to each power storage unit can be suppressed within the range of the limit value while maintaining the active power at the combination point at the basic command value.

[0316] In a specific example (Aspect 4) of Aspect 3, the limit value setting unit selects the limit value for each of the plurality of energy storage units from a plurality of candidate values ​​related to different states of the energy storage unit. In the above aspect, the limit value is selected from a plurality of candidate values ​​related to different states of the energy storage unit. Therefore, the limit value can be appropriately set from a plurality of viewpoints related to the state of the energy storage unit.

[0317] In a specific example (aspect 5) of aspect 4, the plurality of candidate values ​​include a first candidate value according to the voltage of the power storage device, and the first candidate value is set to a first value when the voltage is a value within a first range, is set to a second value different from the first value when the voltage is a value within a second range different from the first range, and is set to a value that varies between the first value and the second value according to the voltage when the voltage is a value within a third range between the first range and the second range. In the above aspect, the first candidate value is set according to the voltage of the power storage device. Therefore, the limit value can be appropriately set in terms of the voltage of the power storage device. Also, when the voltage is a value within the third range, the first candidate value varies between the first value and the second value according to the voltage. Therefore, compared to an aspect in which the first candidate value is set alternatively to either the first value or the second value, it is possible to suppress abrupt and frequent fluctuations in the limit value according to the voltage of the power storage device.

[0318] In a specific example (aspect 6) of aspect 4, the multiple candidate values ​​include a second candidate value according to the charging rate of the power storage device, and the second candidate value is set to a first value when the charging rate is a value within a first range, is set to a second value different from the first value when the charging rate is a value within a second range different from the first range, and is set to a value that varies between the first value and the second value according to the charging rate when the charging rate is a value within a third range between the first range and the second range. In the above aspect, the second candidate value is set according to the charging rate of the power storage device. Therefore, the limit value can be appropriately set from the viewpoint of the charging rate of the power storage device. Also, when the charging rate is a value within the third range, the second candidate value varies between the first value and the second value according to the charging rate. Therefore, compared to a form in which the second candidate value is set alternatively to either the first value or the second value, it is possible to suppress abrupt and frequent fluctuations in the limit value according to the charging rate of the power storage device.

[0319] In a specific example (aspect 7) of aspect 4, the plurality of candidate values ​​include a third candidate value according to the temperature of the power storage device, and the third candidate value is set to a first value when the temperature is a value within a first range, is set to a second value different from the first value when the temperature is a value within a second range different from the first range, and is set to a value that varies between the first value and the second value according to the temperature when the temperature is a value within a third range between the first range and the second range. In the above aspect, the third candidate value is set according to the temperature of the power storage device. Therefore, the limit value can be appropriately set in terms of the temperature of the power storage device. Also, when the temperature is a value within the third range, the third candidate value varies between the first value and the second value according to the temperature. Therefore, compared to an aspect in which the third candidate value is set alternatively to either the first value or the second value, it is possible to suppress abrupt and frequent fluctuations in the limit value according to the temperature of the power storage device.

[0320] In a specific example (Aspect 8) of any one of Aspects 2 to 7, the coefficient setting unit executes a first process of setting a weight value for each of the plurality of power storage units, a second process of setting a correction value for each of the plurality of power storage units according to the operating watt-hour capacity of the power storage unit, and a third process of calculating the distribution coefficient for each of the plurality of power storage units according to the weight value and the correction value. In the above aspects, the distribution coefficient is set according to the operating watt-hour (Wh) capacity of the power storage unit. For example, the distribution coefficient is set to a larger value as the operating watt-hour capacity is larger. Therefore, it is possible to suppress variations in charge / discharge time or charging rate between the power storage units.

[0321] In a specific example (aspect 9) of aspect 8, the first process includes a normalization process for normalizing the charging rate of the power storage device in the power storage unit to a value within a predetermined standard range, a deviation calculation process for calculating a first deviation between the normalized charging rate and a reference value, and a weight setting process for setting the weight according to the first deviation. In the above aspect, the weight is set according to the charging rate of the power storage device in each power storage unit. This reduces the possibility that the output of each power storage unit will be limited due to the charging rate of the power storage device. In other words, the storage capacity of the entire power storage system can be effectively utilized.

[0322] In a specific example (Aspect 10) of Aspect 9, in the weight setting process, when the first deviation changes from a value below a first threshold to a value above the first threshold, the weight is set to a predetermined first value, and when the first deviation changes from a value above a second threshold that is smaller than the first threshold to a value below the second threshold, the weight is set to a second value according to the first deviation. In the above aspect, the relationship between the first deviation and the weight exhibits a hysteresis characteristic. Therefore, even if the first deviation fluctuates near the first threshold or the second threshold, excessively frequent fluctuations in the weight can be suppressed.

[0323] In a specific example (Aspect 11) of Aspect 9, in the weight value setting process, a relationship between the first deviation and the weight value is determined according to the total DC power command value, and a numerical value having the relationship with respect to the first deviation calculated by the deviation calculation process is set as the weight value. In the above aspect, the relationship between the first deviation and the weight value is determined according to the total DC power command value. Therefore, compared to a form in which the relationship between the first deviation and the weight value is fixed, the total DC power command value can be appropriately distributed to a plurality of power storage units.

[0324] In a specific example (Aspect 12) of any one of Aspects 8 to 11, the first process includes a normalization process for normalizing the temperature of the power storage device in the power storage unit to a value within a predetermined standard range, a deviation calculation process for calculating a second deviation between the normalized temperature and a reference value, and a weight setting process for setting the weight according to the second deviation. In the above aspects, the weight is set according to the temperature of the power storage device in each power storage unit. This makes it possible to reduce the possibility that the output of each power storage unit will be limited due to the temperature of the power storage device. In other words, the power storage capacity of the entire power storage system can be effectively utilized.

[0325] In a specific example (Aspect 13) of Aspect 12, in the weight setting process, when the second deviation changes from a value below a first threshold to a value above the first threshold, the weight is set to a predetermined first value, and when the second deviation changes from a value above a second threshold smaller than the first threshold to a value below the second threshold, the weight is set to a second value according to the temperature deviation. In the above aspect, the relationship between the second deviation and the weight exhibits a hysteresis characteristic. Therefore, even if the second deviation fluctuates near the first threshold or the second threshold, excessively frequent fluctuations in the weight can be suppressed.

[0326] In a specific example (Aspect 14) of Aspect 12, in the weight value setting process, a relationship between the second deviation and the weight value is determined according to the total DC power command value, and a numerical value having the relationship with respect to the second deviation calculated by the deviation calculation process is set as the weight value. In the above aspect, the relationship between the second deviation and the weight value is determined according to the total DC power command value. Therefore, compared to a form in which the relationship between the second deviation and the weight value is fixed, the total DC power command value can be appropriately distributed to a plurality of power storage units.

[0327] In a specific example (Aspect 15) of any one of Aspects 8 to 14, the first process includes a normalization process for normalizing the number of times of charging and discharging the power storage device in the power storage unit to a value within a predetermined standard range, a deviation calculation process for calculating a third deviation between the number of times of charging and discharging after the normalization and a reference value, and a weight setting process for setting the weight according to the third deviation. In the above aspects, the weight is set according to the number of times of charging and discharging the power storage device in each power storage unit. This makes it possible to reduce the possibility that the output of each power storage unit will be limited due to the number of times of charging and discharging the power storage device. In other words, the storage capacity of the entire power storage system can be effectively utilized.

[0328] In a specific example (Aspect 16) of Aspect 15, in the weight setting process, when the third deviation changes from a value below a first threshold to a value above the first threshold, the weight is set to a predetermined first value, and when the third deviation changes from a value above a second threshold that is smaller than the first threshold to a value below the second threshold, the weight is set to a second value according to the third deviation. In the above aspect, the relationship between the third deviation and the weight exhibits a hysteresis characteristic. Therefore, even if the third deviation fluctuates near the first threshold or the second threshold, excessively frequent fluctuations in the weight can be suppressed.

[0329] In a specific example (Aspect 17) of Aspect 15, in the weight value setting process, a relationship between the third deviation and the weight value is determined according to the total DC power command value, and a numerical value having the relationship with respect to the third deviation calculated by the deviation calculation process is set as the weight value. In the above aspect, the relationship between the third deviation and the weight value is determined according to the total DC power command value. Therefore, compared to a form in which the relationship between the third deviation and the weight value is fixed, the total DC power command value can be appropriately distributed to a plurality of power storage units.

[0330] In a specific example (Aspect 18) of any one of Aspects 8 to 17, in the first process, the weights are set according to a first weight according to a charging rate of the power storage device in the power storage unit, a second weight according to a temperature of the power storage device, and a third weight according to a number of times the power storage device is charged and discharged. In the above aspects, the weights are set according to the charging rate, temperature, and number of times the power storage unit is charged and discharged. Therefore, compared to a form in which the weights are set according to only a specific state of the power storage unit, it is possible to set appropriate weights (and thus distribution coefficients) from various perspectives regarding the state of the power storage device. The weights are calculated, for example, by a weighted sum of the first weight, the second weight, and the third weight.

[0331] In a specific example (Aspect 19) of any one of Aspects 8 to 18, the first process includes a process of reducing a rate of temporal variation of the distribution coefficient. In the above aspects, the rate of temporal variation of the distribution coefficient is reduced, so that abrupt variations in the distribution value for each power storage unit are suppressed. Therefore, it is possible to reduce the possibility that the active power at the combination point will suddenly vary due to abrupt variations in the distribution coefficient in each power storage unit.

[0332] In a specific example (Aspect 20) of any one of Aspects 3 to 19, when one of the plurality of energy storage units is started or stopped, the coefficient setting unit changes the distribution coefficient over time over a predetermined time, and the limit value setting unit changes the limit value over time over a predetermined time. In the above aspect, discontinuous fluctuations in the distribution coefficient and the limit value caused by starting or stopping the energy storage units are suppressed. Therefore, it is possible to reduce the possibility that the active power at the combination point will suddenly fluctuate due to abrupt fluctuations in the distribution coefficient of each energy storage unit.

[0333] In a specific example (Aspect 21) of any one of Aspects 1 to 20, the energy storage system includes an energy storage unit in a maintenance state, and the command calculation unit adds power for maintenance of the energy storage unit in the maintenance state to the basic command value. According to the above aspect, while maintaining the active power of the combination point at the basic command value, power required for maintenance of the energy storage unit can be accommodated by other energy storage units in operation.

[0334] In a specific example (Aspect 22) of any one of Aspects 1 to 21, the command calculation unit calculates the total DC power command value by subtracting a correction power from the base command value, and the allocation processing unit calculates the active power allocation value from the total DC power command value for each normal unit other than a priority unit among the multiple power storage units, and sets the correction power as the active power allocation value for the priority unit. In the above aspects, the correction power subtracted from the base power is set as the active power allocation value of the priority unit. Therefore, it is possible to preferentially (or forcibly) discharge or charge the correction power to the priority unit.

[0335] In a specific example (Aspect 23) of any of Aspects 1 to 22, the command calculation unit calculates a total reactive power command value which is a total value of reactive power to be generated by the plurality of energy storage units, the command distribution unit calculates a reactive power distribution value to be distributed to each of the plurality of energy storage units from the total reactive power command value, and the operation instruction unit instructs each of the plurality of energy storage units of the reactive power distribution value of that energy storage unit. According to the above aspects, it is possible to control not only the generation of active power but also the generation of reactive power in each energy storage unit.

[0336] In a specific example (Aspect 24) of any one of Aspects 1 to 23, the command calculation unit subtracts the active power generated by the power generation system from the basic command value. According to the above aspect, even in an environment in which a plurality of power storage systems are provided in parallel with power generation equipment, the active power at the combination point can be maintained at the basic command value with high accuracy.

[0337] In a specific example (Aspect 25) of any one of Aspects 1 to 24, the command calculation unit adds the active power consumed by the load equipment to the basic command value. According to the above aspect, even in an environment in which the load equipment consumes the power generated by the power storage system, the active power at the combination point can be maintained at the basic command value with high accuracy.

[0338] A management system according to one embodiment (embodiment 26) of the present disclosure includes a storage system that adjusts active power at a combination point with a power system using a plurality of storage units including storage devices that discharge and charge DC power, and a control system that controls the storage system. The control system includes a command calculation unit that calculates a total DC power command value, which is the total value of the power to be discharged or charged by the storage devices in the plurality of storage units, by adding power losses including conversion losses due to conversion between DC power and AC power and transformation losses due to transformation between the storage system and a substation equipment between the storage system and the combination point to a basic command value of the active power, a command distribution unit that calculates an active power allocation value to be allocated to each of the plurality of storage units from the total DC power command value, and an operation instruction unit that instructs each of the plurality of storage units on the active power allocation value of the storage unit. [Explanation of symbols]

[0339] 100... management system, 10, 10a, 10b... power system, 11, 11a, 11b... combination point, 21, 21a, 21b... substation equipment, 22, 22a, 22b... load equipment, 23... power generation equipment, 24... AC / DC conversion equipment, 30... power storage system, 31... power storage equipment, 32... control device, 321... transformer, 322... AC / DC converter, 33... load equipment, 40... control system, 41... control device, 42... storage device, 43... transmission / reception device, 5 1...command calculation unit, 52...command distribution unit, 521...coefficient setting unit, 522...limiting value setting unit, 523...distribution processing unit, 53...operation instruction unit, 61...first setting unit, 611...candidate value setting unit, 612...candidate value setting unit, 613...candidate value setting unit, 614...candidate value selection unit, 62...second setting unit, 621...candidate value setting unit, 622...candidate value setting unit, 623...candidate value setting unit, 614...candidate value selection unit, 5212...switching unit, 5213...smoothing unit.

Claims

1. A control system for controlling a power storage system that adjusts active power at a combination point with a power grid by using a plurality of power storage units including a power storage device that discharges and charges DC power, comprising: a command calculation unit that calculates a total DC power command value, which is a total value of power to be discharged or charged by the storage devices in the plurality of storage units, by adding a power loss including a conversion loss due to conversion between the DC power and the AC power and a transformation loss due to transformation between the storage system and a substation facility between the storage system and the combining point to a basic command value of active power; a command allocation unit that calculates an active power allocation value to be allocated to each of the plurality of power storage units from the total DC power command value; an operation instruction unit that instructs each of the plurality of power storage units on an effective power allocation value of the power storage unit; A control system comprising:

2. The command distribution unit includes: a coefficient setting unit that sets a distribution coefficient for each of the plurality of power storage units; an allocation processing unit that calculates a first power allocation value to be allocated to each of the plurality of power storage units, out of the total DC power command value, in accordance with an allocation coefficient of each of the power storage units. The control system of claim 1.

3. The command distribution unit includes: a limit value setting unit that sets a limit value for each of the plurality of power storage units; The distribution processing unit: A total excess value obtained by adding up the excess values ​​of one or more power storage units among the plurality of power storage units, the first power allocation value of which exceeds the limit value, is allocated to each of one or more power storage units among the plurality of power storage units, the first power allocation value of which does not exceed the limit value. The control system of claim 2.

4. The limit value setting unit is For each of the plurality of power storage units, the limit value is selected from a plurality of candidate values ​​relating to different states of the power storage unit. The control system of claim 3.

5. the plurality of candidate values ​​includes a first candidate value corresponding to a voltage of the power storage device; The first candidate value is If the voltage is within a first range, it is set to a first value; If the voltage is within a second range different from the first range, the voltage is set to a second value different from the first value; When the voltage is a value within a third range between the first range and the second range, the voltage is set to a value that varies between the first value and the second value depending on the voltage. The control system of claim 4.

6. the plurality of candidate values ​​includes a second candidate value corresponding to a charging rate of the power storage device; The second candidate value is If the charging rate is within a first range, the charging rate is set to a first value; When the charging rate is within a second range different from the first range, the charging rate is set to a second value different from the first value, When the charging rate is a value within a third range between the first range and the second range, the charging rate is set to a value that varies between the first value and the second value depending on the charging rate. The control system of claim 4.

7. the plurality of candidate values ​​includes a third candidate value corresponding to a temperature of the power storage device; The third candidate value is if the temperature is within a first range, it is set to a first value; if the temperature is within a second range different from the first range, the temperature is set to a second value different from the first value; When the temperature is a value within a third range between the first range and the second range, the temperature is set to a value that varies between the first value and the second value depending on the temperature. The control system of claim 4.

8. The coefficient setting unit is a first process of setting a weight value for each of the plurality of power storage units; a second process of setting a correction value for each of the plurality of power storage units according to an operating watt-hour capacity of the power storage unit; and executing a third process of calculating the distribution coefficient for each of the plurality of power storage units according to the weight value and the correction value. The control system of claim 2.

9. The first process includes: a normalization process for normalizing the charging rate of the power storage device in the power storage unit to a value within a predetermined standard range; a deviation calculation process for calculating a first deviation between the normalized charging rate and a reference value; and a weight value setting process for setting the weight value in accordance with the first deviation. The control system of claim 8.

10. In the weight value setting process, When the first deviation changes from a value below a first threshold to a value above the first threshold, the weight is set to a predetermined first value; When the first deviation changes from a value exceeding a second threshold value smaller than the first threshold value to a value below the second threshold value, the weighting value is set to a second value corresponding to the first deviation. The control system of claim 9.

11. In the weight value setting process, determining a relationship between the first deviation and a weighting value in accordance with the total DC power command value; A numerical value having the above-mentioned relationship with respect to the first deviation calculated by the deviation calculation process is set as the weight value. The control system of claim 9.

12. The first process includes: a normalization process for normalizing the temperature of the power storage device in the power storage unit to a value within a predetermined standard range; a deviation calculation process for calculating a second deviation between the normalized temperature and a reference value; and a weight value setting process for setting the weight value in accordance with the second deviation. The control system of claim 8.

13. In the weight value setting process, When the second deviation changes from a value below a first threshold to a value above the first threshold, the weight is set to a predetermined first value; When the second deviation changes from a value exceeding a second threshold value that is smaller than the first threshold value to a value below the second threshold value, the weight is set to a second value according to the temperature deviation.

13. The control system of claim 12.

14. In the weight value setting process, determining a relationship between the second deviation and a weighting value in accordance with the total DC power command value; A numerical value having the above-mentioned relationship with respect to the second deviation calculated by the deviation calculation process is set as the weight value.

13. The control system of claim 12.

15. The first process includes: a normalization process for normalizing the number of times the charge / discharge operation of the power storage device in the power storage unit is performed to a value within a predetermined standard range; a deviation calculation process for calculating a third deviation between the normalized number of charge / discharge operations and a reference value; and a weight value setting process for setting the weight value in accordance with the third deviation. The control system of claim 8.

16. In the weight value setting process, When the third deviation changes from a value below a first threshold value to a value above the first threshold value, the weight is set to a predetermined first value; When the third deviation changes from a value exceeding a second threshold value that is smaller than the first threshold value to a value below the second threshold value, the weighting value is set to a second value according to the third deviation.

16. The control system of claim 15.

17. In the weight value setting process, determining a relationship between the third deviation and a weighting value in accordance with the total DC power command value; A numerical value having the above-mentioned relationship with respect to the third deviation calculated by the deviation calculation process is set as the weight value.

16. The control system of claim 15.

18. In the first process, a first weight value corresponding to a charging rate of the power storage device in the power storage unit; a second weight value according to a temperature of the power storage device; a third weight value according to the number of times the storage device is charged and discharged; Set the weight value according to The control system of claim 8.

19. The first process includes a process of reducing a rate of temporal variation of the distribution coefficient. The control system of claim 8.

20. When starting or stopping one of the plurality of power storage units, The coefficient setting unit changes the distribution coefficient over time over a predetermined period of time, The limit value setting unit changes the limit value over time over a predetermined period of time. The control system of claim 3.

21. the power storage system includes a power storage unit in a maintenance state; The command calculation unit adds power for maintenance related to the power storage unit in the maintenance state to the basic command value. The control system of claim 1.

22. The command calculation unit calculates the total DC power command value by subtracting a correction power from the basic command value; The distribution processing unit: Calculating the active power allocation value from the total DC power command value for each normal unit other than the priority unit among the plurality of power storage units; For the priority unit, the correction power is set as the effective power allocation value. The control system of claim 2.

23. The command calculation unit calculates a total reactive power command value that is a total value of reactive power to be generated by the plurality of power storage units; the command allocation unit calculates a reactive power allocation value to be allocated to each of the plurality of power storage units from the total reactive power command value; The operation instruction unit instructs each of the plurality of power storage units on a reactive power allocation value of the power storage unit. The control system of claim 1.

24. The command calculation unit subtracts an active power generated by a power generation system from the basic command value. The control system of claim 1.

25. The command calculation unit adds an active power consumed by a load equipment to the basic command value. The control system of claim 1.

26. a power storage system that adjusts active power at a combination point with a power grid by using a plurality of power storage units including a power storage device that discharges and charges DC power; A control system for controlling the power storage system, The control system includes: a command calculation unit that calculates a total DC power command value, which is a total value of power to be discharged or charged by the storage devices in the plurality of storage units, by adding a power loss including a conversion loss due to conversion between the DC power and the AC power and a transformation loss due to transformation between the storage system and a substation facility between the storage system and the combining point to a basic command value of active power; a command allocation unit that calculates an active power allocation value to be allocated to each of the plurality of power storage units from the total DC power command value; an operation instruction unit that instructs each of the plurality of power storage units on an effective power allocation value of the power storage unit; A management system comprising:

Images