JP2020188521A - Storage battery operation device and storage battery operation method - Google Patents

Abstract

To provide a storage battery operation device and a storage battery operation method which can acquire a stable power peak reduction amount without setting a target value.SOLUTION: A storage battery operation device plans an operation of a storage battery for supplying power to a load connected with a power system, and comprises an operation plan determination part which prepares a plurality of operation plans in which a storage battery operation time zone and a storage battery output value for each unit time are different, and calculates a power peak reduction amount for each operation plan and compares them with each other to determine the operation plan employed based on the comparison result.SELECTED DRAWING: Figure 1

Description

The present invention relates to a storage battery operating device and a storage battery operating method.

From 2019 onward, the development of self-consumption trends and demand response (DR; The use of feed-in tariffs (VPPs) as power sources for feed-in tariffs (VPPs) is increasing, and the market for storage batteries is expected to expand. Storage batteries are generally well known as effective means for reducing power peaks. As a method for reducing the power peak, it is conceivable to discharge the storage battery when the power receiving target value (power purchase target value) set in advance by the operator is exceeded (Patent Document 1). However, if the set target value is not appropriate, the expected power peak reduction amount may not be obtained, such as insufficient storage battery capacity. Therefore, there is a demand for a method that does not require the setting of the target value and can obtain a stable power peak reduction amount.

International Publication No. 2013/0388483

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a storage battery operating device and a storage battery operating method capable of obtaining a stable power peak reduction amount without setting a target value.

In order to solve the above problems, one aspect of the present invention is a device for planning the operation of a storage battery that supplies power to a load connected to a power system, and includes a storage battery operating time zone and a storage battery output value for each unit time. This is a storage battery operation device including an operation plan determination unit that creates a plurality of operation plans having different characteristics, calculates and compares the power peak reduction amount for each operation plan, and determines the operation plan to be adopted based on the comparison result.

Further, one aspect of the present invention is the storage battery operating device, wherein the power peak reduction amount is the maximum value of the predicted load power for each unit time of the day, and the operation is performed from the maximum predicted load power. It is a value obtained by subtracting the maximum value of the predicted received power, which is the maximum value obtained by subtracting the output value of the storage battery from the predicted load power for each unit time in the plan.

Further, one aspect of the present invention is the storage battery operation device, and the operation plan determination unit adopts the storage battery operation time based on the storage battery operation time when the power peak reduction amounts of the plurality of operation plans are the same. Determine the operation plan.

Further, one aspect of the present invention is the storage battery operating device, further including a load fluctuation compensating unit that adjusts the storage battery output value so as to compensate for fluctuations in the load power of the load.

Further, one aspect of the present invention is a method of planning the operation of a storage battery that supplies power to a load connected to the power system, and the storage battery operating time zone and the storage battery output value for each unit time are determined by the operation planning determination unit. This is a storage battery operation method in which a plurality of operation plans different from the above are created, the amount of power peak reduction is calculated and compared for each operation plan, and the operation plan to be adopted is determined based on the comparison result.

According to each aspect of the present invention, a stable power peak reduction amount can be obtained without setting a target value.

It is a block diagram which shows the structural example of the storage battery operation apparatus which concerns on one Embodiment of this invention. It is a block diagram which shows the structural example of the load fluctuation compensation part 13 shown in FIG. It is a flowchart which shows the operation example of the storage battery operation apparatus 10 shown in FIG. It is a schematic diagram for demonstrating the operation example of the storage battery operation apparatus 10 shown in FIG. It is a schematic diagram for demonstrating the operation example of the storage battery operation apparatus 10 shown in FIG. It is a schematic diagram for demonstrating the operation example of the storage battery operation apparatus 10 shown in FIG. It is a schematic diagram for demonstrating the effect which the operation example of the storage battery operation apparatus 10 shown in FIG. 1 plays. It is a schematic diagram for demonstrating the effect which the operation example of the storage battery operation apparatus 10 shown in FIG. 1 plays.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing a configuration example of a storage battery operating device 10 according to an embodiment of the present invention.

The storage battery operating device 10 shown in FIG. 1 is a device that plans the operation of the storage battery 4 that supplies power to the load 3 connected to the power system 1, and predicts and plans the load power that is the power consumption of the load 3. Alternatively, an operation plan for the storage battery 4 (hereinafter, also referred to as a storage battery operation plan or simply a plan) is created. The storage battery operating device 10 is composed of, for example, a computer such as a personal computer or a server, and peripheral devices of the computer. The storage battery operation device 10 includes a communication unit 11, an operation plan determination unit 12, a load fluctuation compensation unit 13, and a storage battery control unit 14 as functional elements composed of a combination of hardware and software possessed by a computer. Have.

The communication unit 11 performs predetermined communication related to a demand response, a virtual power plant, etc. with a server operated by an electric power company or the like (not shown), or between a communication unit (not shown) having a load 3 or a storage battery 4. Performs predetermined communication.

The operation plan determination unit 12 creates an operation plan for the storage battery 4. The operation plan of the storage battery 4 is information indicating a planned value (target value) (hereinafter, referred to as a storage battery output value) of the output of the storage battery 4 for each predetermined unit time (for example, 30 minutes) in a fixed period in the future. The operation plan determination unit 12 of the present embodiment creates a plurality of operation plans in which the storage battery operation time zone and the storage battery output value for each unit time are different, calculates and compares the power peak reduction amount for each operation plan, and compares them. The operation plan to be adopted is decided based on the result. The power peak reduction amount is, for example, the value obtained by subtracting the storage battery output value from the predicted load power for each unit time in each operation plan from the maximum predicted load power value which is the maximum value of the predicted load power for each unit time in a day. It is the value obtained by subtracting the maximum predicted power received, which is the maximum value. Further, when the power peak reduction amounts of the plurality of operation plans are the same, the operation plan determination unit 12 determines the operation plan to be adopted based on the storage battery operation time.

The load fluctuation compensation unit 13 generates a storage battery output command value, which is a signal obtained by adjusting the storage battery output value based on the operation plan of the storage battery 4 so as to compensate for the fluctuation of the load power of the load 3. That is, the load fluctuation compensation unit 13 adjusts the storage battery output value so as to compensate for the fluctuation of the load power of the load 3.

The storage battery control unit 14 controls the output of the storage battery 4 based on the storage battery output command value generated by the load fluctuation compensation unit 13. The storage battery output command value is a discharge or charge / discharge command value.

FIG. 2 is a configuration diagram showing a configuration example of the load fluctuation compensation unit 13. The load fluctuation compensating unit 13 shown in FIG. 2 includes a bandpass filter 131, an adder 132, and a limiter 133. The bandpass filter 131 inputs the measured value of the load power, and outputs a signal from which the DC component, a predetermined low frequency component, and the high frequency component are removed to the adder 132. The output signal of the bandpass filter 131 represents the fluctuation of the load power. The adder 132 adds the storage battery output value determined by the operation plan determination unit 12 and the output value of the bandpass filter 131, and outputs the addition result to the limiter 133. The output signal of the adder 132 is a storage battery output value that compensates for fluctuations in load power. The limiter 133 limits the output signal of the adder 132 by a predetermined upper and lower limit value, generates a storage battery output command value, and outputs the signal. The storage battery output command value is the command value for the battery output of the storage battery 4. According to the load fluctuation compensation unit 13 shown in FIG. 2, by using the storage battery output value as a bias value during the operating time of the storage battery 4, it is possible to achieve both peak cut by the storage battery 4 and load fluctuation compensation. The storage battery output value is 0 kW except during the operating time zone.

The load 3 is one or more electric loads installed in one or more consumer facilities, such as electric power received from the electric power system 1 operated by a general electric power company such as an electric power company via the distribution system 2. , Operates using the electric power discharged from the storage battery 4 as a power source. The data representing the actual value of the electric power consumed by the load 3 is notified to the storage battery operating device 10, for example, at a predetermined cycle, directly or via another control device (not shown).

The storage battery 4 is one or a plurality of charging / discharging facilities installed in one or a plurality of consumer facilities, is connected to the distribution system 2, and charges electric power based on, for example, a storage battery output command value received from the storage battery operating device 10. Or discharge. The storage battery operation device 10 controls the battery output of one storage battery 4 or bundles and controls the battery output of a plurality of storage batteries 4. The battery output is the charge / discharge power of the storage battery 4. Data representing a measured value such as the current SOC value (described later) of the storage battery 4 is notified to the storage battery operating device 10 at a predetermined cycle, for example, directly or via another control device (not shown).

Next, an operation example of the storage battery operating device 10 shown in FIG. 1 will be described with reference to FIGS. 3 to 8. FIG. 3 is a flowchart showing an operation example of the storage battery operating device 10 shown in FIG. 4 to 8 are schematic views for explaining an operation example and the like of the storage battery operating device 10 shown in FIG.

The storage battery operation device 10 of the present embodiment formulates an operation plan of the storage battery by determining the storage battery operation time zone and the storage battery output value so that the power peak reduction amount is maximized. In this operation example, it is assumed that (load power = received power + battery output) is established in the system configuration shown in FIG. Further, the storage battery operation device 10 formulates an operation plan of the storage battery based on the predicted load power (data in units of 30 minutes). The predicted load power can be predicted based on past actual values and the like as described in Patent Document 1, for example. In addition, (usable capacity of storage battery = rated capacity × (current SOC value-SOC lower limit value) ÷ 100). Here, SOC (State Of Charge) is a unit representing the remaining battery level, and 100% is a fully charged state and 0% is a fully discharged state. Further, the current SOC value [%] is a measured value, and the rated capacity [kWh] and the SOC lower limit value [%] are set values by the operator.

In the process shown in FIG. 3, first, the operation plan determination unit 12 calculates the storage battery output value in each plan in which the operation start time zone and the operation end time zone are different (step S1). In step S1, for example, the operation plan determination unit 12 first calculates the storage battery operation time [h] within the range of the storage battery operation start time zone and the storage battery operation end time zone, as shown in FIG. FIG. 4 shows an example of calculating the storage battery operating time when the start time zone setting is “6:00” to “17:00” and the end time zone setting is “6:00” to “17:00”. In the example shown in FIG. 4, for example, when the start time is 6:00 and the end time is 6:30, the operating time of the storage battery is 0.5 hours. Further, for example, when the start time is 6:00 and the end time is 17:00, the operating time of the storage battery is 11.0 hours. In addition, in FIGS. 4 to 6, the symbol "." Means that the value of the cell is omitted, and the symbol "-" means that the value of the cell is absent.

In step S1, next, the operation plan determination unit 12 determines, for example, the storage battery output value [kWh] of the storage battery usable capacity [kWh] divided by the operation time [h] (= average value) in each storage battery operation time zone. ]. Here, when the storage battery output value exceeds the storage battery output upper limit value [kW], the operation plan determination unit 12 sets the storage battery output upper limit value as the output value. FIG. 5 shows an example of calculating the storage battery output value when the usable capacity of the storage battery is 60 kWh and the upper limit value of the storage battery output value is 30 kW. The usable capacity of the storage battery [kWh] and the upper limit value of the output of the storage battery [kW] are set values by the operator. In the example shown in FIG. 5, for example, when the start time is 6:00 and the end time is 6:30, the storage battery operating time is 0.5 hours as shown in FIG. 4, so that the usable capacity of the storage battery (60 kWh). Is divided by 0.5 hours to be 120 kW, but in this case, since the upper limit value (30 kW) is exceeded, the storage battery output value becomes the upper limit value of 30 kW as shown by the broken line. Further, for example, when the start time is 6:00 and the end time is 17:00, the storage battery operating time is 11.0 hours as shown in FIG. 4, so the storage battery output value is shown by enclosing it with a chain line. The usable capacity of the storage battery (60 kWh) is divided by 11.0 hours to obtain about 5.45 kW. However, the storage battery output value is not limited to one average value for each plan, and may include a plurality of values for each plan.

Next, the operation plan determination unit 12 calculates the maximum predicted load power value (step S2). In step S2, the operation plan determination unit 12 determines the maximum value of the predicted daily load power as the maximum predicted load power.

Next, the operation plan determination unit 12 calculates the maximum predicted power received in each plan (step S3). In step S3, the operation plan determination unit 12 first calculates the predicted received power at each unit time of the day by the formula ((predicted received power) = (predicted load power) − (storage battery output value)). Here, the storage battery output value is the value calculated in step S1. In step S3, the operation plan determination unit 12 then sets the maximum value of the calculated predicted received power as the maximum predicted received power.

Next, the operation plan determination unit 12 calculates the power peak reduction amount in each plan (step S4). In step S4, the operation plan determination unit 12 sets the value obtained by subtracting the predicted maximum received power obtained in step S3 from the maximum predicted load power obtained in step S2 as the power peak reduction amount.

Next, the operation plan determination unit 12 determines the storage battery operation plan (step S5). In step S5, the operation plan determination unit 12 compares the power peak reduction amounts obtained in step S4 with respect to all the plans set from the start time zone to the end time zone, based on the power peak. Decide on a plan to adopt the plan that maximizes the amount of reduction (plan to actually use). At that time, the operation plan determination unit 12 adopts the plan with the shortest storage battery operation time when there are a plurality of plans having the same power peak reduction amount. Further, when the number of operation hours is the same, the operation plan determination unit 12 adopts the plan having the earliest start time. However, the method of selecting the adoption plan when there are multiple plans with the same power peak reduction amount is not limited to this, and for example, the plan with the earliest end time can be selected (for example, securing the preparation time for the next discharge). (Easy), the plan with the largest minimum storage battery output value (for example, easy to maintain the efficiency of the conversion circuit) can be selected.

FIG. 6 is a schematic diagram for explaining a storage battery operation plan determination example, and shows an example of the power peak reduction amount in each plan. In the example shown in FIG. 6, for example, when the start time is 12:30 and the end time is 13:00, the power peak reduction amount is 15 kW. Further, for example, in the case of a plan in which the start time is 12:30 and the end time is 13:30, the power peak reduction amount is 30 kW. In the example shown in FIG. 6, the maximum power peak reduction amount is 30 kW, but there are a plurality of them. The operation plan determination unit 12 adopts a plan in which the operation time with the shortest operation time is from 12:30 to 13:30 (the plan with the value surrounded by the broken line is adopted).

Next, the load fluctuation compensation unit 13 determines the storage battery output command value based on the load power and the storage battery output value determined in step S5 (step S6). Next, the storage battery control unit 14 notifies the storage battery 4 of the storage battery output command value via the communication unit 11 (step S7). In the storage battery 4, the battery output is controlled based on the notified storage battery output command value. The storage battery output value and the storage battery output command value are constant values every unit time (every 30 minutes).

Next, the operation plan determination unit 12 determines whether or not the operation plan update condition is satisfied (step S8). The update condition of the operation plan is, for example, that a predetermined time has elapsed since the last operation plan was determined in step S5. This predetermined time can be set by the operator, for example, and can be a value such as 30 minutes. Alternatively, the update condition of the operation plan may be, for example, when the operator instructs the update. When the update condition is satisfied (when "YES" in step S8), the operation plan determination unit 12 executes the processes of steps S1 to S7, determines the storage battery operation plan again, and updates the storage battery operation plan. The load fluctuation compensation unit 13 determines the storage battery output command value based on the above, and the storage battery control unit 14 notifies the storage battery 4. On the other hand, when the update condition is not satisfied (“NO” in step S8), the operation plan determination unit 12 determines whether or not the end condition of the process shown in FIG. 3 is satisfied (step S9). The end condition of the process shown in FIG. 3 is, for example, that the start time zone has elapsed. Alternatively, the end condition of the process shown in FIG. 3 is when the operator instructs the end. When the end condition is satisfied (when “YES” in step S9), the operation plan determination unit 12 ends the process shown in FIG. On the other hand, when the end condition is not satisfied (when "NO" in step S9), the operation plan determination unit 12 re-executes the determination in step S8, for example, after a certain period of time has elapsed.

Here, the effect of the operation example of the storage battery operating device 10 shown in FIG. 1 described with reference to FIG. 3 will be described with reference to FIGS. 7 and 8. 7 and 8 are schematic views for explaining the effect of the operation example of the storage battery operating device 10 shown in FIG. 7 and 8 are diagrams showing changes in load power for each unit time (30 minutes) when the usable capacity of the storage battery is 60 kWh and the upper limit of the output value of the storage battery is 30 kW. The load power is load power = received power + battery output (discharge power), the received power is represented by a white bar, and the battery output (discharge power) is represented by a shaded bar. FIG. 7 shows an example in which the operation plan is determined based on the power peak reduction amount according to the present embodiment, and FIG. 8 shows an example in which the storage battery is operated and discharged when the received power target value is set to 70 kW and exceeds it. Is. The load power is the same in the example shown in FIG. 7 and the example shown in FIG. In the example shown in FIG. 7, it is assumed that the storage battery output value and the storage battery output command value are the same.

In the example shown in FIG. 7, the discharge of 60 kWh of the usable capacity of the storage battery is allocated to 2 hours from 9:00 to 11:00. In the example shown in FIG. 7, the storage battery output value is set to 30 kW from 9:00 to 11:00, the daily load power maximum value is 120 kW, the received power maximum value is 90 kW, and the power peak reduction amount. Is 30 kW (= maximum load power value-maximum received power value). On the other hand, in the example shown in FIG. 8, the discharge of 60 kWh of the usable capacity of the storage battery is allocated to two and a half hours from 8:30 to 11:00. In the example shown in FIG. 8, the storage battery output value is set to 5 kW from 8:30 to 9:00, the storage battery output value is set to 30 kW from 9:00 to 10:30, and the storage battery output value is set to 30 kW. The storage battery output value is set to 25 kW from 10:30 to 11:00. In the example shown in FIG. 8, the maximum daily load power value is 120 kW, the maximum received power value is 95 kW, and the power peak reduction amount is 25 kW.

According to the storage battery operating device 10 of the present embodiment, it is not necessary to set the power receiving target value. Therefore, it is possible to avoid trial and error regarding the setting of the target value. In addition, charging / discharging in seconds is not required. Therefore, deterioration of the storage battery due to rapid charging / discharging can be suppressed. According to these features, the storage battery operating device 10 of the present embodiment can stably reduce the power peak in a building or the like.

As described above, according to the storage battery operation device 10 of the present embodiment, a stable power peak reduction amount can be obtained (maximum peak cut) and operation time without setting a target value. The band can be determined automatically. Further, for example, since the operation plan of the storage battery can be updated once every 30 minutes, the influence of the prediction error can be reduced, and a plan having high accuracy can be made. In addition, since each unit time has a constant output (does not suddenly charge and discharge), the operation is friendly to the storage battery. In addition, the cost (instrumentation cost) related to data acquisition in units of 1 second can be suppressed.

Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to the above embodiments, and design changes and the like within a range not deviating from the gist of the present invention are also included. In FIG. 1, the storage battery operating device 10 targets the load 3 and the storage battery 4 as management targets (or control targets), but the power generation equipment connected to the distribution system 2 may also be managed (or controlled targets). .. Further, the operating time zone of the storage battery 4 is not limited to one continuous time zone, and may include a plurality of discontinuous time zones. Further, a part or all of the software constituting the storage battery operation device 10 can be distributed via a computer-readable recording medium or a communication line.

1 Power system 2 Distribution system 3 Load 4 Storage battery 10 Storage battery operation device 11 Communication unit 12 Operation plan determination unit 13 Load fluctuation compensation unit 14 Storage battery control unit

Claims (5)

A device that plans the operation of a storage battery that supplies power to the load connected to the power system.
Create multiple operation plans with different storage battery operation time zones and storage battery output values for each unit time, calculate and compare the power peak reduction amount for each operation plan, and determine the operation plan to be adopted based on the comparison result. A storage battery operation device equipped with an operation plan determination unit. The storage battery output value is calculated from the predicted load power maximum value, which is the maximum value of the predicted load power for each unit time of the day, and the predicted load power for each unit time in each operation plan. The storage battery operating device according to claim 1, which is a value obtained by subtracting the predicted maximum received power value, which is the maximum value obtained by subtracting the maximum value. The storage battery operation device according to claim 1 or 2, wherein the operation plan determination unit determines the operation plan to be adopted based on the storage battery operation time when the power peak reduction amount of the plurality of operation plans is the same. The storage battery operating device according to any one of claims 1 to 3, further comprising a load fluctuation compensating unit that adjusts the storage battery output value so as to compensate for fluctuations in the load power of the load. It is a method of planning the operation of a storage battery that supplies power to the load connected to the power system.
The operation plan determination unit creates multiple operation plans with different storage battery operation time zones and storage battery output values for each unit time, calculates and compares the power peak reduction amount for each operation plan, and adopts it based on the comparison result. A storage battery operation method for determining the operation plan.

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