JP7374610B2 - Storage battery operation device and storage battery operation method - Google Patents

Description

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

From 2019 onwards, households will begin to see the expiry of their surplus solar power purchase period under FIT (Feed-in Tariff), and as a result, trends in self-consumption and demand response (DR) will increase. Demand response) and virtual power plants (VPP) are increasingly being adopted as power sources, and the market for storage batteries is expected to expand. Storage batteries are generally well known as an effective means for reducing power peaks. One possible method for reducing power peaks is to discharge the storage battery when the power reception 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, there is a possibility that the expected power peak reduction amount will not be obtained due to insufficient storage battery capacity. Therefore, there is a need for a method that does not require setting the target value and can obtain a stable peak power reduction amount.

International Publication No. 2013/038483

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 operation device and a storage battery operation method that can obtain a stable peak power reduction amount without setting a target value.

In order to solve the above problems, one aspect of the present invention is an apparatus for planning the operation of a storage battery that supplies power to a load connected to an electric power system, the apparatus comprising: a storage battery operation time period and a storage battery output value for each unit time; An operation plan in which a plurality of operation plans with different values are created, a power peak reduction amount is calculated and compared for each of the operation plans, and the operation plan with the maximum power peak reduction amount is determined as the operation plan to be adopted. If there is a plurality of operation plans in which the power peak reduction amount is the maximum, the operation plan determination section determines the length of the storage battery operation time , the operation end time of the storage battery, or the output value of the storage battery. The operation plan to be adopted is determined based on the lowest value, and if the length of the storage battery operation time is the same for the plurality of operation plans in which the power peak reduction amount is the maximum, the operation plan to be adopted is determined based on the operation start time of the storage battery. This is a storage battery operation device that determines the operation plan to be adopted .

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

Moreover, one aspect of the present invention is the storage battery operating device, further comprising a load fluctuation compensator 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 for planning the operation of a storage battery that supplies power to a load connected to an electric power system, in which the operation plan determining unit determines the storage battery operation time period and the storage battery output value for each unit time. creating a plurality of operation plans with different values, calculating and comparing the amount of power peak reduction for each of the operation plans, and determining the operation plan with the maximum amount of power peak reduction as the operation plan to be adopted; If there is a plurality of operation plans in which the power peak reduction amount is maximum, the operation plan to be adopted is determined based on the length of the storage battery operation time , the operation end time of the storage battery, or the lowest value of the storage battery output value. and a storage battery operation method that determines the operation plan to be adopted based on the operation start time of the storage battery when the length of the storage battery operation time is the same for the plurality of operation plans in which the power peak reduction amount is the maximum. It is.

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

1 is a configuration diagram showing a configuration example of a storage battery operating device according to an embodiment of the present invention. 2 is a configuration diagram showing an example of the configuration of a load fluctuation compensator 13 shown in FIG. 1. FIG. 2 is a flowchart showing an example of the operation of the storage battery operating device 10 shown in FIG. 1. FIG. FIG. 2 is a schematic diagram for explaining an example of the operation of the storage battery operating device 10 shown in FIG. 1. FIG. FIG. 2 is a schematic diagram for explaining an example of the operation of the storage battery operating device 10 shown in FIG. 1. FIG. FIG. 2 is a schematic diagram for explaining an example of the operation of the storage battery operating device 10 shown in FIG. 1. FIG. FIG. 2 is a schematic diagram for explaining the effects of the operation example of the storage battery operating device 10 shown in FIG. 1. FIG. FIG. 2 is a schematic diagram for explaining the effects of the operation example of the storage battery operating device 10 shown in FIG. 1. FIG.

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

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

The communication unit 11 performs predetermined communication related to demand response, virtual power plants, etc. with a server operated by an electric power company, etc. (not shown), and communicates with a communication unit (not shown) of the load 3 or the storage battery 4. Perform predetermined communications.

The operation plan determining 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) of the output of the storage battery 4 (hereinafter referred to as a storage battery output value) for each predetermined unit time (for example, 30 minutes) in a certain period of time in the future. The operation plan determining unit 12 of this embodiment creates a plurality of operation plans in which the storage battery operation time period 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 the Determine the operation plan to be adopted based on the results. 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 predicted load power maximum value, which is the maximum value of the predicted load power for each unit time in a day. This is the value obtained by subtracting the predicted maximum received power value, which is the maximum value. Moreover, when the power peak reduction amounts of a 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 compensator 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 fluctuations in the load power of the load 3. That is, the load fluctuation compensator 13 adjusts the storage battery output value so as to compensate for fluctuations in 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 command value for discharging or charging/discharging.

FIG. 2 is a configuration diagram showing an example of the configuration of the load fluctuation compensator 13. As shown in FIG. The load fluctuation compensator 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 and predetermined low frequency components and high frequency components are removed to the adder 132. The output signal of the bandpass filter 131 represents a variation in load power. The adder 132 adds the storage battery output value determined by the operation plan determining 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 variations in load power. The limiter 133 limits the output signal of the adder 132 to predetermined upper and lower limits, generates and outputs a storage battery output command value. The storage battery output command value is a 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 operation time of the storage battery 4, it is possible to achieve both peak cut by the storage battery 4 and load fluctuation compensation. Note that the storage battery output value is 0 kW outside the operating hours.

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

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

Next, an example of the operation 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 example of the operation of the storage battery operating device 10 shown in FIG. 4 to 8 are schematic diagrams for explaining operation examples of the storage battery operating device 10 shown in FIG. 1.

The storage battery operation device 10 of this embodiment creates a storage battery operation plan by determining the storage battery operation time period 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) holds true in the system configuration shown in FIG. Further, the storage battery operation device 10 creates an operation plan for 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 performance values, etc., as described in Patent Document 1, for example. Further, (usable capacity of storage battery = rated capacity x (current SOC value - lower limit SOC value) ÷ 100). Here, SOC (State of Charge) is a unit representing the remaining battery power, and 100% is a fully charged state and 0% is a completely discharged state. Further, the current SOC value [%] is a measured value, and the rated capacity [kWh] and the SOC lower limit value [%] are values set by the operator.

In the process shown in FIG. 3, first, the driving plan determining unit 12 calculates the storage battery output value for each plan in which the driving start time period and the driving end time period are different (step S1). In step S1, for example, the operation plan determining unit 12 first calculates the storage battery operation time [h] in the range of the storage battery operation start time period and the end time period, as shown in FIG. FIG. 4 shows an example of calculating the storage battery operating time when the start time slot setting is "6:00" to "17:00" and the end time slot setting is "6:00" to "17:00." In the example shown in FIG. 4, for example, if 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. Note that in FIGS. 4 to 6, the symbol "." means that the value of the cell concerned is omitted, and the symbol "-" means that there is no value of the cell concerned.

In step S1, next, the operation plan determining unit 12 calculates, for example, the value (=average value) obtained by dividing the storage battery usable capacity [kWh] by the operation time [h] to the storage battery output value [kW ]. Here, when the storage battery output value exceeds the storage battery output upper limit value [kW], the operation plan determining 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 storage battery usable capacity is 60 kWh and the storage battery output value upper limit is 30 kW. Note that the storage battery usable capacity [kWh] and the storage battery output upper limit value [kW] are values set by the operator. In the example shown in Figure 5, for example, if the start time is 6:00 and the end time is 6:30, the storage battery operation time is 0.5 hours as shown in Figure 4, so the storage battery usable capacity (60kWh) The value divided by 0.5 hours is 120 kW, but in this case, since it exceeds the upper limit (30 kW), the storage battery output value becomes the upper limit of 30 kW, as shown surrounded by a broken line. For example, if the start time is 6:00 and the end time is 17:00, the battery operation time is 11.0 hours as shown in Figure 4, so the battery output value is as shown in the chain line. The usable capacity of the storage battery (60 kWh) is divided by 11.0 hours, which is approximately 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 determining unit 12 calculates the predicted maximum load power value (step S2). In step S2, the operation plan determining unit 12 determines the maximum value among the daily predicted load powers as the maximum predicted load power value.

Next, the operation plan determining unit 12 calculates the predicted maximum received power value in each plan (step S3). In step S3, the operation plan determining unit 12 first calculates the predicted received power for each unit time of the day using 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 determining unit 12 next sets the maximum value among the calculated predicted received powers as the maximum predicted received power value.

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

Next, the operation plan determining unit 12 determines a storage battery operation plan (step S5). In step S5, the operation plan determining unit 12 determines the power peak reduction amount based on the result of comparing each power peak reduction amount obtained in step S4 with respect to all plans set from the start time period to the end time period. The plan that provides the maximum amount of reduction is determined as the plan that will be adopted (the plan that will actually be used). At this time, if there are multiple plans with the same peak power reduction amount, the operation plan determining unit 12 adopts the plan with the shortest storage battery operation time. Further, if the number of driving hours is also the same, the driving plan determining unit 12 adopts the plan with the earliest start time. However, when there are multiple plans with the same peak power reduction amount, the method for selecting the adopted plan is not limited to this. It is possible to select a plan with the highest minimum value of the storage battery output value (for example, it is easy to maintain the efficiency of the conversion circuit).

FIG. 6 is a schematic diagram for explaining an example of determining a storage battery operation plan, and shows an example of the power peak reduction amount in each plan. In the example shown in FIG. 6, for example, in the case of a plan in which 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 multiple reductions. Of these, the driving plan determining unit 12 adopts the plan with the shortest driving time from 12:30 to 13:30 (adopts the plan with the value surrounded by the broken line).

Next, the load fluctuation compensator 13 determines a 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. Note that the storage battery output value and the storage battery output command value are constant values for each unit time (every 30 minutes).

Next, the driving plan determining unit 12 determines whether the driving plan update conditions are satisfied (step S8). The driving plan update condition is, for example, that a predetermined period of time has elapsed since the driving plan was last determined in step S5. This predetermined time can be set by the operator, for example, and can be set to a value such as 30 minutes. Alternatively, the update condition for the operation plan may be, for example, when the operator instructs the update. If the update condition is satisfied (“YES” in step S8), the operation plan determining unit 12 executes the processes of steps S1 to S7, determines the storage battery operation plan again, and uses the updated storage battery operation plan. Based on this, the load fluctuation compensator 13 determines a storage battery output command value, and the storage battery controller 14 notifies the storage battery 4 of the command value. On the other hand, if the update condition is not satisfied ("NO" in step S8), the operation plan determining unit 12 determines whether the end condition for the process shown in FIG. 3 is satisfied (step S9). The termination condition for the process shown in FIG. 3 is, for example, that the start time period has elapsed. Alternatively, the termination condition for the process shown in FIG. 3 is that the operator instructs termination. If the termination condition is satisfied (“YES” in step S9), the operation plan determining unit 12 terminates the process shown in FIG. 3. On the other hand, if the termination condition is not satisfied ("NO" in step S9), the operation plan determining unit 12 re-executes the determination in step S8, for example, after a certain period of time has elapsed.

Here, with reference to FIGS. 7 and 8, the effects of the operational example of the storage battery operating device 10 shown in FIG. 1 described with reference to FIG. 3 will be described. 7 and 8 are schematic diagrams for explaining the effects of the operation example of the storage battery operating device 10 shown in FIG. 1. FIGS. 7 and 8 are diagrams showing changes in load power per unit time (30 minutes) when the storage battery usable capacity is 60 kWh and the storage battery output value upper limit is 30 kW. Load power is calculated as follows: load power = received power + battery output (discharged power); received power is represented by a white bar, and battery output (discharged power) is represented by a shaded bar. FIG. 7 is an example in which an operation plan is determined based on the power peak reduction amount according to the present embodiment, and FIG. 8 is an example in which the target received power is 70 kW, and when the target value is exceeded, the storage battery is operated and discharged. 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 two hours from 9:00 to 11:00. In the example shown in Figure 7, the storage battery output value is set to 30 kW from 9:00 to 11:00, the maximum load power for the day is 120 kW, the maximum received power is 90 kW, and the peak power reduction amount is 30 kW (=maximum load power - maximum value of received power). 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 25 kW from 10:30 to 11:00. In the example shown in FIG. 8, the daily maximum load power is 120 kW, the maximum received power is 95 kW, and the peak power reduction amount is 25 kW.

According to the storage battery operation device 10 of this embodiment, setting of a power reception target value is not necessary. Therefore, trial and error regarding setting the target value can be avoided. Furthermore, charging and discharging on a second-by-second basis is not necessary. Therefore, deterioration of the storage battery due to rapid charging and discharging can be suppressed. According to these features, the storage battery operation device 10 of this embodiment allows stable peak power reduction in buildings and the like.

As described above, according to the storage battery operating device 10 of the present embodiment, the storage battery output value and operation time can provide a stable peak power reduction amount (maximum peak cut) without setting a target value. The band can be determined automatically. Further, since the storage battery operation plan can be updated once every 30 minutes, for example, the influence of prediction errors can be reduced, and a highly accurate plan can be drawn up. In addition, since each unit time has a constant output (no rapid charging/discharging), the operation is gentle on the storage battery. Moreover, the cost (instrumentation cost) related to data acquisition in units of one 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-described embodiments, and may include design changes without departing from the gist of the present invention. In addition, in FIG. 1, the storage battery operation device 10 manages (or controls) the load 3 and the storage battery 4, but it may also manage (or control) the power generating equipment connected to the power distribution system 2. . Further, the operating time period of the storage battery 4 is not limited to one continuous time period, but may include a plurality of discontinuous time periods. Further, a part or all of the software constituting the storage battery operating 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 (4)

A device that plans the operation of a storage battery that supplies power to a load connected to an electric power system,
A plurality of operation plans with different storage battery operation time periods and storage battery output values for each unit time are created, and the power peak reduction amount is calculated and compared for each of the operation plans, and the operation in which the power peak reduction amount is the maximum is determined. an operation plan determining unit that determines a plan as the operation plan to be adopted;
When there is a plurality of operation plans in which the power peak reduction amount is the maximum, the operation plan determining unit determines the operation plan based on the length of the storage battery operation time , the operation end time of the storage battery, or the lowest value of the storage battery output value. The operation plan to be adopted is determined, and if the length of the storage battery operation time is the same for the plurality of operation plans in which the power peak reduction amount is the maximum, the operation plan to be adopted is determined based on the operation start time of the storage battery. decide on a plan
Storage battery operation device. The power peak reduction amount is calculated from the maximum predicted load power that is the maximum value of the predicted load power for each unit time in a day, and from the predicted load power for each unit time in each operation plan. The storage battery operating device according to claim 1, wherein the value is a value obtained by subtracting a predicted received power maximum value, which is a maximum value of the subtracted values. The storage battery operating device according to claim 1 or 2, further comprising a load fluctuation compensator that adjusts the storage battery output value so as to compensate for fluctuations in load power of the load. A method for planning the operation of a storage battery that supplies power to a load connected to an electric power system, the method comprising:
The operation plan determination unit creates a plurality of operation plans with different storage battery operation time periods and storage battery output values for each unit time, calculates and compares the power peak reduction amount for each of the operation plans, and calculates the power peak reduction amount. The operation plan with the maximum is determined as the operation plan to be adopted, and if there are multiple operation plans with the maximum power peak reduction amount, the length of the storage battery operation time , the operation end time of the storage battery, Alternatively, the operation plan to be adopted is determined based on the lowest value of the storage battery output value, and when the length of the storage battery operation time is the same for a plurality of the operation plans in which the power peak reduction amount is the maximum, the storage battery The operation plan to be adopted is determined based on the operation start time of
How to operate a storage battery.

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