JP2022021370A - Storage battery control device and storage battery system - Google Patents

Abstract

To provide a storage battery control device capable of suppressing the modulation of a system frequency caused by automatically increasing an output by the other dynamo-electric machine at the time of the stop of some of the dynamo-electric machines.SOLUTION: A storage battery control device 2 that controls a storage battery 1 connected to an electric system, comprises: a measurement acquisition part 21 that acquires a measurement value of each output of a plurality of dynamo-electric machines connected to the electric system; a dynamo-electric machine stopping determination part 22 determining whether or not a first dynamo-electric machine as part of the dynamo-electric machines among the plurality of dynamo-electric machines on the basis of the measurement value; and a charging and discharging amount determination part 23 that increases a charging amount of the storage battery when it is determined by the dynamo-electric machine stopping determination part 22 that the first dynamo-electric machine is stopped.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a storage battery control device that controls a storage battery connected to an electric power system, and a storage battery system including the storage battery control device.

The frequency of electric power (hereinafter, also referred to as a grid frequency) of a power system (hereinafter, also simply referred to as a grid) changes depending on a change in the balance between supply and demand. It is desired to stabilize the frequency of electric power because a large change in the frequency of electric power affects consumer equipment and generators.

Patent Document 1 discloses a technique for controlling the discharge amount of a storage battery connected to a grid in order to stabilize the grid frequency. The system stabilizer described in Patent Document 1 calculates the limit value imposed on the change in the total output of the generator in the power plant by using the rated output of the generator in operation, and calculates the output of the generator and the storage battery. The discharge amount of the storage battery is controlled so that the change in the measured value of the total tidal current is within the calculated limit value. Since the system stabilizer described in Patent Document 1 can limit the change in the output of the entire generator so as not to affect the change in the system frequency, the system frequency can be stabilized.

International Publication No. 2013/140916

In the electric power system, it is required to balance the demand amount and the supply amount of electric power. For this reason, if one of the multiple generators stops due to a failure or the like, the other generators that are continuing to operate automatically increase the output to avoid a shortage of supply capacity. ing. However, this method has a problem that the system frequency fluctuates because the output of the generator that continues to operate increases rapidly. Further, in the technique described in Patent Document 1, since the measured value of the tidal current of the total value of the outputs of the generator and the storage battery is used, it cannot be detected that some generators have stopped. This is because, as mentioned above, other generators automatically increase the output to compensate for the amount of power generated by the stopped generator, so even if some generators stop, the output value of the entire generator is almost the same. This is because it does not change. Therefore, the technique described in Patent Document 1 has a problem that it is not possible to suppress fluctuations in the system frequency caused by the automatic increase in output of another generator when one of the generators is stopped. ..

The present disclosure has been made in view of the above, and it is possible to suppress fluctuations in the system frequency caused by the automatic increase in output of other generators due to the shutdown of some generators. The purpose is to obtain a storage battery control device.

In order to solve the above-mentioned problems and achieve the object, the storage battery control device according to the present disclosure is a storage battery control device that controls a storage battery connected to the power system, and is a plurality of generators connected to the power system. It is provided with a measurement data acquisition unit that acquires the measurement value of each output of. The storage battery control device further includes a generator stop determination unit that determines whether or not the first generator, which is a part of the plurality of generators, has stopped based on the measured values, and a generator stop. It includes a charge / discharge amount determining unit that increases the discharge amount of the storage battery when the determination unit determines that the first generator has stopped.

According to the present disclosure, it is possible to suppress fluctuations in the system frequency caused by the automatic increase in output of other generators due to the shutdown of some generators.

The figure which shows the configuration example of the power system system of embodiment The figure which shows the structural example of the storage battery control device of embodiment The figure which shows the configuration example of the processing circuit when the processing circuit is a circuit including a processor. A flowchart showing an example of control when the generator is stopped in the storage battery control device of the embodiment. The figure which shows the state of the control when the generator of an embodiment is stopped. A flowchart showing another example of control when the generator is stopped in the storage battery control device of the embodiment. A flowchart showing an example of the processing procedure after the increase in the discharge amount of the storage battery is started by the processing illustrated in FIGS. 4 and 6.

Hereinafter, the storage battery control device and the storage battery system according to the embodiment will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a configuration example of a power system system according to an embodiment of the present disclosure. As shown in FIG. 1, the power system of the present embodiment includes a storage battery 1 which is a power storage facility, a storage battery control device 2 for controlling the storage battery 1, generators 3-1 to 3-3, and a supply / demand control device. 5 and. The storage battery 1 and the generator (denoted as G in FIG. 1) 3-1 to 3-3 are connected to the power system 10 via the interconnection line 11. That is, the storage battery 1 and the generators 3-1 to 3-3 are connected to the power system 10. A load (denoted as L in FIG. 1) 4 is connected to the power system 10. Although the load 4 connected to the power system 10 is generally not one, a plurality of loads are collectively described as the load 4. Further, a power generation facility other than the generators 3-1 to 3-3 may be connected to the power system 10. The power system 10 is, for example, a small-scale independent system in a remote island called a microgrid, but the power system 10 is not limited to this.

The supply / demand control device 5 manages the supply / demand balance of the entire power system 10, and controls the start and stop of the operation of the generators 3-1 to 3-3 according to the amount of power consumed by the load 4, that is, the amount of demand. At the same time, the output of the generators 3-1 to 3-3 during operation is controlled. When a generator other than the generators 3-1 to 3-3 is connected to the power system 10, the generator 3-so that the supply and demand can be balanced in the entire power system 10 according to the amount of demand. The amount of power generation, which is the output of 1 to 3-3, is determined.

The generators 3-1 to 3-3 are installed in, for example, a power plant, and generate electricity using liquid, gas, or solid fuel based on a control command from the supply / demand control device 5. The generators 3-1 to 3-3 are, for example, generators whose output for generating power, that is, the amount of power generation can be adjusted. The generators 3-1 to 3-3 are, for example, thermal power generators and hydroelectric generators that generate electricity using liquid, gas, or solid fuel.

The generators 3-1 to 3-3 have a function of automatically controlling the output by a speed governor or the like in order to cope with the fluctuation of the system frequency. The output of the generators 3-1 to 3-3 is managed by the supply and demand control device 5 as described above, but the control command of the supply and demand control device 5 is generated on the assumption that the generators 3-1 to 3-3 are normal. Will be done. The supply / demand control device 5 detects a failure of the generators 3-1 to 3-3 based on an accident signal from a protection relay (not shown) or the like, but after the supply / demand control device 5 receives the accident signal, the said It takes time to detect a failure based on the accident signal and change the control command. Therefore, according to the control command from the supply / demand control device 5, when all the generators 3-1 to 3-3 are in operation, one of the generators 3-1 to 3-3 is stopped due to a failure or the like. If this is the case, the other generators 3-1 to 3-3 that are still in operation will detect the lack of supply capacity for demand as a change in frequency and increase the output by the function of the governor. This prevents the occurrence of an imbalance between supply and demand. That is, each of the generators 3-1 to 3-3 controls the output so that the total output of the generators 3-1 to 3-3 is maintained at the target value. As a result, the imbalance between supply and demand can be suppressed and the fluctuation of the system frequency can be suppressed. In this way, the supply amount of the stopped generator can be supplemented by another generator, so that the total value of the outputs of the generators 3-1 to 3-3 is the generators 3-1 to 3-3. Even if one of them stops, there is almost no change.

The storage battery 1 and the storage battery control device 2 form a storage battery system. The storage battery 1 is a storage facility including a battery body capable of storing electricity, an inverter that converts the power stored in the battery body into AC power, and a converter that converts AC power into DC power. The storage battery 1 charges based on the charge command received from the storage battery control device 2, and discharges based on the discharge command received from the storage battery control device 2.

Hereinafter, when each of the generators 3-1 to 3-3 is shown without being individually distinguished, it is described as a generator 3, and when each of the measuring devices 6-1 to 6-3 is shown without being individually distinguished. Is described as a measuring device 6. In the example shown in FIG. 1, an example including three generators 3 is shown, but the number of generators 3 may be a plurality, and the number of generators 3 is not limited to the example shown in FIG. The measuring device 6 is provided for each generator 3.

As described above, when one of the plurality of generators 3 in operation is stopped, the other generators 3 that are continuing to operate increase the output. At this time, since the output of the other generator 3 that is continuing to operate is rapidly increased, the fuel system having a slow response speed cannot follow. Therefore, with respect to the rotational energy possessed by the rotor of the generator 3, the system frequency becomes unstable due to a large difference between the energy input from the combustion system and the energy consumption due to the conversion into electrical energy. The smaller the demand for the load 4 of the power system 10, the greater the effect of the instability of the system frequency. Therefore, in a small-scale system such as a remote island, the effect of the instability of the system increases. In the present embodiment, the outputs of the generators 3-1 to 3-3 are measured by the measuring devices 6-1 to 6-3, respectively, and the storage battery control device 2 is the measuring devices 6-1 to 6-3. Using the measured value, it is determined whether or not any of the generators 3-1 to 3-3 has stopped, and when it is determined that any of the generators 3-1 to 3-3 has stopped, the storage battery 1 Increases the amount of discharge. As a result, it is possible to suppress the rate of change in the output of the other generator 3 that is continuing to operate, and it is possible to suppress the fluctuation in the system frequency. Further, by discharging the storage battery 1, the fuel cost of the generator 3 can be suppressed.

Further, in the present embodiment, since the stop of the generator 3 is determined by using the measured value of the output of the generator 3, it is not necessary to receive the accident signal or the like. In order to receive the accident signal, it is necessary to communicate with the control system that controls the power system 10, but in the present embodiment, it is not necessary to provide a communication line with the control system. Therefore, even when the storage battery 1 and the storage battery control device 2 are added to the existing equipment, and in the present embodiment, the stop of the generator 3 is determined by using the measured value of the output of the generator 3. Therefore, it is possible to determine the stoppage of the generator 3 more quickly than when determining the stoppage of the generator 3 using the accident signal.

FIG. 2 is a diagram showing a configuration example of the storage battery control device 2 of the present embodiment. As shown in FIG. 2, the storage battery control device 2 of the present embodiment includes a measurement data acquisition unit 21, a generator stop determination unit 22, a charge / discharge amount determination unit 23, a command unit 24, and a data storage unit 25.

The measurement data acquisition unit 21 acquires measurement data indicating the measurement value of the output of the generator 3 corresponding to the measurement device 6 from the measurement device 6. That is, the measurement data acquisition unit 21 acquires the measured values of the outputs of the generators 3-1 to 3-3, which are a plurality of generators. The measuring device 6 measures, for example, active power as the output of the generator 3. Although one measuring device 6 is shown in FIG. 2, the measurement data acquisition unit 21 acquires measurement data indicating the measured value of the output of the corresponding generator 3 from each measuring device 6. The measurement data acquisition unit 21 stores the measurement data acquired from each measurement device 6 in the data storage unit 25.

The generator stop determination unit 22 determines whether or not there is a stopped generator 3 based on the measurement data stored in the data storage unit 25. That is, the generator stop determination unit 22 is the first power generation which is a part of the generators 3-1 to 3-3 based on the measured values of the outputs of the generators 3-1 to 3-3. Determine if the aircraft has stopped. Further, the generator stop determination unit 22 may determine whether or not there is a stopped generator 3 by using the measurement data directly acquired from the measurement data acquisition unit 21.

The charge / discharge amount determination unit 23 determines the charge / discharge amount of the storage battery 1. For example, when the generator stop determination unit 22 determines that there is a stopped generator 3, the charge / discharge amount determination unit 23 determines the discharge power so as to increase the discharge amount of the storage battery 1. The charge / discharge amount determination unit 23 increases the discharge amount of the storage battery 1 when the generator stop determination unit 22 determines that the first generator has stopped. Any method may be used to increase the charging power. For example, the charging power to be increased per second, that is, the slope with respect to the time when the charging power is increased may be predetermined. , The charging power may be determined based on the measurement data. The details of the operation of the charge / discharge amount determination unit 23 will be described later.

The command unit 24 generates a charge command or a discharge command according to the determined charge / discharge amount by the charge / discharge amount determination unit 23, and outputs the generated command to the storage battery 1. The data storage unit 25 stores the above-mentioned measurement data.

Here, the hardware configuration of the storage battery control device 2 will be described. The measurement data acquisition unit 21, the generator stop determination unit 22, the charge / discharge amount determination unit 23, and the command unit 24 of the storage battery control device 2 are realized by a processing circuit. Further, the data storage unit 25 is realized by a memory.

The processing circuit that realizes the measurement data acquisition unit 21, the generator stop determination unit 22, the charge / discharge amount determination unit 23, and the command unit 24 of the storage battery control device 2 may be a circuit including a processor or dedicated hardware. May be. The processing circuit is also called a control circuit.

When the processing circuit that realizes the measurement data acquisition unit 21, the generator stop determination unit 22, the charge / discharge amount determination unit 23, and the command unit 24 is dedicated hardware, the processing circuit may be, for example, a single circuit, a composite circuit, or the like. A programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof is applicable.

FIG. 3 is a diagram showing a configuration example of a processing circuit when the processing circuit is a circuit including a processor. When the processing circuit that realizes the measurement data acquisition unit 21, the generator stop determination unit 22, the charge / discharge amount determination unit 23, and the command unit 24 includes a processor, the processing circuit includes the processor 101 and the memory 102, for example, as shown in FIG. To prepare for. When the processing circuit is the processing circuit shown in FIG. 3, the functions of the measurement data acquisition unit 21, the generator stop determination unit 22, the charge / discharge amount determination unit 23, and the command unit 24 are software, firmware, or software and firmware. It is realized by the combination of. The software or firmware is written as a program and stored in the memory 102. In the processing circuit, each function is realized by the processor 101 reading and executing the program stored in the memory 102. This program may be provided by a recording medium on which the program is recorded, or may be provided by other means such as a communication medium. The memory 102 is also used as a storage area for storing data necessary for the processor 101 to execute processing.

Here, the processor 101 is, for example, a CPU (Central Processing Unit), a processing device, an arithmetic unit, a microprocessor, a microcomputer, a DSP (Digital Signal Processor), or the like. Further, the memory 102 may be non-volatile or volatile, for example, RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable ROM), EEPROM (registered trademark) (Electrically EPROM), or the like. This includes semiconductor memory, magnetic disk, flexible disk, optical disk, compact disk, mini disk, DVD (Digital Versatile Disc), and the like.

The memory that realizes the data storage unit 25 may be a part of the above-mentioned memory 102, or a memory that realizes the data storage unit 25 may be provided separately from the memory 102. Further, a communication circuit including a receiver and a transmitter may be used to realize the measurement data acquisition unit 21 and the command unit 24.

Even if each function of the measurement data acquisition unit 21, the generator stop determination unit 22, the charge / discharge amount determination unit 23, and the command unit 24 is partially realized by dedicated hardware and partly realized by software or firmware. good.

Next, the operation of the storage battery control device 2 of the present embodiment will be described. Hereinafter, control of charge / discharge of the storage battery 1 when the operating generator 3 is stopped due to an accident or the like (hereinafter, also referred to as control when the generator is stopped) will be described, but the storage battery control device 2 is due to an accident or the like. Even when the generator 3 is not stopped, the storage battery 1 is used in order to suppress fluctuations in the system frequency due to fluctuations in the supply-demand balance due to fluctuations in demand, fluctuations in the amount of power generated by power generation equipment using natural energy, and the like. Stabilization control of the existing system frequency may be performed. Any method may be used for the control for suppressing the fluctuation of the system frequency due to the fluctuation of the demand, and for example, the control method described in Patent Document 1 can be used. For example, the storage battery control device 2 acquires power generation information indicating the rated output of the generator in operation from the supply / demand control device 5, and sets the operating information as the limit value imposed on the change in the total output of the generator at the power plant. Calculate using. Then, the storage battery control device 2 acquires the measured value of the tidal current in the interconnection line 11, that is, the measured value of the total value of the outputs of the generator and the storage battery 1, so that the change of the measured value is within the calculated limit value. The discharge amount of the storage battery 1 is controlled.

Next, the control when the generator is stopped in the storage battery control device 2 of the present embodiment will be described. The measuring devices 6-1 to 6-3 periodically transmit measurement data indicating the measured values to the storage battery control device 2. Alternatively, the measurement data acquisition unit 21 of the storage battery control device 2 periodically instructs the measurement devices 6-1 to 6-3 to acquire the data, and when the measurement devices 6-1 to 6-3 receive the instruction, the measurement data is output. It may be transmitted to the storage battery control device 2.

FIG. 4 is a flowchart showing an example of control when the generator is stopped in the storage battery control device 2 of the present embodiment. Here, it is assumed that all of the generators 3-1 to 3-3 are operated in the normal state, and that the generators are controlled to generate power with the same uniform output during the operation. When the supply / demand control device 5 can change how many of the generators 3-1 to 3-3 are to be operated, the storage battery control device 2 is instructed to be operated by the supply / demand control device 5. Information indicating the generator 3 in operation (hereinafter referred to as the operating generator 3) is acquired from the supply / demand control device 5. Then, the storage battery control device 2 performs the process shown in FIG. 4 for the generator 3 in operation.

As shown in FIG. 4, the measurement data acquisition unit 21 acquires measurement data from the measurement devices 6-1 to 6-3 (step S1). As described above, the measurement data is data showing the measured values of the outputs of the generators 3-1 to 3-3. The measurement data acquisition unit 21 stores the measurement data in the data storage unit 25. The generator stop determination unit 22 refers to the measurement data stored in the data storage unit 25, and determines whether or not there is a generator 3 whose measured value is less than the first threshold value (step S2). The first threshold value is a value corresponding to the output when the generator 3 is stopped, and is, for example, 1.5 of the measurement error of the measuring devices 6-1 to 6-3 or the maximum value of the measurement error. It is set to a small value such as double. The first threshold value is not limited to the above-mentioned example as long as it is a threshold value for determining that the generator 3 has stopped due to an accident or the like.

When there is a generator 3 whose measured value is less than the first threshold value (step S2 Yes), the generator stop determination unit 22 has the measured value of the other generator 3, that is, the measured value is the first in step S2. It is determined whether or not the measured value of the generator 3 determined to be less than the threshold value is equal to or more than the second threshold value (step S3). The second threshold value may be the same value as the first threshold value or may be a value larger than the first threshold value. The second threshold value is a threshold value for determining that the other generator 3 continues to operate.

When the measured value of the other generator 3 is equal to or higher than the second threshold value (step S3 Yes), the charge / discharge amount determining unit 23 determines the discharge amount so as to increase the discharge amount of the storage battery 1 (step). S4). Specifically, when the measured value of the other generator 3 is equal to or higher than the second threshold value, the generator stop determination unit 22 has the stopped generator 3 and the other generator 3 continues to operate. That is, the charge / discharge amount determination unit 23 is notified of the stoppage of some generators. Upon receiving the notification that some of the generators are stopped, the charge / discharge amount determining unit 23 determines the discharge amount so as to increase the discharge amount of the storage battery 1.

In step S4, the charge / discharge amount determination unit 23 may increase the charge amount so that the increase amount per unit time becomes a constant value, or may increase the charge amount by a function of a predetermined time. good. Further, the charge / discharge amount determination unit 23 may determine the increase amount per unit time according to the previously acquired measurement value for each generator 3 based on the measurement data stored in the data storage unit 25. , The average value of the measured values for a certain period up to the previous time may be obtained, and the amount of increase per unit time may be determined according to the average value.

After step S4, the command unit 24 transmits a discharge command to the storage battery 1 (step S5). Specifically, the charge / discharge amount determination unit 23 notifies the command unit 24 of the discharge amount determined in step S4. The command unit 24 generates a discharge command based on the notified discharge amount, and transmits the discharge command to the storage battery 1. As a result, the amount of discharge from the storage battery 1 increases.

When No in step S2 and No in step S3, the storage battery control device 2 ends the process without changing the charge / discharge amount of the storage battery 1. As described above, in the example shown in FIG. 4, in the generator stop determination unit 22, the measured value of the first generator of the generator 3 is less than the first threshold value, and the first one. When the measured value of the second generator, which is a plurality of generators 3 other than the generator 3, is equal to or greater than the second threshold value, it is determined that the first generator has stopped.

FIG. 5 is a diagram showing a state of control when the generator of the present embodiment is stopped. In FIG. 5, the horizontal axis represents time and the vertical axis represents power. FIG. 5 shows an example in which the generator 3-1 of the operating generators 3-1 to 3-3 is stopped due to an accident or the like. The output 201 indicates the output of the generator 3-1 that has stopped due to an accident or the like, and the output 202 is the generator 3-2, which is another generator 3 that continues to operate even after the generator 3-1 is stopped. Shows the output of. The output of the generator 3-3 is the same as the output 202. The discharge amount 203 indicates the discharge power of the storage battery 1.

As shown in FIG. 5, before the generator 3-1 is stopped, the output 201 and the output 202 are almost the same values, but when the generator _3-1 is stopped at the time T1, the output 201 drops sharply. do. On the other hand, the output 202 increases sharply due to automatic control by the governor as the output of the generator 3-1 decreases. When the output of the generator 3-2 is suddenly increased, the system frequency fluctuates due to the problem of the response speed of the combustion system as described above. Therefore, in the present embodiment, when the storage battery control device 2 detects that the generator 3-1 is stopped, the output of the generators 3-2 and 3 is suppressed by increasing the discharge amount 203 of the storage battery 1. This makes it possible to suppress fluctuations in the system frequency. In the example shown in FIG. 4 described above, it is determined whether or not the generator 3 has stopped based on whether or not the measured value of the output of the generator 3 is less than the first threshold value. When the stop of the generator 3 is detected, the discharge amount 203 of the storage battery 1 increases. As a result, the output 202 of the generator 3-2 is automatically and gradually reduced. Although FIG. 5 shows an example in which the generator 3-1 is stopped, the same operation is performed when the generator 3-2 or the generator 3-3 is stopped.

It is also possible that the measured value of the output of the generator 3 is less than the first threshold value for reasons other than the stop of the generator 3, such as a temporary change in the demand amount. In the case of a change in the amount of demand, the output of the other generator 3 is expected to change in the same way. Therefore, in order to distinguish it from the case of the change in the amount of demand, the example shown in FIG. In step S3, it is determined whether or not the output of the other generator 3 is equal to or higher than the second threshold value.

The storage battery control device 2 performs the process shown in FIG. 4 every time measurement data is received from the measurement devices 6-1 to 6-3 until the discharge amount of the storage battery 1 is increased by steps S4 and S5. do. Although the transmission cycles of the measurement data of the measurement devices 6-1 to 6-3 are the same, the timing at which the storage battery control device 2 receives the measurement data of the measurement devices 6-1 to 6-3 is not the same. good. The storage battery control device 2 may perform the process shown in FIG. 4 using the measurement data received from the measurement devices 6-1 to 6-3 within the same transmission cycle.

In the example shown in FIG. 4, the measured value of the output of one generator 3 is reduced to be less than the first threshold, and the measured value of the output of another generator 3 is not reduced. That is, when the measured value of the output of the other generator 3 is equal to or higher than the second threshold value, it is determined that the generator 3 whose measured value has decreased has stopped due to an accident or the like, but the generator 3 based on the measured value is determined. The method of determining the suspension of the above is not limited to the above-mentioned example.

FIG. 6 is a flowchart showing another example of control when the generator is stopped in the storage battery control device 2 of the present embodiment. Step S1 is the same as the example shown in FIG. After step S1, the generator stop determination unit 22 determines whether or not the measured value of some generators is equal to or less than the threshold value and the decrease rate is equal to or greater than the rate threshold value (step S6). The rate of decrease is the amount of decrease in the measured value per unit time. Specifically, for example, the generator stop determination unit 22 performs the latest measurement for each generator 3 when the measured value indicated by the latest measurement data is smaller than the measured value indicated by the measurement data received one time before. The value obtained by subtracting the measured value indicated by the previously received measurement data from the measured value indicated by the data is calculated as the reduction rate. The generator stop determination unit 22 determines for each generator 3 whether or not the measured value indicated by the latest measurement data is equal to or less than the threshold value and the reduction rate is equal to or less than the rate threshold value. In the generator stop determination unit 22, the measured value indicated by the latest measurement data of some generators 3 is below the threshold value and the decrease rate is above the rate threshold value, and other generators 3 satisfy this condition. If it is not satisfied, it is determined as Yes in step S6. When the measured value indicated by the latest measurement data of all the generators 3 in operation is equal to or less than the threshold value and the decrease rate is equal to or more than the rate threshold value, the generator stop determination unit 22 sets No to No. in step S6. to decide. The reduction rate may be calculated by dividing the value obtained by subtracting the measurement value indicated by the measurement data received one time before from the measurement value indicated by the latest measurement data by the transmission cycle of the measurement data, but the transmission cycle may be calculated. If is constant, the transmission cycle may be regarded as a unit time and the process of dividing by the transmission cycle may not be performed.

The threshold value is a threshold value for determining that a sudden output is generated due to a stop such as an accident. This threshold value may be the same value as the first threshold value described above, but it may be a somewhat large value such as a value of about 1/3 of the average value of the output of the generator 3 during normal operation. It may be set. Further, the reduction rate is not limited to the difference between the measurement data received one time before and the latest measurement data, and may be calculated based on the latest three or more measurement data. For example, the value obtained by subtracting the measured value indicated by the measured data received three times before from the measured value indicated by the measured data received two times before and the measured value indicated by the measured data received one time before two times before. The reduction rate may be the average value of the value obtained by subtracting the measured value indicated by the received measurement data and the value obtained by subtracting the measured value indicated by the measured data received one time before from the measured value indicated by the latest measured data.

When the measured value is equal to or less than the threshold value and the decrease rate is equal to or greater than the rate threshold value (step S6 Yes), steps S4 and S5 are carried out in the same manner as in the example shown in FIG. If No in step S6, the storage battery control device 2 ends the process without changing the charge / discharge amount of the storage battery 1. As described above, in the example shown in FIG. 6, in the generator stop determination unit 22, the measured value of the first generator of the generator 3 is equal to or less than the threshold value and the measured value of the first generator. When the amount of decrease per unit time is equal to or less than the rate threshold value, it is determined that the first generator has stopped.

In the example shown in FIG. 6, after step S6, the generator stop determination unit 22 may determine whether or not the measured value of the output of the other generator 3 is increasing. Then, the storage battery control device 2 executes steps S4 and S5 when the measured value of the output of the other generator 3 is increasing, and processes when the output of the other generator 3 is not increasing. To finish.

The determination of the stop of the generator 3 may be made based on the output of the generator 3, and may be a specific method, the method shown in FIG. 4, or the method shown in FIG. Often, examples other than these may be used.

There are no particular restrictions on the method of controlling the charge / discharge amount after the increase in the discharge amount of the storage battery 1 is started by the processes illustrated in FIGS. 4 and 6, but for example, after increasing the discharge amount, the operation is continued. When the output of the generator 3 is reduced to the level before the accident, the increase in the discharge amount is stopped. In the example shown in FIG. 5, the output 202 of the generator 3-2 is automatically and gradually decreased by increasing the discharge amount 203 of the storage battery ₁ from the time T1. The charge / discharge amount determination unit 23 of the storage battery control device 2 acquires measurement data of the output of the generator 3-2 via the data storage unit 25 and the generator stop determination unit 22, and the output of the generator 3-2 is output. When the output drops to the level before the accident occurs, that is, before the generator 3-1 is stopped, the increase in the discharge amount is stopped. However, if the discharge output of the storage battery reaches the upper limit value before the increase in the discharge amount is stopped, the charge / discharge amount determination unit 23 stops the increase in the discharge amount when the upper limit value is reached. The charge / discharge amount determination unit 23 may acquire the measurement data of the output of the generator 3-2 directly from the data storage unit 25. After the output is reduced, the generator 3-2 gradually increases the output so as to operate at the high efficiency point until the output reaches the output of two units. In the example shown in FIG. 5, the _output of the generator 3-1 starts to increase at time T2 after a certain period of time after the decrease of the output of the generator 3-2 is completed, but the timing of the increase of the output is this. Not limited to examples. The charge / discharge amount determination unit 23 of the storage battery control device 2 reduces the discharge amount 203 as the output of the generator 3-2 decreases, based on the measurement data of the output of the generator 3-2. By the above operation, the generator 3-2 that is continuing to operate can gradually increase the output, so that the fluctuation of the system frequency due to the slow response speed of the combustion system is suppressed and the generator is stopped. The output of 3-1 can be supplemented by the output of another generator 3-2. Further, when there are a plurality of generators 3 that continue to operate other than the stopped generator 3, the charge / discharge amount determination unit 23, for example, outputs measurement data for all of the plurality of generators 3. When the output drops to the level before the accident or when the upper limit of the discharge amount is reached, the increase in the discharge amount is stopped. As described above, the method of controlling the charge / discharge amount after the increase in the discharge amount of the storage battery 1 is started is not limited to this example, and the control is such that the sudden increase in the output of the generator 3-2 is suppressed. Any method will do. The example shown in FIG. 5 is an example, and the output of each generator 3 and the discharge amount of the storage battery 1 are determined by various conditions such as a load state and a control method of the generator 3.

FIG. 7 is a flowchart showing an example of a processing procedure after the increase in the discharge amount of the storage battery 1 is started by the processing illustrated in FIGS. 4 and 6. As shown in FIG. 6, the measurement data acquisition unit 21 acquires measurement data from the measurement devices 6-1 to 6-3 in the same manner as in step S1 (step S11). The measurement data acquisition unit 21 stores the measurement data in the data storage unit 25. The generator stop determination unit 22 refers to the measurement data stored in the data storage unit 25, and determines whether or not the discharge amount of the storage battery 1 exceeds the measurement value of the other generator 3 (step S12).

When the discharge amount of the storage battery 1 exceeds the measured value of the other generator 3 (step S12 Yes), the charge / discharge amount determination unit 23 determines the discharge amount so as to maintain the discharge amount of the storage battery 1 (step S13). ). Specifically, when the discharge amount of the storage battery 1 exceeds the measured value of the other generator 3, the generator stop determination unit 22 determines that the discharge amount of the storage battery 1 exceeds the measured value of the other generator 3. Notify the charge / discharge amount determination unit 23. Upon receiving the notification, the charge / discharge amount determining unit 23 determines the discharge amount so as to maintain the discharge amount of the storage battery 1.

When the discharge amount of the storage battery 1 does not exceed the measured value of the other generator 3 (step S12 No), the charge / discharge amount determination unit 23 discharges so as to increase the discharge amount of the storage battery 1 as in step S4. The amount is determined (step S15). Specifically, when the discharge amount of the storage battery 1 does not exceed the measured value of the other generator 3, the generator stop determination unit 22 indicates that the discharge amount of the storage battery 1 does not exceed the measured value of the other generator 3. Notify the charge / discharge amount determination unit 23 of this. Upon receiving the notification, the charge / discharge amount determining unit 23 determines the discharge amount so as to increase the discharge amount of the storage battery 1.

After step S13 and after step S15, the command unit 24 transmits a discharge command to the storage battery 1 (step S14). By the above processing, the discharge amount of the storage battery 1 increases until the discharge amount of the storage battery 1 exceeds the measured value of the other generator 3, and when the discharge amount of the storage battery 1 exceeds the measured value of the other generator 3. The discharge amount of the storage battery 1 is maintained at a constant value. After that, when the time has elapsed by ΔT from the start of the increase in the discharge amount of the storage battery 1, the generator stop determination unit 22 notifies the charge / discharge amount determination unit 23 to that effect. Upon receiving the notification, the charge / discharge amount determining unit 23 gradually reduces the discharge amount of the storage battery 1. At this time, since the power generation amount of the generator 3 increases as the discharge amount decreases, the decrease rate of the discharge amount changes the system frequency in consideration of the response speed of the combustion system of the generator 3 and the like. It is determined that the output of the generator 3 is increased while suppressing the output.

In the above-mentioned example, an example in which one generator 3 is stopped when three generators 3 are in operation has been described, but the number of generators 3 in operation and the number of generators 3 to be stopped are different. Not limited to this example. For example, if two of the three generators 3 are stopped, the same control is performed, and the system frequency generated by the other generators automatically increasing the output when some generators are stopped. Fluctuations can be suppressed.

As described above, in the present embodiment, when the storage battery control device 2 determines that the generator 3 is stopped based on the measured value of the output of each generator 3, and determines that the generator 3 has stopped, it is determined that the generator 3 has stopped. The discharge amount of the storage battery 1 was increased. As a result, it is possible to suppress fluctuations in the system frequency caused by the automatic increase in output of other generators due to the shutdown of some generators. Further, since it is not necessary to communicate with a control system or the like that monitors the accident signal, it is not necessary to introduce communication equipment or the like for this purpose, and the configuration can be simplified. In addition, it is possible to suppress an increase in fuel costs of other generators.

The configuration shown in the above embodiments is an example, and can be combined with another known technique, can be combined with each other, and does not deviate from the gist. It is also possible to omit or change a part of the configuration.

1 storage battery, 2 storage battery control device, 3-1 to 3-3 generator, 4 load, 5 supply and demand control device, 6,6-1 to 6-3 measuring device, 10 power system, 11 interconnection lines, 21 measurement data Acquisition unit, 22 generator stop determination unit, 23 charge / discharge amount determination unit, 24 command unit, 25 data storage unit.

Claims (5)

A storage battery control device that controls the storage battery connected to the power system.
A measurement data acquisition unit that acquires the measured values of the outputs of each of the plurality of generators connected to the power system, and
Based on the measured values, a generator stop determination unit that determines whether or not the first generator, which is a part of the plurality of generators, has stopped, and a generator stop determination unit.
When the generator stop determination unit determines that the first generator has stopped, the charge / discharge amount determination unit that increases the discharge amount of the storage battery and the charge / discharge amount determination unit.
A storage battery control device characterized by being equipped with. In the generator stop determination unit, the second power generation is a plurality of generators other than the first generator and the measured value of the first generator is less than the first threshold value. The storage battery control device according to claim 1, wherein when the measured value of the machine is equal to or higher than the second threshold value, it is determined that the first generator has stopped. In the generator stop determination unit, the measured value of the first generator is equal to or less than the threshold value, and the decrease amount of the measured value of the first generator per unit time is equal to or less than the rate threshold value. The storage battery control device according to claim 1, wherein it is determined that the first generator has stopped in a certain case. The storage battery according to any one of claims 1 to 3, wherein each of the plurality of generators controls the output so that the total output of the plurality of generators is maintained at a target value. Control device. The storage battery connected to the power system and
The storage battery control device according to any one of claims 1 to 4, which controls the storage battery.
A storage battery system characterized by being equipped with.

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