JP2012050211A - Power storage system for power system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage system for a power system capable of efficiently controlling a storage battery of each user, and furthermore efficiently controlling the power system by cooperatively controlling the storage batteries of both the power system and the users according to the needs of a supply command station.SOLUTION: A power storage system for a power system comprises: a storage battery 13 for a power system being installed as such; a virtual storage battery 14 formed by a plurality of batteries 15 of users being governed by a collection/distribution device 16; and a storage battery monitoring controller 12 for controlling the storage battery 13 for the power system and the virtual storage battery 14 according to a command from a supply command station 11. The storage battery 13 for the power system responds at a high-speed to a command from the storage battery monitoring controller 12 so as to perform a charging/discharging control for a frequency adjustment and an economical load distribution. The virtual storage battery 14 responds at a low-speed to a command from the storage battery monitoring controller 12 so as to perform a charging/discharging control for an economical load distribution. Thus, the virtual storage battery 14 composed of the batteries 15 of users and the storage battery 13 for the power system are cooperatively controlled.

Description

  The present invention relates to a power system power storage system that performs charge / discharge control of a storage battery linked to a power system for system operation work.

  Renewable energy is being introduced to build a low-carbon society. Renewable energy sources such as wind power and solar power have major problems in maintaining stable power supply and demand due to fluctuations in output and output uncertainty. Under such circumstances, with the spread of electric vehicles (EV), the performance, size, life, and price of storage batteries are increasing, and their use in electric power systems is being sought.

  Storage batteries are broadly classified into grid storage batteries owned by electric power companies and customer storage batteries owned by electric power consumers (hereinafter simply referred to as consumers).

  The storage battery for a system is a large capacity storage battery that is directly connected to the power system, and can be freely used by a power supply command station. The effect of fluctuations in the output of wind power and solar power generation is mitigated throughout the system by the leveling effect. For this reason, it is considered that the variation can be adjusted more efficiently by taking countermeasures for the entire system using the storage batteries for the system rather than separately arranging storage batteries at the power generation point.

  The consumer storage battery is a storage battery that is arranged for use of an emergency power source or late-night power in a household, a building, or a community. Consumer storage batteries are usually used based on the needs of consumers. However, if they can be used for power system control with limited use and timing, it will be an effective use of storage resources.

  As such, it does not distinguish between grid storage batteries and consumer storage batteries, acquires the charge / discharge capabilities of all grid-connected storage batteries, and uses the acquired charge / discharge capabilities to schedule the storage battery operation or charge / discharge There is one in which the amount is determined, the storage battery is controlled based on the determined operation schedule or charge / discharge amount, and the power system is controlled more efficiently (for example, see Patent Document 1).

JP 2006-94648 A

  However, in Patent Document 1, the operation schedule or the amount of charge / discharge is determined using the charge / discharge capabilities of all the storage batteries connected to the grid, and the storage battery is controlled. Since it controls separately with respect to a consumer storage battery, control becomes complicated.

  Moreover, although the storage battery for a system | strain requires large capacity | capacitance for system stabilization, the capacity | capacitance according to individual needs may be sufficient as a consumer storage battery. Furthermore, the grid storage battery can be freely charged / discharged according to the needs of the power supply command station, but the customer storage battery is given priority to charge / discharge according to the needs of the customer, and there are certain restrictions on the use of the power supply command station. Thus, it is further difficult to collectively control the storage batteries having different capacities and control degrees of freedom.

  Accordingly, an object of the present invention is to provide an electric power storage system that can efficiently control individual customer storage batteries and that can efficiently control the storage battery for the system and the customer storage battery in accordance with the needs of the power supply command center. It is to be.

  The power grid storage system according to the invention of claim 1 is formed by bundling a grid storage battery arranged in the power grid and a plurality of consumer storage batteries with a collection and distribution device, and controlling each customer storage battery with the collection and distribution device. And a power storage monitoring control device for controlling the storage battery for the system and the virtual storage battery according to a command from the power supply command station, the storage battery for the system responding to a command from the power storage monitoring control device in frequency Charge / discharge control for adjustment and economic load distribution is performed, and the virtual storage battery performs charge / discharge control for economic load distribution in response to a command from the power storage monitoring and control device.

  A power grid storage system according to a second aspect of the present invention is the power storage system according to the first aspect, wherein the power storage monitoring and control device outputs a reservation control command to the virtual storage battery on a specific day when surplus power is generated in the power system. The virtual storage battery responds to a reservation control command from the power storage monitoring and control device, and the collection and distribution device of the virtual storage battery performs scheduling control of the consumer storage battery.

  A power grid storage system according to a third aspect of the present invention is the power storage monitoring control device according to the first or second aspect, wherein the power storage monitoring control device is in a state in which the storage battery for the grid is not subjected to charge / discharge control for frequency adjustment or economic load distribution The system storage battery is periodically diagnosed.

  The electric power storage system according to the invention of claim 4 is the power storage system according to any one of claims 1 to 3, wherein the virtual storage battery collection and distribution device is an economy of each consumer storage battery of the virtual storage battery. The customer storage battery of each of the virtual storage batteries is periodically diagnosed in a state where charge / discharge control for load distribution and scheduling control are not performed.

  According to the first aspect of the present invention, a plurality of consumer storage batteries are bundled by a concentrator / distributor to form a virtual storage battery. The power storage monitoring and control device treats the virtual storage battery and the power storage battery equally, and the power storage battery controls the power storage monitoring control. Charge / discharge control for frequency adjustment is performed in response to the command from the device, and the virtual storage battery performs charge / discharge control for economic load distribution in response to the command from the power storage monitoring control device. Thus, the virtual storage battery and the system storage battery can be easily cooperatively controlled.

  According to the second aspect of the present invention, the virtual storage battery performs charge / discharge reservation control for absorbing the surplus power on a specific day when surplus power is generated in the power system, and in that case, the virtual storage battery collection and distribution device Since scheduling control is performed on the consumer storage battery, it is possible to control the economic load distribution in which surplus power of the power system is absorbed by the consumer storage battery.

  According to invention of Claim 3, since the storage battery for system | strains is diagnosed regularly, the characteristic change accompanying the secular change of the storage battery for system | strains can be grasped | ascertained. Therefore, the characteristics of the current system storage battery can be accurately grasped, and charge / discharge control of each system storage battery can be appropriately performed.

  According to invention of Claim 4, since each consumer storage battery of a virtual storage battery is diagnosed regularly, the characteristic change accompanying a secular change of a consumer storage battery can be grasped | ascertained. Accordingly, it is possible to accurately grasp the characteristics of the current consumer storage battery and appropriately perform charge / discharge control of each consumer storage battery.

The block diagram of the electric power grid | system electrical storage system which concerns on embodiment of this invention. The graph which shows an example of the electric power demand curve of 1 day. The graph which shows an example of the electric power demand curve and electric power supply curve of a special day.

  Embodiments of the present invention will be described below. FIG. 1 is a configuration diagram of an electric power storage system according to an embodiment of the present invention. The power supply command station 11 is responsible for power system operation. A power station group (not shown) connected to the power transmission system and a 1-to-N information communication network are provided to exchange information and supply and demand balance of power. I try to plan.

  In the embodiment of the present invention, the power supply command station 11 controls the plurality of system storage batteries 13a to 13n and the plurality of virtual storage batteries 14a to 14m installed in the power system via the power storage monitoring control device 12. It is configured to output a command.

  The system storage batteries 13a to 13n are storage batteries installed in the power system for system operation, and can be freely charged and discharged according to the needs of the power supply command center. The system storage batteries 13a to 13n are composed of a storage battery main body and an AC / DC converter PCS (Power Conditioning System). The storage battery main body is a battery main body that stores electric power, such as a sodium sulfur (NAS) battery, a lithium ion battery, or a nickel hydride battery, and the AC / DC converter PCS converts the AC power of the system into DC power to store the main body of the storage battery. It is a power conversion device that converts the DC power charged in the battery or the storage battery body into AC power and outputs it to the system.

  On the other hand, the virtual storage batteries 14a to 14m are formed by bundling a plurality of customer storage batteries 15 by the collection and distribution device 16, and are virtually handled as one storage battery. For example, in FIG. 1, the virtual storage battery 14a is formed by bundling two consumer storage batteries 15a1 and 15a2 with a collection / distribution device 16a, and the virtual storage battery 14b is composed of three consumer storage batteries 15b1, 15b2, and 15b3. It shows the case of being formed by bundling. The customer storage batteries 15 bundled by the collection / distribution device 16 may be collected for each arrangement area or for each equipment type. Similarly to the system storage battery 13, the consumer storage battery 15 includes a storage battery main body and an AC / DC converter PCS. As the storage battery main body, for example, a lithium ion battery or a nickel hydrogen battery is used. This battery includes not only a stationary battery but also an in-vehicle battery of an electric vehicle or a plug-in hybrid vehicle.

  Next, the power storage monitoring control device 12 controls the system storage battery 13 and the virtual storage battery 14 in accordance with a command from the power supply command station 11. For example, if there is a frequency adjustment or load adjustment command from the power supply command station 11, the power storage monitoring control device 12 outputs a command suitable for both the system storage battery 13 and the virtual storage battery 14.

  The system storage battery 13 performs charge / discharge control in response to a command from the power storage monitoring and control device 12 at a high speed (for example, in units of several seconds), and frequency adjustment that fluctuates in a period of about several minutes to about 20 minutes in the frequency fluctuation period. {Frequency control LFC (Load Frequency Control)} and load adjustment {Economic Load Dispatching (ELD)} that fluctuates with a period of several tens of minutes or more are shared. Furthermore, the storage battery 13 for system | strains may be used as an alternative of the governor free which adjusts output automatically by the generator side with respect to the load fluctuation | variation which fluctuates with a period of several minutes or less.

  On the other hand, the virtual storage battery 14 performs charge / discharge control in response to a command from the power storage monitoring and control device 12 at a low speed (for example, from several minutes to several tens of minutes). This is because the virtual storage battery 14 bundles a plurality of customer storage batteries 15 with the concentrator / distributor 16, until the usable capacity of the customer storage battery 15 is individually investigated and the usable capacity of the virtual storage battery 14 as a whole is grasped. This is because it takes time. The virtual storage battery 14 performs charge / discharge control of the customer storage battery 15 with the collector / distributor 16 for the insufficient economic load distribution by charge / discharge control in the system storage battery 13.

  FIG. 2 is a graph showing an example of a daily power demand curve. The power demand curve has a basic fluctuation component S1 that fluctuates in a cycle of several tens of minutes and a short-period fluctuation component S2 that fluctuates in a cycle of several minutes to 20 minutes. The charge / discharge control is performed so as to absorb the fluctuation of S2, and the virtual storage battery 14 performs the charge / discharge control mainly so as to absorb the fluctuation of the basic fluctuation component S1.

  In this way, a plurality of customer storage batteries 15 are bundled by the collection and distribution device 16 to form a virtual storage battery 14, and the power storage monitoring control device 12 treats the virtual storage battery 14 and the system storage battery 13 equally, and the system storage battery 13 stores power. Since it responds at high speed to the command from the monitoring control device 12, charge / discharge control for frequency adjustment can be performed. Since the virtual storage battery 14 responds at a low speed to the command from the power storage monitoring and control device 12, charge / discharge control for economic load distribution can be performed. Therefore, the virtual storage battery 14 including the customer storage battery 15 and the system storage battery 13 can be cooperatively controlled, and both the fluctuation of the basic fluctuation component S1 and the fluctuation of the short cycle fluctuation component S2 can be absorbed.

  Next, on a specific day when surplus power is generated in the power system, the power storage monitoring and control device 12 may output a reservation control command to the virtual storage battery 14 and perform scheduling control on the customer storage battery 15 of the virtual storage battery 14. .

  Surplus power may be generated in the power grid on Sundays and holidays. FIG. 3 is a graph showing an example of a power demand curve and a power supply curve on a specific day. As shown in FIG. 3, the power supply is based on the minimum output curve S10 of nuclear power generation, inflow-type hydropower generation, and thermal power generation, and operation exceeding the minimum output curve S10 in thermal power generation or pumping in a pumped storage power plant It responds to load fluctuations with power generation. Since thermal power generation has a minimum output curve S10 for maintaining output, for example, the water of a pumped storage power plant is pumped into the upper pond at night (from 23:00 to 7:00), and the minimum output of thermal power generation is maintained. . In recent years, solar power generation by a solar power generation facility has been introduced. Since the output of this solar power generation fluctuates depending on the weather, it works in the direction of increasing fluctuations rather than compensating for load fluctuations.

  Since the power demand on a specific day (for example, a holiday) decreases from that on weekdays, the power demand curve S11 may be lower than the power supply curve S12. Then, photovoltaic power is generated as surplus power. FIG. 3 shows a case where surplus power is generated from 10:00 to 19:00.

  Arranging the storage battery 13 for the system that can absorb all of such surplus power increases the burden on the electric power company. Therefore, when it can be predicted that surplus power will be generated, the power storage monitoring control device 12 outputs a reservation control command so that the virtual storage battery 14 absorbs the excess power that cannot be absorbed by the grid storage battery 13. When the collection / distribution device 16 of the virtual storage battery 14 receives a reservation control command from the power storage monitoring control device 12, the consumer storage battery 15 is subjected to scheduling control so as to absorb surplus power. Thereby, it is possible to control the economic load distribution in which surplus power of the power system is absorbed by the customer storage battery.

  Next, the power storage monitoring and control device 12 may periodically diagnose the system storage battery 13. Generally, the state of charge (SOC) of a lithium ion battery is managed by combining two of an open circuit voltage and an integrated current value. However, chemical batteries, not limited to lithium ion batteries, have a battery capacity that decreases with charge / discharge cycles and the passage of time, resulting in a difference between the SOC and the actual charge / discharge capacity. The degree of decrease in battery capacity is greatly influenced by the usage of the battery and the surrounding environment, so it is difficult to uniquely determine only by the charge / discharge cycle and aging parameters. Therefore, it is desirable to periodically diagnose the storage battery for the system, and the characteristics of each storage battery for each system can be efficiently diagnosed by centrally managing the storage battery for the storage system.

  The power storage monitoring and control device creates a state in which the storage battery for system 13 to be diagnosed is not subjected to charge / discharge control for frequency adjustment or economic load distribution. For example, it is performed in the midnight time zone when the operation rate is low. After the system storage battery 13 to be diagnosed is discharged to the discharge end voltage and the SOC is reduced to 0%, the battery capacity of the system storage battery 13 is confirmed when the SOC is charged to 100% by CC-CV charging, and the battery capacity is corrected. To do. Thereby, the characteristic change accompanying the secular change of the storage battery 13 for system | strains can be grasped | ascertained, and the characteristic of the current storage battery 13 for system | strains can be grasped | ascertained accurately. Therefore, charge / discharge control of each storage battery 13 can be appropriately performed.

  Similarly, the collection / delivery device 16 of the virtual storage battery 14 periodically diagnoses each customer storage battery 15 of the virtual storage battery 14. The diagnosis is performed, for example, in the late-night time period in a state where each customer storage battery 15 of the virtual storage battery 14 is not subjected to charge / discharge control or scheduling control for economic load distribution.

  Also, in the diagnosis method, as in the case of the grid storage battery 13, the consumer storage battery 15 to be diagnosed is discharged to the discharge end voltage, the SOC is reduced to 0%, and then charged to 100% SOC by CC-CV charging. The battery capacity of the consumer storage battery 15 at the time is confirmed and the battery capacity is corrected. Thereby, the characteristic change accompanying the secular change of the customer storage battery 15 can be grasped | ascertained, and the characteristic of the present customer storage battery 15 can be grasped | ascertained accurately. Therefore, charge / discharge control of each customer storage battery 15 can be performed appropriately.

DESCRIPTION OF SYMBOLS 11 ... Power supply command place, 12 ... Power storage monitoring control apparatus, 13 ... Storage battery for system | strain, 14 ... Virtual storage battery, 15 ... Consumer storage battery, 16 ... Collection delivery apparatus

Claims (4)

A storage battery for a system arranged in the power system, a virtual storage battery formed by bundling a plurality of customer storage batteries with a collection and distribution device and controlling each customer storage battery with the collection and distribution device, and a command from a power supply command center A power storage monitoring control device for controlling the storage battery for the system and the virtual storage battery, and the storage battery for the system performs charge / discharge control for frequency adjustment and economic load distribution in response to a command from the power storage monitoring control device. The virtual storage battery performs charge / discharge control for economic load distribution in response to a command from the power storage monitoring and control device. The storage monitoring control device outputs a reservation control command to the virtual storage battery on a specific day when surplus power is generated in the power system, and the virtual storage battery responds to the reservation control command from the storage monitoring control device, The electric power storage system according to claim 1, wherein the collection / delivery device of the virtual storage battery performs scheduling control of the consumer storage battery. 3. The power storage monitoring and control device periodically diagnoses the power storage battery in a state where the power storage battery is not subjected to charge / discharge control for frequency adjustment or economic load distribution. The power grid storage system described in 1. The virtual storage battery collecting and distributing device periodically sets the consumer storage batteries of each of the virtual storage batteries in a state where the consumer storage batteries of each of the virtual storage batteries are not subjected to charge / discharge control or scheduling control for economic load distribution. The electric power storage system according to any one of claims 1 to 3, characterized in that diagnosis is performed on a systematic basis.

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