WO2018135716A1

WO2018135716A1 - Energy storage device and energy storage system including same

Info

Publication number: WO2018135716A1
Application number: PCT/KR2017/008590
Authority: WO
Inventors: 이충우
Original assignee: 엘에스산전 주식회사
Priority date: 2017-01-19
Filing date: 2017-08-09
Publication date: 2018-07-26
Also published as: KR20180085453A; KR102197177B1

Abstract

The present invention relates to an energy storage device and an energy storage system including the same. An energy storage device according to an embodiment of the present invention provides an energy storage device connected to a plurality of distributed power generation systems and a grid, comprising: a plurality of power condition systems (PCSs) which manage power of the plurality of distributed power generation systems and the grid, and are connected to each other through a DC link; and a battery which is connected to the DC link, and is charged or discharged by the plurality of PCSs.

Description

Energy storage device and energy storage system comprising the same

The present invention relates to an energy storage device and an energy storage system including the same.

Energy Storage System is a system that saves the generated power in each linked system including power plants, substations and transmission lines, and then uses it selectively and efficiently when the power is needed to increase energy efficiency.

When the energy storage system improves the overall load rate by leveling the electric load with large fluctuations in time and season, it can lower the cost of generating power and reduce the investment cost and operation cost required for the expansion of electric power facilities. can do.

These energy storage systems are installed and used in power generation, transmission and distribution, and customers in the power system, and include frequency regulation, stabilization of generator output using renewable energy, peak shaving, and load leveling. It is used as a function of emergency power.

Energy storage systems can be classified into physical energy storage and chemical energy storage. Physical energy storage includes a method using pumped power generation, compressed air storage, flywheel, etc., and chemical energy storage includes a method using a lithium ion battery, a lead acid battery, and a Nas battery.

On the other hand, a power system that generates power in such an energy storage system, in particular, a renewable energy system has a problem that it is difficult to predict the power flow due to the unstable output. In addition, when a power supply system (i.e., a distributed power supply system) is distributed in various regions, an energy storage device is installed near each power supply system to assist the power output of the power supply system.

1 and 2, conventional energy storage devices E1 and E2 are shown.

1 is a view for explaining a conventional energy storage device, Figure 2 is a view for explaining the PCS of FIG.

1 and 2, the conventional energy storage devices E1 and E2 are connected to distributed power supply systems DG1 and DG2, respectively.

Accordingly, the first distributed power supply system DG1 may be managed by a first power condition system (PCS) 60a. In addition, the power generated in the first distributed power supply system DG1 may be stored in the first battery 70a or provided to the grid GRID or the first load L1. Of course, the first PCS 60a may transfer power stored in the first battery 70a to the grid GRID or the first load L1, and transmit power supplied from the grid GRID to the first battery 70a. Can also be stored in

Similarly, the second distributed power supply system DG2 may be managed with a power state by the second PCS 60b. In addition, the power generated by the second distributed power supply system DG2 may be stored in the second battery 70b or provided to the grid GRID or the second load L2. Of course, the second PCS 60b may transfer the power stored in the second battery 70b to the grid GRID or the second load L2, and transfer the power supplied from the grid GRID to the second battery 70b. Can also be stored in

Specifically, referring to FIG. 2, a control scheme of the PCS (either the first PCS 60a or the second PCS 60b) is illustrated.

That is, the PCS is based on the active power command value P_ref * and the actual measured active power value P_pcs received from the host controller 5 (for example, PMS (Power Management System) or EMS (Energy Management System)). The active power controller 20 and the integrator 25 are used to generate the q-axis current command value Iq_ref.

In addition, the PCS uses the reactive power controller 10 and the integrator 15 based on the reactive power command value Q_ref * and the actual measured reactive power value Q_pcs received from the host controller 5 to determine the d-axis current command value ( Id_ref).

In addition, the PCS inputs the actual measured three-phase voltages Va, Vb, and Vc into a phase locked loop 35 and the actual measured three-phase currents Ia, Ib, and Ic. ) Is input to the coordinate transformation unit 40 to extract the normal portions (Idq_pcs).

After that, the PCS obtains the final voltage command values Vd_ref * and Vq_ref * through the current controller 30 using the q-axis current command value Iq_ref *, the d-axis current command value Id_ref * and the normal value Idq_pcs. .

The final voltage command values Vd_ref * and Vq_ref * obtained as described above are extracted from the three-phase voltage command values Va_ref *, Vb_ref * and Vc_ref * through the coordinate axis inverse transform unit 45, and the extracted three-phase voltage command values ( Va_ref *, Vb_ref *, and Vc_ref *) are provided to a pulse width modulation (PWM) generator 50 to produce a final output.

Through this process, the charge / discharge of the battery may be controlled by the final output generated by the PCS.

However, referring back to FIG. 1, when an accident (for example, a power failure) occurs in the grid GRID, the first switch SW1 and the second switch SW2 are cut off, and the first distributed power system DG1. ), The operations of the second distributed power supply system DG2, the first PCS 60a, and the second PCS 60b are generally stopped.

For example, even when the first distributed power supply system DG1 and the second distributed power supply system DG2 operate, power supply of the first distributed power supply system DG1 and the second distributed power supply system DG2 becomes unstable.

That is, when the first switch SW1 and the second switch SW2 are disconnected, at least one of the first distributed power supply system DG1 and the first battery 70a supplies power to the first load L1. At least one of the second distributed power supply system DG2 and the second battery 70b supplies power to the second load L2.

As a result, the first distributed power supply system DG1 and the second distributed power supply system DG2 may have more power supply than usual, which may cause a problem in power quality.

In addition, when a power supply problem occurs in any one of the first distributed power supply system DG1 and the second distributed power supply system DG2, if the power of the battery connected to the distributed power supply system is insufficient, the power supply of the distributed power supply system There is a problem that the problem is difficult to solve.

When the grid GRID is disconnected, there is a problem in that power of an external device passing through the grid GRID is not transmitted.

In addition, the PCS also has a problem that it is difficult to solve the above problems that may occur in the system (GRID) accident by the conventional control method.

The present invention provides an energy storage system and an energy storage system including the same, which can solve the power supply problem of the distributed power supply system by operating the PCS independently as a voltage source when a problem occurs in the system and the connection between the system and the PCS is cut off. It aims to do it.

In addition, the present invention provides an energy storage system and an energy storage system including the same, the power storage of the external device passing through the system is passed through the plurality of PCS connected through the DC link, the power supply is smoothly maintained when the system is disconnected It aims to provide.

In order to achieve the above object, the energy storage device of the present invention is an energy storage device connected to a plurality of distributed power systems and systems, and manages power of the plurality of distributed power systems and systems, and through a direct current (DC) link. A plurality of power condition systems (PCSs) connected to each other; And a battery connected to the DC link and charged or discharged by the plurality of PCS.

The plurality of PCS includes a first PCS and a second PCS, the first PCS, one end is connected to any one of the plurality of distributed power supply system, the other end is connected to the second PCS via a DC link, the second One end of the PCS is connected to the other of the plurality of distributed power supply systems, and the other end is connected to the first PCS through the DC link.

When the connection between the system and the plurality of PCS is interrupted, the plurality of PCS provides power stored in the battery to the plurality of distributed power supply systems.

When the connection between the system and the plurality of PCS is cut off, the plurality of PCSs are driven based on the voltage reference value and the frequency reference value of the system provided from the host controller.

The power of the external device provided from one point to another point via the grid is provided to another point via a plurality of PCS at one point when the system is disconnected.

In order to achieve the above object, the energy storage system of the present invention manages power of a plurality of distributed power supply systems, a plurality of distributed power supply systems and systems connected to a grid, a grid, and generates power, and is connected to each other through a DC link. It includes a battery connected to a plurality of PCS (Power Condition System) and DC link, and charged or discharged by the plurality of PCS.

The plurality of distributed power supply systems include a first distributed power supply system and a second distributed power supply system, the plurality of PCSs include a first PCS and a second PCS, and the first PCS has one end connected to the first distributed power supply system. The other end is connected to the second PCS through the DC link, the second PCS, one end is connected to the second distributed power supply system, the other end is connected to the first PCS through the DC link.

A battery management system (BMS) for monitoring a state of the battery and controlling charging and discharging of the battery, and a PMS (power management system) for controlling a plurality of PCSs based on data related to the battery provided from the BMS; And an EMS (Energy Management System) for generating information on battery maintenance and repair based on data on the battery provided from the PMS and providing information on maintenance and repair of the generated battery to the BMS through the PMS. do.

The plurality of PCSs are connected to the system and the plurality of distributed power systems, and when the connection between the system and the plurality of PCSs is cut off, the plurality of PCSs are driven based on the voltage reference value and the frequency reference value of the system provided from the PMS or EMS.

According to the present invention as described above, in the event of a system accident, the PCS is independently driven by a voltage source to supply power to the distributed power system or to act as a transmission line to maintain the power supply smoothly and to solve the problems that may occur during a system accident There is this.

In addition to the effects described above, the specific effects of the present invention will be described together with the following description of specifics for carrying out the invention.

1 is a view for explaining a conventional energy storage device.

FIG. 2 is a diagram for explaining the PCS of FIG. 1.

3 is a view illustrating an energy storage device according to an embodiment of the present invention.

4 and 5 are diagrams illustrating how the energy storage device of FIG. 3 is driven when a problem occurs in a system.

FIG. 6 is a diagram illustrating a method in which the PCS of FIG. 3 is controlled when a problem occurs in a system.

7 is a view for explaining an energy storage system according to another embodiment of the present invention.

8 is a view for explaining an energy storage system according to another embodiment of the present invention.

The above objects, features, and advantages will be described in detail with reference to the accompanying drawings, whereby those skilled in the art to which the present invention pertains may easily implement the technical idea of the present invention. In describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

Hereinafter, the energy storage device 100 according to an embodiment of the present invention will be described with reference to FIGS. 3 to 6.

3 is a view illustrating an energy storage device according to an embodiment of the present invention. 4 and 5 are diagrams illustrating how the energy storage device of FIG. 3 is driven when a problem occurs in a system. FIG. 6 is a diagram illustrating a method in which the PCS of FIG. 3 is controlled when a problem occurs in a system.

First, referring to FIG. 3, an energy storage device 100 according to an embodiment of the present invention may include a plurality of PCSs PCS1 and PCS2 and a battery 104. For reference, the energy storage device 100 is connected to the plurality of distributed power systems DG1 and DG2 and the grid GRID.

The plurality of

PCSs

101a and 101b manage power of the plurality of distributed power supply systems DG1 and DG2 and the grid GRID, and may be connected to each other through a direct current link 103.

In detail, the plurality of

PCSs

101a and 101b may include a first PCS 101a and a second PCS 101b.

The first PCS 101a may store the power generated in the first distributed power supply system DG1 in the battery 104, or may transfer the generated power to the grid GRID and the first load L1. In addition, the first PCS 101a may transmit power stored in the battery 104 to the grid GRID or the first load L1. The first PCS 101a may store the power supplied from the grid GRID in the battery 104.

In addition, the first PCS 101a may control the charging and discharging of the battery 104 based on the state of charge (hereinafter, referred to as “SOC level”) of the battery 104, and the DC link 103. It may be connected to the second PCS (101b) through.

That is, one end of the first PCS 101a may be connected to the first distributed power supply system DG1, and the other end thereof may be connected to the second PCS 101b through the DC link 103.

In addition, the first PCS 101a may use an energy storage system (eg, FIG. 7 of FIG. 7) based on the power price of the power market, the power generation plan of the first distributed power supply system DG1, the amount of power generated, and the power demand of the grid GRID. A schedule for the operation of 200 may be generated. Details thereof will be described later.

The second PCS 101b may store power generated in the second distributed power supply system DG2 in the battery 104, or may transfer the generated power to the grid GRID and the second load L2. In addition, the second PCS 101b may transfer power stored in the battery 104 to the grid GRID or the second load L2. The second PCS 101b may store the power supplied from the grid GRID in the battery 104.

In addition, the second PCS 101b may control the charging and discharging of the battery 104 based on the state of charge (hereinafter, referred to as “SOC level”) of the battery 104, and the DC link 103. It may be connected to the first PCS 101a through.

That is, one end of the second PCS 101b may be connected to the second distributed power supply system DG2, and the other end thereof may be connected to the first PCS 101a through the DC link 103.

In addition, the second PCS 101b may use an energy storage system (eg, FIG. 7 of FIG. 7) based on the power price of the power market, the power generation plan of the second distributed power supply system DG2, the amount of power generated, and the power demand of the grid GRID. A schedule for the operation of 200 may be generated. Details thereof will be described later.

The battery 104 is connected to the DC link 103 and may be charged or discharged by the plurality of

PCSs

101a and 101b.

In detail, the battery 104 may receive and store at least one of the powers of the first distributed power supply system DG1, the second distributed power supply system DG2, and the grid GRID, and store the stored power in the grid GRID, One or more of the first load L1 and the second load L2 may be supplied. Of course, the power stored in the battery 104 may be provided to the first distributed power supply system DG1 or the second distributed power supply system DG2 during a GRID accident. The battery 104 may include at least one battery cell, and each battery cell may include a plurality of bare cells.

For reference, the first distributed power supply system DG1 and the second distributed power supply system DG2 are connected to the grid GRID and are spaced apart from each other as a system for generating power using an energy source. That is, the first distributed power supply system DG1 and the second distributed power supply system DG2 may be located in separate locations from each other, but may be located closer to each other than the other distributed power supply systems.

The first distributed power supply system DG1 and the second distributed power supply system DG2 may generate electric power using at least one of fossil fuel, nuclear fuel, and renewable energy. For example, the first distributed power supply system DG1 and the second distributed power supply system DG2 may be renewable power generation systems using renewable energy such as photovoltaic power generation systems, wind power generation systems, and tidal power generation systems.

GRID can include power plants, substations, power lines, and the like. The grid GRID may supply power to at least one of the first PCS 101a, the second PCS 101b, the first load L1, and the second load L2 when the grid GRID is in a steady state. Power may be supplied from 101a or the second PCS 101b.

On the other hand, when the grid GRID is in an abnormal state, it becomes difficult to supply power to at least one of the first PCS 101a, the second PCS 101b, the first load L1, and the second load L2. It may be difficult to receive power from the first PCS 101a or the second PCS 101b.

The first load L1 receives power from at least one of the first distributed power supply system DG1, the battery 104, and the grid GRID, and consumes the supplied power. In addition, the second load L2 receives power from at least one of the second distributed power supply system DG2, the battery 104, and the grid GRID, and consumes the supplied power.

For example, the first load L1 and the second load L2 may include a home, a large building, a factory, and the like.

4, a case where an accident occurs in the grid GRID and the connection between the grid GRID and the plurality of

PCSs

101a and 101b is broken.

Specifically, FIG. 4 illustrates a state in which an accident occurs in the grid GRID, so that the first switch SW1 and the second switch SW2 are switched to an off state (that is, cut off).

Conventionally, when an accident occurs in the system GRID, the first switch SW1 and the second switch SW2 are cut off, and the first distributed power supply system DG1, the second distributed power supply system DG2, and the first switch SW1 are shut off. The operation of the 1 PCS 101a and the 2nd PCS 101b was stopped. Accordingly, problems such as power supply disruption and cost loss also occur.

However, in the energy storage device 100 of the present invention, when an accident occurs in the system GRID and the first switch SW1 and the second switch SW2 are cut off, the first PCS 101a and the second PCS. 101b can be driven independently through the control algorithm (method) shown in FIG. Accordingly, the first distributed power supply system DG1, the second distributed power supply system DG2, the first load L1, and the second load L2 recognize that the grid GRID is connected as before. Can be driven.

That is, when an accident occurs in the grid GRID, the first PCS 101a and the second PCS 101b may be driven as voltage sources, respectively.

Here, the first PCS 101a and the second PCS 101b may be configured with a voltage reference value of a grid GRID provided from an upper control device (for example, PMS (Power Management System) or EMS (Energy Management System)). Can be driven independently based on the frequency reference value, the details thereof will be described later.

As a result, the first PCS 101a and the second PCS 101b can normally charge or discharge the battery 104 within the rated range.

In the drawing shown in FIG. 4, when an accident occurs in the grid GRID, the first PCS 101a provides the first distributed power supply system DG1 with power stored in the battery 104 through independent operation. For example, it is illustrated that the second PCS 101b provides power stored in the battery 104 to the second distributed power supply system DG2 through independent operation.

Meanwhile, referring to FIG. 5, the system GRID is disconnected.

When the grid GRID is disconnected, the first PCS 101a and the second PCS 101b are driven independently through the control algorithm (method) shown in FIG. 6, as mentioned in FIG. Power may be provided to the distributed power supply system DG1 and the second distributed power supply system DG2, but may also serve as a power transmission line as shown in FIG. 5.

That is, when the grid GRID is disconnected, power of an external device (not shown) that has previously passed through the grid GRID may bypass the grid GRID through the plurality of

PCSs

101a and 101b. .

More specifically, the power of an external device (not shown) provided to the other point via the grid GRID at one point may cause the plurality of

PCSs

101a and 101b to be disconnected at the point when the grid GRID is disconnected. It may be provided to the other point through.

Here, referring to FIG. 6, a method in which the first PCS 101a and the second PCS 101b are controlled when an accident occurs in the system GRID or the system GRID is disconnected.

For example, the control method of the first PCS 101a will be described below. For reference, since the second PCS 101b is also driven in the same manner as the first PCS 101a, a detailed description thereof will be omitted.

First, when the first PCS 101a operates as a voltage source, since there is no reference for the voltage and frequency of the grid GRID, the first PCS 101a includes the host controller 105 (for example, PMS or EMS). ) Can receive the voltage command value Vac_ref * of the system GRID and the actually measured voltage value Vac_inv. The first PCS 101a uses the second controller 120 and the integrator 125 based on the voltage command value Vac_ref * and the actually measured voltage value Vac_inv of the received grid GRID to provide the q-axis current command value. You can create (Iq_ref *).

In addition, the first PCS 101a may receive the frequency command value F_ref * and the actually measured frequency value F of the system GRID from the upper controller 105. The first PCS 101a uses the first controller 110 and the integrator 115 based on the received frequency command value F_ref * and the actually measured frequency value F of the grid GRID. You can create (Id_ref *).

That is, the host controller 105 calculates the voltage (eg, rated voltage) and the frequency (eg, rated frequency) of the grid (GRID) in advance in preparation for the grid (GRID) accident by first calculating the PCS 101a. Can be provided to

In addition, the first PCS 101a inputs the actual measured three-phase voltages Va_inv, Vb_inv, and Vc_inv to the phase locked loop 135, and the measured three-phase currents Ia_inv, Ib_inv, and Ic_inv. ) Is input to the coordinate axis conversion unit 140 to extract the normal part Idq_inv. Thereafter, the first PCS 101a uses the q-axis current command value Iq_ref *, the d-axis current command value Id_ref *, and the normal value Idq_inv to determine the final voltage command values Vd_ref * and Vq_ref through the current controller 130. Acquire *). The final voltage command values Vd_ref * and Vq_ref * obtained as described above are extracted from the three-phase voltage command values Va_ref *, Vb_ref * and Vc_ref * through the coordinate axis inverse transform unit 145, and the extracted three-phase voltage command values ( Va_ref *, Vb_ref *, Vc_ref *) are provided to the PWM generator 150 to produce the final output. Through this process, the first PCS 101a may be driven independently to serve as a voltage source.

As described above, in the energy storage device 1 according to the embodiment of the present invention, the first PCS 101a and the second PCS 101b connected through the DC link 103 in a system accident are independently driven as a voltage source. By supplying power to the first distributed power supply system DG1 and the second distributed power supply system DG2, respectively, or by acting as a power transmission line, the power supply can be maintained smoothly and problems that may occur in a system accident can be solved.

In addition, since the energy storage device 1 according to the exemplary embodiment of the present invention is managed by one host controller (for example, PMS or EMS) at the same time, power flow can be easily confirmed even in a system unit.

In addition, in the energy storage device 1 according to an embodiment of the present invention, the first PCS 101a and the second PCS 101b are connected through the DC link 103 to be implemented in a microgrid manner, thereby being distributed. If there is a problem in power supply of one of the power supply systems, there is an advantage that the power generated by the other distributed power supply system can supply the necessary power.

Hereinafter, an energy storage system 200 according to another embodiment of the present invention will be described with reference to FIG. 7.

For reference, the energy storage system 200 according to another embodiment of the present invention includes the energy storage device 100 according to an embodiment of the present invention, and thus description of the energy storage device 100 will be omitted. .

Referring to FIG. 7, the energy storage system 200 according to another embodiment of the present invention may include a grid GRID, a plurality of distributed power supply systems DG1 and DG2, an energy storage device 100, and a first switch SW1. , The second switch SW2, the first load L1, the second load L2, the battery management system 160, the power management system 170, and the energy management system EMS 180. ) May be included.

The grid GRID, the plurality of distributed power systems DG1 and DG2, the energy storage device 100, the first switch SW1, the second switch SW2, the first load L1, and the second load L2. Description of the bar is described above, it will be omitted.

The BMS 160 may monitor the state of the battery 104 and control charging and discharging operations of the battery 104. The BMS 160 may also monitor the state of the battery 104, including the SOC level being the state of charge of the battery 104, and monitor the state of the monitored battery 104 (eg, voltage, current, temperature, residuals). Power amount, lifetime, state of charge, etc.) may be provided to the first PCS 101a and the second PCS 101b.

In addition, the BMS 160 may perform a protection operation to protect the battery 104. For example, the BMS 160 may perform one or more of an overcharge protection function, an over discharge protection function, an overcurrent protection function, an overvoltage protection function, an overheat protection function, and a cell balancing function for the battery 104.

In addition, the BMS 160 may adjust the SOC level of the battery 104.

In detail, the BMS 160 may receive a control signal from the first PCS 101a or the second PCS 101b and adjust the SOC level of the battery 104 based on the received signal.

The PMS 170 may control the plurality of

PCSs

101a and 101b based on data related to the battery 104 received from the BMS 160.

In detail, the PMS 170 may monitor the state of the battery 104 and may monitor the state of the plurality of

PCSs

101a and 101b. That is, the PMS 170 may control the plurality of

PCSs

101a and 101b based on the respective efficiency based on the data related to the battery 104 received from the BMS 160.

In addition, the PMS 170 may provide the EMS 180 with data related to the battery 104 collected by monitoring the state of the battery 104 through the BMS 160.

The EMS 180 generates information about the maintenance and repair of the battery 104 based on data about the battery 104 received from the PMS 170, and the information about the maintenance and repair of the generated battery 104. May be provided to the BMS 160 through the PMS 170.

Energy storage system 200 according to another embodiment of the present invention can manage the power of the grid (GRID) and a plurality of distributed power system (DG1, DG2) through the configuration as described above, accidents in the grid (GRID) Is generated and the connection between the system GRID and the plurality of

PCSs

101a and 101b is interrupted, the plurality of

PCSs

101a and 101b are connected to the system GRID provided from the PMS 170 or the EMS 180. It can be driven independently based on the voltage reference value and the frequency reference value.

Hereinafter, an energy storage system 300 according to another embodiment of the present invention will be described with reference to FIG. 8.

For reference, the energy storage system 300 according to another embodiment of the present invention includes the energy storage system 200 according to another embodiment of the present invention.

Referring to FIG. 8, in the energy storage system 300 according to another embodiment of the present invention, two energy storage systems as shown in FIG. 7 may exist in parallel.

Accordingly, the energy storage system 300 includes the energy storage device 400, the second BMS 460, the third load L3, the fourth load L4, the third switch SW3, and the fourth switch SW4. ), A third distributed power supply system DG3, and a fourth distributed power supply system DG4.

However, two parallel energy storage systems are characterized in that only one grid (GRID), PMS (570), EMS (580) in common.

That is, in the energy storage system 300 according to another embodiment of the present invention, since only one grid (GRID), PMS 570, and EMS 580 exist in common, each energy storage system may be efficiently managed. have. In addition, stable power supply and management are possible for distributed power supply systems DG1 to DG4 distributed in a larger area than the energy storage system 200 of FIG. 7.

Of course, there may be a plurality of PMS 570, EMS 580, a plurality of grids (GRID), respectively, a configuration such as the energy storage system of FIG. Although there may exist a configuration in which a plurality of energy storage systems are connected in parallel, in the present invention, the energy storage system 300 shown in FIG. 8 will be described for convenience of description.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by.

Claims

An energy storage device connected to a plurality of distributed power systems and grids,

A plurality of power condition systems (PCSs) that manage power of the plurality of distributed power systems and the system and are connected to each other through a direct current (DC) link; And

A battery coupled to the DC link, the battery being charged or discharged by the plurality of PCS

Energy storage devices.
The method of claim 1,

The plurality of PCS includes a first PCS and a second PCS,

The first PCS, one end is connected to any one of the plurality of distributed power supply system, the other end is connected to the second PCS through the DC link,

The second PCS, one end is connected to the other of the plurality of distributed power supply system, the other end is connected to the first PCS through the DC link

Energy storage devices.
The method of claim 1,

When the connection between the system and the plurality of PCS is interrupted, the plurality of PCS provides the plurality of distributed power supply systems with the power stored in the battery.

Energy storage devices.
The method of claim 1,

When the connection between the system and the plurality of PCS is cut off, the plurality of PCSs are driven based on the voltage reference value and the frequency reference value of the system provided from the host controller.

Energy storage devices.
According to claim 1,

The power of the external device provided to the other point via the system at one point is provided to the other point via the plurality of PCS at the one point when the system is disconnected.

Energy storage devices.
system;

A plurality of distributed power systems coupled to the grid and producing power;

A plurality of power condition systems (PCSs) managing power of the plurality of distributed power supply systems and the system and connected to each other via a DC link; And

A battery coupled to the DC link, the battery being charged or discharged by the plurality of PCS

Energy storage system.
The method of claim 6,

The plurality of distributed power supply systems include a first distributed power supply system and a second distributed power supply system,

The plurality of PCS includes a first PCS and a second PCS,

The first PCS, one end is connected to the first distributed power system, the other end is connected to the second PCS through the DC link,

The second PCS has one end connected to the second distributed power supply system and the other end connected to the first PCS through the DC link.

Energy storage system.
The method of claim 6,

A battery management system (BMS) for monitoring a state of the battery and controlling charging and discharging operations of the battery;

A power management system (PMS) for controlling the plurality of PCSs based on data associated with the battery provided from the BMS; And

EMS (Energy) for generating information on the maintenance and repair of the battery based on the data about the battery received from the PMS, and providing information on the maintenance and repair of the generated battery to the BMS via the PMS Management System)

Energy storage system.
The method of claim 8,

The plurality of PCSs are connected to the system and the plurality of distributed power systems,

When the connection between the system and the plurality of PCS is cut off, the plurality of PCSs are driven based on the voltage reference value and the frequency reference value of the system provided from the PMS or the EMS.

Energy storage system.