KR20160080914A - Micro Grid System for Grid-Connection of Energy Storage System and Method for Grid-Connection Energy Storage System USING THE SAME - Google Patents

Micro Grid System for Grid-Connection of Energy Storage System and Method for Grid-Connection Energy Storage System USING THE SAME Download PDF

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Publication number
KR20160080914A
KR20160080914A KR1020140192710A KR20140192710A KR20160080914A KR 20160080914 A KR20160080914 A KR 20160080914A KR 1020140192710 A KR1020140192710 A KR 1020140192710A KR 20140192710 A KR20140192710 A KR 20140192710A KR 20160080914 A KR20160080914 A KR 20160080914A
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South Korea
Prior art keywords
grid
energy storage
storage device
power
voltage
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KR1020140192710A
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Korean (ko)
Inventor
김윤현
홍종석
권병기
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주식회사 포스코아이씨티
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Publication of KR20160080914A publication Critical patent/KR20160080914A/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
    • H02J2003/365—Reducing harmonics or oscillations in HVDC
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

A micro grid system for grid connection of an energy storage device according to one aspect of the present invention which can continuously and stably supply power to a load includes an energy storage device for storing power or discharging the stored power to supply to a load; A synchronization detecting device for measuring an output voltage of the energy storage device and a system voltage of the power system and obtaining a phase angle difference, a frequency difference, and a size difference between the measured output voltage and the system voltage; And, if the power system is normal, synchronizing the output voltage with the grid voltage using the obtained phase angle difference, frequency difference, and magnitude difference, and controlling the energy storage device to be connected to the power system And a device.

Figure P1020140192710

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a micro grid system for grid connection of an energy storage device,

The present invention relates to an energy storage device, and more particularly to a microgrid system including an energy storage device.

With the development of the industry, the demand for electric power is increasing, and the gap of electricity use between day and night, season, and day is increasing. In recent years, various technologies have been developed to supply power stably even when a peak load occurs or an abnormality occurs in a power system due to temporary load burden.

As one of these technologies, a micro-grid system capable of self-sustaining power using an energy storage device is emerging as a new alternative.

1, a general micro grid system 100 includes a small-scale power grid 110 consisting of a renewable energy source 110 such as solar, wind, tidal, hydraulic, etc., an energy storage device 120, And it can be connected to the external large-scale power system 140 via the grid interrupter 135, or can be operated independently.

More specifically, microgrid system 100 may supply power from power system 140 in conjunction with power system 140. The micro grid system 100 may disconnect the grid interrupter 135 from the power system 140 and supply power to the load 130 independently when a peak load or an accident occurs in the power system 140 .

At this time, the micro grid system supplies the power generated by the renewable energy source 110 to the load 130, supplies the power to the load 130, and stores the remaining power in the energy storage device 120. Further, the micro grid system 100 may discharge the power stored in the energy storage device 120 and supply the power to the load 130 when the power is insufficient.

When the power system 140 is restored, the micro grid system 100 stops the operation of the energy storage device 120, turns on the grid interrupter 135, and connects the power system 140 to the power system 140 again.

As described above, the conventional micro grid system 100 stops the operation of the energy storage device 120 in order to associate with the power system 140. When the operation of the energy storage device 120 is stopped, There is a problem that power is not supplied to the load 130 because the output is also stopped together with the circle 1120. [ Such a problem is caused by a serious load such as a medical facility or a server of a hospital, which may lead to a risk of life and loss of important data.

In addition, since the conventional micro grid system 100 inputs the grid interrupter 135 without synchronizing the output voltage of the energy storage device 120 with the grid voltage, the inrush current flows very much, And the like.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is a technical object of the present invention to provide a micro grid system for grid connection of an energy storage device which can receive power continuously and stably to a load.

Another object of the present invention is to provide a micro grid system for grid connection of an energy storage device capable of continuously supplying power to a load even if a part of a plurality of energy storage devices is discharged or operation is stopped.

According to an aspect of the present invention, there is provided a micro grid system for grid connection of an energy storage device, comprising: an energy storage device for storing power or discharging the stored power to supply a load; A synchronization detecting device for measuring an output voltage of the energy storage device and a system voltage of the power system and obtaining a phase angle difference, a frequency difference, and a size difference between the measured output voltage and the system voltage; And, if the power system is normal, synchronizing the output voltage with the grid voltage using the obtained phase angle difference, frequency difference, and magnitude difference, and controlling the energy storage device to be connected to the power system And a device.

According to the present invention, by synchronizing the output voltage of the energy storage device and the grid voltage, the inrush current does not occur even when the energy storage device is connected to the power system without stopping, so that the power can be continuously and stably supplied to the load .

In addition, the present invention can supply power continuously to a load by designating at least one of a plurality of energy storage devices to adjust the voltage, and replacing the designated energy storage device with another energy storage device when the specified energy storage device is discharged or stopped, Can be improved.

1 is a view showing a configuration of a micro grid system according to the prior art.
2 is a diagram illustrating a configuration of a micro grid system according to an embodiment of the present invention.
3 is a configuration diagram for explaining the synchronization detecting device of FIG.
FIG. 4 is a configuration diagram illustrating the power management apparatus of FIG. 2. FIG.
5 is a flowchart illustrating a grid connection method of an energy storage device using a micro grid system according to an embodiment of the present invention.
6 is a diagram illustrating a method of synchronizing an output voltage and a system voltage according to an embodiment of the present invention.

The meaning of the terms described herein should be understood as follows.

The word " first, "" second," and the like, used to distinguish one element from another, are to be understood to include plural representations unless the context clearly dictates otherwise. The scope of the right should not be limited by these terms.

It should be understood that the terms "comprises" or "having" does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

It should be understood that the term "at least one" includes all possible combinations from one or more related items. For example, the meaning of "at least one of the first item, the second item and the third item" means not only the first item, the second item or the third item, but also the second item and the second item among the first item, Means any combination of items that can be presented from more than one.

Hereinafter, the same components will be denoted by the same reference numerals for convenience of description.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a diagram illustrating a configuration of a micro grid system according to an embodiment of the present invention.

Before describing the configuration of the micro grid system according to the present invention, the power flow in the micro grid system will be briefly described.

The micro-grid 200 according to an embodiment of the present invention operates in either the grid connection mode or the independent operation mode depending on whether the micro grid 200 is connected to the power system 210 or not. The power system 210 supplies power to the load 220 and may include a power plant, a substation, and a transmission line.

Specifically, in the grid-connected mode, the microgrid system 200 is connected to the power system 210. The micro grid system 200 supplies a part of the power generated by the renewable energy source 230 to the power system 210 or receives power from the power system 210.

Here, the renewable energy source 230 is a device for generating electric power by using renewable energy. For example, the renewable energy source 230 includes a wind power generation device that generates electric power by using wind energy, a solar power A hydropower generator for generating electric power by using hydroelectric energy, and a tidal generator for generating electric power by using tidal energy.

The micro grid system 200 supplies the power supplied from the power system 210 to the load 220 and stores the remaining power in the energy storage device 240. The micro grid system 200 supplies the power generated by the renewable energy source 230 to the power system 210 or the load 220 and stores the remaining power in the energy storage device 240.

Meanwhile, when an error occurs in the power system 210 during the operation in the grid connection mode, the micro grid system 200 disconnects the grid connection interrupter 215 from the power system 210 and operates in the independent operation mode .

In the independent operation mode, the micro grid system 200 independently supplies the power generated by the renewable energy source 230 to the load 220, and stores the remaining power in the energy storage device 240.

In addition, when the power generated by the renewable energy source 230 is insufficient, the micro grid system 200 discharges the power stored in the energy storage device 240 and supplies the power to the load 220 to satisfy the insufficient power.

Accordingly, the micro grid system 200 can supply the electric power generated by the renewable energy source 230 and the electric power stored in the energy storage device 240 to the load 220, even if an abnormality occurs in the power system 210, So that power can be continuously supplied to the load 220 even in an emergency.

Meanwhile, when the power system 210 is restored to the normal state, the micro grid system 200 turns on the grid interrupter 215 and reconnects to the power system 210, and operates in the grid interconnection mode again.

Hereinafter, the operation of each component included in the micro grid system 200 when the micro grid system 200 is switched from the independent operation mode to the grid connection mode will be described in detail.

2, the micro grid system 200 according to an exemplary embodiment of the present invention includes an energy storage device 240, a synchronization detection device 250, a power management system (PMS) 250, , And an energy management system (EMS, 270).

The energy storage device 240 is set to either the grid connection mode or the independent operation mode to store power or to discharge the stored power to the load 220. [

When an error occurs in the power system 210, the energy storage device 240 operates in the independent operation mode under the control of the power management device 260. At this time, the energy storage device 240 performs voltage control at a rated voltage and a rated frequency to store electric power, or discharges the stored electric power to supply the electric power to the load 220.

More specifically, the energy storage device 240 receives and stores power from the renewable energy source 230. At this time, the stored power corresponds to the remaining power supplied to the load 220 among the power generated by the renewable energy source 230. [

In addition, when the power generated by the renewable energy source 230 is insufficient, the energy storage device 240 discharges the stored power to supply power to the load 220.

Meanwhile, when the power system 210 is restored to the normal state, the energy storage device 240 is switched from the independent operation mode to the grid connection mode under the control of the power management device 260. The energy storage device 240 performs current control to store electric power, or discharges the stored electric power to supply the electric energy to the load 220.

More specifically, the energy storage device 240 receives and stores power from at least one of the power system 210 and the renewable energy source 230. At this time, the stored power corresponds to the remaining power supplied from the power system 210 or supplied to the load 220 among the power produced by the renewable energy source 230.

Also, the energy storage device 240 discharges the stored power to supply the load 220 with insufficient power. That is, when the power required in the load 220 exceeds the power supplied from the power system 210 and the renewable energy source 230, the energy storage device 240 discharges the power, 220).

In one embodiment, the energy storage device 240 may be implemented in a plurality of ways as shown in FIG. 2 to implement a large capacity.

Next, the synchronous detection device 250 measures the grid voltage of the power system 210 and the output voltage of the energy storage device 240, and detects the phase angle, frequency, and magnitude of each of the measured grid voltage and output voltage .

At this time, the synchronous detection device 250 acquires the system voltage by measuring the input voltage of the system interconnection interrupter 215, and measures the output side voltage of the interconnection interrupter 215 to obtain the output voltage.

Hereinafter, the synchronization detecting device 250 will be described in more detail with reference to FIG.

FIG. 3 is a view for explaining the synchronization detecting apparatus of FIG. 2. FIG.

3, the synchronization detecting apparatus 250 according to an embodiment of the present invention includes a converting unit 310, a detecting unit 320, a comparing unit 330, and a communication unit 340. In one embodiment, the detection device 220 may further include a state information generation unit 350. [

First, the conversion unit 310 receives the system voltage and the output voltage as analog signals and converts them into digital signals.

More specifically, the conversion unit 310 receives the input three-phase voltages V1 a , V1 b , and V1 c of the system interrupter circuit breaker 215, that is, an analog signal of the system voltage, and converts the analog signal into a digital signal. In addition, the conversion unit 310 is converted into an output-side phase voltage (V2 a, V2 b, V2 c), that is, the digital signal receives the analog signal of the output voltage of the circuit breaker 215 for system interconnection.

Next, the detection unit 320 detects the phase angle, frequency, and magnitude of each of the grid voltage and the output voltage.

More specifically, the detecting unit 320 performs a zero crossing or a PLL (Phase-Locked Loop) algorithm on the grid voltage converted by the converting unit 310 to calculate a phase angle? (f1), and size (V1).

The detector 320 performs a zero crossing or a PLL (Phase-Locked Loop) algorithm on the output voltage converted by the converting unit 310 so that the phase angle? 2 of the output voltage, the frequency f2 ), And a size (V2).

Next, the comparator 330 compares the phase angle? 1 of the system voltage and the phase angle? 2 of the output voltage to calculate the phase angle difference -θ, and calculates the difference between the frequency f1 of the system voltage and the output voltage And compares the frequency f2 to calculate the frequency difference -f. The comparator 330 compares the magnitude V1 of the system voltage with the magnitude V2 of the output voltage to calculate the magnitude difference -V.

Next, the communication unit 340 transmits the phase angle difference -θ, the frequency difference -f, and the magnitude difference -V calculated by the comparison unit 330 to the controller 230.

Next, the state information generator 350 may monitor the state of the power system 210 to generate state information.

More specifically, the state information generator 350 can generate state information for the power system 210 using the grid voltage and the frequency f1 detected by the detector 320. [

The state information generating unit 350 can determine that the power system 210 is restored to normal when the system voltage and the frequency f1 are maintained within the predetermined normal range for a predetermined time. If the power system 210 is determined to be normal, the state information generator 350 may generate state information about the power system 210 and transmit the state information to the controller 230. [

Referring again to FIG. 2, the power management device 260 controls the energy storage device 240 to be reconnected to the power system 210 once the power system 210 is restored to normal.

More specifically, the power management device 260 synchronizes the output voltage of the energy storage device 240 with the grid voltage, and upon completion of synchronization, generates status information indicating completion of synchronization and transmits the generated status information to the energy management device 270, The management device 270 may turn on the grid interrupter 215 to connect the energy storage device 240 to the power system 210.

Hereinafter, the power management apparatus 260 will be described in more detail with reference to FIG.

Fig. 4 is a diagram for explaining the control apparatus of Fig. 2. Fig.

4, a power management apparatus 260 according to an exemplary embodiment of the present invention includes a receiving unit 410, a status determination unit 420, a synchronization control unit 430, a synchronization determination unit 440, a connection control unit 450 ), And a mode control unit 460.

First, the receiving unit 410 receives the phase angle difference -θ, the frequency difference -f, and the magnitude difference -V between the output voltage and the system voltage from the synchronization detecting device 250.

In one embodiment, the receiver 410 may further receive the frequency f1 and magnitude V1 of the system voltage from the synchronization detection device 250. [

In one embodiment, the receiver 410 may further receive status information for the power system 210 from the synchronization detection device 250. [

Next, the state determination unit 420 determines the state of the power system 210 using the information received from the synchronization detection device 250.

In one embodiment, the state determiner 420 may monitor the grid voltage and frequency f1 and determine the state of the power system 210 using the monitored system voltage and frequency f1. More specifically, the state determiner 420 may determine that the power system 210 is restored to normal when the system voltage and the frequency f1 are maintained within a predetermined normal range for a predetermined period of time.

The status determiner 420 may determine the status of the power system 210 by using the status information received from the synchronization detector 250. In this case,

The synchronization control unit 430 controls the output voltage of the energy storage unit 240 to be synchronized with the system voltage of the power system 210 when the power system 210 is determined to be normal by the state determination unit 420.

More specifically, the synchronization controller 430 adjusts at least one of the phase angle, the frequency, and the magnitude of the output voltage to synchronize with the grid voltage. The synchronization control unit 430 controls the energy storage device 240 such that the phase angle difference -θ, frequency difference -f, and magnitude difference -V received from the synchronization detection device 250 are close to zero And at least one of the phase angle, frequency, and magnitude of the output voltage.

The micro grid system 200 according to an embodiment of the present invention may be configured such that when the power system 210 is restored to its normal state, the output voltage of the energy storage device 240 and the grid voltage In synchronization with each other.

Accordingly, since the micro grid system 200 can be connected to the power system 210 without stopping the operation of the energy storage device 240, the power can be continuously supplied to the load 220 without interruption have.

In addition, since the micro grid system 200 is synchronized with the output voltage and the grid voltage, there is another advantage that the inrush current is limited even when the grid interrupter 215 is turned on.

The synchronization control unit 430 may select at least one of the plurality of energy storage devices 230 and may select one of the plurality of energy storage devices 240 for the selected one of the energy storage devices 240, At least one of phase angle, frequency, and magnitude can be adjusted to synchronize with the grid voltage.

Next, the synchronization determination unit 440 determines whether synchronization has been completed by using the information received from the synchronization detection unit 250. More specifically, when the phase angle difference (-θ), frequency difference (-f), and magnitude difference (-V) received from the synchronization detection device 250 are equal to or smaller than a predetermined limit value, the synchronization determination unit 440 Is completed.

Next, the connection control unit 450 controls the energy storage device 240 to be connected to the power system 210 when the synchronization is completed. Specifically, when the synchronization determination unit 440 determines that the synchronization is completed, the connection control unit 450 transmits the status information indicating completion of synchronization to the energy management device 270. [ Accordingly, the energy storage device 240 is connected to the system 210 when the energy management device 270 turns on the system interconnecting circuit breaker 215.

Next, the mode control unit 460 sets the mode for the energy storage device 240 in the independent operation mode when the grid interconnection circuit breaker 215 is completed and the grid interconnection mode switching command is received from the energy management device 270 Switch to grid connection mode. The mode control unit 460 controls the energy storage device 240 to perform current control in voltage control.

Meanwhile, when there are a plurality of energy storage devices 240, the mode control unit 460 may perform mode switching on at least one energy storage device 240 synchronized with the grid voltage by the synchronization control unit 430 .

Referring again to FIG. 2, when the state information indicating the completion of synchronization is received from the power management device 260, the energy management device 270 generates an input command for the system interconnection interrupter 215 to generate a system interconnection interrupter 215 So that the system interrupter 215 is charged. Thus, the energy storage device 240 and the system 210 are connected.

The energy management device 270 generates a grid connection mode switching command for switching the operation mode of the energy storage device 240 when the grid connection circuit breaker 215 is turned on and the grid connection of the energy storage device 240 is completed To the power management device 260, thereby controlling the energy storage device 240 to switch to the grid connection mode to perform the current control.

In one embodiment, long distance communication may occur between the power management device 260 and the energy management device 270, and thus communication delays may occur. Due to such a communication delay, a difference may occur between the time when the grid interrupter 215 is turned on and the time when the energy storage device 240 is switched to the grid interconnection mode, and an error may occur in the phase angle. In addition, an inrush current may flow due to the phase angle error.

In order to compensate for this, the energy management device 270 transmits an instruction to turn on the grid interrupter 215 to the power management device 260, in addition to the grid interconnection mode switching command. Accordingly, after receiving the input command for the grid interconnecting circuit breaker 25, the power management device 260 predicts the time at which the actual grid interconnecting circuit breaker 215 is turned on and outputs the grid interconnecting mode switching command to the energy storage device (240).

5 is a flowchart illustrating a grid connection method of an energy storage device using a micro-grease system according to an embodiment of the present invention.

Referring to FIG. 5, the micro grid system 200 according to an embodiment of the present invention determines the state of the power system 210 (S501).

More specifically, microgrid system 200 monitors the grid voltage and frequency of power system 210 to determine the state of power system 210. The micro grid system 200 may determine that the power system 210 is restored to normal when the system voltage and frequency are maintained within a predetermined normal range for a predetermined time, for example, 5 minutes or more.

Next, the micro grid system 200 synchronizes the output voltage of the energy storage device 240 and the grid voltage of the power system 210 when the power system 210 is determined to be normal (S502).

Hereinafter, a method of synchronizing the output voltage and the system voltage will be described in more detail with reference to FIG.

6 is a view for explaining a method of synchronizing an output voltage and a system voltage according to an embodiment of the present invention.

Referring to FIG. 6, the micro grid system 200 measures the output voltage of the energy storage device 240 and the grid voltage of the power system 210 (S601).

The micro grid system 200 obtains the grid voltage by measuring the input voltage of the grid interrupter 215 and measures the output voltage of the grid interrupter 215 to obtain the output voltage.

Next, the micro grid system 200 detects the phase angle, frequency, and magnitude of each of the grid voltage and the output voltage (S602).

In one embodiment, the microgrid system 200 performs zero crossing or PLL (Phase-Locked Loop) algorithms on the measured output voltages and grid voltages to determine respective phase angles, frequencies, and magnitudes Can be detected.

Next, the micro grid system 200 calculates a phase angle difference, a frequency difference, and a size difference between the output voltage and the grid voltage (S603).

The micro grid system 200 calculates the phase angle difference by comparing the phase angle of the system voltage and the phase angle of the output voltage, and compares the frequency of the system voltage and the frequency of the output voltage to calculate the frequency difference. The micro grid system 200 compares the magnitude of the system voltage and the magnitude of the output voltage to calculate the magnitude difference.

Next, the micro grid system 200 controls the phase angle, frequency, and magnitude of the output voltage so that the calculated phase angle difference, frequency difference, and size difference approach zero (S604).

Referring again to FIG. 5, the micro grid system 200 determines whether the output voltage and the grid voltage have been completely synchronized (S503).

The micro grid system 200 determines that the synchronization is completed when the difference in phase angle, frequency difference, and size difference between the output voltage and the grid voltage is less than a predetermined limit value.

Next, when it is determined that the synchronization is completed, the micro grid system 200 controls to be linked with the power system 210 (S504).

More specifically, the micro grid system 200 generates a closing command to the grid interrupter 215 and transmits the generated closing command to the grid interrupter 215.

The micro grid system 200 generates a grid connection mode switching instruction to the energy storage device 240 and transmits the generated grid connection mode switching instruction to the energy storage device 240 so that the energy storage device 240 Current control.

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

200: microgrid system 210: system
215: circuit interrupter 220: load
230: renewable energy source 240: energy storage device
250: synchronization detecting device 260: power management device
270: Energy management device

Claims (10)

At least one energy storage device for storing power or for discharging the stored power to a load;
A synchronization detecting device for measuring an output voltage of the at least one energy storage device and a system voltage of the power system, and acquiring a phase angle difference, a frequency difference, and a size difference between the measured output voltage and the system voltage; And
Synchronizing the output voltage of the at least one energy storage device with the grid voltage using the obtained phase angle difference, frequency difference, and size difference, and controlling the synchronized energy storage device to be connected to the power system Microgrid system for grid connection of energy storage device including power management device. The method according to claim 1,
A grid interrupter for connecting or disconnecting the at least one energy storage device and the power system; And
When the output voltage and the grid voltage are synchronized with each other by the power management apparatus, an input command of the grid interconnection breaker is transmitted to the grid interconnection interrupter to supply energy to the at least one energy storage device Wherein the system further comprises a management device. ≪ RTI ID = 0.0 > [0002] < / RTI > 3. The method of claim 2,
The energy management apparatus generates a grid connection mode switching command for switching the at least one energy storage device to the grid connection mode when the insertion of the grid connection interrupter is completed and transmits the generated grid connection mode switching instruction to the power management apparatus,
Wherein the power management device switches the at least one energy storage device to the grid connection mode when the grid connection mode switching command is received from the energy management device so that the at least one energy storage device performs current control Micro grid system for grid linkage of energy storage devices. 3. The method of claim 2,
The energy management apparatus transmits the grid connection mode switching command and the input command of the grid interrupter to the power management apparatus,
The power management apparatus switches the energy storage device into the grid-connected mode after a predetermined time of turning on the grid interrupter for grid interconnection has elapsed, upon receipt of a command to input the grid interrupter, Current control of the energy storage device is performed. The power management apparatus according to claim 1,
And a synchronization controller for controlling the phase angle, frequency, and size of the output voltage to reduce the phase angle difference, frequency difference, and size difference. 7. The power management apparatus according to claim 6,
Further comprising a synchronization determination unit configured to determine that synchronization has been completed when the phase angle difference, the frequency difference, and the size difference become less than a predetermined limit value, and to generate status information indicating completion of synchronization. Micro Grid System. The power management apparatus according to claim 1,
And a connection controller for generating status information indicating completion of synchronization when the synchronization is completed and transmitting the generated status information to the energy management apparatus. The power management apparatus according to claim 1,
And a state determining unit for monitoring the frequency of the system voltage and the system voltage and determining that the state of the power system is restored when the system voltage and the frequency of the system voltage are maintained within a predetermined normal range for a predetermined time Micro grid system for grid linkage of energy storage devices. The synchronous detection device according to claim 1,
A detector for detecting a phase angle, a frequency, and a magnitude for each of the output voltage and the grid voltage;
A comparator comparing the detected phase angle, frequency, and magnitude to calculate a phase angle difference, a frequency difference, and a magnitude difference between the output voltage and the grid voltage; And
And a communication unit for transmitting the calculated phase angle difference, frequency difference, and size difference to the power management apparatus. The method according to claim 1,
Wherein the power management device selects at least one of the energy storage devices and synchronizes the output voltage of the selected at least one energy storage device with the grid voltage. system.
KR1020140192710A 2014-12-29 2014-12-29 Micro Grid System for Grid-Connection of Energy Storage System and Method for Grid-Connection Energy Storage System USING THE SAME KR20160080914A (en)

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KR20190107425A (en) * 2018-03-12 2019-09-20 한국전자통신연구원 Apparatus and method for uninterruptably providing power
KR20200029701A (en) 2018-09-11 2020-03-19 주식회사 포스코아이씨티 Microgrid System Connected to Distributed Generation and Method for Controlling The Same
KR20220013069A (en) 2020-07-24 2022-02-04 한국산업기술대학교산학협력단 Optimal scheduling method for microgrid operation under islanding uncertainty

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20190107425A (en) * 2018-03-12 2019-09-20 한국전자통신연구원 Apparatus and method for uninterruptably providing power
KR20200029701A (en) 2018-09-11 2020-03-19 주식회사 포스코아이씨티 Microgrid System Connected to Distributed Generation and Method for Controlling The Same
KR20220013069A (en) 2020-07-24 2022-02-04 한국산업기술대학교산학협력단 Optimal scheduling method for microgrid operation under islanding uncertainty

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