WO2022196846A1

WO2022196846A1 - Energy storage system hierarchical management system

Info

Publication number: WO2022196846A1
Application number: PCT/KR2021/003347
Authority: WO
Inventors: 박상운
Original assignee: 주식회사 트위니
Priority date: 2021-03-17
Filing date: 2021-03-18
Publication date: 2022-09-22
Also published as: KR102324325B1

Abstract

The present invention relates to an energy storage system hierarchical management system and, more particularly, to an energy storage system hierarchical management system comprising: a local EMS which is installed in a power plant, controls at least one selected from among a PCS, a PMS, and a BMS interlocked with the power plant, and collects at least one data selected from among a PCS, a PMS, and a BMS; and a wide-area EMS which receives and collects information collected from the local EMS, determines the current state of each local EMS, receives and processes a control command from an algorithm module so that the current state converges to a preset setting state according to an algorithm control selected by a user through a web-based UI, and displays each local EMS monitoring information on a web UI.

Description

Energy Storage System Hierarchical Management System

The present invention relates to an energy storage system hierarchical management system, and more particularly, to an energy storage system hierarchical management system for generating control commands using multiple algorithms and controlling them in a hierarchical structure.

An energy storage system is a system that increases energy efficiency by storing generated power in each linked system including a power plant, substation, and transmission line, and then selectively and efficiently using it when power is needed.

The energy storage system can lower the power generation unit cost and reduce the investment and operation cost required for power facility expansion, reducing the electricity rate and saving energy when the overall load factor is improved by leveling the electric load with large fluctuations by time and season. can do.

Such an energy storage system is installed and used in power generation, transmission and distribution, and at consumers. Frequency regulation, stabilization of generator output using new and renewable energy, peak shaving, and load leveling , emergency power supply, etc.

Energy storage systems are largely divided into physical energy storage and chemical energy storage according to storage methods. For physical energy storage, there is a method using pumped water power generation, compressed air storage, flywheel, etc., and for chemical energy storage, there is a method using a lithium-ion battery, a lead-acid battery, or a Nas battery.

However, the conventional energy storage system has a problem in that it cannot be managed in an integrated way by relating the power state of a directly managed area (eg, microgrid unit) or a building with the power state of an adjacent area or building. .

In addition, the conventional energy storage system has a problem in that it is difficult to secure a return on investment by performing control using only a single algorithm in power generation, transmission, distribution, and consumer parts in the power system.

Korea Patent [10-1977115] discloses a hierarchical power control system

Accordingly, the present invention has been devised to solve the above problems, and an object of the present invention is to provide an energy storage system hierarchical management system that generates control commands using multiple algorithms and controls them in a hierarchical structure.

The purpose of the embodiments of the present invention is not limited to the above-mentioned purpose, and other objects not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. .

The energy storage system hierarchical management system according to an embodiment of the present invention for achieving the above object controls at least one selected from among PCS, PMS and BMS installed in a power generation facility and interlocked with the power generation facility, a local EMS 100 for collecting at least one data selected from among the PCS, PMS and BMS; and the information collected from the local EMS 100 is received and collected, the current state of each local EMS 100 is determined, and the current state is set to a preset state according to the algorithm control selected by the user through the web-based UI. Wide area EMS 200 for receiving and processing control commands from the algorithm module 221 to converge and displaying monitoring information for each local EMS 100 on a web UI; and characterized in that it includes.

In addition, the local EMS 100 transmits the collected data to the wide area EMS 200, a local communication module 110 that receives a control command from the wide area EMS (200); and a local control module 120 for allowing the control command received from the wide area EMS 200 to be executed through at least one selected from the corresponding PCS, PMS, and BMS.

In addition, the wide area EMS 200 is a wide area communication module 210 for communicating with the local EMS (100); a wide area control module 220 including an algorithm module, and generating a control command through one or more algorithms selected through a web-based UI based on information collected through the wide area communication module 210; a database 230 for storing the collected information of the local EMS 100; and a web server 240 that provides a web-based UI and interworks with the wide area control module 220 to set an algorithm and a driving mode selected by a user through the web-based UI.

In addition, the web server 240 is characterized in that it provides a web-based UI for setting the operation mode and algorithm of the wide area EMS 200 and inquiring data.

In addition, the web server 240 has a function for controlling the power factor of the inverter or PCS, a function for setting an upper limit of active power by limiting power inside or outside the distributed resource, and charging and discharging of the energy storage system A function to set the active power for the energy storage system, a function to set the reactive power for the charging and discharging of the energy storage system, and the ramp rate (Ramp) to suppress the fluctuation range of the charging and discharging of the energy storage system to a specific value per unit time. Rate) function, the function to control the reactive power output of the distributed resource itself in response to the reference voltage, and the connection to suppress the loss caused by the short circuit of the distributed resource during the low voltage failure in the situation where the renewable energy penetration rate is higher than the standard A function to maintain the connection state for a period of time during the disconnect operation, to keep the connection state for a period of time during the disconnect operation to suppress the loss caused by short-circuiting the distributed resource during high voltage failure in a situation where the renewable energy penetration rate is higher than the standard A function to maintain a connected state for a period of time during disconnection operation in order to suppress the loss caused by short-circuiting of distributed resources during low-frequency disturbances when the renewable energy penetration rate is higher than the standard, and the renewable energy penetration rate is higher than the standard In order to suppress losses caused by short-circuiting of distributed resources during high-frequency failure, a function to maintain the connection state for a period of time during disconnection operation, a function to adjust active power according to frequency response, and a function to control the ESS according to load fluctuations The function to maintain the reference frequency while adjusting the active power at a constant rate for charging and discharging, the function to flatten the output power to enable the intermittent generation of renewable energy and compensation for the excessive load, and the threshold given the power level at a specific reference point. It is characterized in that a plurality of functions selected from among functions for controlling not to be exceeded are applied simultaneously without conflict.

According to the energy storage system hierarchical management system according to an embodiment of the present invention, the efficiency of data management and control of each local EMS by including a plurality of local EMS and a wide area EMS in charge of data management and control of local EMS has the effect of increasing

In addition, it is possible to issue consistent control commands from the local EMS through the web-based UI, thereby further increasing the efficiency of data management and control of each local EMS.

In addition, by enabling the user to easily select and use another control algorithm according to the state of the BMS interlocked with the local EMS, there is an effect of more efficiently controlling the charging and discharging of power according to the user's needs.

In addition, by integrating the control points of a plurality of local EMS into a single point (wide-area EMS), there is an effect that enables the collective control of a plurality of local EMS.

In addition, by collecting and analyzing a large number of local EMS data, integrated monitoring of a large number of local EMS is possible in real time, and additional utilization review is easy.

In addition, as the DAB (Dual Active Bridge) converter, battery, and sunlight are connected to the DC-Like capacitor terminal of the dynamic voltage compensator, and the charge/discharge of the battery current is determined using the measured or calculated values according to the system state, It has the effect of increasing energy efficiency by allowing the active power consumed by the DVR to which the existing PAC is applied to be charged to the battery using the DAB converter. It works.

1 is a conceptual diagram of an energy storage system hierarchical management system according to an embodiment of the present invention.

Figure 2 is a conceptual diagram of a facility interlocked with the local EMS of Figure 1;

3 is a detailed conceptual view of the converter unit of FIG. 2 .

4 is a conceptual diagram of the design of the DC-Link voltage controller and the battery charge/discharge current controller of FIG. 2 .

5 is a conceptual diagram showing a current flow according to the system state of FIG.

*Detailed description of the main symbols in the drawing*

100: local EMS

110: local communication module

120: local control module

200: wide area EMS

210: wide area communication module

220: wide area control module

230: database

240: web server

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

When a component is referred to as being “connected” or “connected” to another component, it may be directly connected or connected to the other component, but it is understood that other components may exist in between. it should be

On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

The terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, process, operation, component, part, or combination thereof described in the specification is present, but one or more other features It is to be understood that this does not preclude the existence or addition of numbers, processes, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having meanings consistent with the meanings in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to conventional or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. Based on the principle that it can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention. In addition, unless there are other definitions in the technical and scientific terms used, it has the meaning commonly understood by those of ordinary skill in the art to which this invention belongs, and in the following description and accompanying drawings, the gist of the present invention Descriptions of known functions and configurations that may be unnecessarily obscure will be omitted. The drawings introduced below are provided as examples in order to sufficiently convey the spirit of the present invention to those skilled in the art. Accordingly, the present invention is not limited to the drawings presented below and may be embodied in other forms. Also, like reference numerals refer to like elements throughout. It should be noted that the same components in the drawings are denoted by the same reference numerals wherever possible.

1 is a conceptual diagram of an energy storage system hierarchical management system according to an embodiment of the present invention, FIG. 2 is a conceptual diagram of a facility interlocked with the local EMS of FIG. 1, and FIG. 3 is a detailed conceptual diagram of the converter unit of FIG. 4 is a conceptual diagram illustrating the design of the DC-Link voltage controller and the battery charge/discharge current controller of FIG. 2 , and FIG. 5 is a conceptual diagram showing the current flow according to the system state of FIG. 2 .

As shown in FIG. 1 , the energy storage system hierarchical management system according to an embodiment of the present invention includes a local EMS 100 and a wide area EMS 200 .

The local EMS 100 is installed in the power generation facility to control at least one selected from among PCS, PMS, and BMS interlocked with the power generation facility, and collects at least one data selected from among the PCS, PMS, and BMS.

The local EMS 100 may be provided in plurality.

ESS stands for Energy Storage System and is an energy storage system.

The generated electricity is stored in the ESS, an energy storage device, so that electricity can be supplied when needed.

ESS is largely composed of PCS, BMS, PMS, and EMS.

PCS stands for Power Conversion System, and it is a bidirectional inverter that converts direct current into alternating current and alternating current into direct current in order to charge or discharge power to the battery. The alternating current supplied from the power plant, etc. is converted into direct current to be stored in the battery, and the electricity stored in the battery is discharged by converting the direct current into alternating current. In addition to this, it also serves to adjust the frequency and voltage.

BMS is an abbreviation of Battery Management System, which is a system that manages the batteries of ESS.

The role is to charge the electric energy received from the system or output the stored electric energy to the system.

The first function of BMS is battery cell management. It regulates the voltage by balancing the voltage of each cell and manages the battery so as not to overload the battery. Second, the state of charge is predicted. By detecting the current, voltage, and temperature of the battery, it is possible to determine whether the battery is charged or not, and to predict the remaining amount of the battery. Third, limit the power of the battery. It limits the power to prevent overcharging and overdischarging of the battery. Fourth, make a diagnosis. Diagnose the failure of the battery system and transmit it to other controllers when a failure is found. Fifth, cooling control. Overheating occurs when the battery is used, and cooling control is implemented to prevent this. Sixth, if there is a PRA (Power Relay Assembly), it controls the PRA. This function is to supply and cut off the power of the high voltage battery to the motor. When the high voltage battery fails, the relay is turned off to cut off the power supply and the high voltage battery is protected through the relay off to prevent a major accident.

PMS is an abbreviation of Power Management System. It monitors battery and PCS status and controls PCS.

EMS is an abbreviation of Energy Management System, and it is a system that controls the ESS to operate at optimal efficiency.

For optimal efficiency of ESS, software for monitoring and management, discharging time, charging time, and conditions can be set through programming.

The wide area EMS 200 receives and collects the information collected from the local EMS 100, determines the current state of each local EMS 100, and determines the current state according to the algorithm control selected by the user through the web-based UI. It receives and processes a control command from the algorithm module 221 so as to converge to a preset setting state, and displays monitoring information for each local EMS 100 on the web UI.

The wide area EMS 200 may receive and collect information collected from the local EMS 100 , as well as process and store the collected information.

The energy storage system hierarchical management system according to an embodiment of the present invention controls and manages a plurality of local EMS 100 through the wide area EMS 200 and provides a single interface to a user who manages a plurality of local EMS 100 . provides an environment for efficient management in one place by providing data from the local EMS (100) in real time, and receives data from the safe wide area EMS (200) to perform backup, analysis, statistics, and processing for more in-depth statistics You can provide a hierarchical structure to secure data.

The wide area EMS 200 may be designed to perform an integrated monitoring and control function.

The integrated monitoring and control functions include monitoring, control, reporting, alarming, calculation, DB management, and trend functions. It may include a screen display function, a load prediction function, a household calculation function, a load cutoff function, and an islanding algorithm execution function.

Here, the monitoring function may include a status monitoring and measurement of the local EMS 100 , and a failure monitoring function.

The control function may include operation, stop, scheduling, and optimal operation control functions of facilities provided in the local EMS 100 .

The reporting function may include a function of providing measurement information, operation, and maintenance records for each period for the local EMS 100 .

The alarm function may include an alarm recognition processing and storage function.

The calculation function may include a function of providing a calculation function and a function function to data requiring calculation, such as a power factor.

The DB management function may include a data interface function through a real-time database application program interface (API).

The trend function may include a function to monitor data change trend.

The screen display function may include a function of displaying monitoring, events, alarms, authority, etc. on the screen of the terminal associated with the wide area EMS 200 .

The load prediction function may include a function to design by applying an ensemble multi-model combination algorithm that derives results using various prediction algorithms, and a function to acquire historical data of loads within the system and store it in the Oracle DB.

The household calculation function may include a function of calculating an electricity rate based on electricity usage history data.

The load shedding function may include a function of blocking the load by priority when a reference value is exceeded.

The function of performing the islanding algorithm may include a function of searching for a method of power flexibility and load blocking during independent operation.

That is, the wide-area EMS 200 may receive various information from the local EMS 100 and manage and control the power supply/demand status of the local EMS 100 based on the received information.

As shown in FIG. 1 , the local EMS 100 of the energy storage system hierarchical management system according to an embodiment of the present invention may include a local communication module 110 and a local control module 120 .

The local communication module 110 transmits the collected data to the wide area EMS 200 and receives a control command from the wide area EMS 200 .

The local control module 120 allows the control command received from the wide area EMS 200 to be executed through at least one selected from the corresponding PCS, PMS, and BMS.

That is, the local EMS 100 does not generate a control command by itself, but receives the control command from the wide area EMS 200 and executes it.

1, the wide area EMS 200 of the energy storage system hierarchical management system according to an embodiment of the present invention includes a wide area communication module 210, a wide area control module 220, a database 230 and a web A server 240 may be included.

The wide area communication module 210 communicates with the local EMS 100 .

The wide area control module 220 includes an algorithm module, and generates a control command through one or more algorithms selected through the web-based UI based on the information collected through the wide area communication module 210 .

The wide area control module 220 generates a control command by using one or more algorithms selected by a user from among a plurality of algorithms stored in the algorithm module.

The database 230 stores the collected information of the local EMS 100 .

The web server 240 provides a web-based UI, and is linked with the wide area control module 220 to set the algorithm and operation mode selected by the user through the web-based UI.

The web server 240 of the energy storage system hierarchical management system according to an embodiment of the present invention sets the operation mode and algorithm of the wide area EMS 200 and provides a web-based UI for inquiring data. can do.

The wide-area EMS 200 provides a web-based UI that visualizes statistical data and driving data, and the user issues a control command to each local EMS 100 through the web-based UI and sends each local EMS 100 ) status can be inquired, and wide-area statistics can also be inquired.

The web server 240 of the energy storage system hierarchical management system according to an embodiment of the present invention is

The ability to control the power factor of the inverter or PCS,

A function to set the upper limit of active power by limiting power inside or outside the distributed resource;

A function to set the active power for charging and discharging the energy storage system,

A function for setting reactive power for charging and discharging energy storage systems;

A function to set the ramp rate to suppress the fluctuation range of the charge and discharge of the energy storage system to a specific value per unit time;

A function for controlling the reactive power output of the distributed resource itself in response to the reference voltage;

A function to maintain the connection state for a period of time during disconnection operation in order to suppress losses caused by short-circuiting of distributed resources during low-voltage failure in a situation where the renewable energy penetration rate is higher than the standard;

A function to maintain the connection state for a period of time during disconnection operation to suppress losses caused by short circuiting of distributed resources during high voltage failure in a situation where the renewable energy penetration rate is higher than the standard;

A function to maintain the connection state for a period of time during disconnection operation in order to suppress losses caused by short-circuiting of distributed resources during low-frequency disturbances in a situation where the renewable energy penetration rate is higher than the standard;

A function to maintain a connection state for a period of time during disconnection operation to suppress losses caused by short circuiting of distributed resources during high-frequency failure in a situation where the renewable energy penetration rate is higher than the standard;

A function to adjust the active power according to the frequency response,

A function to maintain the reference frequency while regulating the active power of the ESS at a certain rate (droop coefficient) according to the load change;

A function to flatten the output power to enable intermittent generation of renewable energy and compensation for excessive loads; and

It may be characterized in that a plurality of functions selected from among functions for controlling the power level not to exceed a given threshold at a specific reference point do not conflict and are applied at the same time.

For these functions, if the user sets a specific reference point in advance, the wide area EMS 200 receives the information continuously collected from the local EMS 100 and transmits the applied value calculated through the algorithm to the local EMS 100, The local EMS 100 gives a command to at least one selected from among the connected PCS, PMS, and BMS to control the corresponding function to be performed.

For example, in the case of a function for controlling the power level not to exceed a given threshold at a specific reference point, if the user sets a reference power level (a specific reference point) in advance, the wide area EMS 200 is continuously receives the information collected by , and transmits the applied value calculated through the corresponding algorithm to the local EMS 100, and the local EMS 100 issues a command to at least one selected from among the connected PCS, PMS, and BMS to increase the power level Control to keep it below the threshold.

As shown in FIG. 2, the energy storage system hierarchical management system according to an embodiment of the present invention is a facility interworking with the local EMS 100, and includes a line transformer 110, a dynamic voltage compensator 120, and a converter unit ( 130), the battery unit 140 and the photovoltaic unit 150, and determines the direction of the current of the battery unit 140 using measured or calculated values according to the system state, and based on this, the battery unit (140) It is characterized in that the charge/discharge of the current is determined.

The line transformer 110 is connected in series to the distribution line.

The line transformer 110 is a transformer connected in series to a distribution line, and one coil is connected in series to the distribution line.

The dynamic voltage compensator 120 is connected to the line transformer 110 to compensate for voltage fluctuations and reactive power of the distribution line, and is also referred to as a DVR (Dynamic Voltage Restorer).

The dynamic voltage compensator 120 is connected to the other coil of the line transformer 110 .

The converter unit 130 is connected to both ends of the DC-Like capacitor 121 of the dynamic voltage compensator 120 to perform bidirectional power transfer.

The battery unit 140 is connected to the converter 300 to be charged or discharged.

The battery unit 140 is included in an energy storage system (ESS).

The photovoltaic unit 150 is connected to both ends of the DC-Like capacitor 121 of the dynamic voltage compensator 120 .

The photovoltaic unit 150 generates electricity using sunlight.

The energy storage system hierarchical management system according to an embodiment of the present invention implements voltage compensation while supplying reactive power to the grid (distribution line) using only the single device of the dynamic voltage compensator 120 . At this time, according to the state of the system, active power is charged and discharged to the battery unit 140 through the converter unit 130 connected to the DC-Like capacitor 121 of the dynamic voltage compensator 120 , and the dynamic voltage compensator 120 . It enables bidirectional power transfer between the system and the battery unit 140 through 120 .

When the PAC (Phase Angle Control) technique is applied to the dynamic voltage compensator 120 , voltage compensation and reactive power compensation are possible at the same time, but active power is generated from the grid to the dynamic voltage compensator 120 side. In the energy storage system hierarchical management system according to an embodiment of the present invention, the converter unit 130 and the battery unit are connected to the DC-Like capacitor 121 terminal of the dynamic voltage compensator 120 in order to utilize the active power consumed in this way. (140), and the photovoltaic power generation unit 150 was configured in connection.

Such a configuration enables bi-directional power transfer, such as charging the active power generated by the PAC technique to the battery or discharging the active power required for the system from the battery when an instantaneous voltage sag occurs.

In addition, in connection with the photovoltaic unit 150, the active power generated from the photovoltaic unit 150 is charged to the battery unit 140 depending on the situation, or the active power is supplied to the system through the dynamic voltage compensator 120. The system was configured to do so. For this reason, the separate DC power required for the operation of the dynamic voltage compensator 120 is replaced by the battery unit 140 and the photovoltaic unit 150, so that only a single device of the dynamic voltage compensator 120 can compensate for voltage fluctuations and reactive power. it becomes possible

That is, conventionally, the dynamic voltage compensator 120 as a single device requires a separate DC power source, but the energy storage system hierarchical management system includes the battery unit 140 and the dynamic voltage compensator 120, which is a system power quality compensating device. By linking the photovoltaic unit 150, the active power generated by the photovoltaic unit 150 is charged to the battery unit 140 or the active power required when the dynamic voltage compensator 120 is compensated for the grid voltage can be supplied. made it possible

As shown in FIG. 3 , the converter unit 130 of the energy storage system hierarchical management system may include a first power circuit 131 , a second power circuit 132 , and a converter transformer 133 .

One end is connected to both ends of the DC-Like capacitor 121 of the dynamic voltage compensator 120, and a full bridge circuit is formed by four bridge switching devices.

The second power circuit 132 has the other end connected to the battery unit 140, and forms a full bridge circuit with four bridge switching devices.

One end of the converter transformer 133 is connected to the first power circuit 131 , and the other end is connected to the second power circuit 132 .

That is, the high-frequency transformer is connected between the full-bridge converters at both ends.

Referring to FIG. 3 as an example, the power transfer direction is determined according to the phase difference between the left primary voltage and the right secondary voltage based on the transformer to perform bidirectional power transfer.

On the other hand, since the converter unit 130 uses a high-frequency transformer, it has excellent insulation characteristics, and soft switching such as ZVS is possible, thereby reducing loss due to switching.

In other words, power transfer may be performed through a DAB (Dual Active Bridge) converter, which is an insulated bidirectional DC-DC converter for controlling battery charging and discharging.

If the phase shift modulation method (PSM, Phase-Shift-Modulation) is used, it is possible to transmit power in both directions using the phase difference between the primary side voltage and the secondary side voltage of the DAB converter.

The energy storage system hierarchical management system according to an embodiment of the present invention links the photovoltaic unit 150, and uses the power generated from the photovoltaic unit 150 to provide a dynamic voltage compensator 120 according to the state of the system. By supplying active power or charging the battery unit 140 through (140) to charge active power to the battery unit 140, or to discharge the active power required for voltage compensation in the battery unit 140 when a system voltage change occurs.

In order to perform such bidirectional power transfer, it is preferable to link a DAB (Dual Active Bridge) converter, which is an insulated bidirectional DC-DC converter, with the DC-Link capacitor stage of the DVR.

The converter unit 130 of the energy storage system hierarchical management system according to an embodiment of the present invention converts the solar current and the DVR current to the output of the DC-Like capacitor 121 voltage controller of the dynamic voltage compensator 120 . A current command value of the battery is generated in a compensating manner, and the output of the current controller is controlled by a controller designed to generate a phase difference command of an operation signal for a switching element of the converter unit 130 .

In order to perform power transfer using the DAB converter, a phase difference must be generated in the primary and secondary voltages of the DAB converter.

The command for the phase difference can be obtained through the output of the controller designed as shown in FIG. 4 .

Accordingly, a phase difference between the primary and secondary voltages of the DAB is generated by as much as a phase difference command to perform power transmission.

That is, it is possible to generate the DAB converter operation signal after generating the phase command using the battery current command.

The energy storage system hierarchical management system according to an embodiment of the present invention constitutes a system in which the photovoltaic unit 150 and the battery unit 140 are linked to the dynamic voltage compensator 120, which is a system power quality compensator, and the system Analysis of power transmission by state was performed. Through this, the DVR voltage controller and the battery charge/discharge current controller were designed according to the output power of the photovoltaic unit 150 and the active power generated or consumed by the dynamic voltage compensator 120 as described above.

Accordingly, when the system is in a steady state or a voltage swell occurs, the active power generated by the photovoltaic power generation unit 150 or the dynamic voltage compensator 120 is charged to the battery unit 140 through the converter unit 130 . And, when an instantaneous voltage drop (Voltage Sag) occurs, the battery unit 140 is charged or discharged according to the power generated by the photovoltaic unit 150 and the amount of active power supplied as power from the dynamic voltage compensator 120 .

The energy storage system hierarchical management system according to an embodiment of the present invention is generated through the PAC (Phase Angle Control) of the dynamic voltage compensator 120 or the active power supplied to the system and the DC of the dynamic voltage compensator 120. -Using the Like capacitor 121, the direction of the battery current is determined based on the calculated current of the dynamic voltage compensator 120 and the output current of the photovoltaic unit 150, and the charging and discharging of the battery current is determined. can be done with

Calculate the current value of the dynamic voltage compensator 120 based on the power supply voltage, load voltage, DC-Link capacitor voltage, load current, etc., and if the current value of the dynamic voltage compensator 120 is positive, the battery unit 140 is charged, If the dynamic voltage compensator 120 current value is negative and the solar output current value is greater than the dynamic voltage compensator 120 current value, the battery unit 140 is charged, and the dynamic voltage compensator 120 current value is negative and solar output When the current value is greater than the current value of the dynamic voltage compensator 120 , the battery unit 140 may be discharged.

That is, the charging/discharging current of the battery unit 140 is determined using the effective current generated or consumed by the dynamic voltage compensator 120 and the solar output current, and intuitive analysis is possible through this.

5 is an analysis of power transfer according to the system state of a system in which the dynamic voltage compensator 120 to which PAC is applied, the photovoltaic power generation unit 150, and the battery unit 140 are connected. (However, line loss is ignored)

5, the energy storage system hierarchical management system according to an embodiment of the present invention is

As shown in (a) of FIG. 5, when the system is in a steady state or a voltage swell of the distribution system occurs, the current charged in the battery is the current calculated by the active power generated by the PAC (Phase Angle Control).

and the photovoltaic unit 150 output current

is controlled to be the sum of

As shown in (b) of Figure 5, when an instantaneous voltage drop (Voltage Sag) of the distribution system occurs, the active power supplied from the dynamic voltage compensator 120 to the grid is smaller than the value output from the photovoltaic unit 150. In this case, the power generated from sunlight is supplied to the system through the dynamic voltage compensator 120 and

Control the amount of current to be charged to the battery and

As shown in (c) of Figure 5, when the instantaneous voltage drop (Voltage Sag) of the distribution system occurs and the power to be supplied from the dynamic voltage compensator 120 to the system is greater than the solar output power, together with the solar current from the battery

It may be characterized in that the amount of current is controlled to be discharged.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention as claimed in the claims.

Claims

a local EMS (100) installed in a power plant to control at least one selected from among PCS, PMS, and BMS interlocked with the power plant, and to collect at least one data selected from among the PCS, PMS, and BMS; and

The information collected from the local EMS 100 is received and collected, the current state of each local EMS 100 is determined, and the current state converges to a preset setting state according to the algorithm control selected by the user through the web-based UI. Wide area EMS 200 for receiving and processing a control command from the algorithm module 221 so as to display monitoring information for each local EMS 100 on a web UI;

Energy storage system hierarchical management system including.
According to claim 1,

The local EMS 100 is

a local communication module 110 that transmits the collected data to the wide area EMS 200 and receives a control command from the wide area EMS 200; and

a local control module 120 for allowing the control command received from the wide area EMS 200 to be executed through at least one selected from among PCS, PMS and BMS;

Energy storage system hierarchical management system including.
According to claim 1,

The wide area EMS 200 is

Wide area communication module 210 to communicate with the local EMS (100);

a wide area control module 220 including an algorithm module, and generating a control command through one or more algorithms selected through a web-based UI based on information collected through the wide area communication module 210;

a database 230 for storing the collected information of the local EMS 100; and

a web server 240 that provides a web-based UI and is interlocked with the wide area control module 220 to set an algorithm and a driving mode selected by a user through the web-based UI;

Energy storage system hierarchical management system including.
According to claim 1,

The web server 240 is

Energy storage system hierarchical management system, characterized in that it provides a web-based UI for setting the operation mode and algorithm of the wide area EMS (200) and inquiring data.
According to claim 1,

The web server 240 is

The ability to control the power factor of the inverter or PCS,

A function to set the upper limit of active power by limiting power inside or outside the distributed resource;

A function to set the active power for charging and discharging the energy storage system,

A function for setting reactive power for charging and discharging energy storage systems;

A function to set the ramp rate to suppress the fluctuation range of the charge and discharge of the energy storage system to a specific value per unit time;

A function for controlling the reactive power output of the distributed resource itself in response to the reference voltage;

A function to maintain the connection state for a period of time during disconnection operation in order to suppress losses caused by short-circuiting of distributed resources during low-voltage failure in a situation where the renewable energy penetration rate is higher than the standard;

A function to maintain the connection state for a period of time during disconnection operation to suppress losses caused by short circuiting of distributed resources during high voltage failure in a situation where the renewable energy penetration rate is higher than the standard;

A function to maintain the connection state for a period of time during disconnection operation in order to suppress losses caused by short-circuiting of distributed resources during low-frequency disturbances in a situation where the renewable energy penetration rate is higher than the standard;

A function to maintain a connection state for a period of time during disconnection operation to suppress losses caused by short circuiting of distributed resources during high-frequency failure in a situation where the renewable energy penetration rate is higher than the standard;

A function to adjust the active power according to the frequency response,

A function to maintain the reference frequency while regulating the active power of the ESS at a certain rate according to the change of the load;

A function to flatten the output power to enable intermittent generation of renewable energy and compensation for excessive loads; and

An energy storage system hierarchical management system, characterized in that a plurality of functions selected from among functions for controlling the power level not to exceed a given threshold at a specific reference point are applied simultaneously without conflict.