KR20200103505A - Apparatus for stabilizating of pwer system - Google Patents

Abstract

The present invention relates to a system stabilization device using a local control method. According to an embodiment of the present invention, the system stabilization device comprises: a section in which a line is divided into one or more sections in accordance with a load, an energy storage system (ESS) and renewable energy generation sources included in large-scale business operators; and a local control center (LCC) operated in a substation unit and controlling a voltage of each section. The LCC includes: a section control unit which determines a line capacity of each section and a state of charge (SOC) of the ESS, and controls a current between the sections through voltage control of the line; an ESS control unit controlling charge and discharge capacities of the ESS controlled by the section control unit included in the section and controlling a power factor of the line using a power conditioning system (PCS) installed in the ESS; and a renewable energy business operator control unit controlling a system linkage of the renewable energy generation sources, and controlling the power factor of the line using the PCS installed in the renewable energy business operator.

Description

System stabilization device {APPARATUS FOR STABILIZATING OF PWER SYSTEM}

The present invention relates to a system stabilization apparatus using a local control method.

1 is a diagram schematically illustrating a system device according to the prior art. Referring to FIG. 1, in the conventional case, solar light, energy storage system (ESS), etc. are individually controlled to stably operate the system voltage. It was difficult to do. Most of the facilities that supply power to the grid, such as photovoltaics systems (PVs) and ESS, were private property and could not be controlled. Therefore, the ESS, which acts as a damper for electric power flowing into the system, operates separately, and thus, control over charging/discharging is sporadically performed. For this reason, there are cases in which the ESS capacity is insufficient. In this case, there is a limitation in that the grid voltage becomes unstable due to power flowing from renewable energy sources such as PV. In addition, when the SG (smart grid) and MG (micro grid) methods are used, it is necessary to install measurement equipment for the load and power generation source, which inevitably increases the system operation cost.

The above-described background technology is technical information possessed by the inventor for derivation of the present invention or acquired in the derivation process of the present invention, and is not necessarily known to be known to the public prior to filing the present invention.

Korean Patent Publication No. 2018-0124182

The present invention was conceived to solve the above-described problems and/or limitations, and an object of the present invention according to an aspect is to measure and control the receiving and shear voltage of an ESS operated in a local control center (LCC) to install a measuring device. It is to reduce the quantity.

An object of the present invention according to another aspect is to secure the reliability of a line at a distribution end by using a voltage control method.

An object of the present invention according to another aspect is to enable connection of new and renewable energy such as PV without increasing the line capacity by utilizing the ESS installed in the LCC.

The system stabilization apparatus according to an embodiment of the present invention includes a line divided into one or more sections according to a load, an ESS (energy storage system), and a renewable energy power generation source included in a large-scale operator; And an LCC (local control center) operating in a substation unit and controlling the voltage of each of the sections, wherein the LCC determines the line capacity of each section and the state of charge (SOC) of the ESS, and the A section controller for controlling the flow between the sections through voltage control of the line; An ESS control unit controlling the charging and discharging capacity of the ESS controlled by a section controller included in the section, and controlling a power factor of the line using a power conditioning system (PCS) installed in the ESS; And a new and renewable energy provider control unit controlling the system linkage of the renewable energy power generation source and controlling the power factor of the line using the PCS installed in the renewable energy provider.

The LCC includes another LCC linking unit that performs linkage with another LCC in consideration of at least one of the SOC of the ESS installed in the LCC, the amount of generation of the renewable energy source, the amount of change in the load, and the capacity of the line; It may further include.

In the device, the LCC and the other LCC are connected to each other using one or more of an on load tap changer (OLTC) and a static synchronous compensator (STATCOM), and the remaining capacity of the ESS is insufficient or the capacity of the line LCCs judged to be insufficient can receive insufficient capacity from LCCs that do not.

The apparatus may further include a sensor provided only in the renewable energy generation source as an element having a large influence on the line capacity among the sections to obtain information on the line.

The section may further include a section controller that controls the operation of the section by the LCC and transmits a state of the section to the LCC.

The section controller acquires data related to the line capacity of the section and transmits it to the LCC, determines the capacity of the ESS, and controls the charging and discharging of the ESS according to the command of the LCC. An ESS controller that controls the power factor of the line by using the PCS installed in the ESS according to a command; A large-scale operator controller that predicts the generation amount of the new and renewable energy and controls a power factor by using a PCS installed in the large-scale operator according to a command of the section controller; And a data processor that predicts the amount of power generation of the large-scale operator using meteorological data and predicts a load fluctuation rate using big data.

Other aspects, features, and advantages other than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

According to embodiments, in the case of the prior art, measurement equipment had to be installed in all parts connected to the system, such as a load and a renewable energy source, but in this embodiment, the conventional method by measuring and controlling the receiving voltage of the ESS operated by the LCC. It is more economical because it can reduce the number of measurement equipment installed.

In addition, since the voltage control method is used, it is not necessary to change the tap of the transformer on the line, so it is easier to secure the reliability of the line at the distribution stage than before.

In addition, by using the ESS installed in the LCC, it is possible to connect new and renewable energy such as PV without increasing the line capacity.

The effects of the present invention are not limited to those mentioned above, and other effects that are not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a diagram schematically illustrating a system device according to the prior art.
2 is a diagram schematically illustrating a system stabilization apparatus according to an embodiment of the present invention.
3 is a diagram schematically illustrating a connection concept and a communication concept between LCCs in the system stabilization apparatus shown in FIG. 1.
FIG. 4 is a diagram schematically illustrating a detailed configuration of the voltage stabilizing device shown in FIG. 1.
5 and 6 are diagrams schematically illustrating a control method of the voltage stabilizing apparatus shown in FIGS. 1 and 3.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to embodiments described in detail together with the accompanying drawings. However, it should be understood that the present invention is not limited to the embodiments presented below, but may be implemented in a variety of different forms, and includes all transformations, equivalents, or substitutes included in the spirit and scope of the present invention. . The embodiments presented below are provided to complete the disclosure of the present invention, and to fully inform a person of ordinary skill in the art to which the present invention belongs. In describing the present invention, when it is determined that a detailed description of a related known technology may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

The terms used in the present application are used only to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance. Terms such as first and second may be used to describe various elements, but the elements should not be limited by the terms. These terms are used only for the purpose of distinguishing one component from another component.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings, and in the description with reference to the accompanying drawings, identical or corresponding components are assigned the same reference numbers, and redundant descriptions thereof are omitted. I will do it.

2 is a diagram schematically illustrating a system stabilization apparatus according to an embodiment of the present invention. 2, the system stabilization device 1 operates a local control center (LCC) 110 in a substation (S/S) unit to divide the line into sections according to one or more loads, ESS and renewable energy power generation sources. It is a method of controlling voltage. In the present embodiment, the section is divided into a first section 120 and a second section 130, but is not limited thereto, and may be extended to a first section to an Nth section. In addition, each section (the first section 120, the second section 130) includes one or more loads, a renewable energy source, and an ESS, and contains the line information of a large-scale operator 12-1 such as a renewable energy source. A section controller (first section controller 123, second section) that controls the operation of the section by the acquired sensors 122 and 123 and the corresponding LCC 110 and transmits the state of the section to the LCC 110 It may further include a controller (133).

In the case of a sensor that acquires information of a line (the first PMU (phasor measurement unit) sensor 122, the second PMU sensor 132), the initial facility is installed in all of the existing loads and power sources 121 and 131. Although the investment cost was inevitably high, in the case of this embodiment, the sensor (the first PMU sensor 122, the first PMU sensor 122, the only elements having a large influence on the line capacity, such as the main load (large-capacity customer) and the large-scale power generation operator 121-1) By installing the second PMU sensor 132), it is possible to reduce the initial cost. In addition, it is possible to reduce the number of sensors (first PMU sensor 122, second PMU sensor 132) installed through information exchange with DR (demand response), ESS, and large-scale solar power generation companies. .

FIG. 3 is a diagram schematically illustrating a connection concept and a communication concept between LCCs shown in FIG. 1. Referring to FIG. 3, a first LCC 110 including a first section 120 and a second section 130 is a second LCC 210 including a first section 220 and a second section 230. ) Can be linked.

The first LCC 110 continuously checks the remaining capacity of the ESS installed in the first section 120 or the second section 130, and if it is determined that the remaining capacity of the ESS is insufficient or the capacity of the line is insufficient, the OLTC ( The insufficient capacity may be supplied in connection with the second LCC 210 using one or more of an on load tap changer, a transformer on-load tap changer) and a back-to-back static synchronous compensator (STATCOM) 310. That is, an LCC that is judged to have insufficient remaining capacity of the ESS or insufficient capacity of a line may receive insufficient capacity from an LCC that does not.

FIG. 4 is a diagram schematically illustrating a detailed configuration of the voltage stabilizing device shown in FIG. 1. Referring to FIG. 4, the voltage stabilization device may include an LCC 110, a section controller 123, or 133 (hereinafter referred to as 123), and a large-scale operator 121-1. In this embodiment, the LCC 110 may include a section control unit 111, an ESS control unit 112, a large-scale operator control unit 113, another LCC linking unit 114, and a data processing unit 115, and the section controller 123 may include an ESS controller 123-1, a large-scale operator controller 123-2, and a data processor 123-3.

The section control unit 111 can grasp the line capacity and the state of charge (SOC) of the ESS for each section (the first section 120, the second section 130), and the section through the line voltage control (the first section ( 120), it is possible to control the flow between the second section (130).

The ESS control unit 112 may control the charging/discharging capacity of the ESS controlled by the section controller 123 and control the power factor of a line using a power conditioning system (PCS) installed in the ESS.

The large-scale operator control unit 113 can link and control the system of the large-scale operator 121-1, and control the power factor of the line using a power conditioning system (PCS) installed in the large-scale operator 121-1. have. In this embodiment, a large-scale business operator may be interpreted as having a similar meaning to a renewable energy source business operator or may be interpreted as including a renewable energy source business entity.

The other LCC linking unit 114 is connected with other LCCs (for example, the second LCC 210 of FIG. 3) in consideration of the SOC of the ESS installed in the controlling LCC, the amount of renewable energy generation, the amount of load fluctuation, and the line capacity. It performs linkage, and can link with other LCCs using power facilities such as OLTC and STATCOM.

The data processing unit 115 may store data received from the first section controller 123 and predict the amount of power generation and load fluctuations using the data received from the first section controller 123.

The ESS controller 123-1 included in the section controller 123 may acquire data related to line capacity, such as a load and a power generation amount for a controlled section, and transmit the data to the LCC 110. The ESS controller 123-1 can determine the capacity of the ESS and control charging/discharging of the ESS according to the command of the LCC 110. The ESS controller 123-1 may control the power factor of the line using the PCS installed in the ESS according to the command of the LCC 110.

The large-scale operator controller 123-2 included in the section controller 123 predicts the amount of generation of renewable energy and utilizes the PCS installed in the large-scale operator 121-1 according to the command of the section controller 123. Power factor can be controlled.

The data processor 123-3 included in the section controller 123 may predict new renewable energy, that is, the amount of power generation of the large-scale operator 121-1, using meteorological data, and predict the load fluctuation rate using big data. .

The large-scale operator 121-1 may control the amount of renewable energy generated by the command of the section controller 123 and control the power factor using the PCS.

The main factors affecting the system and the control method can be shown in Table 1 below.

Main factor Control method Voltage -Line voltage control through ESS charge/discharge amount control -Renewable energy generation inflow control Power factor -Power factor control using PCS installed in ESS -Power factor control using PCS installed in large-scale operators -Power factor control using compensator installed in the system Line capacity -ESS charge/discharge amount control -Linkage with other LCCs using power facilities such as STATCOM and OLTC

5 is a diagram schematically illustrating a control control method according to an embodiment of the voltage stabilizing apparatus shown in FIG. 1. 5A, when the capacity of the ESS operated by the LCC 110 is sufficient, the voltage of the line increases due to the inflow of power generated from the renewable energy source, and each section controller (the first section controller 123), The line voltage rise is measured through sensors (the first PMU (phasor measurement unit) sensor 122, the second PMU sensor 132) attached to the second section controller 133, and transmits an ESS charging command. 5B, each section controller (the first section controller 123, the second section controller 133) that has received the ESS charging command is each section (the first section 120, the second section 130) Starts charging the ESS installed in and adjusts the line voltage.

FIG. 6 is a diagram schematically illustrating a control control method according to an embodiment of the voltage stabilizing apparatus illustrated in FIG. 3. Referring to FIG. 6A, when the ESS operated by the first LCC 110 has insufficient capacity, the line voltage of the line managed by the second LCC 210 cannot be sufficiently stored due to insufficient storage of renewable energy flowing into the system. . In this case, as shown in FIG. 6B, the second LCC 210 having a margin of line capacity around the first LCC 110 transmits power to the first LCC 110 using OLTC and back-to-back STATCOM 310, and In order to maintain the line voltage, the first LCC 110 charged with power is charged to an ESS having a charge capacity.

The embodiment according to the present invention described above may be implemented in the form of a computer program that can be executed through various components on a computer, and such a computer program may be recorded in a computer-readable medium. In this case, the medium is a magnetic medium such as a hard disk, a floppy disk, and a magnetic tape, an optical recording medium such as a CD-ROM and a DVD, a magneto-optical medium such as a floptical disk, and a ROM. A hardware device specially configured to store and execute program instructions, such as, RAM, flash memory, and the like.

Meanwhile, the computer program may be specially designed and configured for the present invention, or may be known and usable to those skilled in the computer software field. Examples of the computer program may include not only machine language codes produced by a compiler but also high-level language codes that can be executed by a computer using an interpreter or the like.

In the specification of the present invention (especially in the claims), the use of the term "above" and a similar reference term may correspond to both the singular and the plural. In addition, when a range is described in the present invention, the invention to which an individual value falling within the range is applied (unless otherwise stated), and each individual value constituting the range is described in the detailed description of the invention. Same as

If there is no explicit order or contradictory description of the steps constituting the method according to the present invention, the steps may be performed in an appropriate order. The present invention is not necessarily limited according to the order of description of the steps. The use of all examples or illustrative terms (for example, etc.) in the present invention is merely for describing the present invention in detail, and the scope of the present invention is limited by the above examples or illustrative terms unless limited by the claims. It does not become. In addition, those skilled in the art can recognize that various modifications, combinations, and changes may be configured according to design conditions and factors within the scope of the appended claims or their equivalents.

Therefore, the spirit of the present invention is limited to the above-described embodiments and should not be determined, and all ranges equivalent to or equivalently changed from the claims to be described later as well as the claims to be described later are the scope of the spirit of the present invention. It will be said to belong to.

1: system stabilization device
110, 210: LCC
120, 220: first section
130, 230: second section
122, 132: PMU
123, 223: first section controller
133, 233: second section controller

Claims (6)

A section divided into one or more lines according to a load, an ESS (energy storage system), and a renewable energy generation source included in a large-scale operator; And
Including; LCC (local control center) operating in a substation unit to control the voltage of each of the sections,
The LCC,
A section control unit that determines the line capacity of each section and the state of charge (SOC) of the ESS, and controls the current between the sections through voltage control of the line;
An ESS control unit controlling the charging and discharging capacity of the ESS controlled by a section controller included in the section, and controlling a power factor of the line using a power conditioning system (PCS) installed in the ESS; And
Containing, a system stabilization device comprising; a renewable energy business control unit for controlling the system linkage of the renewable energy generation source and controlling the power factor of the line using the PCS installed in the renewable energy business. The method of claim 1, wherein the LCC,
Another LCC linking unit that performs linkage with another LCC in consideration of at least one of the SOC of the ESS installed in the LCC, the amount of generation of the renewable energy source, the amount of change in the load, and the capacity of the line; further comprising , System stabilization device. The method of claim 2,
The LCC and the other LCC are linked to each other using one or more of an on load tap changer (OLTC) and a static synchronous compensator (STATCOM), and determine that the remaining capacity of the ESS is insufficient or the capacity of the line is insufficient. System stabilization device in which the LCC that is being supplied receives insufficient capacity from the LCC that does not. The method of claim 1,
The system stabilization apparatus further comprises a sensor provided only in the renewable energy generation source as an element having a large influence on the line capacity of the section to obtain information on the line. The method of claim 1, wherein the section,
Controlling the operation of the section by the LCC, and a section controller for transmitting the state of the section to the LCC; further comprising, system stabilization device. The method of claim 5, wherein the section controller,
Acquires data related to the line capacity of the section and transmits it to the LCC, determines the capacity of the ESS, controls charging and discharging of the ESS according to the command of the LCC, and controls the ESS according to the command of the LCC. ESS controller for controlling the power factor of the line by using the PCS installed in the;
A large-scale operator controller that predicts the generation amount of the new and renewable energy and controls a power factor by using a PCS installed in the large-scale operator according to a command of the section controller; And
System stabilization apparatus comprising a; data processor for predicting the amount of power generation of the large-scale operator using meteorological data and predicting a load fluctuation rate using big data.

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