KR20230057689A - System and Method for voltage control using digital grid power router - Google Patents

Abstract

A voltage control system capable of providing a voltage control method suitable for loop operation of a distribution system is disclosed. The voltage control system includes a grid connection block that distributes power, a power relay block installed at a connection point of the grid connection block and performing voltage control using a Digital Grid Power Router (DGPR), and and a digital grid to which the power is supplied from the grid connection block by the voltage control.

Description

System and method for voltage control using digital grid power relay router {System and Method for voltage control using digital grid power router}

The present invention relates to voltage control technology, and more particularly, to a voltage control system and method using a digital grid power relay router in a power distribution system.

The domestic distribution system is operated in an open-loop system with a always-open loop point between two lines. With the introduction of the automation system, the outage time has been drastically reduced, but the feeling of the number of outages has not improved significantly.

Against this background, the necessity of introducing a closed-loop system has been raised for the purpose of improving supply reliability. In 2009, starting with the 'Research on Establishment of Operating Standards for Loop Distribution System', the enactment of related regulations was promoted, and a plan for pilot operation was established. In 2013, a study on ‘low voltage underground distribution loop method’ was conducted for the purpose of improving the supply reliability of the low voltage system.

(High Voltage CLS) In order to improve the supply reliability of the domestic distribution system, KEPCO conducted a study on the establishment of operating standards for the loop distribution system in 2009. The Closed-Loop distribution line constitutes a closed loop with two distribution lines (Feeders) drawn from the same main voltage generator (M.Tr), and a high-speed circuit breaker is installed at the connection point.

When a fault occurs, fault information is mutually exchanged during the blocking period using a high-speed optical communication network to generate a trip in the circuit breaker closest to the faulty line, thereby separating the faulty section from the healthy section and minimizing the blackout section.

In addition, it is possible to block even when an internal failure of the circuit breaker and a failure of the branch line connected to the circuit breaker occur, so that the failure of the branch line does not spread.

In order to increase supply reliability in the high-voltage distribution loop system, it is important to isolate the faulty point by simultaneously blocking both ends of the faulty point. In order to simultaneously operate the breakers on both sides, relays are connected 1:1 through optical communication and developed to enable mutual communication. When excessive current flows due to a fault, information on the current direction is exchanged with each other to effectively isolate the fault point.

In Korea, starting with the establishment of the Sejong phase 1 supply project development plan in 2008, Seogwipo Innovation City (`09.2), Sejong City 1-2, 1-4, 1-5, 2-3 districts (`13.12), high voltage distribution lines A closed loop system was pilot operated. As a result of the pilot operation, it was judged that malfunction occurred due to the transient phenomenon of the distributed power supply and the defective protection coordination module, and that the protection coordination algorithm and communication function needed improvement.

In addition, as a result of the simulation, when two or more banks are included in the high-voltage loop, there is a problem in that a circulating current is generated due to a phase difference between the transformers, contributing to an increase in loss.

In addition, it was judged that the loop distribution system would contribute to the improvement of supply reliability and loss reduction, but as a result of the pilot operation, problems such as poor protection cooperation or facility utilization did not meet expectations.

In addition, even if the loop is operated, the power flow cannot be controlled and is determined in inverse proportion to the impedance of the line, so the current may be biased to one line. In addition, in order to isolate the fault point in the event of a fault, both circuit breakers must operate simultaneously, which complicates protection coordination and has a risk of breaking failure.

Meanwhile, current distribution systems are mostly normally open, and distribution voltage is controlled by tap switching of ULTC (Under Load Tap Changer) or OLTC (On Load Tap Changer) of the substation. Recently, since it is often operated in connection with the distribution system of new and renewable energy sources, the voltage is controlled using SVR (Step Voltage Regulator) for long-distance lines or lines with severe load fluctuations.

In the voltage control method using SVR, mechanical wear occurs due to frequent tap switching due to the introduction of new and renewable energy sources in distribution lines, and it is difficult to control the voltage of reverse current generated when the line is under low load. In addition, when the distribution system is operated in the form of a loop, there is a problem in that line loss may increase due to generation of circulating current between transformers when voltage regulation of ULTC or OLTC is performed.

Recently, as the introduction of distributed power in the distribution system increases, a method of performing power factor or voltage control in the distributed power itself is being studied. However, when a specific distributed power source performs voltage control in an environment in which a large number of distributed power sources are introduced, the control method has a disadvantage in that the control method is complicated because it affects the nearby voltage and requires cooperative control between generators to solve this problem.

Meanwhile, voltage control using ESS (Energy Storage System) is also being studied. ESS can control reactive power and can also store active power. However, there are problems in that the storage of active power is limited, and limitations such as high cost of the battery and risk of fire are clear. As a result, a voltage control method suitable for the loop operation of the distribution system is required.

1. Korea Patent Registration No. 10-2199222 (registration date: December 30, 2020)

The present invention has been proposed to solve the problems caused by the above background art, and an object of the present invention is to provide a voltage control system and method capable of providing a voltage control method suitable for loop operation of a distribution system.

Another object of the present invention is to provide a voltage control system and method capable of effectively performing voltage control in a loop distribution environment composed of multi-terminal converters.

In order to achieve the above object, the present invention provides a voltage control system capable of providing a voltage control method suitable for loop operation of a distribution system.

The voltage control system,

a grid connection block that distributes power;

A power relay block installed at a connection point of a grid connection block and performing voltage control using a Digital Grid Power Router (DGPR); and

and a digital grid to which the electric power is supplied from the grid connection block by the voltage control.

In addition, the power relay block may include a controller that performs the voltage control through the digital grid power relay router.

In addition, the digital grid power relay router may include an inductor connected in series to the resistance of the grid connection block; and an inverter connected in series to the inductor to convert AC power into DC power.

In addition, the digital grid power relay router may include a filter capacitor connected in series to the inverter to remove noise from the DC power.

In addition, the controller may include a measurement module for generating a measurement voltage by measuring an output voltage at an output terminal of the power relay block; a calculation module for calculating an active power control range and a reactive power control range according to whether the measured voltage is within a preset voltage holding range; and a compensation module for executing active power output compensation and reactive power output compensation, respectively, according to the active power control range and the reactive power control range.

(여기서, P_a1,2는 유통 가능량이고,

,

, P₊, P_-는 각각 방출, 흡수하는 유효전력을 의미하며, 아래첨자 1, 2는 기준이 되는 터미널 번호이고, V_{max, min}은 각각 규정전압의 최대/최소를 의미하며, Z_eq는 출력단에서 보는 등가 임피던스를 나타낸다)으로 정의되는 것을 특징으로 한다.In addition, the active power control range is expressed by Equation

(Where P _a1,2 is the circulating amount,

,

, P ₊ , P _- mean the active power emitted and absorbed, respectively, subscripts 1 and 2 are terminal numbers that are standard, V _{max and min} mean the maximum/minimum of the specified voltage, respectively, and Z _eq is represents the equivalent impedance seen at the output terminal).

으로 한정되는 것을 특징으로 한다.In addition, the ranges of P _a1 and P _a2 are each expressed by Equation

It is characterized by being limited to.

In addition, the active power output compensation and the reactive power output compensation are characterized in that they are calculated using voltage compensation amounts (Δ _max , ΔV _min ) and active power amounts for voltage ancestors (Δ _max , ΔP _min ).

으로 정의되는 것을 특징으로 한다.In addition, the voltage compensation amount (Δ _max ,ΔV _min ) is expressed by the equation

It is characterized by being defined as

In addition, the active power amount (Δ _max , ΔP _min ) is expressed by Equation

(Here, Z _eq represents the equivalent impedance seen at the output terminal, and V' _m is the compensation measurement voltage measured during active power output compensation).

In addition, the compensation module is terminated when the compensation measurement voltage (V' _m ) satisfies a predetermined value (V _min <V' _m1,2 < V _max ), and the voltage control is impossible only with the active power output compensation. In this case, it is characterized in that the reactive power output compensation is additionally executed.

In addition, the additionally executing the reactive power output compensation is characterized in that compensation is performed in proportion to the amount of active power of the distributed power source.

On the other hand, additionally executing the reactive power output compensation is characterized in that the control of reactive power according to the system voltage.

On the other hand, another embodiment of the present invention, (a) the grid connection block to distribute power; (b) installing a power relay block at a connection point of a grid connection block and performing voltage control using a digital grid power router (DGPR); and (c) the digital grid receiving the power from the grid connection block 110 by the voltage control.

Meanwhile, the step (c) may include generating a measured voltage by measuring an output voltage at an output terminal of the power relay block by a measurement module; calculating, by a calculation module, an active power control range and a reactive power control range according to whether the measured voltage is within a preset voltage holding range; and executing, by a compensation module, active power output compensation and reactive power output compensation according to the active power control range and the reactive power control range, respectively.

According to the present invention, by implementing a loop operation method using a digital grid power router (hereinafter referred to as DGPR), it is possible to serially connect and operate power electronic device infrastructure (ex: Back to Back) at a line connection point. there is.

In addition, other effects of the present invention include improving line utilization using active power control, reducing loss by preventing circulating current between transformers, and improving power quality through reactive power and voltage control using converter phase control.

In addition, as another effect of the present invention, in the case of a converter, it is possible to control the phase of voltage and current, thereby supplying reactive power, and as a result, voltage control is possible, so that voltage drop compensation of long-span lines is possible. It can be said that

In addition, as another effect of the present invention, it is possible to increase the amount of connection of new and renewable energy by controlling the terminal voltage increase according to recently increasing distributed power sources.

In addition, as another effect of the present invention, it is possible to significantly increase the amount of new and renewable energy sources introduced into the distribution system by solving the distribution voltage problem due to distributed resources.

1 is a block diagram of a voltage control system according to an embodiment of the present invention.
FIG. 2 is a circuit diagram of the voltage control system shown in FIG. 1 .
3 is a conceptual diagram of 4-quadrant operation according to an embodiment of the present invention.
4 is an example of active power control according to an embodiment of the present invention.
5 is an example of reactive power control according to an embodiment of the present invention.
6 is a voltage control flowchart according to an embodiment of the present invention.
7 is a conceptual diagram showing a controllable range of active power according to an embodiment of the present invention.

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

In describing each figure, like reference numbers are used for like elements.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another.

For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention. The term "and/or" includes any combination of a plurality of related listed items or any of a plurality of related listed items.

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 the present invention belongs.

Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in this application, it should not be interpreted in an ideal or excessively formal meaning. Should not be.

Hereinafter, a voltage control system and method using a digital grid power relay router according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a voltage control system 100 according to an embodiment of the present invention. Referring to FIG. 1 , the voltage control system 100 may include a grid connection block 110, a power relay block 120, a digital grid 130, and the like.

The grid connection block 110 performs a function of distributing power. To this end, a closed-loop distribution line is constructed and a connection point is arranged.

The power relay block 120 is installed at a line connection point of the grid connection block 110 and performs a voltage control function using a digital grid power router (DGPR). In particular, the power relay block 120 is operated by serially connecting power electronic device infrastructure (ex: Back to Back) to a line connection point in a closed-loop distribution line.

The digital grid 130 is a new power supply method capable of bidirectional power transfer between MGs in order to improve the reliability of the distribution system and/or reduce the system burden by grid connection of distributed power sources by using a plurality of microgrids (MGs). A microgrid is a regional power grid that manages the supply and demand of energy on a small scale by accommodating distributed energy sources. In other words, it is a regional grid that economically supplies the energy needed in the area by economically combining not only renewable energy sources but also various distributed energy sources.

FIG. 2 is a circuit diagram of the voltage control system 100 shown in FIG. 1 . Referring to Figure 2. A closed-loop distribution line is formed in the grid connection block 110, and the closed-loop distribution line constitutes a closed loop with two or more distribution lines (feeders) drawn from the same main transformer 211, and the connection point A circuit breaker 212 is installed for each phase (U1, V1, W1). The main transformer 211 may use a three-phase transformer, and receives a three-phase voltage (U, V, W) of about 22.9 kV as an input and transforms it into a three-phase 380V voltage (U1, V1, W1). .

When a fault occurs, fault information is mutually exchanged during the blocking period using a high-speed optical communication network to generate a trip in the circuit breaker closest to the faulty line, thereby separating the faulty section from the healthy section and minimizing the blackout section. As the circuit breaker 212, an air circuit breaker (ACB) is used, but a vacuum circuit breaker or the like is also possible.

An end of the circuit breaker 212 may be branched into two, and a contactor 213 may be configured at the branched part. At the end of the contactor 213, a resistor CHRe 214 and an inductor ACL 221 may be disposed in series for each phase U5, V5, and W5.

In addition, it is possible to block even when an internal failure of the circuit breaker and a failure of the branch line connected to the circuit breaker occur, so that the failure of the branch line does not spread.

In addition, in order to increase supply reliability in the distribution loop system, it is important to isolate the faulty point by simultaneously blocking both ends of the faulty point. In order to simultaneously operate the circuit breaker, relays (not shown) are connected 1:1 through optical communication and mutual communication is possible.

The power relay block 120 is composed of a digital grid power relay router (DGPR) 220 and a controller 200 that performs voltage control through the digital grid power power relay router 220. The digital grid power relay router 220 includes an inductor 221 serially connected to the resistor 214 of the grid connection block 110, and an inverter connected in series to the inductor 221 to convert AC power into DC power. 222, a filter capacitor 223 connected in series to the inverter 222 to remove noise from the DC power, and the like. The inductor ACL 221, the inverter 222, and the filter capacitor FC 223 are sequentially connected in series.

The inverter 222 has a structure in which two power switching devices 222-1 for power are symmetrically configured for each phase. That is, two power switching devices 222-1 for power are configured in pairs on one phase, and the phase is connected to the central point where the two power power switching devices 222-1 are connected.

As the power switching device 222-1, IGBT (Insulated Gate Bipolar Mode Transistor) is mainly used, but is not limited thereto, and FET (Field Effect Transistor), MOSFET (Metal Oxide Semiconductor FET), power rectifier diode, etc. A semiconductor switching element, a thyristor, a gate turn-off (GTO) thyristor, a triode for alternating current (TRIAC), a silicon controlled rectifier (SCR), an integrated circuit (IC) circuit, and the like may be used. In particular, in the case of a semiconductor device, a bipolar or power MOSFET (Metal Oxide Silicon Field Effect Transistor) device may be used. The power MOSFET device has a DMOS (Double-Diffused Metal Oxide Semiconductor) structure unlike general MOSFETs due to its high-voltage, high-current operation.

The power relay block 120 is configured in the form of a multi-terminal back-to-back converter in which a plurality of inverters 222 are combined, and the distribution system is configured as a single loop or three or more multi-loops by determining the number of inverters as necessary. can do.

The power relay block shares the DC side of the inverter and is connected as one, and the AC side (terminal) is directly connected to each other distribution line to make a dendritic distribution system in the form of a loop.

The converter can control the phase of the voltage and current, and accordingly, the supply of reactive power is possible. As a result, since voltage control is possible, it is possible to compensate for the voltage drop of long-span lines, and it is possible to improve the amount of connection of new and renewable energy by controlling the terminal voltage rise according to the recently increasing distributed power supply.

The controller 200 measures the output voltage at both ends of the multi-terminal (more precisely, both ends of the filter capacitor) and measures the output voltage to generate a measurement module 201, which is effective according to whether the measured voltage is within a preset voltage holding range. Comprising a calculation module 202 that calculates the power control range and reactive power control range, and a compensation module 203 that executes active power output compensation and reactive power output compensation according to the active power control range and reactive power control range, respectively do. According to the operation of the compensation module 203, the inverter 222 is turned on/off.

The measurement module 201 performs a function of converting an output voltage into a measurement voltage using the sensors 201a and 201b. The sensors 201a and 201b may be current sensors or voltage sensors. As the current sensor, a hall sensor, an optical fiber current sensor, a current transformer (CT) type current sensor, or the like may be used. A voltage sensor may be a PT (Potential Transformer).

The measurement module 201, calculation module 202, and compensation module 203 shown in FIG. 2 refer to units that process at least one function or operation, and may be implemented in software and/or hardware. In hardware implementation, ASIC (application specific integrated circuit), DSP (digital signal processing), PLD (programmable logic device), FPGA (field programmable gate array), processor, microprocessor, other It may be implemented as an electronic unit or a combination thereof.

In software implementation, software component components (elements), object-oriented software component components, class component components and task component components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, data , databases, data structures, tables, arrays, and variables. Software, data, etc. may be stored in memory and executed by a processor. The memory or processor may employ various means well known to those skilled in the art.

Meanwhile, in FIG. 2, for convenience of understanding, it is shown as one circuit block, but several circuit blocks may be configured in parallel. For example, it may be exemplified that three transformers, circuit breakers, and inverters are configured in parallel, and three or more may also be configured in parallel. In this case, multiple terminals are configured.

3 is a conceptual diagram of 4-quadrant operation according to an embodiment of the present invention. Referring to FIG. 3 , in general, the converter is capable of 4-quadrant operation as shown in FIG. 3 . When the active power (P) is +, it means that the forward current flow control in the reference direction is controlled in the reverse direction when the active power (P) is -. Reactive power (Q) of + and - means ground and advancing operation, respectively. Since this is widely known, further description will be omitted.

4 is an example of active power control according to an embodiment of the present invention, and FIG. 5 is an example of reactive power control according to an embodiment of the present invention. 4 and 5, when the flow of active power (substation S / S 410, transformer 420, distribution line (D / L)) in one direction is -, power is absorbed and the same amount in the other direction emits SoP is the Substation Failure Recovery Operation Procedure (Standard Operation Procedure).

On the other hand, reactive power can be controlled within the operation range of unmarked power (Q) by being generated by the phase difference between voltage and current regardless of the direction of the flow of reactive power on one side.

In FIGS. 4 and 5, PV means photovoltaic power generation, and D1 and D2 mean each dendritic distribution line. When the PV outputs active power in the dendritic line, the voltage at the output terminal rises. In order to control this, it is an example that voltage control can be performed by diverting active power to D1 > D2 or controlling reactive power with a digital power relay router.

6 is a flowchart of voltage control according to an embodiment of the present invention, and FIG. 7 is a conceptual diagram showing an active power controllable range according to an embodiment of the present invention. An operation according to an embodiment of the present invention is utilized for voltage control in a high-voltage loop or multi-loop method. Since the distribution system has a smaller X/R ratio compared to transmission and distribution, voltage fluctuations due to active power cannot be ignored. Here, X is reactance and R is resistance.

If voltage control is performed only with reactive power, distribution loss may increase due to an increase in apparent power. Therefore, first of all, the utilization rate of the loop operating line is increased through active power control, and when control of the specified voltage is impossible only with active power control, inactive power control is simultaneously performed.

Accordingly, voltage control follows the sequence shown in FIG. 6 .

Referring to FIG. 6, the measurement module 201 of the controller 200 measures the output voltage at the output terminals of both sides of the multi-terminal through the sensors 201a and 201b to generate the measured voltage V _m1,2 (step S610). ).

Thereafter, the calculation module 202 determines whether the measured voltage (V _m1,2 ) falls within a preset voltage holding range (V _min < V _m1,2 < V _max ) (step S620). Here, V _min is the upper limit and V _max is the lower limit.

As a result of the determination in step S620, if the measured voltage (V _m1,2 ) is within the preset voltage holding range (V _min < V _m1,2 < V _max ), the process proceeds to step S610.

Unlike this, as a result of the determination in step S620, if the measured voltage (V _m1,2 ) is not within the preset voltage holding range (V _min < V _m1,2 < V _max ), the available distribution amount (P _a1,2 ) (710 ) is calculated (step S630). To elaborate, since the voltage is different across the converter, the range of active power that can be emitted or absorbed is different.

If the currently measured voltage is V _m1,2 , the active power control range of each output stage considering the specified voltage can be calculated as follows.

,

, P₊, P_-는 각각 방출, 흡수하는 유효전력을 의미하며, 아래첨자 1, 2는 기준이 되는 터미널 번호이다.here,

,

, P ₊ , P _- means active power emitted and absorbed, respectively, and subscripts 1 and 2 are terminal numbers that are standard.

If the standard terminal number is 1, the opposite terminal in 2 terminal means 2.

V _{max and min} mean the maximum/minimum of the specified voltage, respectively, and Z _eq represents the equivalent impedance seen from the output terminal.

As shown in FIG. 7 , the area where the ranges of P _a1 and P _a2 overlap is the active power control range.

Referring to FIG. 6, as an example when the specified voltage is exceeded at output terminal 1, the active power control range P _a is from -P ₊₂ to P ₊₁ , and based on this, the application range at each output terminal is Equivalent to the expression below.

Since 1 and 2 have opposite directions, the controllable range of terminal 2 is the range taken by taking - from the range of terminal 1 in the reference direction. In other words, in the structure of BTB (Back-to-Back), when active power is emitted from one side, the same amount of active power must be absorbed from the other side, so the direction is opposite.

Thereafter, the voltage compensation amount (ΔV _max ,ΔV _min ) can be calculated as in the following equation.

The amount of active power for voltage compensation (ΔP _max , ΔP _min ) is calculated as follows.

Here, V' _m is a compensation measurement voltage measured during active power output compensation.

When the active power is compensated, the compensation measurement voltage is terminated when the specified value (V _min <V' _m1,2 < V _max ) is satisfied. ).

There are two ways to compensate for reactive power. First, it is a method of compensating in proportion to the amount of active power of the distributed power source. Although the control method is relatively simple without considering the linkage point voltage, there is a possibility that the voltage range is exceeded.

The second is the control of reactive power according to the grid voltage V. This is a method of emitting and absorbing reactive power as needed by analyzing the voltage sensitivity according to the input of free power. As mentioned before, the control range of reactive power is possible within the output range of each converter and can be controlled independently of each other.

On the other hand, it is possible to improve power quality such as voltage and frequency by connecting in series to a long-span distribution line rather than operating a loop.

In addition, the steps of a method or algorithm described in connection with the embodiments disclosed herein are implemented in the form of program instructions that can be executed through various computer means such as a microprocessor, processor, CPU (Central Processing Unit), etc. It can be recorded on any available medium. The computer readable medium may include program (instruction) codes, data files, data structures, etc. alone or in combination.

The program (command) code recorded on the medium may be specially designed and configured for the present invention, or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs, DVDs, and Blu-rays, and ROMs and RAMs ( A semiconductor storage element specially configured to store and execute program (instruction) codes such as RAM), flash memory, or the like may be included.

Here, examples of the program (command) code include high-level language codes that can be executed by a computer using an interpreter, as well as machine language codes such as those produced by a compiler. The hardware devices described above may be configured to act as one or more software modules to perform the operations of the present invention, and vice versa.

100: voltage control system
110: grid connection block
120: power relay block
130: digital grid
200: controller
201a, 201b: sensor
201: measurement module 202: calculation module
203: compensation module
211: main transformer 212: circuit breaker
213: contactor 214: resistor
220: digital grid power relay router
221: inductor 222: inverter
222-1: switching power element for power
223 filter capacitor

Claims (18)

Grid connection block 110 for distributing power;
A power relay block 120 installed at a connection point of the grid connection block 110 and performing voltage control using a Digital Grid Power Router (DGPR) 220; and
a digital grid 130 to which the power is supplied from the grid connection block 110 by the voltage control;
A voltage control system using a digital grid power relay router comprising a.
According to claim 1,
The power relay block 120,
A voltage control system using a digital grid power relay router, characterized in that it comprises a; controller 200 for performing the voltage control through the digital grid power relay router 220.
According to claim 2,
The digital grid power relay router 220,
an inductor 221 connected in series with the resistor 214 of the grid connection block 110; and
an inverter 222 connected in series with the inductor 221 to convert AC power into DC power;
A voltage control system using a digital grid power relay router comprising a.
According to claim 3,
The digital grid power relay router 220,
A voltage control system using a digital grid power relay router comprising a; filter capacitor 223 connected in series to the inverter 222 to remove noise from the DC power.
According to claim 3,
The controller 200,
a measurement module 201 generating a measurement voltage by measuring an output voltage from an output terminal of the power relay block 120;
a calculation module 202 for calculating an active power control range and a reactive power control range according to whether the measured voltage is within a preset voltage holding range; and
A voltage control system using a digital grid power relay router comprising a; compensation module 203 for executing active power output compensation and reactive power output compensation, respectively, according to the active power control range and the reactive power control range. .
According to claim 5,
The active power control range is expressed by Equation

(Where P _a1,2 is the circulating amount,

,

, P ₊ , P _- mean the active power emitted and absorbed, respectively, subscripts 1 and 2 are terminal numbers that are standard, V _{max and min} mean the maximum/minimum of the specified voltage, respectively, and Z _eq is A voltage control system using a digital grid power relay router, characterized in that it is defined as the equivalent impedance seen at the output end).
7. The method of claim 6, wherein the ranges of the P _a1 and the P _a2 are each Equation

A voltage control system using a digital grid power relay router, characterized in that limited to.
According to claim 5,
The active power output compensation and the reactive power output compensation are digital grid power, characterized in that calculated using the voltage compensation amount (Δ _max , ΔV _min ) and the active power amount (Δ _max , ΔP _min ) for voltage ancestors Voltage control system using relay router.
According to claim 8,
The voltage compensation amount (Δ _max ,ΔV _min ) is expressed by the equation

A voltage control system using a digital grid power relay router, characterized in that defined as.
According to claim 9,
The active power amount (Δ _max ,ΔP _min ) is expressed by the equation

(Where, Z _eq represents the equivalent impedance seen at the output terminal, and _V'm is a compensation measurement voltage measured during active power output compensation). Voltage control system using a digital grid power relay router, characterized in that defined.
According to claim 10,
The compensation module 203 is terminated when the compensation measurement voltage (V' _m ) satisfies a predetermined value (V _min <V' _m1,2 < V _max ), and voltage control is impossible only with the active power output compensation. In this case, a voltage control system using a digital grid power relay router, characterized in that for further executing the reactive power output compensation.
According to claim 11,
Further executing the reactive power output compensation is a voltage control system using a digital grid power relay router, characterized in that for compensating in proportion to the amount of active power of the distributed power source.
According to claim 11,
Further executing the reactive power output compensation is a voltage control system using a digital grid power relay router, characterized in that the control of reactive power according to the grid voltage.
(a) the grid connection block 110 distributing power;
(b) the power relay block 120 is installed at the connection point of the grid connection block 110 and performs voltage control using a Digital Grid Power Router (DGPR) 220; and
(c) the digital grid 130 receiving the power from the grid connection block 110 by the voltage control;
A voltage control method using a digital grid power relay router comprising a.
15. The method of claim 14,
The power relay block 120,
A voltage control method using a digital grid power relay router, characterized in that it includes; a controller (200) performing the voltage control through the digital grid power relay router (220).
According to claim 15,
The digital grid power relay router 220,
an inductor 221 connected in series with the resistor 214 of the grid connection block 110; and
an inverter 222 connected in series with the inductor 221 to convert AC power into DC power;
A voltage control method using a digital grid power relay router comprising a.
17. The method of claim 16,
In step (c),
measuring an output voltage from an output terminal of the power relay block 120 by the measurement module 201 to generate a measurement voltage;
calculating, by the calculation module 202, an active power control range and a reactive power control range according to whether the measured voltage is within a preset voltage holding range; and
Compensation module 203 executing active power output compensation and reactive power output compensation according to the active power control range and the reactive power control range, respectively; voltage using a digital grid power relay router comprising: control method. 18. The method of claim 17,
The active power control range is expressed by Equation

(Where P _a1,2 is the circulating amount,

,

, P ₊ , P _- mean the active power emitted and absorbed, respectively, subscripts 1 and 2 are terminal numbers that are standard, V _{max and min} mean the maximum/minimum of the specified voltage, respectively, and Z _eq is A voltage control method using a digital grid power relay router, characterized in that defined as an equivalent impedance seen at an output terminal).

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