WO2012043938A1 - System and method for controlling power flow - Google Patents

Abstract

Disclosed are a system and a method for controlling power flow. The power flow control system for controlling power flow according to one embodiment of the present invention comprises: a power flow limiting device connected to a sending end and a receiving end in a series, and limiting the power flow to the sending end and the receiving end; a managing device for generating a power flow volume of the sending end and the receiving end using system data; and a controlling device for generating control data using measurement data that measures the power flow volume received from the managing device and the sending end and the receiving end, and generating a gate signal to the power flow limiting device using the control data.

Description

Power current control system and method

The present invention relates to a power current control system, and more particularly, the present invention relates to a power current control system and method using a thyristor.

AC power transmission system is a system that sends electric power to AC by using the electric method used for power transmission. In the early days when electricity was practically used, direct current was mainly used, but power generation, transmission, and distribution were mostly made of alternating current as three-phase alternating current, which can easily increase and decrease voltage (ie, boost and step down), became practical. In addition, the AC power transmission system has an advantage that it is easy to change the voltage compared to the DC power transmission system to operate the power system economically. However, the AC system is difficult to freely control the electric power, and has difficulty in operating the electric power system due to the characteristics of the AC power transmission, which is difficult to control the current flow while the power system is large and the electric power is transmitted over a long distance.

It is necessary to control the power flow in order to solve the transmission constraint and circulating current, which are highlighted by the problems of the AC transmission line.

As a method for controlling power flow, flexible AC transmission systems (FACTS) using the latest power electronic devices are being introduced into the system. Facilities of the flexible power transmission system controlling the power flow include a Unified Power Flow Controller (UPFC), a Static Synchronous Series Compensator (SSSC), and a Thyristor Controlled Series Compensator (TCSC). ) And Thyrister Switched Capacitor (TSSC) have been developed and applied to the transmission system.

In the case of the integrated power flow controller and stationary synchronous series compensator, it is very expensive as a flexible power transmission system using voltage source inverter technology, and a large capacity inverter must be applied to apply to a real power transmission system. It is not suitable as a device for controlling a large power flow.

In the case of the thyristor control series compensator and the thyristor switch capacitor, there is a limit in the amount of power current control by controlling the impedance of the transmission line. That is, the thyristor control series compensator and the thyristor switch capacitor control the impedance of the transmission line, so there is a limit of the control amount of the transmission line.

Therefore, when the power current is large, it is necessary to lower the power current to facilitate system operation, and when the accident occurs due to the low power current, it is necessary to limit the overload by limiting the power current.

The present invention provides a power flow control system and method that can control the power flow in the entire range of the transmission line capacity using the thyristors.

In addition, the present invention is to provide an electric current control system and method that is installed in the overload line to prevent overload and limit the electric current in the event of a failure.

The present invention also provides a power current control system and method that can reduce power transmission constraints and suppress circulating currents.

According to one aspect of the invention, there is provided a power current control system for controlling the power current.

According to an embodiment of the present invention, a power current control system for controlling power current, comprising: a power current limiting device connected in series with a power transmission end and a power receiving end, and limiting the power current for the power transmission end and the power receiving end; A management device for generating a power current amount of the power transmitter and the power receiver using system data; And generating control data by using the amount of power current received from the management device and measured data obtained by measuring the power transmission end and the power reception end, and generating a gate signal to the power current limiting device using the control data. A power flow control system is provided that includes an apparatus.

The power current limiting device is turned on by the gate signal (power-on) to control the phase of the power supply stage and the power receiving end to limit the power flow to the power supply stage and the power receiving end It may include.

The control device may include a controller configured to generate the control data for controlling the power current limiting device based on the measured data based on the amount of power current.

The controller may generate the control data including a supply period indicating a period of supplying the gate signal to the power electronic device.

The control device may include a gate driver for generating the gate signal to the power electronic device according to a supply period included in the control data.

The power electronic device may be a thyristor.

The control device may further include an analog-to-digital converter converting the measurement data from an analog signal to a digital signal, converting the measured data into the digital signal and transmitting the converted digital signal to the controller.

The management device may include: a power system analysis unit configured to analyze the system data to generate a power current amount of the power transmission stage and the power reception stage when stationary; And a system accident analysis unit configured to analyze the system data and the accident occurrence event data to determine a system accident, and to generate a power current amount of the power transmission terminal and the power receiving terminal when transient according to the system accident.

The power current limiting device may further include a high frequency filter connected to each of the power transmitting end and the power receiving end, and suppressing harmonics of power currents flowing through the power transmitting end and the power receiving end.

The power current limiting device is connected to each of the power supply terminal and the power receiver, and suppresses harmonics of the power current flowing through the power supply terminal and the power receiver, and a transformer for raising or lowering the voltage of the power supply terminal and the power receiver. It may further include.

The measurement data may include at least one of voltage measurement data, current measurement data, phase measurement data, and bird flow direction measurement data.

The control device may include a voltage measuring unit configured to generate voltage measurement data by measuring voltages of the power transmitting end and the power receiving end; A current measuring unit configured to generate current measurement data by measuring currents of the power transmitter and the power receiver; A phase determination unit configured to determine phases of the power transmission end and the power reception end to generate the phase measurement data; And a tidal current direction recognizing unit generating the tidal flow direction measurement data by recognizing the directions of the power current flowing through the power transmission stage and the power receiving stage.

The power current control system may further include a cooling device connected to the power current limiting device and cooling the heat generated by the power current limiting device.

The power current control system may further include a protection device connected to the power current limiting device and protecting the power current limiting device.

The management device collects system data from at least one of an Energy Management Systems (EMS), a Supervisory Control and Data Acquisition (SCADA), and a Phaser Measurement System (PMU). Can be received.

And, according to another aspect of the present invention, there is provided a power bird control method for the power bird control system to control the power bird.

According to an embodiment of the present invention, a power flow control method for controlling a power flow in a power flow control system, comprising: (a) generating a power flow rate of the power transmission stage and the power receiving stage using system data; (b) generating control data using the measured amount of power current and the transmission end and the power receiving end; (c) generating a gate signal to a power current limiting device using the control data; And (d) a power current element included in the power current limiting device is turned on by the gate signal to limit power flow to the power transmission stage and the power reception stage. A control method is provided.

The step (b) may include: (b1) generating power reference data or current reference data according to the amount of power current; And (b2) generating the control data according to the current measurement data of the measurement data or the power measurement data generated using the current measurement data based on the current reference data or the power reference data. .

The step (b2) may include generating power comparison data by comparing the power reference data and the power measurement data or generating current comparison data by comparing the current reference data and the current measurement data; And generating control data by performing PI control on the power comparison data or the current comparison data.

The step (b) may include generating the control data including a supply period indicating a period of supplying the gate signal to the power electronic device using the power current amount and the measurement data.

Step (c) may be a step of transmitting the gate signal to the power current limiting device according to the supply period included in the control data.

The method of controlling the power current may further include determining whether at least one of the amount of power current and the system data corresponds to a gate-off condition before the step (b).

The step (b) may include generating the control data using the power flow amount and the measurement data when at least one of the power current amount and the system data does not correspond to the gate-off condition. .

In the step (a), the system data is analyzed to generate power currents of the power transmitter and the power receiver when stationary, or the power transmitter when transient according to a system accident that analyzes the system data and accident occurrence event data. And generating a power current amount of the power receiver.

1 is a view showing a power current control system according to an embodiment of the present invention.

2 is a block diagram illustrating an apparatus for managing a power flow control system according to an exemplary embodiment of the present invention.

3 is a block diagram showing a control device of a power current control system according to an embodiment of the present invention.

4 is a flowchart illustrating a method of controlling power flow according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating a method for controlling power current according to an embodiment of the present invention.

6 is a circuit diagram illustrating an apparatus for limiting power current according to an embodiment of the present invention.

7 to 10 are diagrams showing simulation results of applying the power current control system according to an embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

10: Electric current control system

100: power current limiting device

110, 120: high frequency filter

130, 140: Transformer

150: power electronic device

200: management device

220: power system analysis unit

230: system accident analysis unit

300: control unit

320: measuring instrument

340: analog to digital converter

350: control unit

360: Gate Driver

380: Cooling Unit

390: protective device

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

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

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Hereinafter, an embodiment of a power current control system and method according to the present invention will be described in detail with reference to the accompanying drawings, in the following description with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals and Duplicate explanations will be omitted.

Power flow control system according to an embodiment of the present invention will be described with reference to FIGS.

1 is a view showing a power current control system according to an embodiment of the present invention.

Referring to FIG. 1, the power flow control system 10 includes a power flow control device 100, a management device 200, a control device 300, a cooling device 380, and a protection device 390.

The power current limiting device 100 is connected in series with the power transmitting end 20 and the power receiving end 40, and limits the power current for the power transmitting end 20 and the power receiving end 40. The power current limiting device 100 includes first and second high frequency filters 110 and 120, first and second transformers 130 and 140, and a power electronic device 150.

The first high frequency filter 110 is connected in series with the power transmission terminal 20, suppresses harmonics of power current flowing in the power transmission terminal 20, and the second high frequency filter 120 is in series with the power receiving terminal 40. It is connected, and suppresses the harmonics of the power algae flowing in the power receiver 40. That is, the first and second high frequency filters 110 and 120 mainly suppress the 11th, 13th, 23rd, and 25th harmonics, thereby improving the power quality of the power system.

The first transformer 130 is connected in series with the power transmission terminal 20 and increases or decreases the voltage to suppress harmonics of the power current flowing through the power transmission terminal 20. The first transformer 130 may be connected to the power transmission line 30 connected to the power transmission terminal 20.

The second transformer 140 is connected in series with the power receiving end 40 to suppress harmonics of the power current flowing through the power receiving end 40, and boost or step down.

The first and second transformers 130 and 140 may be formed as delta connection transformers to suppress harmonics, reduce voltage sharing of the power electronic device 150, and conveniently control power flow. In this case, the first and second transformers 130 and 140 may be formed of any one of a delta connection transformer of YD-DY, YD-DD, YD-YY, and DD-DD. The first and second transformers 130 and 140 can sufficiently suppress harmonics such as third and fifth orders. Accordingly, since the harmonics are suppressed in both the first and second transformers 130 and 140 and the first and second high frequency filters 110 and 120, the power current flowing through the power transmission stage 20 and the power receiving stage 40 is reduced. Almost all harmonics can be suppressed.

The power electronic device 150 is connected in series with the power transmission terminal 20 and the power receiving terminal 40, and limits the power current through phase angle control. That is, when the power electronic device 150 receives the gate signal from the control device 300, the power electronic device 150 is turned on by the gate signal to control the phases of the power transmission end 20 and the power reception end 40 so as to control the power transmission end 20. And limiting the power flow for the power receiver 40.

In this case, the power electronic device 150 may be a thyristor, and may be a gate turn-on (GTO) thyristor among the thyristors. The reason for using the power electronic device 150 as a thyristor is to simply configure the power electronic device 150 and to minimize driving loss. The thyristor, which is the power electronic device 150, is suitable for large-capacity power control, and has a low loss since the thyristor is automatically turned off when the current reaches zero even when no turn-off signal is input. That is, the power electronic device 150 is turned on when the gate signal is received, and is turned off when the current reaches zero. Since the power electronic device 150 uses a thyristor, the power current limiting device 100 may be referred to as a thyrister controlled power flow limiter (TCPFL).

The management device 200 is connected to the control device 300. The management device 200 receives system data from the outside. The management device 200 generates a power current amount of the power transmission stage 20 and the power receiving stage 40 using the system data. At this time, the power current amount may indicate the capacity of the power current when the power current limiting device 100 is stationary. This, the management device 200 will be described in detail with reference to FIG.

The control device 300 is connected to the management device 200 and the power current limiting device 100. The control device 300 receives a power current amount from the management device 200. The control device 300 generates control data by using the measured data and the power current amount measured by the power transmitter 20 and the power receiver 40. The control device 300 generates a gate signal to the power electronic device 150 to control the power electronic device 150 of the power current limiting device using the control data. Such a control device 300 will be described in detail with reference to FIG. 3.

The cooling device 380 is connected to the power current limiting device 100. The cooling device 380 cools heat generated by the power electronic device 150 of the power current limiting device 100. For example, the cooling device 380 may cool the heat generated by the power electronic device 150 using water, a heat pipe, or the like. Accordingly, the cooling device 380 cools the heat generated by the power electronic device 150, thereby ensuring the health of the power electronic device 150.

The protection device 390 protects the power flow restricting device 100 from the power system. That is, the protection device 390 determines a state of a power system including at least one of a circuit breaker (CB), a disconnecting switch (DS), an earthing switch (ES), and a transformer from an external device. Protect the power current limiting device 100.

2 is a block diagram illustrating an apparatus for managing a power flow control system according to an exemplary embodiment of the present invention.

2, the management apparatus 200 includes a receiver 210, a power system analyzer 220, a system accident analyzer 230, a transmitter 240, a first storage unit 250, and a first output. The unit 260 is included.

The receiver 210 receives system data from an external device (not shown). Here, the external device may include at least one of an Energy Management System (EMS), a Supervisory Control and Data Acquisition (SCADA), and a Phaser Measurement System (PMU). Can be. At this time, the system data represents data necessary for power generation. For example, the grid data may include bus voltage data, bus current data, bus phase data, power generation data, load data, and the like.

The receiver 210 provides system data received from an external device to at least one of the power system analyzer 220 and the system accident analyzer 230.

The receiver 210 receives an accident occurrence event event from the protection relay device. In this case, the accident occurrence event data may indicate data on an accident occurring in the power system connected to the power current limiting device 100 and may include at least one of voltage event data, current event data, and phase event data.

In other words, the receiver 210 receives voltage event data from a Potential Transformer (PT) of the protective relay device and receives current event data from a Current Transformer (CT) of the relay. At this time, the voltage event data represents the amount of change in voltage instantaneously, and the current event data represents the amount of change in instantaneous current.

In addition, the receiver 210 provides accident occurrence event data including voltage event data and current event data to at least one of the power system analyzer 220 and the system accident analyzer 230.

The power system analyzer 220 generates a power current amount using the system data. That is, the power system analysis unit 220 performs a system analysis using the system data at the time of stationary to generate a power current amount according to the system data. In this case, the power current amount represents the capacity of the power current flowing in the power transmission stage 20 and the power receiving stage 40. The static state represents a state in which the power system can continuously transmit and receive power against a constant load or an extremely slowly increasing load.

The power system analyzer 220 provides the generated power algae to the control unit 300 to transmit the generated power current amount.

The system accident analysis unit 230 generates a power current amount using system data and an accident occurrence event event. In other words, the system fault analysis unit 230 generates phase event data by performing calculation using voltage event data and current event data. At this time, the phase event data represents an amount of phase change in an instant. The system accident analysis unit 230 analyzes the accident occurrence event data and system data through system analysis to determine a system accident, and generates a power algae according to the system accident. The amount of power current generated by the system accident analysis unit 230 indicates a capacity of the power current corresponding to the transient time. In this case, the transient represents a state in which a sudden disturbance such as a sudden failure of the power system occurs.

Herein, the generation of the phase event data by the system accident analyzer 230 is described as an example, but the present invention is not limited thereto, and components generated when the phase event data is generated using the current event data and the voltage event data are irrelevant. It may be input from the outside, or may be generated in the control device 300 or another component.

The system accident analysis unit 230 provides the generated power current amount to the transmission unit 240 to transmit the control device 300.

The transmitter 240 transmits the power current amount to the control device 300. That is, the transmitter 240 is connected to the control device 300 and transmits the amount of power current generated by the power system analysis unit 220 or the system accident analysis unit 230 to the control device 300.

The first storage unit 250 stores data generated by the components of the management device 200 and data necessary for generating the power current amount. In other words, the first storage unit 250 may store the system data and the accident occurrence event data received from the receiver 210. The first storage unit 250 may store the amount of power current generated by the power system analyzer 220. The first storage unit 250 may store phase event data and power current amount generated by the system accident analyzer 230.

On the other hand, the first storage unit 250 provides the necessary data at the request of the power system analysis unit 220, the system accident analysis unit 230, the transmission unit 240 and the first output unit 260.

The first output unit 260 may display a process and a result performed by the receiver 210, the power system analyzer 220, the system accident analyzer 230, and the transmitter 240. For example, the first output unit 260 may display system data and accident occurrence event data received from the receiver 210. The first output unit 260 may display a process of generating a power current amount and the power current amount in the power system analyzer 220 or the system accident analyzer 230. The first output unit 260 may display the power system where the accident occurred and the location where the accident occurred using the accident event data. In addition, the first output unit 260 may display data stored in the first storage unit 250.

The first output unit 260 displays error occurrences generated by the receiver 210, the power system analyzer 220, the system accident analyzer 230, the transmitter 240, and the first storage unit 250. can do. Accordingly, the user may check the error occurrences displayed through the first output unit 260 and may solve the error occurrences.

The first output unit 260 may include a cathode ray tube, a liquid crystal display (LCD), an organic light emitting display (OLED), an electrophoretic display (EPD), and a plasma display panel ( It may be a display device such as a plasma display panel (PDP). In addition, the first output unit 260 may be implemented as a touch screen.

Meanwhile, the first output unit 260 may be a print. In this case, the first output unit 260 may output the power current generated by the power system analyzer 220 or the system accident analyzer 230 through an output such as paper.

3 is a block diagram showing a control device of a power current control system according to an embodiment of the present invention.

Referring to FIG. 3, the control device 300 includes a communication unit 310, a measuring unit 320, an analog-digital converter 340, a control unit 350, a gate driver 360, a second storage unit 370, and a second unit. An output unit 375 is included.

The communicator 310 is connected to the management device 200 to receive a power current amount from the management device 200. The communication unit 310 provides the control unit 350 with the amount of power current received from the management device 200.

The measuring unit 320 measures the power transmitter 20 and the power receiver 40 to generate measurement data. The measurer 320 includes at least one of a voltage measurer, a current measurer, a phase measurer 335, and a bird flow direction recognizer.

The voltage measuring unit measures voltages of the power transmission terminal 20 and the power receiving terminal 40 to generate voltage measurement data.

The current measuring unit measures the current of the power transmitting end 20 and the power receiving end 40 to generate current measurement data.

The phase measurer 335 determines phases of the power transmitter 20 and the power receiver 40 to generate phase measurement data.

The flow direction recognition unit recognizes the direction of the power current flowing in the power transmission end 20 and the power receiving end 40 to generate the flow direction measurement data.

The analog to digital converter 340 converts the measurement data generated by the meter 320. That is, the analog-to-digital converter 340 converts the digital signal to use the measurement data, which is an analog signal, at least one of voltage measurement data, current measurement data, phase measurement data, and bird flow direction measurement data. . The analog to digital converter 340 provides the control unit 350 with the measured data converted into a digital signal.

The controller 350 is connected to the analog to digital converter 340 and the communication unit 310. The controller 350 receives the power current amount from the communication unit 310 and receives the measured data converted from the analog-to-digital converter 340. The control unit 350 generates control data to control the power current limiting device 100 by using the power current amount and the measurement data. In other words, the control unit 350 controls the power electronic device 150 of the power current limiting device 100 to control the phases of the power transmission end 20 and the power reception end 40 according to the measurement data based on the amount of power current. Generate data. In this case, the control data may include a supply period indicating a period of supplying a gate signal to the power electronic device 150.

The gate driver 360 is connected to the control unit 350 and receives control data from the control unit 350. The gate driver 360 generates a gate signal to the power current limiting device 100 using the control data. That is, the gate driver 360 generates a gate signal to the power electronic device 150 of the power current limiting device 100 in accordance with a supply period included in the control data. The gate driver 360 may include a signal generator (not shown) that generates a gate signal.

The second storage unit 370 generates data generated by the communication unit 310, the measuring unit 320, the analog-digital converter 340, the control unit 350, and the gate driver 360, and data necessary for controlling the power current limiting device. Save it. For example, the second storage unit 370 may store the amount of power current received through the communication unit 310. The second storage unit 370 stores the measurement data generated by the measuring unit 320. That is, the second storage unit 370 generates voltage measurement data generated by the voltage measuring unit, current measurement data generated by the current measuring unit, phase measurement data generated by the phase measuring unit 335, and generated by the bird flow direction recognition unit. The bird flow measurement data can be stored. The second storage unit 370 may store the measurement data converted by the analog-to-digital converter 340 and the control data generated by the controller 350.

Meanwhile, when the second storage unit 370 requests data from the communication unit 310, the measuring unit 320, the analog-digital converter 340, the control unit 350, the gate driver 360, and the second output unit 375. You can provide the component with the data you request.

The second output unit 375 may display a process and a result performed by the component of the control device 300. In other words, the second output unit 375 may display the amount of current current received through the communication unit 310 and the measurement data generated by the measuring unit 320. The second output unit 375 may display a process of generating control data and the control data in the control unit 350.

The second output unit 375 may display the capacity of the power current flowing in the power transmission end 20 and the power receiving end 40 restricted by the power current limiting device 100. On the other hand, if an error occurs in the second output unit 375, the communication unit 310, the measuring unit 320, the analog-digital converter 340, the control unit 350, the gate driver 360, and the second storage unit 370. Error occurrences can be displayed.

The second output unit 375 may be a display device displaying data. In addition, the second output unit 375 may be implemented as a touch screen.

On the other hand, the second output unit 375 may be a print. In this case, the second output unit 375 may output the control data or the measurement data through an output such as paper.

Although the first output unit 260 and the second output unit 375 have been described separately, the present invention is not limited thereto, and data generated by the management device 200 and the control device 300 may be displayed through one output unit. Can be. In addition, the first output unit 260 and the second output unit 375, like the control device 300 and the management device 200 is not included, it may be implemented as a separate output device.

A method for controlling power flow according to an embodiment of the present invention will be described with reference to FIGS. 4 and 5.

4 is a flowchart illustrating a method of controlling power flow according to an embodiment of the present invention.

Referring to FIG. 4, the management device 200 receives system data from an external device (S410). That is, the receiver 210 of the management device 200 receives system data from an external device including at least one of an EMS, a SCADA, and a PMU.

The management device 200 generates a power current amount using the grid data (S420). In other words, in the static state, the power system analysis unit 220 of the management apparatus 200 analyzes the system data through system analysis to indicate the capacity of the power current flowing through the power transmission stage 20 and the power receiving stage 40. To generate a quantity. On the other hand, when there is a transient (that is, when an accident occurs in the power system), the system accident analysis unit 230 determines a system accident by analyzing system data and an accident occurrence event through system analysis. The system accident analysis unit 230 generates a power current amount according to the system accident. At this time, the system accident analysis unit 230 may generate a power current amount for the system accident using a preset table.

The control device 300 determines whether at least one of the power current amount and the system data corresponds to the gate-off condition (S430). That is, the control unit 350 of the control device 300 determines whether the power current amount is greater than or equal to the reference value that can be controlled, and whether the system impedance of the transmission line 30 is greater than or equal to the maximum value using the system data, and the system impedance is the minimum value. It judges whether it is below. Here, the reference value represents the capacity of the power algae that can be generated in the power transmission stage 20 and the power receiving stage 40, the maximum value and the minimum value represents a reference value that can determine that the accident occurred in the bus. .

If at least one of the power current amount and the grid data corresponds to a gate-off condition, the control device 300 does not generate a gate signal (S440). That is, since the gate signal is not generated in the power electronic device 150 in the control device 300, the power electronic device 150 maintains a turn-off state. Accordingly, the power current control system 10 connects the power current limiting device 100 to the overload line to prevent an overload in case of a failure, and thus restricts the power current so as to share the power with another transmission line 30. In addition, the power current control system 10 protects the power current limiting device 100 by turning off the power current limiting device 100 when an accident occurs in a nearby power system in which the power current limiting device 100 is installed. The power supply terminal 20 and the power receiver 40 connected to the power current limiting device 100 may be protected.

If the power current amount and system data do not correspond to the gate-off condition, the control device 300 generates control data using the power current amount and measurement data (S450). In other words, the measuring unit 320 of the control device 300 generates the measurement data by measuring the power transmitting end 20 and the power receiving end 40 as shown in FIG. In this case, the measurement data includes voltage measurement data, current measurement data, phase measurement data, and flow direction characteristic data by measuring voltage, current, phase, and flow direction. The control unit 350 receives measurement data from the measuring unit 320 through the analog-digital converter 340. The controller 350 generates power measurement data using voltage measurement data, current measurement data, and phase measurement data included in the measurement data.

The controller 350 generates current reference data and power reference data for the amount of power current. For example, the controller 350 may generate current reference data and power reference data for the amount of power current using the preset table. As illustrated in FIG. 5, the calculator 353 of the controller 350 compares the current reference data Iref and the current measurement data Imeas to generate current comparison data Ie, and compares the power reference data Pref with the power reference data Pref. The power comparison data Pe is compared to generate the power comparison data Pe.

The proportional-integral (PI) controller 355 of the control unit 350 controls the current comparison data Ie and the power comparison data Pe, respectively. The comparator of the controller 350 receives the voltage measurement data V from the meter 320 and compares the voltage measurement data with the voltage reference data to generate voltage generation data. The comparator of the controller 350 provides the generated voltage generation data to the generator 359. The reason for comparing the voltage measurement data and the voltage reference data is to generate the control data according to the voltage because the phase changes according to the voltage because the transmission stage 20 and the receiving terminal 40 flows through the alternating current.

The generation unit 359 of the controller 350 generates control data using current comparison data Ie and power comparison data Pe controlled by the PI controller 355 according to the voltage generation data.

Herein, the control data is generated using both current and power, but is not limited thereto. The control data may be generated using current or power.

The control device 300 generates a gate signal for the control data to the power flow control system 10 (S460). In detail, the gate driver 360 generates a gate signal to the power electronic device 150 of the power current limiting device 100 through a signal generator in accordance with a supply period included in the control data.

The power current limiting device 100 limits the power current of the power transmission terminal 20 and the power receiving terminal 40 by using the gate signal (S470). That is, the power electronic device 150 of the power current limiting device 100 is turned on by the gate signal generated from the control device 300 to control the phases of the power transmission terminal 20 and the power receiving terminal 40 to control power. Limit the capacity of algae.

FIG. 6 is a circuit diagram illustrating an apparatus for limiting power flow according to an embodiment of the present invention, and FIGS. 7 to 10 are diagrams showing simulation results of applying a power flow control system according to an embodiment of the present invention.

Referring to FIG. 6, reference numeral 600 is a circuit diagram for simulating a power current limiting device according to the present invention. 7 to 10 are simulation results of the power current limiting device 600 shown in FIG. 6 by PS-CAD.

The transformer at the power stage is D-Y connected, and the transformer at the power stage is Y-D. The phase angle was designed from 0deg minimum to 60deg maximum. When the phase angle is 0deg, the power current is maximized to 100%, and when 60deg, the power bird is minimized to 0%. The load on the receiver stage was simulated assuming a resistance of 100 ohms, and the simulation was performed without changing the load of the generator and the receiver of the power stage in each phase angle change. The delta connection of the transformer minimizes harmonics, and high frequencies that are not resolved in the delta connection can be eliminated through the harmonic filter.

FIG. 7 is a graph illustrating a voltage waveform 710 of a power receiver, a current waveform 720, and an active power 730 of a power receiver when the phase angle is 0 deg. As shown in FIG. 7, the active power 730 of the power receiver is 440 kW, and the power current is 100%, and is 440 kW. In addition, distortion of the voltage waveform 710 and the current waveform 720 hardly occurred.

8 is a graph illustrating a voltage waveform 810 of a power receiver, a current waveform 820, and an active power 830 of a power receiver when the phase angle is 30 deg. As shown in FIG. 8, the active power 830 of the power receiver is limited to 302 kW, and the power current is limited to 302 kW.

9 is a graph showing the voltage waveform 910 of the power receiver, the current waveform 920, and the active power 930 of the power receiver when the phase angle is 50 deg. As shown in FIG. 9, the active power 930 of the power receiver is limited to 148 kW and the power current is limited to 148 kW.

8 and 9, the voltage waveform 810, the current waveform 820, the voltage waveform 910 and the current waveform 920 of the power receiver are somewhat distorted. It can be sufficiently removed by using a high frequency filter connected to.

FIG. 10 is a graph illustrating a voltage waveform 1010, a current waveform 1020, and an active power 1030 of a power receiver at a phase angle of 60 deg. As shown in FIG. 10, the active power 1030 of the power receiver is limited to 0 kW and the power current is limited to 0 kW. This is the same as removing the firing of the power electronic device.

Accordingly, the power current control system according to an embodiment of the present invention may limit the power current flowing through the power transmission end and the power reception end by controlling the phase angles of the power transmission end and the power receiving end.

Power current control system according to an embodiment of the present invention can control the power current 0 to 100% of the capacity of the transmission line by using the thyristor, installed in the overload line to prevent overload in the event of a failure, power current Can be limited.

In addition, the power flow control system according to an embodiment of the present invention solves the widow of the transmission line, thereby reducing the transmission contract, more economical power generation operation, it is installed in the place where unnecessary transmission loss caused by the circulation current circulation Current can be suppressed.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art to which the present invention pertains without departing from the spirit and scope of the present invention as set forth in the claims below It will be appreciated that modifications and variations can be made.

Claims (23)

In the power current control system for controlling the power current, A power current limiting device connected in series with the power transmission terminal and the power receiving terminal, the power current limiting device restricting power flow to the power transmission terminal and the power receiving terminal; A management device for generating a power current amount of the power transmitter and the power receiver using system data; And A control device for generating control data by using the amount of power current received from the management device and the measurement data of the power transmission end and the power receiving end, and generates a gate signal to the power current limiting device using the control data. Power current control system comprising a. The method of claim 1, The power current limiting device, And a power electronic device that is turned on by the gate signal to control phases of the power transmission end and the power reception end to limit power flow to the power transmission end and the power reception end. Power current control system. The method of claim 2, The control device, And a controller configured to generate the control data for controlling the power current limiting device according to the measured data based on the amount of power current. The method of claim 3, wherein The control unit, And generating the control data including a supply period indicative of a period in which the gate signal should be supplied to the power electronic device. The method of claim 4, wherein The control device, And a gate driver for generating the gate signal to the power electronic device in accordance with a supply period included in the control data. The method of claim 2, And the power electronic device is a thyristor. The method of claim 3, wherein The control device, And an analog-to-digital converter for converting the measured data from an analog signal to a digital signal, converting the measured data into the digital signal and transmitting the converted data to the controller. The method of claim 1, The management device, A power system analyzer configured to analyze the system data and generate a power current amount of the power transmitter and the power receiver when stationary; And The system comprises a system accident analysis unit for analyzing the system data and the accident occurrence event data to determine a system accident, and generates a power current amount of the power transmitter and the power receiver in case of a transient according to the system accident. Control system. The method of claim 1, The power current limiting device, And a high frequency filter connected to each of the power transmitting end and the power receiving end, the high frequency filter suppressing harmonics of power current flowing through the power transmitting end and the power receiving end. The method of claim 1, The power current limiting device, A transformer connected to each of the power transmission terminal and the power receiving terminal, further comprising a transformer for suppressing harmonics of power currents flowing through the power transmission terminal and the power receiving terminal, and increasing or decreasing voltages of the power transmission terminal and the power receiving terminal. Power current control system. The method of claim 1, The measurement data may include at least one of voltage measurement data, current measurement data, phase measurement data, and bird flow direction measurement data. The method of claim 11, wherein The control device, A voltage measuring unit measuring the voltages of the power transmitting end and the power receiving end to generate the voltage measurement data; A current measuring unit configured to generate current measurement data by measuring currents of the power transmitter and the power receiver; A phase determination unit configured to determine phases of the power transmission end and the power reception end to generate the phase measurement data; And And a tidal current direction recognizing unit configured to generate the tidal flow direction measurement data by recognizing a direction of the electric current flowing through the power transmission stage and the power receiving stage. The method of claim 1, And a cooling device connected to the power control device and cooling the heat generated by the power control device. The method of claim 1, And a protection device connected to the power control device and protecting the power control device. The method of claim 11, wherein The management device collects system data from at least one of an Energy Management Systems (EMS), a Supervisory Control and Data Acquisition (SCADA), and a Phaser Measurement System (PMU). Power flow control system, characterized in that for receiving. In the power current control method in which the power bird control system controls the power bird, (a) generating power currents of the power transmission stage and the power receiving stage using system data; (b) generating control data using the measured amount of power current and the transmission end and the power receiving end; (c) generating a gate signal to a power current limiting device using the control data; And (d) a power current control device comprising a power current device included in the power current limiting device being turned on by the gate signal to limit power flow to the power transmission stage and the power reception stage; Way. The method of claim 16, In step (b), (b1) generating power reference data or current reference data according to the power current amount; And (b2) generating the control data according to the current measurement data of the measurement data or the power measurement data generated using the current measurement data based on the current reference data or the power reference data. Power bird control method. The method of claim 17, Step (b2), Generating power comparison data by comparing the power reference data and the power measurement data or generating current comparison data by comparing the current reference data and the current measurement data; And And controlling the power comparison data or the current comparison data to generate control data by controlling the proportional-integral (PI). The method of claim 16, In step (b), Generating the control data including a supply period indicating a period at which the gate signal should be supplied to the power electronic device using the power current amount and the measurement data. The method of claim 19, In step (c), And transmitting the gate signal to the power current limiting device according to the supply period included in the control data. The method of claim 16, Before step (b), And determining whether at least one of the power current amount and the system data corresponds to a gate-off condition. The method of claim 21, In step (b), And generating the control data using the power flow amount and the measurement data if at least one of the power flow amount and the system data does not correspond to the gate-off condition. The method of claim 16, In step (a), Analyzing the grid data to generate the power flow of the power supply stage and the power receiver in the static state, or the power flow of the power transmission terminal and the power receiver in case of transient according to the system accident analyzed the system data and accident event data And a step of generating a quantity.

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