KR100711816B1 - Hybrid upfc simulator - Google Patents

Abstract

The present invention provides a hybrid UPFC simulator, comprising: an analog UPFC simulator connected to a substation busbar to perform analog flow control; By connecting to the analog UPFC simulator, and configured to include a digital power system simulator that performs the power system simulation, it is possible to implement the hybrid UPFC simulator to take advantage of the analog simulator and to supplement the disadvantages of the digital simulator.

Hybrid Simulator, Hybrid, Power, Simulator, Comprehensive Current Controller, UPFC, Stationary Compensator, STATCOM, Series Compensator, SSSC, Flexible Power Transmission System, FACTS, Amplifier, Converter, Analog Simulator, Digital Simulator

Description

Hybrid UPFC simulator

1 is a conceptual diagram of a conventional analog UPFC simulator.

2 is a conceptual diagram of a hybrid UPFC simulator according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

100: analog UPFC simulator 110: stationary compensation unit

111: parallel transformer 112: parallel inverter

120: series compensator 121: series transformer

122: serial inverter 130: transmission line

140: first system linkage unit 141: first converter

142: first current transformer 150: second system linkage

151: second converter 152: second current transformer

200: digital power system simulator 210: first substation bus simulator

211: first substation bus voltage 212: first substation bus current

213: first D / A converter 214: first A / D converter

220: the second substation busbar simulator 221: the second substation busbar voltage

222: second substation bus current 223: second D / A converter

224: second A / D converter

The present invention relates to the simulation of the Unified Power Flow Controller (UPFC), and more particularly to a hybrid UPFC simulator that utilizes the advantages of analog simulators and supplements the disadvantages of digital simulators.

In general, flexible AC transmission system (FACTS) is a technology that can solve the bottleneck of power supply by controlling the flow of electricity at high speed by using a large capacity inverter equipment. One such type of flexible power transmission system is UPFC.

In the case of UPFC developed in the 90's, the development and performance of UPFC was verified by using a miniature analog simulator.In the case of digital UPFC simulator, it is impossible to implement all switching valves. Only limited functionality simulations are possible.

1 is a conceptual diagram of a conventional analog power simulator, showing the configuration of the UPFC.

As shown here, a stationary compensator (STATCOM) for controlling the first substation bus voltage (V1) 40 having a parallel transformer unit 11 and a parallel inverter 12 connected in parallel to the substation busbars 10; A series transformer 21 having a series transformer 21 and a series inverter 22 connected in series to a substation bus, and having a series compensator (SSSC) 20 for controlling a voltage at the rear end of the series transformer 21; ; A transmission line 30 connected to the series compensator 20; A first substation bus voltage (V1) 40 connected to the substation bus; It consists of a second substation bus voltage (V2) 52 connected to the power transmission line (30).

The UPFC is thus composed of a stationary compensator (STATCOM) 10 which is a parallel inverter system and a series compensator (SSSC) 20 which is a series inverter system, and the inverters 12 and 22 of each system are transformers 11. Lineage is linked via 21.

In the case of the stationary compensator 10 which is a parallel inverter, the reactive power of the grid is compensated for to perform grid voltage control on the first substation bus voltage V1 40. In addition, the series compensator 20, which is a series inverter, injects a voltage into the transmission line 30 between the substations to control the flow of the power transmission line 30.

Analog simulator for simulating UPFC has no difference between real system and analog simulator configuration because it implements UPFC and system in same scale. However, since the UPFC simulator connected to the first substation bus voltage (V1) 40 and the transmission line 30 is configured only with a system for checking the performance of the UPFC, simulation is performed, so that errors may occur somewhat from the actual system simulation. do.

The analog UPFC simulator is configured by reducing the configuration of FIG. 1, and since the rest of the system cannot be implemented, the simulation system is shortened to analog so that the performance of the UPFC can be confirmed. This dynamic simulation of the UPFC is the most accurate way to verify the inverter operation.

However, this conventional technology has the following problems.

In other words, it is impossible to simulate the system dynamics of various UPFCs. In this case, it is not easy to expand or change the system, and simulation of various system components such as distributed power sources remains a great difficulty.

In addition, in the real-time digital simulator, the calculation time changes according to the number of switching elements, and the availability of the real-time simulation is determined according to the number of switching elements. Thus, real-time simulation of FACTS installations with more than 36 switching elements is currently impossible, and only real-time digital simulations of FACTS installations with fewer switching elements are attempted.

Therefore, the present invention has been proposed to solve the above-mentioned conventional problems, and an object of the present invention is to use a hybrid UPFC simulator that can implement the hybrid UPFC simulator that utilizes the advantages of an analog simulator and compensates for the disadvantages of a digital simulator. To provide.

Hybrid UPFC simulator according to an embodiment of the present invention to achieve the above object,

An analog UPFC simulator connected to the substation busbar and performing analog flow control; It is characterized by the technical configuration that is connected to the analog UPFC simulator, and comprises a digital power system simulator for performing a power system simulation.

Hereinafter, an embodiment according to the present invention and the technical spirit of the hybrid UPFC simulator will be described with reference to the accompanying drawings.

2 is a conceptual diagram of a hybrid UPFC simulator according to an embodiment of the present invention.

As shown in the figure, an analog UPFC simulator 100 connected to the substation busbar and performing analog flow control; The digital power system simulator 200 is connected to the analog UPFC simulator 100 and performs a power system simulation.

The analog UPFC simulator 100 includes: a stationary compensator (STATCOM) 110 connected to the substation busbars in parallel to perform bus voltage control; A serial compensator (SSSC) 120 connected in series with the substation bus to perform power system control; A transmission line 130 connected to the series compensator 120; A first grid linker 140 connected in parallel to the substation busbar and connected to the digital power system simulator 200 to perform grid linkage; It is connected to the power transmission line 130, it is characterized in that it comprises a second system linkage unit 150 is connected to the digital power system simulator 200 performs a system linkage.

The stationary compensator 110 includes: a parallel transformer 111 connected to and transformed in parallel with the substation busbar; It is connected to the parallel transformer 111, characterized in that it comprises a parallel inverter 112 for controlling the voltage of the substation bus.

The series compensator 120 includes a series transformer 121 connected to the substation busbars in series and transformed; It is characterized in that it comprises a series inverter 122 is connected to the series transformer 121, and performs a power flow control of the power transmission line 130.

The first system linking unit 140 includes: a first converter 141 for amplifying the digital voltage signal received by the digital power system simulator 200 and converting the digital voltage signal into a driving voltage of the UPFC connection bus; It is connected to the substation busbar, and includes a first current transformer (Current Transformer, CT) 142 to take out the current signal of the first converter 141 and transfer the analog current signal to the digital power system simulator (200). Characterized in that configured.

The second system linker 150 includes: a second converter 151 for amplifying the digital voltage signal received by the digital power system simulator 200 and converting the digital voltage signal into a driving voltage of the UPFC connection transmission line 130; It is connected to the transmission line 130, and comprises a second current transformer 152 to take out the current signal of the second converter 151 and transfer the analog current signal to the digital power system simulator 200. It features.

The digital power system simulator 200 includes: a first substation bus simulator 210 connected to the analog UPFC simulator 100 and performing simulation verification of a first substation bus bus; The second substation bus simulator 220 is connected to the analog UPFC simulator 100 and performs simulation verification for the second substation bus.

The first substation bus simulator 210 includes: a first substation bus voltage 211 for outputting a substation bus voltage as a digital signal; A first digital-to-analog (D / A) converter 213 for converting the digital signal of the first substation bus voltage 211 into an analog signal and outputting the digital signal to the first system linker 140 in the analog UPFC simulator; A first analog-to-digital (A / D) converter 214 for converting the analog current signal received by the first system linkage unit 140 in the analog UPFC simulator into a digital signal; And a first substation bus current 212 configured to receive the digital current signal converted by the first A / D converter 214.

The second substation bus simulator 220 includes: a second substation bus voltage 221 for outputting a substation bus voltage as a digital signal; A second D / A converter 223 for converting the digital signal of the second substation bus voltage 221 into an analog signal and outputting the digital signal to the second system linker 150 in the analog UPFC simulator; A second A / D converter 224 for converting the analog current signal received by the second system linkage unit 150 in the analog UPFC simulator into a digital signal; And a second substation bus current 222 that receives the digital current signal converted by the second A / D converter 224.

The operation of the hybrid UPFC simulator according to the present invention configured as described above will be described in detail with reference to the accompanying drawings.

First of all, the present invention is to implement a hybrid UPFC simulator that utilizes the advantages of an analog simulator and supplements the disadvantages of a digital simulator.

In case of realizing UPFC and system by real time digital simulator, limited simulation verification is possible because FACTS simulation of various structures is not possible due to the limitation of implementation according to the number of valve configurations by current digital technology. Therefore, as shown in FIG. 2, a hybrid simulator is implemented by mixing and connecting the analog UPFC simulator 100 and the digital power system simulator 200.

Since the analog UPFC simulator 100 is a scaled-down model of the actual system except for the first and second substation bus voltages 211 and 221, UPFC performance and dynamic characteristics can be simulated. In addition, the digital power system simulator 200 is a real-time digital simulation, only by modifying the program, it is possible to simulate a variety of real system dynamic characteristics.

In the analog UPFC simulator 100, the stationary compensator 110 is connected to the substation busbar in parallel to perform busbar voltage control.

In such a stationary compensation unit (STATCOM) 110, the parallel transformer 111 is connected in parallel to the substation busbar, and connected to the parallel inverter 112 to transform.

In addition, in the stationary compensator 110, the parallel inverter 112 is connected to the parallel transformer 111 and controls the voltage of the substation bus.

Therefore, the stationary compensator 110 is connected to the substation bus in parallel by the AC (Alternating Current, AC) voltage source by the parallel transformer 111 and the parallel inverter 112, it is possible to control the voltage of the substation bus. .

In the analog UPFC simulator 100, the series compensator 120 is connected in series to a substation busbar to perform power system control.

In the series compensator (SSSC) 120, the series transformer 121 is connected in series with the power transmission line 130 and connected with the series inverter 122 to transform the transformer.

In the series compensator 120, the series inverter 122 is connected to the series transformer 121 and performs power control of the power transmission line 130.

The series compensator 120 may inject a voltage in series between the lines by the series transformer 121 and the series inverter 122. Therefore, when the user inserts the desired voltage into the voltage of the substation bus, it is possible to control the power flowing through the system, thereby controlling the current of the other line.

In addition, the transmission line 130 is connected to the series compensator 120 to allow power system control to be performed.

Meanwhile, the first grid linker 140 is connected in parallel to the substation busbar and is connected to the substation bus simulator 210 of the digital power system simulator 200 to perform grid linkage.

In the first system linkage unit 140, the first converter 141 amplifies an analog signal of the first substation bus voltage 211 received by the first D / A converter 213 in the digital power system simulator 200. To press the substation bus to which the UPFC is connected.

In the first system linkage unit 140, the first current transformer 142 is connected to the substation busbar, and extracts a current signal that responds according to the output signal of the first converter 141 to operate in the digital power system simulator 200. It is sent to the first substation bus current 212 through the first A / D converter 214.

In addition, the second grid linker 150 is connected to the transmission line 130, and is connected to the second substation bus simulator 220 of the digital power system simulator 200 to perform grid linkage.

In the second system linkage unit 150, the second converter 151 amplifies an analog signal of the second substation bus voltage 221 received by the second D / A converter 223 in the digital power system simulator 200. Pressurizes the transmission line 130 to which the UPFC is connected.

In the second system linkage unit 150, the second current transformer 152 is connected to the power transmission line 130 and extracts a current signal from the second converter 151 to generate a second A in the digital power system simulator 200. It is sent to the second substation bus current 222 through the / D converter 224.

Meanwhile, in the digital power system simulator 200, the first substation bus simulator 210 is connected to the first system linkage unit 140 of the analog UPFC simulator 100 and performs simulation verification for the substation bus.

In the first substation bus simulator 210, the first substation bus voltage 211 outputs the digital substation bus voltage to the first D / A converter 213.

The first substation bus current 212 also receives the digital current signal converted by the first A / D converter 214.

In addition, the first D / A converter 213 converts the digital signal of the first substation bus voltage 211 into an analog signal and outputs the analog signal to the first converter 141 in the first system linkage unit 140 in the analog UPFC simulator. .

In addition, the first A / D converter 214 converts the analog current signal received by the first current transformer 142 in the first system linker 140 in the analog UPFC simulator 100 into a digital signal to convert the first substation busbar. To current 212.

In the digital power system simulator 200, the second substation bus simulator 220 is connected to the second system linkage unit 150 of the analog UPFC simulator 100 and performs simulation verification for the substation second substation bus.

In the second substation bus simulator 220, the second substation bus voltage 221 outputs the digital substation bus voltage to the second D / A converter 223.

In addition, the second substation bus current 222 receives the digital current signal converted by the second A / D converter 224.

Also, the second D / A converter 223 converts the digital signal of the second substation bus voltage 221 into an analog signal and outputs the analog signal to the second converter 151 in the second system linkage 150 in the analog UPFC simulator. .

In addition, the second A / D converter 224 converts the analog current signal received by the second current transformer 152 in the second grid linker 150 in the analog UPFC simulator 100 into a digital signal to convert the second substation busbar. Is sent to current 222.

As such, the analog UPFC simulator 100 and the digital power system simulator 200 are interconnected through the first and second converters 141 and 151 in the analog UPFC simulator 100. In addition, the bus voltage signal of the digital power system simulator 200 is supplied to the voltage source of the analog UPFC simulator 100 through the first and second converters 141 and 151, and electrical losses required for the analog UPFC simulator 100 are provided. And the effective energy is supplied through the first and second converters 141 and 151.

The operation result of the digital power system simulator 200 is output to the external analog UPFC simulator 100 through the first and second D / A converters 213 and 223, and the external analog UPFC simulator 100 may be used. The operation result is input to the digital power system simulator 200 through the first and second A / D converters 214 and 224.

The first and second substation bus voltages 211 and 221, which are the voltages of the transmission line link buses of the actual system, and the first and second substation bus currents 212,222, which are the transmission line currents, are connected through one connection point. Although the physical quantity appears, in the digital power system simulator 200, since two signals cannot be input and output at the same time through one connection point, the analog current and the simulation voltage output point are two input / output points between the analog and digital simulators. Correlate with

In addition, the voltage signal output inside the digital power system simulator 200 is amplified by the first and second converters 141 and 151 and used as a voltage source to drive the analog UPFC simulator 100.

In addition, since the current signal resulting from the operation of the analog UPFC simulator 100 is input to the digital power system simulator 200 through the first and second current transformers 142 and 152 and utilized for calculation, the digital power system simulator 200. The difference between the voltage and the current used in the calculation inside the time step is that the calculation time difference of the time step is generated, which is a factor in determining the real-time implementation.

UPFC is a FACTS facility that controls the flow of transmission lines. When one of the substation busbars at both ends of the transmission line transmits active power, the other one must receive the active power. A converter capable of bidirectional active power transfer should be used as an amplifier. That is, if the power current in the first substation bus voltage (V1) 211 flows toward the second substation bus voltage (V2) 221, the first converter 141 for V1 operates as a converter for supplying active power. The second converter 151 for V2 is operated as a converter for receiving active power, so that the active power for receiving the power is regenerated to the power input terminal of the converter. Therefore, when considering the UPFC characteristics, the hybrid UPFC simulator can be configured only when the converter capable of input side regeneration of active power is used as an amplifier.

As such, the present invention implements the linkage of the hybrid UPFC simulator utilizing the advantages of the analog simulator and supplementing the disadvantages of the digital simulator.

Although the preferred embodiment of the present invention has been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments. Therefore, the above description does not limit the scope of the invention defined by the limitations of the following claims.

As described above, the hybrid UPFC simulator according to the present invention has the effect of utilizing the advantages of the analog simulator and implementing the linkage of the hybrid UPFC simulator to compensate for the disadvantages of the digital simulator.

In addition, the present invention not only facilitates the construction of the power system, but also makes it possible to advance the FACTS facility simulation technology by developing a hybrid simulator by supplementing the shortcomings of the analog simulator, which is difficult to verify various dynamic characteristics of the power system. Various accident simulation of the power system is possible, and the UPFC algorithm and system influence can be reviewed in advance by the simulation operation before applying the UPFC, which can improve the reliability of the system when applied to the actual system.

Claims (9)

A stationary compensation unit connected to the substation bus line to perform analog current flow control, but connected in parallel to the substation bus bar to perform bus voltage control, and a series compensator connected in series to the substation bus line to perform power system control; A first grid linker connected to the transmission line connected to the series compensator, the substation busbar in parallel, and a grid linkage connected to the digital power system simulator to perform grid linkage; An analog UPFC simulator configured to include a second grid linker connected to the grid simulator to perform grid linkage; And a digital power system simulator connected to the analog UPFC simulator and configured to perform a power system simulation. delete The method of claim 1, wherein the stationary compensation unit, A parallel transformer unit connected to the substation busbars in parallel and transformed; And a parallel inverter connected to the parallel transformer and configured to control a voltage of the substation bus. The method of claim 1, wherein the series compensator, A series transformer unit connected to the substation busbar in series and transformed; And a series inverter connected to the series transformer and configured to perform power flow control of the transmission line. The method according to claim 1, wherein the first system linkage, A first converter for amplifying the digital voltage signal received by the digital power system simulator and converting the digital voltage signal into a driving voltage of the UPFC connection bus; And a first current transformer connected to the substation busbar and configured to extract a current signal of the first converter and transmit an analog current signal to the digital power system simulator. The method according to claim 1, The second system linkage unit, A second converter for amplifying the digital voltage signal received by the digital power system simulator and converting the digital voltage signal into a driving voltage of an UPFC connection line; And a second current transformer connected to the power transmission line and extracting a current signal of the second converter to transfer an analog current signal to the digital power system simulator. The digital power system simulator according to any one of claims 1 and 3 to 6, A first substation bus simulator connected to the analog UPFC simulator and performing simulation verification of a first substation bus; And a second substation bus simulator connected to the analog UPFC simulator and performing simulation verification of a second substation bus. The method of claim 7, wherein the first substation bus mother simulator, A first substation bus voltage for outputting a substation bus voltage as a digital signal; A first D / A converter converting a digital signal of a first substation bus voltage into an analog signal and outputting the digital signal to a first system linkage unit in the analog UPFC simulator; A first A / D converter for converting an analog current signal received by a first system linkage unit in the analog UPFC simulator into a digital signal; And a first substation bus current configured to receive the digital current signal converted by the first A / D converter. The method of claim 7, wherein the second substation bus mother simulator, A second substation bus voltage which outputs the substation bus voltage as a digital signal; A second D / A converter for converting a digital signal of a second substation bus voltage into an analog signal and outputting the digital signal to a second system linkage unit in the analog UPFC simulator; A second A / D converter for converting an analog current signal received by a second system linkage unit in the analog UPFC simulator into a digital signal; And a second substation bus current which receives the digital current signal converted by the second A / D converter.

Images