• 대한전기학회논문지:전력기술부문A
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• 제49권10호
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• pp.509-515
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• 2000

This paper addresses a damping control strategy of Static Synchronous Series Compensator(SSSC) and analysis model for stability study. The effect of injected voltage source generated by SSSC is modelled as equivalent load. This model is thought to be reasonable for the stability study because the dynamics of SSSC is very fast compared with that of power system. Damping controller of SSSC is based on Transient Energy Function method. The proposed control strategy is insensitive to the operating conditions like power flow level because control law depends on the phase angles. The proposed analysis model and control strategy was confirmed by WSCC 9 bus system and two area system. Especially, the robustness of proposed control strategy is demonstrated with respect to multiple operating conditions in two area system.

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1258-1268
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• 2014

Improving grid connection of wind farms is a relevant issue to be addressed, especially for fixed-speed wind turbines. Certain elements, such as FACTS (Flexible AC Transmission Systems), are able to perform voltage and reactive power regulation in order to support voltage stability of wind farms, and compensate reactive power consumption from the grid. Several devices are grouped under the name of FACTS, which embrace different technologies and operating principles. Here, three of them are evaluated and compared, namely STATCOM (Static Synchronous Compensator), SVC (Static Var Compensator) and SSSC (Static Synchronous Series Compensator). They have been modeled in MATLAB/Simulink, and simulated under various scenarios, regarding both normal operation and grid fault conditions. Their response is studied together with the case when no FACTS are implemented. Results show that SSSC improves the voltage stability of the wind farm, whereas STATCOM and SVC provide additional reactive power.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.539-545
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• 2001

This paper proposes a static synchronous series compensator based on multi-bridge inverter. The proposed system consists of 6 H-bridge modules per phase, which generate 13 pulses for each half period of power frequency. The dynamic characteristic was analyzed by simulations with EMTP code, assuming that it is inserted in the 154-kV transmission line of one-machine-infinite-bus power system. The feasibility of hardware implementation was verified through experimental works using a scaled model. The proposed system does not require a coupling transformer for voltage injection, and has flexibility in expanding the operation voltage by increasing the number of H-bridge modules.

• Journal of Power Electronics
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• 제19권3호
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• pp.803-814
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• 2019

This paper proposes a three-phase current balancing strategy in a power transmission system employing distributed static series compensators (DSSCs). With the proposed variable quadrature voltage injection method, the DSSC emulates either an inductive or a capacitive impedance into the transmission line, and the magnitudes of the phase currents are balanced. Hence, the phase imbalances in the power transmission system are significantly reduced. As a result, the power transfer capability of the transmission lines can be improved. The operational principle of the DSSCs, the hardware structure and the control algorithm are described in detail. Finally, the theoretical analyses and the proposed strategy are experimentally verified through a scaled down transmission system with DSSC prototypes.

• 전기전자학회논문지
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• 제23권1호
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• pp.99-106
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• 2019

본 논문에서는 UPQC 시스템과 SVC를 결합한 새로운 형태의 보상장치를 제안하고자 한다. 기존의 UPQC는 직렬형 인버터, 병렬형 인버터, DC 링크로 구성되어 있어있으며 우수한 전력품질 보상 성능을 보이지만 높은 인버터 정격을 요구한다. 제안된 방식은 직렬형 인버터, 병렬형 인버터와 DC 링크 그리고 병렬형 인버터의 출력단에 결합된 SVC로 구성되어 있으며, 기존 UPQC에 비해 넓은 무효전력 보상 범위와 낮은 DC 링크 전압의 장점을 가지고 있다. 또한, SVC가 결합된 새로운 UPQC의 구성은 Matlab 시뮬레이션을 통해 성능을 검증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 추계학술대회 논문집
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• pp.29-30
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• 2016

This paper describes a distributed static series compensator (DSSC) which is a type of distributed flexible ac transmission system (DFACTS). The control principles including the power flow control and the current regulation are explained in detail. In order to verify the effectiveness of the DSSC, the simulation results are offered.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 전력전자학술대회
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• pp.214-215
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• 2017

Distributed Flexible AC Transmission System(D-FACTS) was proposed as a solution for weakness of FACTS device s. The D-FACTS device DSSC(Distributed Static Series Co mpensator) can provide controllable reactance compensation in transmission line such as SSSC(Static Synchronous Series Compensator). This paper introduce the algorithm of reactive power injection on DSSC and propose the method of current balancing by reactive power injection. The proposed algorithm has been verified with simulation and experiment results.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권9호
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• pp.422-430
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• 2005

This paper describes experimental analysis of UPFC, which is composed of cascaded H-bridge modules and single-phase multi-winding transformers for isolation. The operational characteristic was analyzed through experimental works with a scaled model, and simulation results with PSCAD/EMTDC. The UPFC proposed in this paper can be directly connected to the transmission line without series injection transformers. It has flexibility to expand the operation voltage by increasing the number of H-bridge modules. The analysis results can be utilized to design the actual WFC system applicable for the transmission system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
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• pp.262-265
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• 2001

최근 전력계통의 과부하, 전압안정도 등의 문제에 대한 해결책으로 FACTS (Flexible AC Transmission Systems)가 대두되고 있다. FACTS 설비에는 TCSC (Thyristor-Controlled Series Capacitor), SSSC (Static Synchronous Series Capacitor)와 같은 직렬 기기와 SVC(Static Var Compensator), STATCOM(STATic COMpensator) 와 같은 병렬기기 그리고, 본 논문에서 다루는 UPFC와 같은 직 병렬기기로 나누어진다. UPFC는 SSSC와 STATCOM을 결합한 형태로 유 무효전력을 동시에 보상할 수 있는 FACTS 기기이다. 본 논문에서는 한전 계통의 전압안정도 향상과 과부하 해소를 위해 강진S/S에 설치예정인 80MVA UPFC의 하드웨어 특성과 주변계통의 특성을 소개하고, UPFC와 한전 계통의 연계방안과 시험방안을 설명한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1035-1038
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• 1999

To improve the damping of all poorly damped oscillation modes, a control strategy of Static Synchronous Series Compensator (SSSC) based on energy method is presented in this Paper As a synchronous voltage-sourced inverter, SSSC is used to provide controllable series compensation. SSSC can provide controllable compensating voltage over an identical capacitive and inductive range. The damping effect of control strategy based on energy function is robustness with respect to loading condition, fault location and network configuration. Furthermore, the control inputs are based on local signals. In two area system, the effect of damping inter-area mode oscillation is demonstrated by the robust control strategy of SSSC.