• KIEE International Transactions on Power Engineering
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• v.5A no.4
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• pp.344-349
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• 2005

In conventional small signal stability analysis, the system is assumed to be invariant and the state space equations are used to calculate the eigenvalues of the state matrix. However, when a system contains switching elements such as FACTS equipments, it becomes a non-continuous system. In this case, a mathematically rigorous approach to system small signal stability analysis is performed by means of eigenvalue analysis of the system's periodic transition matrix based on the discrete system analysis method. In this paper, the RCF (Resistive Companion Form) method is used to analyze the small signal stability of a non-continuous system including switching elements. Applying the RCF method to the differential and integral equations of the power system, generator, controllers and FACTS equipments including switching devices should be modeled in the form of state transition equations. From this state transition matrix, eigenvalues that are mapped into unit circles can be computed precisely.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.12-13
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• 2006

In this paper, RCF(Resistive Companion Form) analysis method which is used to analyze small signal stability problems of non-continuous systems including switching device. The RCF analysis method are applied to the power systems with the thyristor controled FACTS equipments such as TCSC. As a result of simulation, the RCF method is very powerful to calculate the oscillation modes exactly after the switching operations, and useful to analyze the small signal stability of power systems with switching devices such as FACTS equipments. As an applicable example of the RCF method in power system, the one machine infinite bus system including TCSC at generator terminal bus is investigated and the results proved that variations of oscillation modes after periodic switching operations of TCSC can be calculated exactly.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.23-25
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• 2000

In recent deregulation and competitive power market environment, electric utilities plan and operate their systems for economic benefit with secure system condition. Flexible AC transmission system(FACTS) technology opens up new opportunities of controlling power and enhancing the usable capacity of present transmission system. This paper presents a method for security constrained optimal allocation of FAETS considering contingencies for the purpose of enhanced system operation. The proposed scheme uses Benders decomposition to account of both corrective and preventive mode.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.7-8
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• 2008

유연 송전시스템(FACTS)은 송전선의 효율을 높임으로서 발전소의 추가 설비 없이도 전력수요에 맞는 전력공급을 가능하게 하는 제어기이다. 특히, 직렬형 유연 송전시스템에서 사용하는 외부제어기는 미소 리액턴스 신호를 발생하여 내부제어기에 인가함으로서 전력시스템의 저주파 댐핑을 효과적으로 향상시키는데 사용된다. 본 논문에서는 효과적인 외부제어기 설계를 위해 하이브리드시스템 모델링 이론을 유연 송전시스템을 포함한 전력시스템에 적용하였다. 하이브리드시스템은 전력시스템의 고유의 비선형성을 포함하여 모델링을 함에도 불구하고 전체 시스템 행렬을 계산할 수 있게 도와줌으로서 고유치 분석을 통한 적절한 외부제어기 설계를 가능하게 한다. 본 논문에서 제시한 방법을 적용하여 설계된 외부제어기의 성능을 1기 무한모선 시스템에 적용하여 평가하였다.

• Journal of Electrical Engineering and Technology
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• v.5 no.4
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• pp.522-529
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• 2010

Distance relay plays an important role in the protection of transmission lines. The application of flexible AC transmission systems (FACTS) devices, such as the static synchronous compensator (STATCOM), could affect the performance of the distance relay because of compensation effect. This paper analyzes the application of distance relay on the protection of a transmission line containing STATCOM. New setting principles for different protection zones are proposed based on this analysis. A typical 500 kV transmission system employing STATCOM is modeled using Matlab/Simulink. The impact of STATCOM on distance protection scheme is studied for different fault types, fault locations, and system configurations. Based on simulation results, the performance of distance relay is evaluated. The setting principle can be verified for the transmission line with STATCOM.

• Journal of Power Electronics
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• v.11 no.1
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• pp.90-96
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• 2011

Congestion management is one of the most challenging aspects in the recently deregulated electricity markets. FACTS devices have been shown to be an efficient alternative to control the flow of power in lines, resulting in increased loadability, lower system loss and a reduced cost of production. In this paper, the application of a static series synchronous compensator (SSSC) for the purpose of congestion management of power systems has been studied. A sensitivity-based analysis method is utilized for effective determination of the SSSC location in an electricity market. The method is topology based and it is independent of the system operation point. A power injection p-model is developed for the SSSC in this study. Numerical results based on the modified IEEE 14 bus system with/without the SSSC demonstrate the feasibility as well as the effectiveness of the SSSC for congestion management in a network. The results obtained when using the SSSC to improve system transfer capability and congestion management is encouraging.

• Journal of Power Electronics
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• v.11 no.3
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• pp.375-380
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• 2011

A STATic synchronous COMpensator (STATCOM) is a shunt connected voltage source converter (VSC) based FACTS controller using Gate Turn Off (GTO) power semiconductor devices employed for reactive power control. The operation principal is similar to that of a synchronous condenser. A typical application of a STATCOM is voltage regulation at the midpoint of a long transmission line for the enhancement of power transfer capability and/or reactive power control at the load centre. This paper presents the modeling of STATCOM with twenty four pulse three level VSC and Type-1 controller to regulate the reactive current or the bus voltage. The performance is evaluated by transient simulation. It is observed that, the STATCOM shows excellent transient response to step change in the reactive current reference. While the eigenvalue analysis is based on D-Q model, the transient simulation is based on both D-Q and 3 phase models of STATCOM (which considers switching action of VSC).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.5
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• pp.661-666
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• 2015

This paper proposes a method for solving running cost problem by minimizing switching reactive power compensation devices. An objective function was modeled by calculating the weighting value of cost, and a solution was derived using ILP. This paper suggests optimal coordinative control method between FACTS, Shunt Reactors, Capacitors and OLTC. Therefore, it is valuable for decision maker in determining order and capacity of devices which gaining a voltage stabilization. As a result, the objectives of voltage stabilization and cost minimization were achieved simultaneously. This realizes the economic efficiency of the system. We start by showing how to solve systems of linear equations using the language of pivots and tableaus. The effectiveness of this technique is demonstrated in modified PSS/E MIGUM 45 bus system. The simulation results show the effectiveness of this algorithm by comparing the outcome withseveral established methods.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.1121-1123
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• 1997

The control strategy for damping analysis of STATCON is derived based on an energy function of the power system equation. The center-of-angle(COA) coordinated system by a simple equivalent physical system is used and the control law for this system is induced for FACTS devices as TCSC and STATCON. Damping results from the transient performance simulations carried out on the model system.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.193-195
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• 2003

In this paper, we present the analysis results of TCSC(Thyritor Controlled Series Capacitor) operating characteristics with damping resisters. This TCSC system is designed for KERI simulator. It consists of many power system components, which are generator models, scale-downed transmission line modules, transformers, switches, FACTS(Flexible AC Transmission System) devices.