• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.26 no.8
• /
• pp.88-95
• /
• 2012

When controling combustion air flow in coal fired power plant the furnace safety must be considered first prior to plant efficiency. therefore it is very important to set air flow demand exactly for safe operation and maintenance. This paper analyze air flow control loop in power plant and introduce the method to improve dynamic response time. Simulation result shows this scheme is adoptable and provide better performance.

• Proceedings of the KIEE Conference
• /
• 2000.07a
• /
• pp.233-235
• /
• 2000

SVC(Static Var Compensator) is commonly installed with conventional mechanically switched existing reactor or capacitor banks for wide range voltage control. The frequencies of switching of external banks have a great impact on the quality of voltage, but is limited since the life time of the external banks depends severely on the number of switching. So it is a complete multi-objective nonlinear optimization problem with conflicting objectives. This paper presents a method to determine the optimal coordination of SVC and external banks using genetic algorithm based on the multi-objective criteria. Optimal dead band and delay time of external banks is sought for reliable and efficient operation

• Proceedings of the KIEE Conference
• /
• 2006.07a
• /
• pp.533-534
• /
• 2006

Micro-source units having power ratings in thousands of watts can provide power quality with higher reliability and efficiency than the conventional large scale units. This paper develops switching level model of micro-source and studies the characteristics of the micro-grid consisting of multiple micro-sources and interfaced with electric power system. The developed model adopts the space vector PWM to fully utilize the capacity of inverter. The interaction of the grid connected micro-sources and the characteristics of the control system parameters are investigated. Micro-sources and micro-grid are implemented using PSCAD/EMTDC. Simulation results show that the proposed model is efficient for studying micro-grid system.

• Proceedings of the KIEE Conference
• /
• 2006.07a
• /
• pp.198-199
• /
• 2006

FACTS(Flexible AC Transmission System) 기기들은 전력계통의 경제적이고 안정적인 운용과 제어에 더 많은 유연성을 제공할 수 있다. 그러나 이러한 FACTS 기기들은 기존의 전력 계통 설비들과는 달리 그 특성이 매우 비선형적이고 복잡하기 때문에 기존 전력 계통의 동적 시뮬레이션 알고리즘에 적용시키는 것이 매우 어렵다. 이러한 어려움을 해결하기 위하여 전압원 인버터(Voltage Sourced Inverter) 형태의 FACTS 기기를 병렬 형태로 주입되는 전류로 등가화 하여 기존의 시뮬레이션 알고리즘에 적용하는 방법이 제안되었다. 본 논문에서는 이 전류 주입형 기법을 이용하여 다수의 FACTS 기기들이 설치된 계통의 동적 안정도 해석 방법을 제안한다. 제안된 방법은 서로 다른 형태의 FACTS 기기들이 설치된 경우에도 적용될 수 있으며 이를 이용하여 서로 다른 FACTS 모델들 간의 조합에 의한 계통의 안정도 변화를 사례연구를 통하여 보일 것이다.

• Proceedings of the KIEE Conference
• /
• 2005.07a
• /
• pp.332-334
• /
• 2005

This paper presents a dynamic simulation of the unified power flow controller (UPFC) using a current injection method. Flexible AC Transmission System (FACTS) devices give more flexibility of control for security and economic operation of power systems. Diffculties of modeling UPFC in the conventional dynamic simulation programs arise from the fact that the injected voltage by the series inverter is superimposed on the shunt inverter side voltage. A solution can be a current injection method, in which a serial part of UPFC is converted to a parallel equivalent circuit using source transformation, and two current sources affect each other at every time step. To verify efficiency of this method, the proposed model is applied for the transient analysis of an example power system.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.49 no.10
• /
• pp.502-508
• /
• 2000

This paper presents a dynamic simulation algorithm for studying the effect of United Power Flow Controller(UPFC) on the low frequency power system oscillations and transient stability studies. The proposed algorithm is a Newton-type one and uses current injection type UPFC model, which gives a fast convergence characteristics. The algorithm is applied to studying inter-area power oscillation damping enhancement of a sample two-area power system both in time domain and frequency domain. The case study results show that the proposed algorithm is very efficient and UPFC is very effective and robust against operating point change.

• Proceedings of the KIEE Conference
• /
• 2000.11a
• /
• pp.217-219
• /
• 2000

Recently a static var compensator(SVC) is installed at Seo-deagu Substation. It is a power system controller using power electronics commonly called Flexible AC Transmission Systems(FACTS). This paper presents the characteristics and configuration of the Seo-deagu SVC. This paper discusses the modeling aspect of the Seo-deagu SVC systems. EMTDC simulation model of the Seo-deagu SVC is developed and verified.

• Proceedings of the KIEE Conference
• /
• 1999.07c
• /
• pp.1170-1172
• /
• 1999

HALS(Hypermidia Aided Learning System) is very useful computer networking educational system in high information society, and was developed by Kyungwon University. This system has three characteristics; 1) face-to-face learning, 2) ultra-high-speed information networking, 3) web-based hypermedia courseware. So, the purpose of this paper is to introduce the application to university educational program(electrical engineering: electric power system, control system). For this purpose it is described the definition and characteristics of HALS. Next, it is represented the model of electrical engineering educational program applied to HALS and the developed courseware.

• Proceedings of the KIEE Conference
• /
• 1995.11a
• /
• pp.110-112
• /
• 1995

Now days, voltage stability is well recognized as an important problem. It is well known that voltage stability is influenced by the characteristics of load. Up to present, voltage stability researches were done by the static load modeling, but it is needed that the precise analysis by the view point of dynamic load modeling. In this paper, with induction motor as dynamic load, I show the voltage collapse mechanism followed by load increase. Then I propose the protective method of voltage collapse by using TCSC.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.520-521
• /
• 2008

This paper deals with simulation model of the micro-grid system based on the real power system and applying PV generation system to micro-grid system. PSCAD/EMTDC simulation model is developed for use in studying the effect of the dynamics of PV generation to the micro-grid system. Simulation results show that the addition of the PV system improves the voltage profile of the area. Case studies also show that power quality at the load side is improved via voltage compensation at the load bus.