• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.93-95
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• 2002

This paper presents the design of a Unified Power Flow Controller(UPFC) for enhancing the small signal voltage stability in the multi-machine power systems. Recently a lot of attention has been paid to the subject of dynamic stability. The paper deals with analysis of eigenvalue sensitivities with respect to parameters of UPFC Controller. The series branch of the UPFC is designed to damp the power oscillation during transients, while the shunt branch aims at maintaining the bus voltage. Comprehensive time-domain simulation studies using Pss/E show that the proposed robost UPFC controller can enhance the small signal stability efficiently in spite of the variations of power system operating conditions.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.55-57
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• 2000

This paper presents the measurement of phasor angle of power system using Synchronized Phasor Measurement System(SPMS). SPMS includes the GPS receiver, so it can add the exact time information to the data acquired from the power system by SPMS. Using that data, we can compare the difference of phasor angles of voltages currents acquired at the exactly same time, and monitor the RMS values of voltage and current. In this paper, we present the difference of voltage angles between 345kV Sinjechon S/S and 345kV Asan S/S, where two SPMS were installed separately, and prove their performance by comparing to simulation result of PSS/E.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1042-1045
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• 1999

This paper presents a new method for contingency selection of the transient stability. Contingency ranking in transient stability is done by estimating the change in the imaginary part of electro-mechanical oscillation mode, which represents modal synchronizing coefficient. And the change in the imaginary part is obtained by applying eigen-sensitivity theory of augmented matrix to linear system model. The Proposed algorithm was tested for New England System and compared the results with PSS/E dynamic simulation.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.237-238
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• 2015

This paper analyzed the impact of Voltage Sourced Converter High Voltage Direct Current(VSC HVDC) connected an offshore wind power on the Jeju Island electrical power system. Wind power output fluctuates with the changing of wind speed. By changing wind power output occupancy into 100%, 60%, 10% respectively, we can understand the bus voltage distribution controlled by VSC HVDC. PSS/E is used to analyze steady-state simulation results which show effectiveness of the VSC HVDC for Jeju Island power system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.252-254
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• 2008

In this paper, the PSCAD/EMTDC modeling of JeJu AC power system with wind farms will be discussed. And the modelling of the synchronous generator, exciter, governor will also be defined in the JeJu power system by using the PSCAD/EMTDC. At the same time the fault analysis and the power flow analysis in JeJu AC power system are presented to demonstrate the JeJu AC power system can perfectly simulate the real JeJu power system function. Through the simulation using PSCAD/EMTDC we have gained the same results compared with the results accomplished by the PSS/E. so the validity of the modelling for the JeJu power system by using PSCAD/EMTDC is confirmed.

• Journal of Electrical Engineering and Technology
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• v.6 no.3
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• pp.311-318
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• 2011

Small-scale reactors have recently attracted attention as a potential power generation source for the future. The Regional Energy Research Institute for Next Generation is currently developing a small-scale reactor called Regional Energy rX 10 MVA (REX-10). The current paper deals with a power system to be used with small-scale reactors for multi-purpose regional energy systems. This small nuclear system can supply electric and thermal energy like a co-generation system. The electrical model of the REX-10 has been developed as a part of the SCADA system. REX-10's dynamic and electromagnetic performance on the power system is analyzed. Simulations are carried out on a test system based on Ulleung Island's power system to validate REX-10 availability on a power system. RSCAD/RTDS and PSS/E software tools are used for the simulation.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.193-196
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• 1999

This paper presents a new systematic contingency selection and screening method for transient stability. The variation of modal synchronizing torque coefficient(MSTC) is computed using eigen-sensitivity analysis of the electromechanical oscillation modes in small signal stability model and contingencies are ranked in decreasing order of the sensitivities of the MSTC(SMSTC). The relevant clusters are identified using the eigenvector or participating factor. The proposed algorithm is tested on the KEPCO system. Ranking obtained by the SMSTC is consistent with the time simulation results by PSS/E.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.73-76
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• 2001

This paper presents a new systematic contingency selection, screening and ranking method for on-line transient security assessment. Transient stability of a particular generator is influenced most by fault near it. Fault at the transmission lines adjacent to the generators are selected as contingency. Two screening methods are developed using the sensitivity of modal synchronizing torque coefficient and computing an approximate critical clearing time(CCT) without time simulation. The first method, which considers only synchronizing power, may mislead in some cases since it does not consider the acceleration power. The approximate CCT method, which consider both the acceleration and deceleration power, worked well. Finally the Single Machine Equivalent(SIME) method is implemented using IPLAN of PSS/E for detailed stability analysis.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.68-70
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• 2001

Because of the difficulty of acquiring new generation sites and right- of-way, additional units have been added to the existing generation sites and the transmission system has been developed into highly meshed configuration. The reliable operation of power systems has been restricted by this system characteristics. The enhancement of system analysis techniques and establishment of appropriate measures have been required in this situation. In addition the deregulation of electric power industry in Korea would give rise to better tools fur power system analysis and control. In this paper, dynamic models were developed and stability studies were implemented using developed dynamic models of EUROSTAG and compared with the simulation results of PSS/E.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.9-11
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• 2003

In power system planing and operation, voltage and reactive power control are very important. The voltage deviation and system losses can be reduced through control of reactive power sources. In general, there are several different reactive power sources, we used UPFC and switched shunt capacitor to improve the voltage profile and to reduce system losses in this study. Since there are many switched shunt capacitors in power system, so it is necessary to coordinate these switched shunt capacitors. In this study, Genetic Algorithm(GA) is used to find optimal coordination of UPFC and switched shunt capacitors in a local area of power system. In case study, the effectiveness of the proposed method is demonstrated in KEPCO's power system. The simulation is performed by PSS/E.