• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2184-2186
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• 1997

Potential-source controlled rectifier excitation system has been developed by KEPRI for synchronous generator in YOUNG-DONG thermal power plant. This paper describes the characteristics of redundant control system and transfer function of dual channel excitation control system. This system has been using a analog and digital circuit devices(hybrid type)

• KEPCO Journal on Electric Power and Energy
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• v.1 no.1
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• pp.9-13
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• 2015

Energy storage systems (ESS) can be used to provide frequency regulation services in a power system to replace traditional frequency regulation power plants. Battery ESS, in particular, can provide "fast-responding frequency regulation," wherein the facility can respond immediately and accurately to the frequency regulation signal sent by the system operator. This paper presents the development and the trial run results of a frequency regulation control system that uses large-scale ESS for use in a large power system. The control system was developed initially for the 4 MW ESS demonstration facility in Jocheon Jeju Island, and was further developed for use in the 28 MW ESS facility at the Seo-Anseong substation and the 24 MW ESS facility at the Shin-Yongin substation to provide frequency regulation services within mainland Korea. The ESS facility in Seo-Anseong substation responds to a sudden drop in frequency via governor-free control, while the ESS facility in Shin-Yongin responds via automatic generator control (AGC).

• KEPCO Journal on Electric Power and Energy
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• v.6 no.4
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• pp.419-425
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• 2020

DC distribution system has been evaluated as an excellent one in comparison with existing AC distribution network because it needs fewer power conversion stages and the full capacity of the equipment can be used without consideration for power factor. Recently, research and development on the implementation of DC distribution networks have been progressed globally based on the rapid advancement in power-electronics technology, and the technological developments from the viewpoint of infrastructure are also in progress. However, to configure a distribution network which is a distribution line for DC, more accurate and rapid introduction of analysis technology is needed for the monitoring, control and operation of the system, which ensure the system run flexible and efficiently. However, in case of a bipolar DC distribution network, there are two buses acting as slack buses, so the Jacobian matrix cannot be configured. Without solving this problem, DC distribution network cannot be operated when the network is unbalanced. Therefore, this paper presented a comprehensive method of analysis with consideration of operating elements which are directly connected between neutral electric potential caused by the unbalanced of load in DC distribution network with bipolar structure.

• Journal of Electrical Engineering and Technology
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• v.5 no.1
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• pp.54-60
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• 2010

This paper presents a new algorithm for determining generator operation point for maintaining stability considering generator faults in Jeju-Haenam HVDC system. As the HVDC system consumes reactive power for the transmission of active power substantially, compensation of reactive power is essential. And the HVDC system is operated on frequency control mode. That is to say, the HVDC system almost manages system frequency. Therefore, we recognized that the Jeju system could be unstable if the reactive power consumed by the HVDC is insufficient when out-of-step occurs with large generators. When the solution of power flow analysis does not converge due to the unstable system phenomenon, we have difficulty in establishing countermeasures as the post-fault information is not available. In this paper, for the purpose of overcoming this difficulty in establishing countermeasures, we introduce the CPF(Continuation Power Flow) algorithm. This paper suggests an algorithm for calculating the output limitation of the generator to maintain the stability in case of generator fault in the Jeju system.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.58_59
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• 2009

Generator excitation system, supplying the voltage to power system, is controlled by various manners as aspects of power system. Previously excitation systems mainly used AVR(Automatic Voltage Regulator) and FCR(Field Current Regulator) to control voltage, but nowadays the excitation systems have the tendency to adopt AQR(Automatic Reactive power Regulator) and APFR(Automatic Power Factor Regulator) to do it so as to get into step with diverse requirements of power system and high digital technology. This paper presents which operation methods is effective for the equipment, according to increase the unmanned power station thanks to automation technic.

• Journal of Electrical Engineering and Technology
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• v.5 no.3
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• pp.353-362
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• 2010

This paper presents a centralized control algorithm for power system performance in the Korean power system using Flexible AC Transmission Systems (FACTS) devices. The algorithm is applied to the Korean power system throughout the metropolitan area in order to alleviate inherent stability problems, especially concerns with voltage stability. Generally, control strategies are divided into local and centralized control. This paper is concerned with a centralized control strategy in terms of the global system. In this research, input data of the proposed algorithm and network data are obtained from the SCADA/EMS system. Using the full system model, the centralized controller monitors the system condition and decides the operating point according to the control objectives that are, in turn, dependent on system conditions. To overcome voltage collapse problems, load-shedding is currently applied in the Korean power system. In this study, the application of the coordination between FACTS and switch capacitor (SC) can restore the solvability without load shedding or guarantee the FV margin when the margin is insufficient. Optimal Power Flow (OPF) algorithm, for which the objective function is loss minimization, is used in a stable case. The results illustrate examples of the proposed algorithm using SCADA/EMS data of the Korean power system in 2007.

• Proceedings of the SAREK Conference
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• 2005.06a
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• pp.203-203
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• 2005

• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.135-138
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• 2005

This paper focuses on emergency source and control of substation against the consequence of power system breakdown or outage. the aim of the paper is to provide ideas and guidance concerning methods of using AC/DC combined emergency source for power system control to restore power system after unforseen events, such as outages caused by natural disaster. so the emergency source and lamp is very important for restoration control of substation after outage. therefore, this paper proposes countermeasure and method for security of substation emergency source and lamp which is restored at breakdown.

• KEPCO Journal on Electric Power and Energy
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• v.1 no.1
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• pp.99-104
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• 2015

In this study, it has been initiated to investigate the specific abnormal vibration signal that has been captured in the power equipment. Array Microphone can be used in order to detect the direction and the position of the noise source. It is possible to track the abnormal mechanical noise in the power plant by utilizing the program and the microphone array system developed from this research. Array microphone system can be operated as a constant monitoring system.

• Polymer Science and Technology
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• v.9 no.5
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• pp.411-420
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• 1998