• Journal of Electrical Engineering and Technology
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• v.13 no.3
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• pp.1079-1088
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• 2018

A line overload emergency control strategy based on the source-load synergy coefficient is proposed in this paper. First, the definition of the source-load synergy coefficient is introduced. When line overload is detected, the source-load branch synergy coefficient and source-load distribution synergy coefficient are calculated according to the real-time operation mode of the system. Second, the generator tripping and load shedding control node set is determined according to the source-load branch synergy coefficient. And then, according to the line overload condition, the control quantity of each control node is determined using the Double Fitness Particle Swarm Optimization (DFPSO), with minimum system economic loss as the objective function. Thus load shedding for the overloaded line could be realized. On this basis, in order to guarantee continuous and reliable power supply, on the condition that no new line overload is caused, some of the untripped generators are selected according to the source-load distribution synergy coefficient to increase power output. Thus power supply could be restored to some of the shedded loads, and the economic loss caused by emergency control could be minimized. Simulation tests on the IEEE 10-machine 39-bus system verify the effectiveness and feasibility of the proposed strategy.

• Journal of Power System Engineering
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• v.19 no.5
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• pp.67-72
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• 2015

The reliable operation of onsite emergency diesel generator(EDG) should be ensured by a conditioning monitoring system designed to maintain, monitor and forecast the reliability level of diesel generator. The purpose of this paper is to develop condition diagnosis algorithm(logic) and analysis program of engine for the accurate diagnosis in actual condition of emergency diesel generator engine. As a result of this study, we confirmed that developed engine condition diagnosis algorithm and analysis program could be efficiently applied for actual EDG engine in nuclear power plant.

• Journal of Electrical Engineering and Technology
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• v.3 no.4
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• pp.499-508
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• 2008

Frequency regulation in off-normal conditions has been an important problem in electric power system design/operation and is becoming much more significant today due to the increasing size, changing structure and complexity of interconnected power systems. Increasing economic pressures for power system efficiency and reliability have led to a requirement for maintaining power system frequency closer to nominal value. This paper presents a decentralized frequency control framework using a modified low-order frequency response model containing a proportional-integral(PI) controller. The proposed framework is suitable for near-normal and emergency operating conditions. An $H_{\infty}$ control technique is applied to achieve optimal PI parameters, and an analytic approach is used to analyse the system frequency response for wide area operating conditions. Time-domain simulations with a multi-area power system example show that the simulated results agree with those predicted analytically.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.495-502
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• 2020

In this paper, a power management circuit was designed to drive the emergency lighting LED in the underground facility for public utilities using magnetic energy harvest. The magnetic energy harvest consists of a harvest elements and power management circuits. The proposed circuit was made of a rectifier, a battery charging circuit, and an LED driving circuit. In normal times, the battery is charged with the harvested power, and in the event of an emergency, the energy stored in the battery is used to drive the LED. As a result of the measurement, it took two minutes to charge the 47 mF capacitor. This is the amount of power that can drive an LED for emergency lighting for about three and a half minutes. Through this, it was confirmed that the power management circuit for magnetic energy harvest proposed in this paper can be used as an emergency lighting LED-driven power device in an underground facility for public utilities where it is difficult to draw separate power.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.849-853
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• 2009

A generator is in use for a moving vehicle like car, aircraft, ship as well as key industry including a thermal power plant, a water power plant, a nuclear power plant, and so on. Such the AC generator plays an important role in vehicle, ship, aircraft, and so forth, at the point of generating electric power. Especially in the matter of the ship, the emergency generator system is mounted to provide against malfunction of main generator on a voyage. So, it is ordered that the system can monitor the main generator and operate the emergency generator when the emergency happens. This study is about controller for the emergency diesel engine generator and design of a various software.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.83-91
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• 2015

This paper presents preventive and emergency control measures for on line transient stability (security) enhancement. For insecure operating state, generation rescheduling based on a real power generation shift factor (RPGSF) is proposed as a preventive control measure to bring the system back to secure operating state. For emergency operating state, two emergency control strategies namely generator shedding and load shedding have been developed. The proposed emergency control strategies are based on voltage magnitudes and rotor trajectories data available through Phasor Measurement Units (PMUs) installed in the systems. The effectiveness of the proposed approach has been investigated on IEEE-39 bus test system under different contingency and fault conditions and application results are presented.

• Fire Science and Engineering
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• v.14 no.1
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• pp.22-26
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• 2000

Emergency lamp is installation usage on an emergency situation or firing. It's an offer at least of brightness. It's lighting to common source usually. It's transferred to reserve battery on power stoppage. This emergency lamp is lighted from solar cell system. The solar cell should be operated at the maximum power point. This paper proposes the new control method that half-bridge inverter using the solar cell can operate emergency lamp.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.908-911
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• 2011

Aircraft Auxiliary Power Unit can start and operate using not only main fuel(JP-8) but also specified emergency fuels for emergency operation. In oder to verify emergency fuel requirement, emergency fuel test using commercial diesel fuel was performed. Changes in specific fuel consumption due to use of diesel fuel are 3.5%~7.8%, which satisfied requirement. Diesel fuel showed similar starting characteristic to the JP-8. The specific fuel consumption of diesel increased by 2.0%~3.4% compared with that of JP-8.

• Journal of IKEEE
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• v.18 no.4
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• pp.442-446
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• 2014

A method for applying emergency ratings to improve the reliability of power supply in ACSR overhead transmission lines is described in this paper. Due to re-regulate power industry, most power companies worldwide as well KEPCO have been searching for only economical strategies without new investment. Power demand was rapidly increasing, however, generation amount did not follow sufficiently. Hence in order to increase the transmission capacity for the existing transmission lines in case of peak load, or contingency in transmission lines, an application method of emergency ratings such as short or long term rating is proposed. If applying long term emergency rating instead of static line rating for the period of a peak load, power transmission can be increased to 10 % or more. Furthermore, it was shown that emergency rating can be effectively used in the contingency of double-circuit transmission lines and/or overload cases.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.2
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• pp.224-232
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• 2018

According to government policy, renewable energy facility such as solar power generation is being implemented for newly constructed buildings. In recent years, the introduction of Energy Storage System (ESS) served as an emergency power for replacing an existing diesel generator has been increasing. Furthermore, in order to expand the efficacy of the ESS operation, operation in combination with renewable energy sources such as solar and wind power generation is increasing. Hence, development of the ESS operation algorithms for emergency mode as well as the peak power cut mode, which is the essential feature of ESS, are necessary. The operational scenarios of ESS need to consider load power requirement and the amount of the power generation by renewable energy sources. For the verification of the developed scenarios, tests under the actual situation are demanded, but there is a difficulty in simulating the emergency operation situation such as system failure in the actual site. Therefore, this paper proposes simulation models for the HILS(Hardware In the Loop Simulation) and operation modes developed through HILS for the ESS operated with renewable energy source under peak power reduction and emergency modes. The paper shows that the ESS operation scenarios developed through HILS work properly at the actual site, and it verifies the effectiveness of the control logic developed by the HILS.