• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1605-1606
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• 2007

An electrical generator in power plant is driven and maintained its speed at rated by steam turbine. By the way, after synchronization in parallel with the power system, as the steam flow into turbine can not be reduced fast even though the electrical load is lost, the turbine gets into dangerous situation due to the increase of its speed. At this time, the duty of the turbine governor is to limit the speed to its overspeed trip set point by stopping the steam flow as soon as possible, the test of which is called load rejection test. It is introduced in this paper for a field simulation test of generator load rejection to be implemented on the turbine governor in a 680MW nuclear power plant before its startup.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1191-1192
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• 2011

• Journal of Advanced Marine Engineering and Technology
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• v.26 no.3
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• pp.313-319
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• 2002

Since the oil crisis in 1970, a great deal of effort has been made to develop automatic electric load sharing systems as a part of the efforts to save energy. A large scale electric generating system composes more than two generators whose characteristics may be different. When such a system is operated individually or in parallel, the lagrange multiplier's method has difficulty in achieving optimal load distribution because generators usually have the limitations of the operating range with inequality constraints. Therefore, a suitable operating mode of generators has to be decided according to the selection of the generators to meet electric power requirements at the minimum cost. In this study, a method which solves the optimal electric load distribution problem using the dynamic programming technique is proposed. This study also shows that the dynamic programming method has an advantage in dealing with the optimal load distribution problem under the limitations of the operating range with inequality constraints including generator operation mode. In this study, generator operating cost curve of second order equation by shop trial test results of diesel generators are used. The results indicate that the proposed method can be applied to the ship's electric generating system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.8 s.251
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• pp.993-1000
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• 2006

Operating experience of steam generators has shown that cracks of various morphology frequently occur in the steam generator tubes. These cracked tubes can stay in service if it is proved that the tubes have sufficient safety margin to preclude the risk of burst and leak. Therefore, integrity assessment using exact limit load solutions is very important for safe operation of the steam generators. This paper provides global and local limit load solutions for surface cracks in the steam generator tubes. Such solutions are developed based on three-dimensional (3-D) finite element analyses assuming elastic-perfectly plastic material behavior. For the crack location, both axial and circumferential surface cracks, and for each case, both external and internal cracks are considered. The resulting global and local limit load solutions are given in polynomial forms, and thus can be simply used in practical integrity assessment of the steam generator tubes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.927-933
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• 2014

Ship Power Management System(SPMS) based on Communication Network(CN) is one of the most significant factor for a safe voyage. Therefore, most of the vessels are using greater capacity generator than necessary to prevent pulsating load for safety purposes. However, It provokes low-load damage and reduces generator efficiency that using large capacity generator. Accordingly, in this paper propose hybrid power system for prevent damage of pulse load. Simulation using NI's LabVIEW was conducted for the design of the power system based on actual navigation data of the ship. Also, propose applying methods for hybrid power system in connection with the auxiliary power system for safe navigation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.10
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• pp.172-177
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• 2006

This paper presents a method to improve reliability considering dispersed generator(DG) installation and interruption cost with load types. It is used to the different interruption costs with load pattern of daily peak load. The objective functions such as power losses cost operation cost of DG, power buy cost and interruption cost are minimized for reliability improvement and efficient operation. The several indices for reliability evaluation are improved by dispersed generator installation. The proposed method is applied to IEEE 13 bus test systems to demonstrate its effectiveness.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.11
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• pp.1813-1821
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• 2004

Until now, the 40% of wall thickness criterion, which is generally used for the plugging of steam generator tubes, has been applied only to a single cracked geometry. In the previous study by the authors, a total number of 9 local failure prediction models were introduced to estimate the coalescence load of two collinear through-wall cracks and, then, the reaction force model and plastic zone contact model were selected as the optimum ones. The objective of this study is to estimate the coalescence load of two collinear through-wall cracks in steam generator tube by using the optimum local failure prediction models. In order to investigate the applicability of the optimum local failure prediction models, a series of plastic collapse tests and corresponding finite element analyses for two collinear through-wall cracks in steam generator tube were carried out. Thereby, the applicability of the optimum local failure prediction models was verified and, finally, a coalescence evaluation diagram which can be used to determine whether the adjacent cracks detected by NDE coalesce or not has been developed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.5
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• pp.53-57
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• 2008

Diesel generator is most widely used for supplying of emergency electrical power. There have been extensive research efforts to develop ways to Ensure stable electrical power delivery to the loads using hybrid power sutures, such as power source, storage batteries, fuel cells and solar cells. Furthermore, as the role of these diesel generators for emergency electrical power supply has recently become very important, they should assure high reliability and flexibility according to the operation load. Therefore, in this paper, we introduce a controller to be used in diesel generator toenable tracking control of maximum power according to the load variation and suppressing high-order harmonics while maintaining stable frequency.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.3
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• pp.425-431
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• 2016

Supply Capability of the generator, if the maximum demand occurs, refers to the maximum power that can be stably supplied and it is possible to maintain stable power supply to be greater than actual load. However, unexpected power demand and reduction in supply Capability due to stop of unexpected generator in operation can temporarily make a big chaos in power system. In fact, due to a lack of power supply Capability in the country, enforced emergency load adjustment to the September 15, 2011, the circulation power outage has occurred in several cities. As the result, interrupted operation of the elevator and stopped hospital medical equipment led to a great deal of trouble to people's lives, causing a social problem. At that time, it was found that a failed frequency control because of smaller actual supply Capability than that of predicted. The difference was about 1,170 MW with Gas turbine power plant. By accurately calculating the generator supply capability, we can not only grasp the power reserve rate, but also correspond to the time of power supply instability.

• Journal of the Korean Society of Industry Convergence
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• v.4 no.3
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• pp.311-318
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• 2001

The application of a pulsed power system is being extended to a environmental and industrial fields. The non-dissolution waste water pollutants from industrial plants can be processed by applying high voltage pulses with a fast rising time (a few nanoseconds) and short duration (nano to microseconds) in a pulsed corona discharge reactor. The nano-pulse generator with a magnetic switch has been developed. Its corona current in load can be adjusted by pulse width and repetition rate. we investigated the performance of the nano-pulse generator using the dummy load which is composed of resistor and capacitor equivalent to the actual reactor. This paper descibes the electrical characteristics of the nano-pulse generator that produces a 300 ns pulse at maximum repetition rate of 400 pps with a voltage of 40 kV across a $640{\Omega}$ load. In this paper we briefly discuss a configuration of system and test results.