• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.62-64
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• 2001

This paper presents a new loss allocation scheme using power contribution method Power contribution is to find how much power at each generating/1oad bus is contributed to individual load/generating bus. In this paper power contribution is calculated using fundamental circuit theory. In numerical simulation, an illustrative example applying the proposed scheme to 6-bus test system is shown.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.12
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• pp.1873-1878
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• 2017

Both the introduction of the Renewable Energy Portfolio Standard (RPS) system into the electric energy market in 2012 and a decrease in the cost of constructing photovoltaic (PV) power plants have been increasing the number of MW PV plants in South Korea. Jeju Island is located at the center of three nations, South Korea, China and Japan, and its provincial government declared in 2012 that the island will be a clean region where greenhouse gases are not emitted by 2030. The Jeju provincial government is now doing its best to install PV plants and wind farms to realize a carbon-free island. In this study we investigated contribution of MW PV plants to the power of the electric grid during summer peak times on Jeju Island. Mt. Halla the highest mountain in South Korea, is located at the center of Jeju Island, and we divided the island into four regions and carried out analyses of a total of 24 PV plants. The average contribution of the PV plants in the respective region to electric power of Jeju Island during summer peak times was investigated and compared with those of the other regions. The best average contribution during the 12.5% maximum load period was obtained from the PV plants in the western region, and the value was 33% during 2015 and 2016.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.22-24
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• 2008

Construction of wind power plant is rapidly increasing since Jeju is known as the most suitable regarding wind power plants in Korea. But implementing wind power generation inevitably introduces new challenges due to its intermittent nature. In the paper, it is introduced the influence analysis and Han-Kyung wind power plants contribution on Jeju power system.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.1
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• pp.41-47
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• 2020

The contribution of damage mechanisms to failure of steam turbine casing made of Cr-Mo-V steel was investigated. Creep-fatigue interaction on the HP side corner of turbine casing was revealed as the root cause of the catastrophic failure performed by metallurgical analysis. The steady-state pressure and transient thermal stress were analyzed based on the actual operating condition of the thermal plant. Damage of creep-fatigue interaction to crack initiation was evaluated with multiaxial effects. The contribution ratio of creep and fatigue to the crack initiation was estimated to 3:1. Temporary geometrical correct action with repair weld was executed. For long-term operation, design improvement of casing equipment for creep resistance should be needed.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.731-736
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• 2001

Nowadays various simulation tools are widely used for the design and the analysis of power electronic converters. From the engineering point of view it is rather difficult to parameterize power semiconductor device models without the knowledge of basic physical parameters. In recent years some data sheet driven behavioral models or so called 'wizard' tools have been introduced to solve this problem. In this contribution some experiences with some user-friendly power semiconductor models will be discussed. Using special simulation test circuits it is possible to get information on the static and dynamic behavior of the parameterized models before they are applied in more complex schemes. These results can be compared with data sheets or with measurements. The application of these models for power loss analysis of inverter type arc welding power sources will be described.

• Journal of the Korean Society of Safety
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• v.26 no.5
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• pp.23-26
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• 2011

The aim of this paper is to evaluate noise characteristics of an electric power driven hammer. These investigation and analysis were made according to the ISO 1680/1 and MIL-STD 7410-1 and lead-wrapping experiment method that was used to identify the principal noise sources and analyze its noise. Hammer generates loud noise and it irritates and affects many people. Repeated exposures to loud noise can lead people to permanent hearing loss. Based on the contribution analysis, we confirm that the striker part is a major noise source and it has directional noise radiation pattern, which is left and right.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.2
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• pp.123-127
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• 2020

KEPCO has installed Frequency Regulation ESS (FR ESS) of 376 MW since 2015. Frequency Regulation is ancillary service to support stabilizing system frequency, which is divided into governor free and automatic generation control. KEPCO operates FR ESS as governor free application and leads FR ESS market with capability of diverse demonstration and operation experiences. To expand FR ESS role during transient states of power system, KEPCO has extended operating time of charging and discharging. KEPCO has also changed speed droop lower than before to improve contribution on frequency compensation, and acquired much experiences of differentiating bad cells from others. Based on these technologies and know-hows, KEPCO Research Institutes received request of feasibility study and technical cooperation for overseas FR ESS business. This paper suggests the simple and practical method for making technological feasibility study of FR ESS.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.703-705
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• 1999

The Power supplies used commonly in the Nuclear, Thermal and Hydraulic Power Plant are required to test the function and reliabilities. For the better contribution of reliable operation and speedy maintenance of Power Plant, it is necessary to gather and analyze the datum, to print out the result of testing using PC and proper controllers. Various kinds of power supply shall be tested and examined automatically. By storing the test results in the Database it is possible to find out the changing of characteristics of power supplies. So it is very useful to prevent any problems that may occur in the power supplies.

• Journal of Families and Better Life
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• v.27 no.4
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• pp.141-160
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• 2009

Recently, some policies for reducing standby power, which has quite an effect on electricity consumption, have been employed all over the world. This study surveys the present condition of standby power for major electric home appliances during three years and analyzes the result of technical development reducing standby power. It presents how the industry paid attention to applying the technique of reducing standby power to electric appliances and how it affects the product's energy efficiency. We survey the standby power's change for six items, which were selected from the major electric appliances available on the market. It analyzes the difference of standby power consumption between appliances with a standby power reducing technique and those without during the latest three years. The amount of the average standby power is also compared. The comparison data confirms that the industry's effort and application of reducing standby power contribution has contributed to increasing an appliance's energy efficiency. This study restricted the analyzed items to six appliances, which has been a low volunteered involvement in the standby power reducing program. It is important for reducing standby power consumption of appliances because it contributes to saving electric energy at home and abroad. The development of the standby power reducing technique is needed for more appliances. Along with the development of the standby power reducing technique in the industrial field, it also necessary for consumers to enlarge their understanding of standby power reduction for economic, social, and environmental values.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1143-1146
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• 1998

Static excitation systems with high gain and fast response times greatly aid transient stability. but at the same time tend to reduce small signal stability. The objective of the power system stabilizer(PSS) control is to provide a positive contribution to damping of the generator rotor angle swings, which are in a broad range of frequencies in the power system. Therefore, this paper shows the field test results for the GE's EX2000 PSS tuning on units at Seo-Incheon power plant. The test is to verify that the PSS response meets GE's design, criteria. The responses of generator terminal voltage, active power, field voltage and current were analyzed and PSS gain was tuned by 10 finally.