• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.113-114
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• 2008

For the supported high-technology, it is in need of estimation about power quality and reasonable price through machinism. The power system made much of precision digital industrial damage under sag. This study suggested electric machine under effects of power quality in the theory and test. A electric machine was simulated and experimented about sag. The test system made up IPC as voltage sag device. The test machine was magnetic contactor and PLC. The result, electric machines appeared to influence sag with CBEMA curve. It was make possible analysis of power system about a fault. This study was expected to method that investment and development of equipment on power market in the future.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.37-40
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• 2008

This paper presents the results of a simulation to analyze the effects of voltage sag on high-pressure discharge lamp(400[W]). In this paper, voltage sag is considered a reduction between 0 and 0.9[p.u] in nominal voltage magnitude, with duration between 0.01 and 90cycle. The simulation results depict the characteristics of the lamp about operating limits during voltage sag by the magnitude and duration of sag in CBEMA curve.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.9-14
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• 2002

In front of the opening of electric distribution market in 2004. it is indispensable to have a proper estimation of power quality index and power quality cost calculation mechanism are indispensable to stabilize highly industrialized society and to vitalize the investment for electric power system. However, there were not enough measures to reflect the voltage characteristics such as voltage sags and interruptions which make electric load in unstable operation. This paper suggests power quality index(LDI) and power quality cost(LDC) which translate various kinds of voltage records into load drop index and cost based on aggregated load CBEMA curve. A sample calculation result shows that this method can produces the acceptable power quality index and costs for utilities and customers requirements.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.36-38
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• 2003

In this paper, It was evaluated that the customer's effects of momentary voltage sag in power distribution system considering reclosing interval. Above all, power quality problems were discussed widely, various international standards about power quality were compared to each other. after the continuous voltage sag waves of power distribution system on fault were induced, the experimentation about voltage sag for critical load was performed using source simulator. The results of experimentation were displayed as the form of 2 and 3-dimensional CBEMA Curve.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.54-56
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• 2003

With the advancement of superconductor materials, especially in HTC YBCO(Gen II), the feasibility of SMES in power systems become much higher than previous days application[1]. Also, with the de-regulation of electricity market, it is indispensable to have a proper estimation of power quality index and power quality cost calcluation mechanism to stabilize highly industrialized society and to vitalize the investment for electric power system. This paper suggests a comprehensive algorithm[2] to determine the policy of SMES investment with the PQ Indices[3] based on aggregated load CBEMA curve reflecting the voltage characteristics such as volatge sags and interruptions which make electric load in unstable operation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.3
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• pp.82-87
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• 2007

This paper measures power quality of bus in case electric charges about customer are imposed by each bus, supposed that can calculate this cost. When reflected this in system planning, expected cost proposed following method through sample system. To calculate nodal cost operating condition of power equipment calculates nodal cost[$/MVAH] supposing by situation that is optimized by OPF(optimal power flow) in system. The damage cost that is shed by fault that happen during year of loads in system that is linked on each bus was produced. As a result, proposed method was very effective in case of calculating bus total cost including power quality cost.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.12
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• pp.678-684
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• 2004

Automatic reclosing is a typical protection method in power distribution systems for clearing the temporary faults. However, it has a fatal weakness in regards to voltage sags because it produces successive voltage sags. In this paper, we explored successive impact of voltage sag due to the automatic reclosing of power distribution systems. The actual tests of low voltage loads were accomplished for obtaining the susceptibility of voltage sags. The final results of the test yielded power acceptability curves of voltage sag, and the curves were transformed the 3-dimensional CBEMA(Computer Business Equipment Manufacturer Association) format. For the quantitative evaluation of the impact of successive voltage sags, an assessment formulation using the voltage sag contour was proposed. The proposed formulation was tested by using the voltage sag contour data of IEEE standard and the results of the test. Through the case studies, we verified that the proposed method can be effectively used to evaluate the actual impact of successive voltage sans.

• KIEE International Transactions on Power Engineering
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• v.5A no.3
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• pp.293-299
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• 2005

Automatic reclosing is a typical protection method in power distribution systems for the clearing of temporary faults. However, it has a fatal weakness in regards to voltage sags because it produces repetitive voltage sags. In this paper, we explored the repetitive impact of voltage sag due to the automatic reclosing of power distribution systems. The actual tests of low voltage loads were carried out for obtaining the susceptibility of voltage sags. The final results of the tests yielded power acceptability curves of voltage sag, and the curves transformed the 3-dimensional CBEMA (Computer Business Equipment Manufacturer Association) format. For the quantitative evaluation of the impact of repetitive voltage sags, an assessment formulation using the voltage sag contour was proposed. The proposed formulation was tested by using the voltage sag contour data of IEEE standard and the results of the test. Through the case studies, we verified that the proposed method can be effectively used to evaluate the actual impact of repetitive voltage sags.