• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.3
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• pp.50-55
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• 2007

A large steel industry which has nonlinear loads including electric arc furnaces is one of the extra high voltage customers. These nonlinear loads generate harmonic currents and create distortions on the sinusoidal voltage of the power system. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. A cumulative propablistic approach is the most commonly used method to solve time varying harmonics. In this paper the in varying harmonics of electric arc furnace loads are evaluated by international harmonic standards(IEC 61000-3-6, IEEE 519 and JIS C 61000-3-2).

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.2
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• pp.82-86
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• 2012

Recently, due to the expansion of electric power demands, nonlinear load such as converters and inverters connected to the electric power distribution system, and extensive application of harmonic generation sources with power electric devices, disturbance of the electric power system and its influences on industries have been continuously increasing. In this research, power quality was analyzed for 11 extra-high voltage customers by considering voltage unbalance condition, power factor, THD and TDD. This research will be utilized as fundamental data to improve power quality for power utility.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.1
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• pp.1-7
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• 2018

IEC 61000-3-7 provides guidance for limiting flicker and enabling the connection of fluctuating load installations, that is, producing flicker in MV, HV and EHV power systems. In Korea, the flicker have been restricted by Japanese standard of ${\Delta}V_{10}$ method. ${\Delta}V_{10}$ was developed only for arc furnaces in 1960's. And now it is revealed that it is not suitable for application to other fluctuating load installations through many researches. $P_{st}$ which is a flicker index used in IEC 61000-3-7, indicates visual inconvenience due to voltage fluctuation across large range of frequency and can be applied to fluctuating load installations as well as arc furnaces. In this paper, we introduce how to calculate and assess flicker emission level for the individual fluctuating load installations connected in EHV system and how to manage the emission levels in the power system according to IEC 61000-3-7.