• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.205-207
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• 2005

In this paper, the Point of Common Coupling (PCC) is selected to analyze harmonic characteristic of distribution system by IEC 61000 - 3 - 6 in Electromagnetic Compatibility(EMC). Harmonic voltage and current were measured at the PCC of real distribution system. Harmonic distribution, nonlinear load component and Total Harmonic Distortion(THD) were verified by measurement. The effective and accurate modelling of real distribution system were proved through a analysis of harmonic impedance, voltage and current in steady-state. Harmonic transfer characteristic in distribution system were summarized and investigated through a analysis of harmonic voltage and harmonic current in harmonic current source.

• Journal of Electrical Engineering and Technology
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• v.4 no.2
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• pp.175-184
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• 2009

In this paper, a method for optimal measurement placement in the problem of static harmonic state estimation in power systems is proposed. At first, for achieving to a suitable method by considering the precision factor of the estimation, a procedure based on Genetic Algorithm (GA) for optimal placement is suggested. Optimal placement by regarding the precision factor has an evident solution, and the proposed method is successful in achieving the mentioned solution. But, the previous applied method, which is called the Sequential Elimination (SE) algorithm, can not achieve to the evident solution of the mentioned problem. Finally, considering both precision and economic factors together in solving the optimal placement problem, a practical method based on GA is proposed. The simulation results are shown an improvement in the precision of the estimation by using the proposed method.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.202-203
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• 2006

The equipment using the Power electronic device is recently increased in the distribution system, so power utility and customers increase in concerning about harmonics level. Accordingly, The power utility which prepares a measure for the harmonic public standard and manege process must analysis of the harmonics level and the effect on equipment interconnecting distribution system. In the past, the measurement equipment and technique is imperfect, so very difficult to investigate the harmonics and trend. But the improvement of the measurement equipment recently is possible to obtain the data realtime for harmonic analysis. In this paper, we research the measuring domestic harmonic and constructing of DB based on the IEC standard.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.12
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• pp.601-608
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• 2001

The ever increasing density of adjustable speed drives(ASD) device with non-linear operating characteristics has been to put tremendous harmonic stress on end user's electrical application. All ASD controllers which employ solid state power devices cause harmonic currents in the source side line. This paper describes harmonic problems for use of ASD. In order to investigate the effect of harmonics caused by using of nonlinear load at the low voltage system, we fixed up simple load model and measured the voltage and current waveforms. Measurement results show that additional operation of linear load at the parallel bus with nonlinear load such as ASD is helpful to the reduction of harmonic influence.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.1
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• pp.81-88
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• 2005

The Langmuir monolayers of polyamic acid salts with three kinds of alkyl chains have been investigated by means of conventional $\pi$-A isotherms and second harmonic generation measurements proposed in this paper. The surface molecular density dependence of second harmonic intensity clearly shows the region of aggregation while corresponding $\pi$-A isotherm doesn't show any changes in the surface morphology at the same region. The surface morphology analysis based on the second harmonic measurement was consistent with the Brewster angle microscope measurement results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.5
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• pp.48-57
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• 2012

This paper analyzes the characteristic of gird connected photovoltaic power generation system which is available to connect the utility. Renewable energy photovoltaic power system has been linked to the system to analyze the impact of photovoltaic system. It is measured that power data for the Grid connected photovoltaic power plant with instantaneous measuring and 3-sec measuring for 7 days. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. A cumulative probability approach is the most commonly used method to solve time varying harmonics. So, it is used 50[%] cumulative probability approach. This paper provides an in depth analysis on power quality field measurement of the Grid connected photovoltaic power plant.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.149-151
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• 1996

This paper reports the measurement results of the harmonic currents in the household and office appliances. The harmonic currents of 10 items are measured up to 20th order using the no distortion source. These results can be used as a raw data in determining the harmonic current limit in the household and office appliances.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.272-277
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• 2006

High speed electric trains have nonlinear loads including converters and inverters for the contol synchronous motors. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. Direct application of the harmonic assessment to the snapshot measurements would result in ambiguous conclusions depending on which instant is sampled. A cumulative probablistic approach is the most commonly used method to solve time varying harmonics. This paper provides an in depth analysis on harmonics field measurement of the high speed electric train loads, harmonics assessment by the international harmonic standards IEC 61000-3-6 and IEEE std. 519-1992, and harmonics simulation using EDSA program for the case study.

• Journal of the Korean Society for Railway
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• v.7 no.1
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• pp.65-69
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• 2004

In reference to this study, Part Ⅰ showed how the system respond to the harmonics originated from electric locomotives. That is, the system response to the harmonics was derived by computational algorithm with numerical formulas in theoretical aspects. However, Real catenary system has complex configuration of conductors and it is an important point that if we can consider the circuit element of catenary conductors as an uniformly distributed RLC element. Moreover, harmonic characteristics in electric locomotive depend on its operational modes. From these point of view, measurements of harmonics are performed for real railway power supply systems under the various operational modes, and spectrum and distortion analyses in measurement data are described.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.4
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• pp.12-20
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• 2006

Heavy chemical industries have nonlinear loads including electrolyzers. The electrolysis consists of AC-BC converters which generate harmonic currents and create distortions on the sinusoidal voltage of the power system. This paper provides in depth an analysis on harmonics field measurement for the electrolyzer loads, adding a single-tuned filter at the customer bus for reducing harmonic distortion and harmonic assessment by the international harmonic standards IEC 61000-3-6 and IEEE Std. 519. The EDSA program was used as a simulation tool for the case study.