• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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• pp.304-307
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• 1998

High speed railway is under construction from Seoul to Pusan. A traveling train is large single phase load that consumes 14MW power in feeding system of high speed railroad. In this paper, measurement scheme and method of power system harmonics which are generated from those loads in railroad supply system are described. This measurement scheme will be used as a first step to pave a way to power quality management due to harmonic distortion by the highspeed rail way.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권8호
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• pp.441-448
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• 2002

Harmonics studies have been an important aspect of power conversion system analysis and design in recent years. Harmonics using power conversion device, have a harmful effect on power qualify. Nonlinear load such as converter causes harmonic and effects self & other system. There are linear and nonlinear loads in the end-user application. For filter design to reduce harmonics, it is important to understand how loads interact with each other. In this paper, effects on the power conversion system at the low voltage local bus are discussed.

• 전기학회논문지
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• 제60권4호
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• pp.733-738
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• 2011

As increase of nonlinear loads and renewable energy generators (REGs) being connected to power distribution system via inverters, the concern on harmonic problems have increased. Recently, the harmonics evaluation method considering TDD (Total Demand Distortion) is used to analyze the effect of harmonics from inverters on power distribution quality. Harmonic current sources are typically used for simulation of nonlinear load. Most inverter type for REGs is voltage source inverter (VSI). So, harmonic voltage sources are more suitable to analyze impact of renewable energy generator on harmonics problem in power distribution system. In this paper, we presented the circuit model to analyze interaction between harmonics from nonlinear load and REGs. We verified that the harmonic analysis using the proposed circuit model is more appropriate than the harmonics evaluation method considering TDD through case study using PSCAD/EMTDC.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.59-61
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• 2003

This paper demonstrates an analysis of harmonics at the high speed railway substation and proved on this countermeasure using the PSCAD/EMTDC simulation tool. First, high speed railway feeding system is composed using PSCAD/EMTDC electrical railway feeding system model in advance. Second, This paper applications line capacitance values as feeder-trolley, trolley-rail and feeder-rail to analysis harmonics more accuracy in advance did not application. This capacitance values calculate using the EMTP(Electro Magnetic Transient Program). Third, the tractions are arranged in the section that substation supplies power, and this paper take the simulation each case(fractions composition amount) to see harmonic propagation from traction to substation. As a result, generated harmonics at traction can confirmed that harmonics did not reduce at utility source. This harmonics have an influence on bulk power system. Finally, this paper introduces the methods of harmonics effect minimum. This paper proved harmonics reduce effect through the passive filters application.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술대회 논문집 전문대학교육위원
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• pp.110-112
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• 2003

Harmonics happened due to nonlinear systems such as UPS, SCR controlled motors, and fluorescent lighting in distribute power system is very important subject to optimal operate and control of power system. Harmonics sometimes takes place incorrect operation of protective relaying system under normal condition on power system. This paper presents the actual recording data of transformer located at substation of industrial installation for harmonic analysis in detail.

• 한국정보통신학회논문지
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• 제20권7호
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• pp.1283-1289
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• 2016

전력은 현대 사회를 구성하는데 있어 필수적인 자원이다. 최근, 전력에 대한 수요가 급격하게 증가하였으며 전력 수요 증가는 전력 품질의 저하를 야기하였다. 현대 사회에서 전력 품질은 일반 가정과 산업 전반에 걸쳐 큰 문제를 일으킬 수 있는 중요한 요소가 되었다. 전력 품질 문제를 예방하기 위해서는 전력 품질에 대한 계측과 초기 대응이 중요하다. 본 논문에서는 실시간으로 전력 품질을 계측하고 고조파를 분석하여 모니터링 할 수 있는 시스템 제안한다. 마이크로칩의 dsPIC33FJ256GP710A칩을 이용한 DM240001보드를 이용하여 최대 3상 3선에 해당하는 배선 방식의 전력 품질을 계측하는 시스템을 설계하였고, 계측 알고리즘의 최적화로 전력 품질의 순간적인 변화를 측정할 수 있도록 하였다. 또한, 최대 31차에 해당하는 고조파들에 대하여 전압과 전류의 왜율과 수요 전류 왜율에 대해서도 측정 가능하도록 설계하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.277-280
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• 2002

With significant development of power electronics technology, the proliferation of nonlinear loads such as static power converters has deteriorated power quality in power transmission and distribution systems. Notably, voltage harmonics resulting from current harmonics produced by the nonlinear loads have become a serious problem in many countries. There are already a lot of PV power generation systems installed in building systems whose harmonics are the worst object for distribution systems as a utility interactive system and also it tends to spread out continuously. In this paper, the authors propose a multy-function inverter control strategy which puts a shunt active filter function to the power inverter of the PV power generation system established on a building system. The effectiveness of the proposed system is demonstrated through the simulation of hypothetical power system using PSCAD/EMTDC.

• 조명전기설비학회논문지
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• 제18권4호
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• pp.124-130
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• 2004

본 논문에서는 고조파 저감을 위해 사용하는 수동필터를 부하의 운전조건에 따라 자동으로 개$.$폐할 수 있는 DSP 기반의 제어시스템을 개발하였다. 수동필터 제어시스템은 부하에서 발생하는 전압, 전류, 고조파, 무효전력, 역률 등을 측정 및 감시하여 수동필터 개ㆍ폐 장치에 신호를 보내어 부하의 운전조건에 따라 필터의 각 분로를 자동으로 개$.$폐하게 된다. 이러한 제어시스템을 100마력 직류전동기 구동장치를 사용하는 계통에 수동필터와 함께 설치하고 전동기 운전조건에 따라 수동필터를 개$.$폐시키며 고조파 및 무효전력 등을 측정함으로써 성능을 입증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.472-474
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• 2008

According to the development of power switching device technology, the power conversion system is used from the small electric power units to the large industrial instruments. These instruments are operated as harmonic sources in the grid and the harmonics cause zero sequence harmonics in the neutral line. To reduce zero sequence harmonics, the zigzag transformer is used conventionally. But the zigzag transformer can reduce only 60~70% of harmonics. In this paper, hybrid power filter for zero sequence harmonics reduction and the harmonic detection method are proposed.

• 전기학회논문지P
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• 제60권4호
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• pp.181-185
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• 2011

Due to the increasing of nonlinear loads such as converters and inverters connected to the electric power distribution system, and extensive application of harmonic generation sources with power electronic devices, disturbance of the electric power system and its influences on industries have been continuously increasing. Thus, it is difficult to construct accurate load model for active and reactive power in environments with harmonics. In this research, we develop current harmonics estimation method based on Extreme Learning Machine (ELM) with fast learning procedure for residential loads. Using data sets acquired from various residential loads, the proposed method has been intensively tested. As the experimental results, we confirm that the proposed method makes it possible to effective estimate current harmonics for various input voltage.