• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.113-115
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• 2000

This paper presents the modeling and simulation studies, using PSCAD/EMTDC, for the operation of DR(Distributed Resources) connected to the power system. In this study, we model the DR operated in parallel with the distribution system and simulate several operation modes of DR. Finally, the transient characteristics of the operation modes are evaluated with IEEE Standard 519-1992. IEEE Recommended Practice and Requirements for Harmonic Control in Electric Power Systems

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.411-414
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• 2009

본 논문에서는 PSCAD 시뮬레이션을 이용하여 실계통도와 유사한 배전계통 분산전원 연계 시스템을 모델링하였다. 모델링한 계통도의 연계지점에 따른 THD와 TDD를 시뮬레이션하고, 고조파 연계기준(IEEE Std 1547와 IEEE Std 519)을 적용하여 기존의 전력계통에 태양광발전 시스템 연계시 발생되는 고조파를 평가하였고 평가결과를 분석하였다.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.290-291
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• 2011

전력산업이 발전함에 따라 전력품질 요구도 증가하고 있으나 고조파왜형률에 대한 국제기준이 제조사와 운영자의 입장에 따라 계산방법이 상충되는 부분이 현실적으로 존재하고 있는 것으로 검토되었다. 본 논문에서는 원자력발전소에 사용되는 축전지 및 충전기의 시험 및 관리규격인 ANSI/IEEE 519와 NEMA PE-5에 대한 THD 계산방식에 대한 차이점을 설명하고 현장 규제경험 사례를 통해 바람직한 관리 방향을 제시하고자 한다.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.109-110
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• 2012

본 논문에서는 불평형 전원 전압 하에서 삼상 PWM 컨버터의 전류 보상 기법을 제안하였다. 전원 전압이 불평형인 경우 PLL(Phase Locked Loop)를 이용하여 추출한 위상각에는 왜곡 성분이 포함된다. 이러한 왜곡된 위상각으로 컨버터를 제어하는 경우 입력 전류에도 고조파가 포함되게 된다. 본 논문에서는 불평형 전원 전압 하에서도 입력 전류의 THD(Total Harmonic Distortion)를 IEEE Std. 519 규정인 5% 이내로 제한할 수 있도록 하는 전류 보상 기법을 제안하였다. 제안된 기법은 시뮬레이션을 통해 그 타당성을 검증하였다.

• Journal of Power Electronics
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• v.8 no.2
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• pp.109-120
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• 2008

In this paper, a novel delta/double-fork transformer based 18-pulse full-wave AC-DC converter is designed, modeled, simulated and developed to feed isolated DC varying loads. The proposed AC-DC converter is used for low voltage and large current DC loads in applications such as electrowinning, where isolation is required mainly for stepping down the supply voltage. The proposed converter improves power quality at AC mains and meets IEEE-519 standard requirements at varying loads.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.5C
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• pp.519-533
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• 2006

The number of channels specified in IEEE 802.15.4 Low-Rate Wireless Personal Area Networks(LRWPANs) is too few to operate many applications of WPANs in the same area. To overcome this limit, we introduce Virtual Channel, a novel concept to increase the number of available channels when various WPAN applications coexist. Basically, a virtual channel is a newly-created channel via superframe scheduling within the inactive period of a logical channel preoccupied by other WPANs. To maximize the coexistence capability of WPANs using virtual channels, we propose Least Collision superframe scheduler(LC-scheduler), its less complex heuristics both for a given single channel, and Virtual Channel Selector(VCS) to efficiently manage multiple available logical channels. In addition, a simple but practical synchronization method is developed to compensate different time drifts among coexisting WPANs. The simulation results demonstrate that a remarkable improvement on the coexistence capability of the 802.15.4 can be achieved through the proposed schemes.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.1
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• pp.64-70
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• 2010

This paper presents how to decide on tuning factor(${\delta}$) and quality factor(Q) values in design of single-tuned passive harmonic filters. Tuning factor(${\delta}$) and quality factor(Q) values have to consider before decision on circuit parameters of passive filters. A Study on these two value has not been scarcely performed and only experienced values has been used in passive harmonic filter design by far. As a experienced value, in cases of 5th and 7th filter, tuning factor(${\delta}$) is about 0.94 and 0.96 respectively and quality factor(Q) is, in all cases of, 50. If Single-tuned passive harmonic filter will be off-tuned, performance of filter will be decreased steeply and occur to parallel resonance between system reactance and filter capacitance. Therefore During the operation, In order not to off-tuning, Filter must be tuned at former order than actual tuning order. This is the same that total impedance of filter must have a reactive impedance. In this paper, Tuning factor(${\delta}$) is decided via example of real system and using the bode-plot and then performance of filters confirmed by filter current absorbtion rate. And Quality factor(Q) decided using the bode plot in example system and then performance of filters confirmed by filter current absorbtion rate also, which makes a calculated filter parameters to satisfy IEEE-519 distortion limits. Finally, Performance of the designed passive harmonic filter using the tuning factor(${\delta}$) and quality factor(Q) values, decided in this paper is verified by experiment and shows that 5th, 7th, 9th, 11th and 13th current harmonic distortions are decreased within IEEE-519 distortion limits, respectively.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1885-1887
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• 2004

This paper presents the aspect and distribution of voltage and current harmonics being made at low voltage power systems. The voltage and current harmonics in power systems supplying various loads were monitored and analyzed. We have examined the results compared to advanced countries' harmonics control standards. As a result, the current harmonics were significantly greater than the voltage harmonics. In particular, the harmonics of currents flowing through loads with power switching electronics was pronounced. Also, the contents of current harmonics of street lamp circuits was about 30%, and it was decreased to 12.3% with the installation of scries reactor. On the whole, The measured results of voltage and current harmonics exceeds the regulation limits recommended by IEEE std 519-1992.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.247-250
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• 2006

This paper presents the single-stage High Power Factor TSFC(Two-Switch Forward Converter). Recently, due to growing concern about the harmonic pollution of power distribution systems and the adoption of standards such as ICE 61000-3-2 and IEEE 519, There is a need to reduce the harmonic contents of AC line currents of power supplies. This research proposed the single-stage two switch forward circuit for low voltage and high current output. The principle of operation, feature and design considerations are illustrated and verified through the experiment with a 200W(5V, 40A) 200kHz MOSFET based experimental circuit.

• Proceedings of the KIPE Conference
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• 1996.06a
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• pp.121-123
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• 1996

교류전원은 직류전원과는 다르게 전력 이용 및 전달에 있어서 유효역률과 고조파의 영향을 분리하여 생각할 수 없다. 특히, 고조파의 영향과 전력전자의 발달과 더불어 그 문제점이 크게 부각되고 있다. 유럽을 중심으로 세계 각국에서는 규격제정(EN61000, IEC 519, IEEE 555 등) 과 규제 강화에 나서고 있다. 국내에서는 아직까지 크게 주목받지 않고 있으나, 전력의 효율개선, 양질의 전력공급 등의 측면에서 기술 향상에 필수적으로 고려되어야 할 분야이다. 이에 본 연구에서는 간단한 제어기 구성을 통해 병렬 인버터와 하이브리드 능동필터 개념을 도입하여 역률 개선, 고조파 저감 등을 통해 교류전력 품질 개선 장치을 구성하였다. 본 연구결과로 고압 대전력 전력변환장치의 무효 전력을 감소시켜 발전 전력의 효율적 이용과 부하측의 고주파 문제를 최소화 하는데 기여할 수 있을것으로 기대된다.