• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2010년도 추계학술발표논문집 1부
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• pp.151-154
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• 2010

본 논문에서는 분산전원 연계선로의 분산전원 과도특성과 전력품질을 분석하기 위해 AC전원 모의 장치를 이용하여 저압 배전계통 측에서 순간전압강하(Voltage Sag), 순간전압상승(Voltage swell), 고조파(THD) 주입 등의 배전계통에 일어날 수 있는 비정상 상태를 발생시켜, 분산전원의 과도특성을 분석하여, 그 결과가 분산전원 계통연계 기술기준[9]-[11]에서 정한 규정치에 적합한가에 대한 기술적인 검토사항을 분석하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.286-287
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• 2011

Kalman filter(KF) algorithm is a very useful application being used in many engineering fields. Through the KF, the next time step's estimation can be almost simultaneously calculated by the recursive least square optimization method with the present measurement data. It provides us with the superior detection performance of power quality events. This paper deals with the concrete programming example of KF to detect various kinds of PQ disturbances, such as voltage sag, swell, harmonics, voltage fluctuation and Frequency variation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.146-148
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• 2006

This paper deals with a simple structured power quality disturbance generator for nonlinear load devices. The proposed generator can be applied to the performance test of custom power devices. Voltage sag, swell, outage, unbalance and phase jump after outage are provided by the generator. The improving phase jump operating principle of the generator is described and analysed. The usefulness of the generator is verified through simulation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.570-574
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• 2004

This paper deals with a novel 3-phase power quality disturbance generator. The proposed generator can be applied to the performance that of custom power devices. Voltage sag, swell, outage unbalance and phase shift are provided by the generator. The control scheme for the disturbance generation is simple, and hardware setup is cost effective compared with conventional scheme. The operating principle of the generator is described and the usefulness verified through simulation with 10kVA power rating.

• 대한전기학회논문지:전력기술부문A
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• 제53권3호
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• pp.152-160
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• 2004

A novel UPQC(Unified Power Quality Conditioner), which consists of series inverter, shunt inverter, distributed generation system, is proposed. The proposing system can compensate reactive power, harmonics, voltage sag and swell, voltage interruption etc. through the change of paralleling operation mode and islanding operation mode. The control strategy for the proposing system was derived using the instantaneous power method. The performance of proposing system was analyzed by means of the PSCAD/EMTDC simulation and the experimental work with the hardware prototype. The proposing system has the ultimate capability of improving power quality at the point of installation on power distribution systems or Industrial power systems and can be utilized for the custom power device in th future distribution system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1254-1256
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• 2004

This paper deals with a novel 3-phase power quality disturbance generator. The proposed generator can be applied to the performance that of custom power devices. Voltage sag, swell and outage are provided by the generator. The control scheme for the disturbance generation is simple, and hardware setup is cost effective, compared with conventional scheme. The operating principle of the generator is described and the usefulness verified through simulation with 10KVA power rating.

• Journal of Electrical Engineering and Technology
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• 제2권4호
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• pp.445-451
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• 2007

Voltage quality problems such as voltage sag, swell, flicker, undervoltage, and overvoltage have been of great concern for both utilities and customers over the last decade. In this paper, a new approach based on the $H_{\infty}$ algorithm to monitor voltage disturbances is presented. The key idea of this approach is to estimate the amplitude of the fundamental component of distorted and noisy voltage waveform instantaneously, and then the information can be extracted from the estimated envelope to identify and classify different voltage related power quality problems. The $H_{\infty}$ algorithm is characterized by a fast tracking, unlike that of existing techniques. The $H_{\infty}$ algorithm outperforms the Kalman Filter (KF) by its fast convergence and robust tracking performance against non-Gaussian noise. The paper investigates the effects of various types of noise on the performance of the $H_{\infty}$ algorithm. Digital simulation results confirm the validity and accuracy of the proposed method. The proposed $H_{\infty}$ algorithm is examined by tracking the flicker produced by a resistance welder simulated in the PSCAD/EMTDC package.

• 대한전기학회논문지:전력기술부문A
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• 제55권1호
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• pp.7-12
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• 2006

This paper proposes the new voltage event detection method using the weight factor of neural network and describes control system design for the DVR(Dynamic Voltage Restorer) consisted of a rectifier and series inverter applied to 22.9kV distribution system. As this method can express the fault level of each phase, we expect the proposed method can make up for disadvantage of synchronous detection method. Also, in this paper, the control system was designed using double deadbeat controller, As it has an inner current control loop and an outer voltage control loop, we can easily limit the current level during the transient intervals by using the current control loop. Simulation and experiment are performed to prove the analysis of the voltage event detection method and double deadbeat controller.

• Journal of Power Electronics
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• 제9권4호
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• pp.553-566
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• 2009

In-phase control and energy-optimized control are the two major control strategies proposed for series power quality controllers (SPQC). However quantitative analysis and comparison between these two control strategies is quite limited in previous publications. In this paper, an extensive quantitative analysis is carried out on these two control strategies through phasor diagram approach, and a detailed quantitative comparison is conducted accordingly. The load current is used as the reference phasor, and this leads to a simpler and clearer phasor diagram for the quantitative relationship. Subsequently detailed analysis of SPQC using in-phase control and energy-optimized control are provided respectively, under different modes both for under voltage/voltage sag and for over voltage/voltage swell. The closed form analytic expressions and the curves describing SPQC compensation characteristics are obtained. The detailed system power flow is figured out for each mode, and the detailed quantitative comparison between the two control strategies is then carried out. The comparison covers several aspects of SPQC, such as required compensating voltage magnitude, required capacity of energy storage component, and maximal ride-through time. In the end, computer simulation and prototype experimental results are shown to verify the validity of all the analysis and the result of the comparison.

• 한국정보통신학회논문지
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• 제9권1호
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• pp.146-151
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• 2005

본 논문에서는 단상 무정전 전원공급 장치의 성능시험을 위한 새로운 방식의 전압변동 발생기를 제안하였다. 제안한 방식의 컨버터는 정상적으로 공급되는 상용전원으로부터 순시접압강하, 순시전압상승, 순간정전 등을 발생시켜서 시험하고자 하는 단상 무정전 정원공급 장체에 인가할 수 있다. 제안한 발생기의 구조는 매우 간단하며 경제적이고 전압변동을 발생시키기 위한 제어방식 또한 간단하여 신뢰도와 효율이 높은 장점을 갖는다. 제안한 방식에 대한 회로분석과 동작원리를 기술하였으며 제안한 방식의 타당성을 컴퓨터 시뮬레이션과 실험을 통하여 확인하였다.