• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.468-469
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• 2010

DSTATCOM(Distribution STATic COMpensator) is one of the custom power devices, and protects a distribution line from unbalanced and harmonic current caused by non-linear and unbalanced loads. Conventional researches use a LPF(Low Pass Filter) to eliminate ripple component at the calculation of compensation current. This paper proposes a calculation of compensation current using phase shift that can be a counterproposal of conventional methods using LPF.

• 한국산업정보학회논문지
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• 제21권3호
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• pp.29-33
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• 2016

청정에너지 발전설비의 요구가 늘면서 태양광, 풍력, 연료 전지 등의 분산전원 개발이 급속도로 증가하고 있다. 반면에 이러한 증가로 인하여 배전시스템은 복잡해지고 있으며 무효전력으로 인한 역률 저감, 불평형 부하에 의한 불평형 전류 등의 문제점을 가지고 있다. 이러한 문제점들을 해결하기 위하여 본 논문에서는 태양광용 3상 4선 타입의 전력변환장치에 무효전력, 불평형 전류를 보상하는 알고리즘을 적용하였다. 제안한 태양광 전력변환장치는 기본 출력동작 뿐만 아니라 계통 전력 품질의 저해요소들에 대해서 보상이 가능하며 PSCAD/EMTDC를 이용한 시뮬레이션을 통하여 그 성능을 검증하였다.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1502-1507
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• 2015

This paper deals with shunt compensation to eliminate voltage violation and enhance transfer capability, which is motivated towards implementation in the Korean power system. The optimal shunt compensation algorithm has demonstrated its effectiveness in terms of voltage accuracy and reducing the number of actions of reactive power compensating devices. The main shunt compensation devices are capacitor and reactor. Effects of control devices are evaluated by cost computations. The control objective at present is to keep the voltage profile of a key bus within constraints with minimum switching cost. A robust control strategy is proposed to make the control feasible and optimal for a set of power-flow cases that may occurs important event from system. Case studies with metropolitan area of the Korean power system are presented to illustrate the method.

• Journal of Power Electronics
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• 제12권2호
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• pp.333-343
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• 2012

This paper proposes a strategy of flicker mitigation for doubly-fed induction generator (DFIG) wind turbine systems. In the weak grid system where the grid impedance ratio is low, the reactive power compensation only cannot suppress the flicker sufficiently due to the limited power capacity of the converters or the DFIG. For the full suppression of flickers, the active power smoothening using the energy storage system (ESS) needs to be utilized together with the reactive power compensation. The effectiveness of the proposed method is verified by PSCAD/EMTDC simulation results for a 2[MW] DFIG wind turbine system and by experimental results for a 3[kW] wind turbine simulator.

• 전력전자학회논문지
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• 제15권1호
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• pp.69-74
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• 2010

풍력발전기가 계통에 연계되어 운전 중 바람의 변동에 따라 유효전력이 변동하면 연계지점에서는 전압변동이 발생하며 풍력발전기의 연계 위치 (PCC, Point of Common Coupling) 에 따라 그 값은 변동한다. 본 논문에서는 이러한 계통 연계 지점의 전압변동이 이상 전원에서 PCC지점까지의 등가 선로 임피던스와 풍력발전기 출력 전류의 곱에 비례함을 보였으며 이러한 전압변동을 억제하기 위하여 필요한 무효전력 요구량을 해석적인 방법으로 구하였다. 만일 풍력발전기 출력단 인버터의 용량 제한에 의해 무효전력 주입량에 한계가 있거나 전압변동 허용범위가 주어진 경우에는 그에 따라 무효전력 주입량을 변화시킬 수 있다. 제안된 알고리즘을 가변속 풍력발전시스템의 출력단 인버터에 사용하면 수시로 변동하는 유효전력에 따라 무효전력 요구량을 실시간으로 계산함으로서 PCC전압변동을 최소화할 수 있다. 제안된 알고리즘의 타당성을 검증하기 위해 실제 서해 도서지역에 설치된 소형 풍력발전기 및 전력 시스템 파라메터를 사용하여 Matlab과 PSCAD/EMTDC 시뮬레이션을 수행하였다.

• 전기학회논문지P
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• 제67권3호
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• pp.155-159
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• 2018

Recently, the expansion or establishment of facilities for the logistics system is increasing. Conveyor facilities play a major role in sorting and transporting logistics. Induction motors are widely used for the operation of these conveyor systems. In the logistics system, a large number of induction motors are used. These motors have a considerable distance from the power source side and have a low power factor. The installation position for the power factor compensation of the induction motor is very important. Since the voltage drop depends on the length of the line, it is an important parameter in capacitor capacity determination for power factor compensation. The capacity of the capacitors installed to compensate the power factor of the inductive load should be designed to the extent that self-excitation does not occur. In this study, we analyze the method of compensating the proper power factor considering the voltage drop and the installation position of the induction motor in the logistics system.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.291-294
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• 1998

This paper presents a new active power filter with low DC voltage for compensating reactive power and harmonics of three-phase high power/voltage harmonic producing load. It has a structure of converter connected in series with power factor correction capacitor. Appropriate size and number of filter capacitor are determined by an equation and applied to simulation of 10kvar 6-pulse SCR rectifier.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.876-881
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• 1998

The compensation strategy of shunt active power filters is one of the most important link that determine its compensation characteristics. In this paper, a new interpretation of the instantaneous reactive power theory in three-phase circuits was proposed. A compensation strategy (ip, iq mode) was introduced on the basis of the new interpretation. This compensation strategy was compared with other two compensation strategies(P, q mode and UPF mode). When source voltage is distorted, a sinusoidal, the three compensation strategies are equivalent to each other. When source voltage is distorted, a sinusoidal source current may result only by using ip, iq mode. This is the advantage of ip, iq mode. The result is verified by simulation.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 제17회 워크샵 및 추계학술대회
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• pp.702-705
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• 2005

The wind power is known as the most promising future energy source to obtain the electricity. Induction generator is a simple energy conversion wit in the wind power generation system but it consumes the reactive power from the interconnected power system. Switched capacitor banks are normally used to compensate the reactive power, which bring about the transient overvoltage. This paper proposes a method for compensating the reactive power with STATCOM. A detail simulation model for analyzing the interaction between the wind power system and the commercial power system was developed using EMTDC software. The developed simulation model can be effectively utilized to plan the reactive power compensation for newly designed wind power system.

• 대한전기학회논문지:전력기술부문A
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• 제53권6호
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• pp.309-315
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• 2004

The wind power is known as the most promising future energy source to obtain the electricity Induction generator is a simple energy conversion unit in the wind power generation system but it consumes the reactive power from the interconnected power system. Switched capacitor banks are normally used to compensate the reactive power, which bring about the transient overvoltage. This paper proposes a method for compensating the reactive power with STATCOM. A detail simulation model for analyzing the interaction between the wind power system and the commercial power system was developed using EMTDC software. The developed simulation model can be effectively utilized to plan the reactive power compensation for newly designed wind power system.