• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권8호
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• pp.405-412
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• 2003

This paper presents a three-phase Line-Interactive uninterruptible power supply (UPS) system with series-parallel active power-line conditioning capabilities, using synchronous reference frame (SRF) based controller, which allows an effective power factor correction, source harmonic voltage compensation, load harmonic current suppression, and output voltage regulation. The three-phase UPS system consists of two active power compensator topologies. One is a series active compensator, which works as a voltage source in phase with the source voltage to have the sinusoidal source current and high power factor under the deviation and distortion of the source voltage. The other is a parallel active compensator which works as a conventional sinusoidal voltage source in phase with the source voltage, providing to the load a regulated and sinusoidal voltage with low THD (total harmonic distortion). The control algorithm using SRF method and the active power flow through the Line-interactive UPS systems are described and studied. The simulation and experimental results are depicted in this paper to show the effect of the proposed algorithm.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권3호
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• pp.211-218
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• 2000

The performance and dynamic characteristics of three-phase active power filter with PCC voltage compensation is presented and analyzed in this paper. The characteristics of parallel active filter are discussed when they are applied to nonlinear loads with current source and voltage source type, the characteristics of voltage compensator and comparison of two functions are discussed. The proposed scheme in this paper employs a PWM voltage-source inverter and has two operation modes. First, it operates as a conventional active filter with reactive power compensation while PCC voltage is in a certain range. Second, is operates as a voltage compensator while PCC voltage is out of range. Finally, the validity of this scheme is investigated through analysis of simulation and experimental results for a prototype active power filter system rated at 10KVA.

• Journal of Power Electronics
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• 제1권1호
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• pp.9-18
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• 2001

The performance analysis of a three-phase parallel active power filter that compensates PCC voltage and the unbalanced loads is presented in this paper. The proposed scheme in this paper employs a PWM voltage-source inverter and has two operation modes. Firstly, it operates as a conventional active filter with reactive power compensation when PCC voltage is within the 15% voltage drop range. Secondly, it operates as a voltage compensator when PCC voltage is not within the 15% voltage drop range. And both APF and voltage compensator compensate asymmetries caused by nonlinear loads. Finally, two methods of detecting the negative sequence are reviewed, and the validity of this scheme is investigated through analysis of simulation and experimental results for a prototype active power filter system rate at 10KVA.

• 조명전기설비학회논문지
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• 제19권3호
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• pp.27-34
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• 2005

본 논문에서는 2개의 컨버터 구조를 갖는 삼상 계통 연계형 UPS에 대하여 연구한다. 삼상UPS시스템은 2개의 능동 전력 보상기 구조로 이루어져 있다. 하나는 직렬형으로 .전원전압과 동상의 전압원으로 동작하여 전원전압의 변동, 왜곡시에도 정현파 전원전류와 고역률을 갖도록 동작한다. 병렬형은 전원전압과 위상을 맞춘 종전의 정현파 전압원으로 동작하여 부하에 안정되고 낮은 THD를 갖는 정현파 전압을 공급한다. 본 논문에서는 직렬형, 병렬형 능동보상기에서 전원전압의 크기에 따라 충전 방법에 대하여 제시한다. 종전의 계통 연계형 UPS는 DC 충전과 출력전압을 동시에 제어하였는데, 2개의 컨버터 구조를 갖는 UPS 시스템에서는 직렬형 보상기도 DC 충전을 할 수 있어 직렬형과 병렬형을 사용한 충전 알고리듬을 연구할 필요가 있다. 따라서 DC link단의 전압을 안정시켜 본래의 직렬형, 병렬형 구조의 보상기의 안정성 향상에 기여할 수가 있다. 제안된 방법의 타당성은 시뮬레이션과 실험 결과를 통하여 입증된다.

• Journal of Electrical Engineering and Technology
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• 제6권3호
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• pp.293-301
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• 2011

This paper presents a novel theoretical method based on power analysis to obtain voltage reference values for an inverter-based compensator. This type of compensator, which is installed in parallel with the load, is usually referred to as the active filter. The proposed method is tailored to design the compensator in such a way that it can simultaneously balance the asymmetric load, as well as correct the power factor of the supply side. For clarity, a static compensator is first considered and a recursive algorithm is utilized to calculate the reactance values. The algorithm is then extended to calculate voltage reference values when the compensator is inverter based. It is evident that the compensator would be asymmetric since the load is unbalanced. The salient feature associated with the proposed method is that the circuit representation of system load is not required and that the load is recognized just by its active and reactive consumptions. Hence, the type and connection of load do not matter. The validity and performance of the new approach are analyzed via a numerical example, and the obtained results are thoroughly discussed.

• 전력전자학회논문지
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• 제5권5호
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• pp.484-492
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• 2000

본 논문에서는 고조파전류 보상기능을 갖는 전압 보상기에 관한 연구를 수행하고 그 보상 특성을 해석하였다. 제안된 보상시스템은 하이브리드형 능동전력필터에서와 같이 LC로 구성되어 전력선에 병렬로 연결되는 수동필터와 직렬 변압기를 사용하여 전력선에 직렬로 연결되는 PWM 컨버터를 동시에 사용하는 회로구조를 갖는다. 제안된 보상시스템을 통해 다이오드 정류기와 같은 비선형 부하로 인해 발생되는 고조파 전류의 보상 및 전원 이상 현상으로 발생되는 전원측 이상 전압의 보상을 모두 수행한다. 단상 등가회로를 통해 보상시스템의 동작 원리를 설명하고 d-q 동기좌표계 축 상에서 보상시스템의 모든 제어를 수행하는 제어 알고리즘의 개발을 수행하였으며 실험을 통해 제안된 보상시스템의 보상특성을 확인하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.649-654
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• 2005

This paper proposes analysis on new equipment for power quality in electric railway. The proposed equipment consists of series inverter and parallel inverter. Each inverter is connected by capacitor as dc link. This structure can be compensated for active and reactive power in catenary through transformer.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.334-336
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• 1994

The conventional APF(Active Power Filter) system performs only function which is compensated for source harmonic by injecting harmonic compensation current as well as reactive power component by PWM. This paper presents a new APF which provides the combined functions of VC(Voltage Compensator) and conventional APF, because the structure of APF is similar to stand- alone UPS in parallel type. Single-chip microprocessor plays an important role in controlling each function. Simulation obtained from ACSL are shown to verify multi-functions of new APP.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1065-1067
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• 2000

This paper describes performance analysis of ARCP Inverter, which can offer zero voltage switching at nominal voltage stress. The system consists of a voltage-source inverter with sort-switching module. Each main switch is connected in parallel with resonant capacitor and two auxiliary switches are placed in series with a resonant reactor for soft-switching capability. The described ARCP inverter could be effectively applied for active power filter reactive power compensator, and UPS.