• Journal of Electrical Engineering and Technology
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• v.1 no.4
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• pp.503-512
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• 2006

This paper proposes a new configuration for the Unified Power Quality Conditioner, which has a DC/DC converter with super-capacitors for energy storage. The proposed UPQC can compensate the reactive power, harmonic current, voltage sag and swell, voltage imbalance, and voltage interruption. The performance of the proposed system was analyzed through simulations with PSCAD/EMTDC software. The feasibility of system implementation is confirmed through experimental works with a prototype. The proposed UPQC has ultimate capability to improve the power quality at the point of installation on power distribution systems and industrial power systems.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.305-307
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• 2001

This paper deals with single-phase unified power quality conditioner(UPQC), which aims at the integration of series-active and shunt-active filter. The series filter is used to compensate for the voltage distortions and the shunt filter is used to provide reactive power and counteract the harmonic current injected by the load. Also, the voltage of the DC link capacitor is controlled to a desired value by the shunt active filter. The performance of UPQC under load nonlinearities conditions is investigated using simulation as well as experimental results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.10
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• pp.102-110
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• 2012

This paper propose the advanced topology of UPQC, its DC link is connected with Lithium battery, to compensate the momentary interruptions. The proposed system can be operated as UPS mode using the parallel inverter, which control the charge or discharge of battery, in case of the interruption. We dvelop 100kVA UPQC using the proposed topology to rise the power quality and the reliability of Microgrid. We verify its usefulness through voltage compensation test, UPS operation test and etc. using Microgrid test facility.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.543-547
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• 2001

A protection scheme for Unified Power Quality Conditioner (UPQC) is presented and analyzed in this paper. The proposed UPQC has the series active power filter operated as a high impedance k($\Omega$) to the fundamentals when short-circuit faults occur in the power distribution system, and three control strategies are proposed in this paper. The first is the method by detecting the fundamental source current through the p-q theory, the second is the method by detecting the fundamental component of load current in Synchronous Reference Frame(SRF) and the third is the method by detecting the input voltage. When the short-circuit fault occur in the power distribution system, the proposed scheme protects the UPQC without additional protection circuits. The validity of proposed protection scheme is investigated through simulation results.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.380-381
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• 2018

Under-voltage and over-voltage are the big problems in submarine distribution system. To solve that problems, integrated PV with voltage compensation method is proposed in this paper. This paper describes a simple method for controlling the series connection converter while the shunt connection operates as a back-up for sensitive load and verified by the PSIM software.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.2
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• pp.90-98
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• 2003

Recently, the increasing application of electronic equipments and information devices has heightened the interest in power qualify. The term power quality is applied to a wide range of electromagnetic phenomena on the power system and is also concentrated by all areas such as utilities, their customers and suppliers of load equipments. In engineering terms, power Qualify is expressed by voltage qualify because the power supply system can only control the quality of the voltage. Therefore, the standards in power quality area are devoted to keep the supply voltage within allowable limits. This paper deals with single-phase unified power quality conditioner (UPQC), which ai s at the integration of series-active and shunt-active filter. The series filter il used to compensate for the voltage distortions and the shunt filter is used to provide reactive power and counteract the harmonic current injected by the load. Also, the voltage of the DC link capacitor is controlled to a desired value by the shunt active filter. The validity of the proposed UPQC is demonstrated using both the MATLAB/SIMULINK simulation and the experimental device with DSP (TMS320C32).

• Journal of Power Electronics
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• v.19 no.2
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• pp.519-528
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• 2019

The unified power quality conditioner (UPQC) is an effective custom power device that is used at the point of common coupling to protect loads from voltage and current-related PQ issues. Currently, most researchers have studied series unit and parallel unit models and an idealized transformer model. However, the interactions of the series and parallel converters in AC-link are difficult to analyze. This study utilizes an equivalent transformer model to accomplish an electric connection of series and parallel converters in the AC-link and to establishes a precise unified mathematical model of the UPQC. The strong coupling interactions of series and parallel units are analyzed, and they show a remarkable dependence on the excitation impedance of transformers. Afterward, a feed-forward decoupling method based on a unified model that contains the uncertainty components of the load impedance is applied. Thus, this study presents an adaptive method to estimate load impedance. Furthermore, simulation and experimental results verify the accuracy of the proposed modeling and decoupling algorithm.

• Journal of Electrical Engineering and Technology
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• v.8 no.6
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• pp.1352-1364
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• 2013

This paper describes a novel structure for single phase Unified Power Quality Conditioner-Distributed Generation (UPQC-DG) with direct grid connected DC-AC converter for low DC output DG systems which can be used not only for compensation of power quality problems but also for supplying of load power partly. This converter has been composed of one full-bridge inverter, one three winding high frequency transformer with galvanic isolation and two cycloconverters. Proper control based on Input Output feedback Linearization is used to tracking the reference signals. The simulation and experimental results are presented to confirm the validity of the proposed approach.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.673-676
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• 2004

본 논문은 3상 입력전원의 불평형과 고조파문제를 대칭 좌표계를 통해 각각 정상분과 역상분으로 분리하여 동기 회전 좌표계 상에서 보상할 수 있는 알고리즘을 제안하였다. 동기 회전 좌표계 상에서 보상이 이루어지므로 UPQC와 같은 다양한 목적의 능동전력필터에 쉽게 적용될 수 있다 제안된 알고리즘의 타당성을 뒷받침하기 위해 시뮬레이션을 수행 하였다.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.542-543
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• 2010

본 논문에서는 전기에너지 절약과 계통의 전력품질을 향상시킬 수 있는 다기능 전기에너지 절전 장치를 제안한다. 제안된 시스템은 UPQC(Unified Power Quality Conditioner)를 응용한 형태로 전압제어형 전압원 인버터와 전류제어형 전압원 인버터로 구성된다. 계통과 병렬로 연결된 전류제어형 전압원 인버터는 부하에서 발생하는 무효전력성분을 보상하고, 부하와 직렬로 연결되는 전압제어형 전압원 인버터는 부하전압의 크기를 조정하여 전력소비를 절감시킨다. 본 논문에서는 제안된 시스템의 유용성을 확인하기 위해 비선형 부하조건에서 시뮬레이션 및 실험을 수행하였다.