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Design and Implementation of a High Quality Power Supply Scheme for Distributed Generation in a Micro-Grid
School of Electrical Engineering, Beijing Jiaotong University, Beijing 100044, China
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Received: 23 July 2013; in revised form: 12 September 2013 / Accepted: 17 September 2013 / Published: 23 September 2013
Abstract: A low carbon, high efficiency and high quality power supply scheme for Distributed Generation (DG) in a micro-grid is presented. A three-phase, four-leg DG grid-interfacing converter based on the improved structure of a Unified Power Quality Conditioner (UPQC, including a series converter and a parallel converter) is adopted, and improved indirect and direct control strategies are proposed. It can be observed that these strategies effectively compensate for voltage sags, voltage swells and voltage distortion, as well as voltage power quality problems resulting from the nonlinear and unbalanced loads in a micro-grid. While solving the coupling interference from series–parallel, the grid-interfacing converter can achieve proper load power sharing in a micro-grid. In particular, an improved minimum-energy compensation method is proposed that can overcome the conventional compensation algorithm defects, ensure the load voltage’s phase angle stability, improve the voltage compensating ability and range, reduce the capacity and cost of converters, and reduce the shock of micro-grid switching between grid-connected mode and islanded mode. Moreover, the advantages/disadvantages and application situation of the two improved control strategies are analyzed. Finally, the performance of the proposed control strategies has been verified through a MATLAB/Simulink simulation under various operating conditions.
Keywords: high quality power; UPQC; voltage sags; three-phase four-leg converter; nonlinear and unbalanced loads; DG
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MDPI and ACS Style
Xia, M.; Li, X. Design and Implementation of a High Quality Power Supply Scheme for Distributed Generation in a Micro-Grid. Energies 2013, 6, 4924-4944.
Xia M, Li X. Design and Implementation of a High Quality Power Supply Scheme for Distributed Generation in a Micro-Grid. Energies. 2013; 6(9):4924-4944.
Xia, Mingchao; Li, Xiaoliang. 2013. "Design and Implementation of a High Quality Power Supply Scheme for Distributed Generation in a Micro-Grid." Energies 6, no. 9: 4924-4944.