Grid-Interfacing Converter Systems With Enhanced Voltage Quality for Microgrid Application-Concept and Implementation

• Published in: IEEE transactions on power electronics Vol. 26; no. 12; pp. 3501 - 3513
• Main Authors: Wang, Fei, Duarte, Jorge L., Hendrix, Marcel A. M.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.12.2011; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Compensation; Control systems; Converters; Convertors; Design engineering; Distributed generation; Electric currents; Electric potential; Electrical engineering. Electrical power engineering; Electrical machines; Electrical power engineering; Electricity generation; Electronics; Energy storage; Exact sciences and technology; grid-interfacing; Harmonic analysis; Inverters; microgrid; Miscellaneous; Operation. Load control. Reliability; Power networks and lines; Power quality; Regulation and control; smart grid; Smart grids; Topology; Voltage; Voltage control; voltage quality; Performance evaluation; voltage quality; Control synthesis; Implementation; Series parallel connection; Non linear load; System performance; Parallel system; microgrid; Power supply quality; Voltage; Converter; Energy quality; Distributed generation; Distribution network; Multilevel system; Phase reversal; Parallel architectures; Distributed system; Topology; Experimental study; Smart grid; Phase shifter; Electrical network; Three phase circuit; Concrete; grid-interfacing; Electric power production; Service quality; Energy transfer
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2011.2147334

Grid-interfacing converter systems with enhanced voltage quality are proposed for microgrid applications in this paper. By adapting the conventional series-parallel structure, a group of grid-interfacing system topologies are proposed for the purpose of interfacing local generation/microgrid to the grid, or interconnecting microgrids. The functionality of the proposed systems is also reconfigured in order to ease the control design and to improve overall system performance, differing from existing series-parallel structure-based systems. Experiments with a concrete laboratory system are given to detail the proposed concepts and to demonstrate the practical implementations. Two three-phase four-leg inverters, together with dc microsources and nonlinear loads, are employed to construct a general series-parallel grid-interfacing system. Through the introduction of multilevel control objectives, it is illustrated that the proposed system could ride through voltage disturbances and continue the power transfer between the local generation and the grid, while a high-quality voltage is maintained for the local loads. The system also shows the possibility to achieve auxiliary functions such as voltage unbalance correction and harmonic current compensation. The main design aspects of the controllers are specified, and the entire system is effectively validated on a laboratory setup.