Shaozi Li, Qun Jin, Xiaohong Jiang, Jong Hyuk Park
1 Department of Learning and Philosophy, The Faculty of Humanities, Aalborg University, VBN2 The Faculty of Humanities, Aalborg University, VBN3 Research in Education and Cultures of Learning, The Faculty of Humanities, Aalborg University, VBN4 The Techno-Anthropology Research Group, The Faculty of Humanities, Aalborg University, VBN5 PBL Research Unit, The Faculty of Humanities, Aalborg University, VBN6 unknown
A Developed Knowledge Model for IT in Learning
Line interactive Uninterruptable Power Supply (UPS) systems are good candidates for providing energy storage within a microgrid to help improve its reliability, economy and efficiency. In grid-connected mode, power can be imported from the grid by the UPS to charge its battery. Power can also be exported when required, e.g., when the tariffs are advantageous. In stand-alone mode, the UPS supplies local distributed loads in parallel with other sources. In this paper, a line interactive UPS and its control system are presented and discussed. Power flow is controlled using the frequency and voltage drooping technique to ensure seamless transfer between grid-connected and stand-alone parallel modes of operation. The drooping coefficients are chosen to limit the energy imported by the USP when re-connecting to the grid and to give good transient response. Experimental results of a microgrid consisting of two 60kW line interactive UPS systems are provided to validate the design.
Lecture Notes in Electrical Engineering: Itme 2013, 2014, Vol 61, Issue 3, p. 3373-3377
Line interactive UPS; Distributed generation; Microgrid