{Aggregation of microgrids with DC system}

Title{Aggregation of microgrids with DC system}
Publication TypeJournal Article
Year of Publication2014
AuthorsMajumder R
JournalElectric Power Systems Research
Date Publishedmar
KeywordsBack to back converter, DC system, Microgrid, Voltage source converter
AbstractAbstract The aspiration of this paper is to scrutinize the feasibility of DC system connecting multiple AC microgrids for improved system reliability. In this paper, first multiple microgrids connected through a back to back connection (with better power flow control as well as frequency isolation) is contemplated. Each of the microgrids can operate in island or grid connected mode. The control and power flow management of the multiple microgrids system are first depicted with a common DC link capacitor. As second step, the DC capacitor is dispersed among the converter terminals as separate converter DC capacitor. As final step, the back to back converters are assumed to be far from each other and connected through DC cables. This result in a multi terminal medium voltage DC system connected to multiple AC microgrids. The active power, reactive power and output current capability of each converter terminal depends on the corresponding microgrid operating mode, DG output, local load demand etc. A DC system connecting multiple AC microgrids (with VSC interfaced DGs and ability to operate in island) bestows a test bench for studying the possibility smaller grids for higher reliability and better power flow management. The control schemes, generalized guidelines for such integrated system are proposed based on currently available standards, equipment, devices, system solutions and market requirements.