Supervisory Power Quality Control Scheme for a Grid-Off Microgrid

Presently, microgrids based on renewable energy sources require proper control functions to meet the power quality requirement in the distribution system. In order to maintain the power generation/consumption balance and stable functioning, such as voltage and frequency of microgrid, the power systems traditionally utilize necessary control actions. However, the present practice requires the independent power producers and/or developers who want to build a microgrid for a stable operation in both grid-off modes and grid-tie modes. Therefore, this paper proposes an innovative supervisory power quality control scheme of a grid-off microgrid, especially voltage and frequency control objectives, at a given location. In doing so, the active and reactive powers are manipulated from the power conversion systems with taking into account their operating states and limits.