Secondary Level Voltage Control of Microgrid in Grid-connected And Islanded Modes
This paper presents the synchronization of microgrid with the medium voltage (MV) grid and a method based on achieving secondary level control of microgrid in both islanded and grid-connected modes. Small distributed generators (DG) act as a source for a low voltage (LV) grid or microgrid in order to satisfy the wide-spread power demand of consumer. The gate pulses for the Voltage Source Converters of each Distributed Generation (DG) unit are generated using PWM technique and the secondary level voltage control of microgrid is achieved in both grid-connected and islanded modes. The cascade microgrid system comprising of three distributed generators (DG) on which the studies are performed is simulated in time-domain using PSCAD/EMTDC software. The study results manifest appropriateness of synchronization of microgrid with the medium voltage (MV) grid and the admissibility of the hierarchical secondary level voltage control of a microgrid.