An Inbuilt Synchronization Controller for Three-Phase Synchronverters

Virtual synchronous generator control or synonymously referred as synchronverter control of converters which integrates renewable energy sources to the utility grid or microgrid is emerging as a suitable control where the response of a conventional synchronous generator is emulated, thereby improving system stability. In this paper, a three-phase synchronverter control with an inbuilt synchronization unit is proposed in order to eliminate the external phase-locked loop (PLL) unit. The inbuilt synchronization unit does not use any additional PI control or integral control unlike the PLL unit. Thus, the computation burden of the overall controller is reduced. In this work a grid-tied synchronverter with the proposed inbuilt synchronization unit is simulated with different initial frequency and initial phase difference conditions. Also, variable grid frequency during synchronization is simulated in order to verify the effectiveness of proposed synchronization control.