Hybrid Microgrid System Design with Renewable Energy Sources

Abstract

This study presents both a hybrid microgrid system design with renewable energy and their control methods, analysis result. This renewable energy resources (RES) consist of 33kW PVs, 100kW fuel cell stack and a 50kW wind turbine with permanent magnet synchronous generator (PMSG). PV plant includes the PV arrays and DC-DC boost converter. Fuel cell plant includes the fuel cell stacks and DC-DC boost converter. The wind energy plant contains the wind turbine, PMSG, uncontrolled rectifier and DC-DC boost converter. The boost converter connected to PV plant has been controlled by using incremental conductance maximum power point tracking algorithm (IC-MPPT A). Both the boost converters of the wind energy system and fuel cell system have been operated with PI controllers. The switching element of all boost converters is M OSFE T. The switching frequency for boost converters of the wind energy system and fuel cell system is 30 kHz and 50 kHz for boost converter connected PV array. The hybrid microgrid has been coupled on 1000V DC-bus bar. 400V/120 kV transformer and 120 kV, 50 Hz AC supply have been used to create the grid model. To convert from DC to AC, as the topology, full bridge inverter circuit has been used and IGBT has selected as the switching element. Phase locked loop (PLL) algorithm has been used as a control for the AC voltage generated at the inverter output to be the same phase, frequency and amplitude with the grid. The system has been operated under the various operating conditions such as wind speed and solar irradiation. And despite these variables, the desired results have been obtained from the system.