Energy Management of a Renewable Hybrid Isolated DC Microgrid

Abstract

Abstract: Hybrid microgrid is the key solution to energize remote rural areas. The microgrid system incorporates more than one Distributed Renewable Energy (DRE) source to complement one another. This paper proposes a hybrid DC microgrid system to be operated in isolated mode. The proposed microgrid consists of a PMSG based Wind Turbine, PV array, and Lead-acid battery as an energy storage device. The Wind Turbine generator is connected to the DC bus through a Three-phase Diode Bridge Rectifier. The PV array is tied to the DC bus by a Boost converter and incremental conductance algorithm is used to extract the maximum power from the PV array. The battery uses a bidirectional converter for charging and discharging. A simple PI-based closed-loop control system is incorporated for proper energy management. The bus voltage is maintained either by the boost converter or the bidirectional converter depending upon the operating condition. The proposed microgrid system is modeled in MATLAB/SIMULINK software. Simulation of this model is done for varying irradiance, temperature, wind condition, and different load condition. The simulation results show that the system is stable under various load and supply conditions. Keywords: Hybrid microgrid, Distributed Renewable Energy (DRE), PMSG, PV array, DC bus, Boost converter, incremental conductance, bidirectional converter