A multi objective control technique for interfacing hybrid renewable energy sources in an islanded microgrid subsequent to unbalanced and non linear load conditions

Abstract

The paper demonstrates a control technique for medium voltage islanded microgrid to integrate hybrid renewable energy source (RES) units into the microgrid system while maintaining active power balancing among the RES units and to control interfaced power electronics converters under unbalanced and non linear load conditions. The control strategy aims to eliminate the risk associated with voltage fluctuations and to maintain power balance in order to maintain better power quality under unbalanced and nonlinear load conditions. The operation of the micrigrid is examined by connecting hybrid RES units to the load through a multilevel inverter. The control scheme consists of a multi loop control solution for the CHB multilevel inverter employing multi proportional resonant converters and a energy management section for hybrid RES units. The hybrid RES units employ fuel cell(FC) and photovoltaic (PV) sources as the prime energy sources while supercapacitor (SC) is considered as the complementary energy source. The multi-PR controller helps to tune the bus voltages even during unbalanced conditions and non linear load conditions. The proposed control scheme has been validated through MATLAB/Simulink based simulation model for varying load demands.