Robust Parallel Operated Inverters in Microgrid with SRF(Synchronous Reference Frame) – PLL(Phase Locked Loop) and SRF - Virtual Impedance Compensation Loop for Proportional Load Sharing

Abstract

Power flow control is most important in inverter interfaced Microgrids with highly penetrated DERs in islanded mode for their functionality to feed the connected loads. The different types of interfacing inverters connected to DERs, have been discussed for their principle of operation. The conventional inverters with droop control method of, P-f, Q-v alone failed to control with unequal line impedances. New inverters with SRF-virtual impedance compensation and SRF-phase locked loop along with droop characterstics have been implemented for defined functionalities in this paper. The design guidelines have been provided and the results are evaluated in Matlab/ Simulink platform to prove the effectiveness of the methodology.