Single-loop voltage and frequency control of stand-alone three-phase four-wire renewable energy conversion system with battery storage

Abstract

In this paper, single control loop based scheme for regulation of voltage and frequency of Self Excited Induction Generator (SEIG) based stand-alone 3-phase 4-wire renewable energy conversion system under source and balanced/unbalanced load perturbations is presented. The regulation is accomplished by maintaining reactive and active power balance across individual phases of SEIG using a Generalized Impedance Controller (GIC). GIC is a PWM voltage source converter with battery at its dc-bus, having controlled four-quadrant equivalent impedance. Unique feature of the scheme is successful control of both amplitude and frequency of the SEIG terminal voltage using only 3-phase stator voltage feedback and no frequency feedback. A mathematical model of the SEIG-GIC-Load 3-phase 4-wire integrated system has been developed and simulated in MATLAB/Simulink to validate practicability of the generating system under variety of source and load perturbations.