A novel non-fragile single-loop voltage and frequency controller for induction generator based isolated renewable energy conversion system

Poor voltage and frequency regulation under source and load perturbations limit the use of self excited induction generator (SEIG) in isolated and dispersed generation, which can exploit wind/microhydro type renewable energy sources. In the present work, a Generalized Impedance Controller (GIC), which is a pulse-width-modulated voltage-source-inverter with a dc-link battery, is used to regulate both, amplitude and frequency of the SEIG terminal voltage using only PI controller in voltage feedback loop. The important aspect of the present work is to show the dependence and sensitivity of the dynamic response of both amplitude and frequency of the SEIG terminal voltage, following source and load perturbations, on the PI controller gain settings of the voltage feedback loop. For non-fragile system operation, optimum gain settings of the voltage-loop controller are selected within a stabilizing range to minimize the frequency disturbances caused by the source/load perturbations.