Voltage and Frequency Control of a Stand Alone Brushless Wind Electric Generation Using Generalized Impedance Controller

Abstract

In this paper, a new strategy for the control of terminal voltage and frequency of a stand-alone self-excited induction generator-(SEIG) based wind generator, working with variable speed and load is proposed. With a generalized impedance controller (GIC) (voltage source pulsewidth-modulated inverter with a dc-link battery), a new strategy to maintain the active and reactive power balance at the SEIG terminals has been introduced to control its terminal voltage and frequency. In the proposed control strategy, only a voltage feedback loop has been used to control both the SEIG terminal voltage and the frequency. A mathematical model of the SEIG-GIC system under wind generator environment has been developed and simulated in the MATLAB/Simulink. The simulation results are validated with the experimental ones conducted on a laboratory prototype of the SEIG-GIC system. The novelty of the present technique is that the GIC is capable of maintaining a constant SEIG terminal voltage and frequency, following both speed and load perturbations, with only a single (voltage) feedback loop.