A simple and effective control scheme for improved power quality in a stand alone Wound Rotor Induction Generator feeding non-linear and unbalanced loads

This paper presents a simple and effective control scheme for a stand-alone Wound Rotor Induction Generator (WRIG) feeding non-linear and unbalanced loads under varying rotor speed and load conditions. Synchronous Reference Frame (SRF) method is used for the estimating the harmonic and the negative sequence components from the load current without the need to decompose load current into sequential components. Based on this estimation, the front end converter is commanded to produce currents to compensate for the content of imbalance and distortion in load current so that the stator voltage and current are of good quality. Simulation are carried out for the test set up with the generator supplying linear, non linear as well as unbalanced loads. The results establish the effectiveness of the proposed control approach.