VSC supported active load control for SEIG under load perturbations

Three-phase self excited induction generator (SEIG) is increasingly getting attention for its use in distributed electricity generation and consumption viz wind, mini/micro hydro, biogas etc. The major advantage of induction generator over alternator includes its low cost, easy construction, ruggedness, maintenance free structure etc, whereas, varying demand of reactive power and poor voltage regulation under varying speed are the major limitations. The paper proposes a Voltage Source Converter (VSC) backed SEIG to actively meet the demand of load and to dynamically maintain the frequency by absorbing deficit power under varying load conditions to ascertain rated loading conditions across the SEIG. The load controller implemented on d.c. link, controls the real power flow across the VSC under variable loading. The voltage and frequency, thus regulated at the SEIG terminals has been successfully demonstrated through simulation results. The proposed scheme works well for the uncontrolled constant power turbine, which is low in cost and easy to implement. Performance of the system is simulated in Matlab/Simulink.