Power Quality Enhancement Using VSI Based STATCOM for SEIG Feeding Non Linear Loads

Mrs. R. Lilly Renuka, Mr. R. Ilango, Mr. B. Muruganandam

This paper deals with the performance analysis of static compensator (STATCOM) based voltage regulator for self- excited induction generators (SEIGs) feeding non-linear single phase loads. The presence of non-linear loads in some applications injects harmonics into the generating system. Because an SEIG is a weak isolated system, these harmonics have a great effect on its performance. Additionally, SEIG’s offer poor voltage regulation and require an adjustable reactive power source to maintain a constant terminal voltage under a varying load. A three-phase insulated gate bipolar transistor (IGBT) based current controlled voltage source inverter (CC-VSI) known as STATCOM is used for harmonic elimination. It also provides the required reactive power an SEIG needs to maintain a constant terminal voltage under varying loads. A dynamic model of an SEIG-STATCOM system with the ability to compensate the unbalanced current caused by single-phase loads that are connected across the two terminals of the three-phase SEIG  under  varying loads  has been analyzed by using D-Q frame theory algorithm. This enables us to predict the behavior of the system under transient conditions. The simulated results shows that by using a STATCOM based voltage regulator the SEIG can balance the current; in addition to that the STATCOM is able to regulate the terminal voltage of the generator and suppresses the harmonic currents injected by non- linear loads.