Voltage control of an isolated self-excited induction generator using static synchronous compensator

Abstract

Voltage fluctuations due to random load variation are amongst the most important power-quality problem in a self-excited induction generator (SEIG) and wind energy conversion system. This paper presents a comprehensive modeling analysis and control strategy of a three-phase cage induction machine used as a self-excited induction generator. The proposed load voltage control strategy is based on the action of the static synchronous Compensator (STATCOM) which can not only provide the necessary reactive power but also may enhance the load ability. Moreover, a feed forward control method for the STATCOM is introduced and applied for controlling the SEIG's terminal voltage by using an outer control loop. An inner loop was also used to control the STATCOM's output reactive power to achieve the regulation of the AC bus voltage during load variation. To achieve this objective, we have designed and introduced an RST inner loop controller. To demonstrate the effectiveness of the proposed RST controller, a comprehensive set of simulation results are presented and thoroughly discussed in comparison with those of two other classical controllers, namely, the proportional-integral controller and the integral-proportional controller.