An improved control strategy of self excited induction generator taking magnetization nonlinearity

Self excited induction generators (SEIG) are being widely used in wind power generation, especially for supplying electric power in remote areas. The major problem of such generation is to maintain constant voltage and frequency under variable load and variable wind speed condition. In this paper a control strategy involving supply of reactive power to the generator partially through fixed capacitor bank connected at the stator terminals and switched dc power source is proposed for constant voltage and constant frequency operation. The dc source can be a battery charged from the generator during a light loaded condition. The method is simple and can be implemented through a low cost inverter of smaller size for supplying reactive power only and for a large change in operating condition another additional set of fixed capacitor can be switched to reduce the reactive power loading on the inverter. Suitable simulations and experiments are performed to validate the proposed concept.