Wind driven self-excited induction generator with simple de-coupled excitation control

An induction generator is a good option for low power stand-alone, nonconventional energy generation. Induction generators require low maintenance costs and are cheaper but require an external excitation controller. A recently proposed PWM controller, whose principle was demonstrated in an earlier work for resistive and reactive loads, has been satisfactorily employed for harmonic and unbalanced three phase loads. The closed loop, IGBT based controller, which does not require any mechanical position/speed sensors, has been used to regulate the three-phase AC output voltage of a self-excited induction generator with varying rotor speed, transient load conditions and unbalanced as well as reactive loads. Since no online computations are required, it turns out to be a low cost, simple controller. Computer simulation and experiments show good results