Novel Voltage Controller for Stand-alone Induction Generator using PWM-VSI

This paper presents a DSP-based constant voltage controller for stand alone wind energy conversion system using an induction generator. The system uses a pulse-width modulated voltage source inverter (PWM-VSI) with a start-up battery. The limitation of having stand alone wind energy conversion system with self-excited induction generator (SEIG) is poor voltage regulation which occurs with change in speed and load condition. To overcome this problem, a DSP-based voltage controller is developed. It regulates the voltage when SEIG is subjected to a sudden application/removal of load. It is now possible to operate the induction generator (IG) at constant voltage from no load to full load. The amplitude of the terminal voltage of the IG is regulated by varying the modulation index of the PWM inverter. The system has an inherent current limiting feature and it requires only sensing of dc link voltage. To predict the performance of the proposed system, a MATLAB/SIMULINK-based simulation study is carried out. The control algorithm is implemented on a TMS320F243 DSP platform at the assembly language level for optimum performance of the voltage controller. Viability of the compensation process is ascertained through experimental results obtained from the laboratory prototype