Comparative analysis of variable speed wind energy conversion systems

The modelling of PWM Doubly Fed Induction Generator (DFIG) for wind turbine application is used for improving the power quality of the grid and it is more attractive in comparison to the PWM Synchronous and PWM-Induction generator with a variety of reasons. While the technology of PWM-Synchronous (PWM-SYN) and PWM-induction (PWM-IND) generator is used for constant speed of wind velocity, more recently, the variable wind speed induction generator was introduced. Doubly Fed Induction Generator is used for wind energy conversion . This allows the operation of the turbine at variable wind speed enhancing the conversion system. This paper gives an overview of the simulation results for comparing the DFIG with the PWM based induction and synchronous machine. Doubly Fed Induction machines uses AC-AC converter in the rotor circuit which is the best option for high power applications with limited speed ranges. The power converter rated only to handle the rotor power. It allows the power output in both stator winding and rotor winding of an induction machine with a wound rotor winding to yield good power factor even the machine is running at speed different from synchronous speed.