Active & Reactive Power Control Of A Doubly Fed Induction Generator Driven By A Wind Turbine

Wind Energy is gaining interest now-a – days as one of the most important renewable sources of energy due to its ecofriendly nature. But the major disadvantage lies in variable speed wind generation and this paper gives a study on control of Wind driven doubly fed Induction Generators. The speeds above and below Synchronous speeds are obtained using a bidirectional power flow converter. By using this reactive power is controlled and hence the overall Power factor of system can be kept at unity under varying load conditions. . This paper presents simulation results of a Grid-connected DFIG. A switch-by-switch representation of the PWM converters with a carrier-based Sinusoidal PWM modulation for both rotor- and stator-side converter has been proposed. Stator-Flux Oriented vector control approach is deployed for both stator- and rotor-side converters to provide independent control of active and reactive power and keep the DC-link voltage constant. A 7.5 KW generator is designed and its effectiveness in controlling is verified in different operating conditions i.e. above and below synchronous speeds