A novel sensorless speed controller design for doubly-fed reluctance wind turbine generators

A brushless doubly-fed reluctance generator has been seen by research communities as a potential solution to higher operation and maintenance costs associated with the compromised reliability of brush compartment of conventional doubly-fed induction generators, while offering comparable performance and similar cost benefits of using a partially-rated power electronic converter in wind power applications. A new flux vector oriented encoder-less scheme for speed and inherently decoupled torque and reactive power control has been proposed and successfully experimentally verified on a small machine prototype by emulating the typical torque-speed operating characteristics of ordinary horizontal-axis wind turbines. The obtained test results have clearly indicated the excellent controller response and disturbance rejection abilities over the entire speed range of interest.