Type-2 fuzzy logic based pitch angle controller for fixed speed wind energy system

In this paper, an interval Type-2 fuzzy logic based pitch angle controller is proposed for fixed speed wind energy system (WES) to maintain the aerodynamic power at its rated value. The pitch angle reference is generated by the proposed controller which can compensate the non-linear characteristics of the pitch angle to the wind speed. The presence of third dimension in the Type-2 fuzzy logic controller (FLC) membership function offers an additional degree-of-freedom in the design of the Type-2 FLC controller to improve the system performance. The applicability of the proposed controller is evaluated by considering a nonlinear simulation model of the WES which is developed and implemented using OPAL-RT real time digital simulator. The results show that the proposed controller offers better performance than the conventional PI and fuzzy logic controllers.