Sensorless Maximum Power Point Tracking control for Wind Energy Conversion System using DFIG

Abstract

This paper proposes a variable speed Wind Energy Conversion System (WECS) using Doubly Fed Induction Generator (DFIG). The vector control of the DFIG is achieved according to the generator speed in order to maximize the wind power capture (MPPT). The proposed control scheme is ensured without mechanical and wind speed sensors from the aspect of reliability and increase in cost. The system drive considers a reduced state model of the DFIG with an oriented stator flux. An adaptive observer has been developed to the considered structure in which the electrical sizes are estimated from the stator currents measure and the shaft speed is adjusted optimally through an adaptation law derived from Lyapunov stability theory. An extended Luenberger observer is also applied to a linear mechanical state model to estimate the wind torque. This system design provides wind speed estimation, which is required in the maximization control algorithm. The simulation results show the effectiveness of the considered DFIG drive.