Mechanical speed estimation of a DFIG based on the Unscented Kalman Filter (UKF)

Abstract

This work proposes a new estimation technique for the doubly-fed induction generator (DFIG) variables. Researchers have designed numerous sensorless control strategies for the DFIG used either for mechanical speed, electromagnetic torque, or rotor position estimation. In this paper, an analysis of an Unscented Kalman Filter (UKF) will be presented as an observer for both rotor and stator currents, and mechanical speed, which are key information in DFIG control. The performance of the proposed observer has been validated in a 9 MW wind turbine under MATLAB/Simulink. Based on the results obtained, UKF is safely able to replace mechanically coupled sensors which have many disadvantages such as high cost, maintenance, and cabling requirements