A Modified MRAS based Sensorless Control of DFIG in Wind Energy Conversion System

The wind energy conversion system (WECS) is one of the most developed renewable energy sources. In WECS, the doubly-fed induction generator (DFIG) has become the leader among all the types of generators, due to several advantages. For control of DFIG, rotor speed and position data are required. These data can be collected either using speed/position sensors or can be estimated using already available sensed parameters. Due to the issues related to robustness, economy, cabling, and maintenance, of speed-transducers or position-encoders, the speed/position sensor-less techniques are expected in DFIG-WECS control. In this paper, a Modified Rotor-Current-dependent Model reference adaptive system (MRAS) Observer (MRCMO) based estimation technique is proposed with improved rotor speed estimation. In the proposed method stator voltage, stator current, and rotor current data are used to estimate rotor position and speed using one additional estimator structure to the existing Rotor-Current based MRAS Observer (RCMO). To validate this modified technique, one comparative case study is carried out with the existing RCMO approach, in MATLAB/Simulink platform.