MRAS observer based on rotor current for DFIG sensorless control in network voltage drop condition

This paper introduces a new application of the Rotor based-current MRAS observer (RCMO) method for Doubly fed induction generator (DFIG) sensorless control in the condition of network voltage drop. DFIG control is Field oriented control (FOC) vector and Model reference adaptive system (MRAS) observer is used instead of speed and position sensor based on rotor current. It is possible to estimate the speed and position of the rotor. Simulation and analysis have been done based on 10% balanced voltage drop in the wind power plant terminal. The results of the simulation show the estimated speed (ω̂r), accurate and appropriate sequence of speed has real (ωr). Also, the graph of the machine variables in the state of balanced three-phase voltage drop in the state sensored is obtained and compared with the state sensorless, which shows the lack of influence of the estimated speed fault on the simulation results and the acceptability of using the RCMO method in estimating the speed in the condition of balanced voltage drop. Finally, the effect of various voltage drops on the estimated speed fault has been investigated.