A MRAS Observer Based Sensorless Control of Doubly-Fed Reluctance Wind Turbine Generators

A new model reference adaptive system (MRAS) based estimation technique for vector control of a brushlesss doubly fed reluctance generator (BDFRG) without a shaft position sensor is proposed. The rotor speed is being precisely observed in a closed-loop fashion through an iterative error eradication process between the measured and estimated secondary current angles in a stationary frame. Contrary to the existing MRAS designs reported in the BDFRG literature, the reference model only utilises direct measurements of the secondary currents with-out any machine parameters. Furthermore, the current estimates coming from the adaptive model are obtained using the measured grid voltages and currents, which has provided prospects for much higher accuracy and superior overall performance. The realistic simulations and the accompanying parameter sensitivity studies have shown the great controller potential for typical operating conditions of wind turbines as the main target application.