An MRAS Speed Observer Based on Control Winding Flux for Sensorless Control of Stand-Alone BDFIGs

This article presents a new rotor speed observer for the sensorless control of stand-alone brushless doubly fed induction generators based on the control winding flux model reference adaptive system structure. The observer is incorporated in the control strategy for regulating the terminal voltage magnitude and frequency under the different operating conditions. The capability of the proposed observer and control method is demonstrated by comprehensive simulation results and verified by experiments. As shown, without using physical speed sensors, the sensorless control algorithm incorporating the proposed speed observer can effectively maintain the amplitude and frequency of power winding voltage constant at different rotor speeds and under different conditions of load and machine parameter, e.g., inductance and/or resistance, variations.