Reactive Power Based Speed Sensorless Controller for Permanent Magnet Synchronous Motor Drive

In this paper a reactive power based model reference adaptive system (MRAS) is utilized to estimate the speed of a vector controlled permanent magnet synchronous motor drive (PMSM) for all speed range. The uniqueness of this system is that both the steady-state and instantaneous reactive power are used to form the MRAS. Such new structure of MRAS is independent of stator resistance and is less parameter sensitive (only dependent on q-axis stator inductance). Also, the use of simplified expression of reactive power makes the scheme easier to implement. Extensive simulation results are presented to validate the proposed technique.