Sensorless speed estimation of AC machines using inphase method

This paper proposes a new method for sensorless speed estimation of AC machines which can be implemented on an AVR microcontroller chip. The proposed method uses a time based frequency transform of the current signal of the stator of the motor. This estimation is based on the effect of slot harmonics of the motor. A real experiment is performed over one type of motor driven by an Inverter and simulation results are presented. Considering the simplification of this method and the less computation requirement, this method could be useful and economical for industrial use.