Sensorless Position and Speed Control of IPMSM with Sliding Mode Observer and Voltage Signal Injection

A sensorless control approach based on a sliding mode observer for predicting the rotor position and speed is studied in this work. For predicting the motor speed and position, the sliding mode observer followed by a phase locked loop is formulated by means of the back EMF model. The voltage signal injection method is utilized for accurate estimation in zero or low speed region. Numerical simulation results are provided for an 8-pole IPMSM, which shows that the motor speed and position in zero or low-speed region are accurately estimated with the designed observer and voltage signal injection approach.