A new simplified fundamental model‐based sensorless control method for surface‐mounted permanent magnet synchronous machines

For sensorless control of surface-mounted permanent magnet synchronous machines (SPMSMs), the major issue is in zero- and low-speed ranges. Since back-electromotive force (EMF) is proportional to speed, back-EMF based methods fail at zero and low speed. A solution considering the starting process and low speed sensorless control is presented. A simplified fundamental model-based method is proposed. Based on the simplified model, the measured stator currents in the stationary reference frame can be directly utilised for position estimation so that the sensorless control performance at low speed and starting is improved. Moreover, with the knowledge of rotor initial position sector information, a stable and reliable starting performance is achieved with the proposed method. The effectiveness of the proposed method is verified through experimental results.