Low speed sensorless control of PMSM drive using high frequency signal injection

Conventional techniques for sensorless control of permanent magnet synchronous motor drive (PMSM) which requires information of rotor position are reviewed and recent developments in this area are introduced in this paper along with their inherent advantages and drawbacks. The paper presents an improved method for sensorless speed control of PMSM drive with emphasis placed on signal injection method. It examines the rotor position sensorless control performance based on sensing by external signal injection. The main objective of this drive system is to have speed control at standstill and low speed regions. Several tests are carried out to demonstrate the ability of proposed models at different operating conditions with the help of simulation results in Matlab/Simulink environment. Simulation results confirm that the proposed sensorless control approach of PMSM can achieve high performance at standstill and low speeds but not at very high speeds.