Performance Investigation of Initial Rotor Position Estimation Methods in Synchronous Reluctance Motors

Lack of permanent magnet, low cost, significant constant-power speed range, high loadability, and high efficiency of SynRMs, have made these motors an attractive option In different applications such as traction and aircraft. Due to the saliency on the rotor of SynRM, calculating the exact value of the initial position is inevitable in sensitive applications. Also, Initial rotor position information is required to have high-performance control and achieve high starting torque. In this paper, different methods of initial rotor position estimation consisting of symmetric DC pulse injection, high frequency pulsating voltage injection, and high frequency square-wave signal injection are studied. These methods are described in procedure aspect, simulation under different rotor position conditions are discussed, and the performance of each method in different initial positions is surveyed. Finally, a comparative study between different methods in terms of performance accuracy, implementation complexity, convergence time, motor parameters dependency, and etc. based on simulation results are provided.