A New Rotor Position Estimation Method for Spherical Reluctance Motor Based on Inductance Characteristics Obtained From Measurement

Since the spherical reluctance motor (SPRM) works in saturation, it is difficult to estimate the rotor position. In this article, a new rotor position estimation method for SPRM is proposed. In order to accurately estimate the rotor position, according to the inherent characteristics between phase inductance, rotor angle, and phase current, the phase inductance–rotor angle curve is divided into three segments. The idea of scaling is adopted to deal with the analytical expression of each segment, and the three analytical expressions corresponding to the three segments are generated through linear function and quadratic function. The coefficients of each analytical expression are determined through a small amount of the measured inductance data. Experiment and comparison results show that the proposed method can effectively and accurately estimate the rotor position.