Analysis and Improvement on the Structure of Variable Reluctance Resolvers

Resolvers are often used in inverter-driven permanent magnet synchronous motors as the rotor position sensors. This paper analyzes a variable-reluctance (VR) resolver structure capable of generating absolute position signals on the basis of a review of conventional multipole VR resolvers. The analyzed VR resolver is made by varying rotor-pole shape according to a certain waveform, which can be determined by solving an inverse electromagnetic field problem. Finally, the paper proposes several procedures, based on the samples tested and an error analysis, to improve the accuracy of the VR resolver.