Variable-Reluctance Permanent Magnet Resolver Design Guidelines

This article presents the design considerations and geometrical optimization of a variable-reluctance permanent magnet resolver (VRPM resolver). The above-mentioned resolver utilizes permanent magnets (PMs) and magnetic flux measurement units (MFMUs) instead of excitation windings and signal windings. The operating principle of the VRPM resolver is presented, and the geometric and magnetic properties of its various components that influence the accuracy are identified. To study the performance of the resolver, the magnetic equivalent circuit (MEC) model is utilized to ensure both calculation speed and accuracy, while taking saturation and nonlinear B-H curve effects into account. The developed analytical model is coupled with a multiobjective optimization solver to conduct repetitive simulations and attain an optimal design for the studied VRPM resolver. The objective of the optimization process is to achieve the minimum position error, while simultaneously improving the computational time. Time-stepping finite-element analysis (TSFEA) is used to validate and measure the performance in detail. Finally, experimental tests on a prototyped VRPM resolver are employed to verify the simulation results.