Comparing different configurations for rotary transformer of wound-rotor resolvers

Wound-rotor resolvers are the oldest and most widely used resolvers. They are two-phase synchronous generators with high-frequency AC excitation. Rotary Transformers (RTs) are used to supply the rotating excitation winding of the resolver. Although RTs offer the benefits of contactless power transmission, the harmonic contents of the secondary voltage, phase shift error between the primary and secondary voltages, and high leakage flux are the main challenges in their applications in the resolvers. The current study aims to examine different configurations of the ferromagnetic core of the RTs to overcome the mentioned problems. To this end, all simulations were done using 3D Time Variant Finite Element Method (TVFEM), and the best configuration was chosen for experimental prototyping and measurements. Close agreement between the simulation and experimental test results approved the performed analysis. (c) 2023 Sharif University of Technology. All rights reserved.