Investigating the Effect of the Rotary Transformer Leakage Flux on the Detected Position of Axial Flux Brushless Resolvers

Resolver is an electromagnetic position sensors that are used for determining the position of rotating shaft. In this paper, effect of the leakage flux of the rotary transformer on the induced voltage in signal windings and detected position is discussed. Then, different electromagnetic shields are proposed to decrease the influence of detected position form leakage flux. The proposed methods are examined using 3-D time stepping finite element method for two axial flux brushless resolvers. Finally, prototypes of both resolvers based on the optimized proposed topologies are constructed and tested. Good agreement is obtained between the simulation and experimental results, validating the success of the proposed shielding.