Analytical Model of a High Frequency Rotary Transformer in Non-Resonant Topologies

This paper provides a detailed analysis of the behavior of a high frequency rotary transformer that supplies the excitation winding of a prototype electrically excited synchronous motor. This work includes the study of two different system topologies carried out through an analytical model, finite element analysis and experimental tests: the former is the standard model that should be used on an electric drive, the latter presents a capacitor connected in parallel to the load branch. The paper highlights the impact of the air gap width between the two cores of the transformer on its performance and provides recommendations for the design of high-performance rotary transformer.