Design of a Rotary Transformer for Installations on Large Shafts

Abstract

Rotary transformers are adopted to transfer energy from primary to secondary in situations in which the two sides are in relative rotation. These devices are cylindrical transformers with two cores and the corresponding winding separated by an air gap. Their employment became quite convenient with the availability of power electronics, allowing the operation of electrical systems at relatively high frequencies. In particular, this paper proposes the design of a light and efficient transformer which can be used in applications involving large shafts. Moreover, a sliced arrangement for the magnetic core is proposed together with the experimental validation of this solution on a reduced-size prototype.

Modelling of the Electrically Excited Synchronous Machine with the Rotary Transformer Design Influence

“…Motor real-time voltage and current models are important to implement in the EESM control system for the load angle δ s calculation (21) and the estimation of the stator fluxlinkage ψ s,calc (20) that is used as feedback value for the flux-linkage PI controller (Figure 1). Equations ( 18) and (19) are used for correction of the values obtained from voltage and current models and contain proportional and integral gains (i.e., K p and K i ).…”

“…The single-phase rotary transformer topologies being used in industry are predominantly based on the axial and radial topologies [17]. To enhance the transferred power, efficiency and to decrease the size, high supply frequency is used, as recently reported in [19][20][21]. However, the complexity of inverters and their high price are the major inconveniencies imposed by supply of high frequencies.…”