A brushless doubly fed induction machine with flat plane rotary transformers

This paper presents and analyses a 350kW brushless doubly fed three-phase induction machine with its wound rotor circuit connected to flat plane rotary transformers. It presents the advantages of substituting brushes and slip-rings by rotary transformers. In addition, it shows rotary transformer design and presents the doubly fed induction machine operation. The steady state model considers electrical circuit techniques to provide information about current, power factor and efficiency on load. Equivalent circuit parameters used on simulations were obtained through analytical calculation of a prototype.