Preliminary investigations of an inductive power transfer system for the rotor power supply of an electric traction drive

The paper is devoted to the substitution of slip rings through an inductive power transfer system (IPT) for field winding supply in wound rotor traction drives. By an inductively coupled rotational transformer, the rotor-side energizing of the excitation windings can be provided isolated and free of wear. For preliminary investigations, an analytical model of the inductive link and the compensation network has been set up. Based on this, possible types of compensation networks regarding an optimal integration into an electric traction drive were carried out and compared among themselves by parameter studies. Using an experimental prototype system and on the basis of accompanying FEM calculations, the analytical model has been validated and the system tested both stationary and transient.