Five-to-Three Phase Doubly-Fed Induction Machine for Wireless Energy Transfer in Rotary Assembly Stations

Rotary assembly stations are commonly used in automated manufacturing processes. One of the problems that designers have to address is how to supply the electric actuators, sensors and controllers located on the rotating disk of the machine. These requirements are usually met through a gearmotor and sliding electrical contacts. However, slip-rings suffer from aging and thus a scheduled maintenance program is required. This paper avoids the use of slip-rings by means of an integrated electric drive consisting of a gearless multiphase induction machine with different numbers of stator and rotor phases fed by two inverters, one placed on the stator frame and one placed on the rotating one. The theoretical analysis derives a control algorithm that can decouple the torque control from the power transfer control.The feasibility of the proposed drive and the accuracy of the machine model is supported by analytical and finite element simulations.