A Contactless Slipring System with Integrated Matrix Transformer for Low-Voltage High-Current Applications

This paper presents a contactless slipring system with integrated matrix transformer to expand output current capacity. A U-I-shaped rotating transformer core structure suitable for high-speed rotation is adopted to reduce the weight and stress of the rotor. To enlarge the output current capacity with less winding losses and core size, a PCB-based cross-coupled fractional-turn rotor winding is proposed. An analysis of the proposed winding structure for symmetrical magnetic flux distribution is subsequently performed. The current sharing characteristic and symmetrical magnetic flux is verified by finiteelement analysis (FEA) simulation and thermal experiment. Furthermore, the experimental validation is conducted using a 3.3-kW/ 120 A prototype with a peak efficiency of 97.12%.