Solid-State Transformer with PCB Litz Wire

演讲者:   Zheqing Li，Tesla, Inc Senior Power Electronics Engineer

时间:      2025年12月26日 10:00-11:00  

邀请人:   信息学院 王浩宇教授

地点:      信息学院 1A200

摘要:

Litz wire, renowned for its efficacy in minimizing winding losses at high frequencies, encounters notable challenges when implemented in printed circuit board (PCB) windings. This paper introduces an innovative PCB Litz wire concept designed to mitigate winding losses, particularly in the context of developing the solid-state transformer using PCB-winding-based technology. The proposed PCB Litz wire employs a unique zig-zag wire pattern to achieve a flux cancellation effect, thereby reducing magnetic flux and promoting a uniform current distribution. Configured in a circular winding layout with spiral strands, the PCB Litz wire is optimized for performance and layout simplicity. The construction method, as well as turn-to-turn connections, is demonstrated for practical implementation. An efficient optimization method is presented for designing transformers with PCB Litz wire, considering parameters such as strand width and strand angle. Results indicate that, in comparison to traditional PCB winding, the PCB Litz wire yields a notable 30% reduction in winding losses, enhancing current distribution, and contributing to improved thermal performance. To validate the efficacy of this concept, a prototype of a 1.6/1.05 kV, 192 kHz, 30 kW CLLC converter is constructed. The prototype demonstrates an impressive 99.0% efficiency, underscoring the effectiveness of the proposed PCB Litz wire concept in high-frequency applications.

报告人简介:

Zheqing Li received the B.S. degree in electrical engineering from Zhejiang University, Hangzhou, China, in 2018. He got his Ph.D. degree in Electrical Engineering with the Center for Power Electronics Systems (CPES), Virginia Tech, Blacksburg, VA, USA under the supervision from Dr. Qiang Li and Dr. Fred C. Lee. He is now a senior power electronics engineer in Tesla.

His research interests include solid-state transformer (SST), magnetic integration, medium voltage insulation, and high frequency resonant converter design.