A Power Electronics Traction Transformer for High-Speed Trains in China: Toward a Lighter and More Compact Traction System

The pursuit of a lighter and more compact traction system in high-speed trains drives the development of a power electronics traction transformer for China’s high-speed trains. This article introduces the topology, control and implementation of the proposed PET, which features a double-side modulation for the isolated dc/dc LLC converters and state-of-the-art medium-frequency transformers with compact insulation and cooling solutions. Field tests on a test railway have validated the PET’s performance, achieving a remarkable 96.7% efficiency with 0.34 kW/L and 0.47 kW/kg in power density which is 20% smaller in size and 15% lighter in weight than traditional line-frequency systems for a CRH-6 train.