This paper discusses an isolated switching mode power supply (SMPS) with an AC 30 kV_rms insulation capability for application to the solid-state transformers (SSTs) in railway vehicles. The insulation capability of the SMPS should be higher than AC 25 kV_rms for application at the SSTs in railway vehicles. The proposed highly isolated SMPS is superior to commercial isolated power supplies with low insulation capability, which is normally less than 20 kV. The input side of the proposed isolated SMPS is physically separated from its output side by a specially designed miniature high-frequency (HF) transformer to obtain high insulation capability. The core of the miniature HF transformer is separated by insulation material. The primary and secondary coils are wound around each separated core. A CLLC resonant converter that consists of a primary resonant capacitor (C), two inductors (LL), and a secondary resonant capacitor (C) is applied as the proposed isolated SMPS topology to improve the output voltage regulation performance, which varies due to a large leakage inductance derived from the airgap of the proposed miniature HF transformer. Experiments are carried out to verify the CLLC resonant converter of the proposed isolated SMPS. Electrostatic finite element method (FEM) simulations and high potential (HiPot) tests are carried out to verify the AC 30 kV_rms insulation capability of the proposed isolated SMPS. The electrostatic FEM simulations demonstrate the DC 42.43 kV insulation capability, and the HiPot tests verify the insulation capability from AC 5 kV_rms to AC 30 kV_rms.

本文讨论了具有交流30 kV _rms绝缘能力的隔离式开关电源（SMPS），该电源将应用于铁路车辆的固态变压器（SST）。SMPS的绝缘能力应高于AC 25 kV _rms用于铁路车辆的SST。提议的高度隔离的SMPS优于绝缘能力低的商用隔离电源，该电源通常低于20 kV。拟议的隔离式SMPS的输入侧通过专门设计的微型高频（HF）变压器与输出侧物理隔离，以获得较高的绝缘能力。微型高频变压器的铁芯由绝缘材料隔开。初级线圈和次级线圈缠绕在每个分离的铁芯上。包含初级谐振电容器（C），两个电感器（LL）和次级谐振电容器（C）的CLLC谐振转换器被用作建议的隔离式SMPS拓扑，以改善输出电压调节性能，由于所建议的微型HF变压器的气隙会产生较大的漏感，因此其变化很大。进行实验以验证所提出的隔离式SMPS的CLLC谐振转换器。进行了静电有限元方法（FEM）模拟和高电势（HiPot）测试，以验证交流30 kV拟议的隔离式SMPS的_均方根绝缘能力。静电FEM仿真显示了DC 42.43 kV的绝缘能力，HiPot测试验证了AC 5 kV _rms到AC 30 kV _rms的绝缘能力。