Half-Bridge Intermediate Frequency Converter with Auxiliary Transformer Applied to Medium Voltage Direct Current System

This paper presents a unique half-bridge intermediate-frequency converter architecture, augmented with an auxiliary transformer, specifically tailored for Medium Voltage Direct Current (MVDC) systems. The converter design incorporates two half-bridge circuits that leverage shared switching devices, operating at an intermediate frequency to facilitate efficient power transmission. An innovative auxiliary circuit employs high-frequency chopping techniques to regulate power and voltage, ensuring zero-current switching (ZCS) across the intermediate-frequency devices. This design minimizes switching losses and enhances overall system efficiency. Through a comprehensive analysis of operational principles and parameter design methodologies, we validate the converter's performance with a prototype operating within a voltage range of 240 to 3000 V and rated at 7200 W.