A Wide-Input High Step-Up Resonant Converter With High-Ratio Transformer in High-Voltage Applications

This article uses a transformer and a resonant network to present an isolated dc/dc resonant converter with a step-up ratio of tens to hundreds of times. The transformer leakage inductance replaces the resonant inductor, and the integration of the transformer and the resonant network is realized. The step-up frequency characteristics of the resonant network are analyzed in detail, and the operating range for soft-switching is given. Analyzing the power characteristics shows that it is very suitable for wind power conversion and high-voltage dc collection applications. The optimal design method between transformer ratio and resonant network step-up ratio is given. A 3000 W experimental prototype operating at 46 V/3000 V is built to verify the analysis and performance of the proposed converter. The results show that the step-up ratio of 65-278 is achieved in the output power range of 3000-500 W, with the maximum efficiency reaching 97.4% .