High‐efficiency topology‐morphing multi‐resonant DC–DC converter with wide voltage gain range for small‐scale wind generation applications

Abstract

In this study, a high-efficiency topology-morphing multi-resonant DC-DC converter is proposed. The converter employs two auxiliary switches to control the equivalent resonant tank, and thus exhibits adaptive resonant characteristics for diverse situations. The dual-transformer MRC structure is applied when high-voltage gain is required, while a five-element MRC operates at the rated state for high-conversion efficiency. Besides, good protection for the over-current issue is guaranteed. Also, beneficial from the topology-morphing technology, the operating frequency range is very narrow and near every mode's high-efficiency region. Therefore, the proposed converter has an expanded voltage gain range and maintains high-efficiency throughout. These features make it well suitable for small-scale wind generation applications. Finally, a 500 W prototype is fabricated in the laboratory to test the performances. The input voltage varies from 80 to 600 V and the output voltage is constant at 400 V. The efficiency remains high (>96.5%) among the entire voltage gain range and the peak value reaches 97.93%.

A robust passivity based control strategy for quasi‐resonant converters

“…Resonant converters are defined as the combination of converter topologies and soft switching strategies that result in zero voltage switching (ZVS) or zero current switching (ZCS) [1]. The resonant converters have low switching losses and high‐power densities which are widely used in industries [2, 3]. There are many topological variations of the resonant converters.…”