A Family of Zero-Voltage-Switched Resonant Converters: Derivation, Operation, and Design

Soft switching based on resonant operation, through mitigating switching loss and alleviating electromagnetic interference, is essential to high-frequency operation to achieve high power density. To overcome the obstacles of high switch voltage stress and ease the contradiction between voltage stress and conduction loss for traditional single-switch resonant converters, a family of zero-voltage-switched (ZVS) isolated resonant converters is proposed which utilizes a novel resonant switch. The converters enable parasitic components, including transformer leakage inductance, switch output capacitance, and diode junction capacitance to act as a part of resonant components, which facilitates ZVS and zero-current-switching operation and pushes up switching frequency. The specific derivation of the topologies is expounded, and one of the proposed converters is taken for example to perform in-depth analysis, whose mode analysis, operation principles, and parameter design method are minutely presented. Synchronous rectification is employed to further improve efficiency. A prototype was built in the laboratory and the experimental results validate the theoretical analysis well.

Automated summary

Soft switching based on resonant operation is essential for achieving high power density at high frequencies by reducing switching loss and minimizing electromagnetic interference. A family of zero-voltage-switched (ZVS) isolated resonant converters has been proposed to overcome traditional single-switch resonant converters' voltage stress issues and improve efficiency. The use of parasitic components as part of resonant components allows for zero-voltage switching operation, higher switching frequency, and improved efficiency.