Analysis and Modeling of Zero-Voltage-Switching Condition for LCC Resonant Converter in Above-Resonance Operation Mode

• Published in: IEEE transactions on power electronics 2024-09, Vol.39 (9), p.10950-10961
• Main Authors: Wang, Runze, Mao, Saijun, Yin, Shan, Liu, Hongyao, Tan, Qiuyang, Fan, Jiajie
• Format: Article
• Language: English
• Subjects: <named-content xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" content-type="math" xlink:type="simple"> <inline-formula> <tex-math notation="LaTeX"> LCC</tex-math> </inline-formula> </named-content> resonant converter; dead time; Generators; parasitic capacitance; Resonant converters; Steady-state; Switches; Transformers; transient analysis; Voltage; Zero voltage switching; zero-voltage switching (ZVS)
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2024.3411553

The LCC resonant converter in the above-resonance operation mode is gaining popularity in high-voltage generator applications due to its favorable characteristics, including zero-voltage switching (ZVS), step-up capability, and the absorption of parasitics. Nevertheless, with the increase of the voltage gain G_{o} of the resonant tank, the ZVS condition is undermined for the LCC resonant converter. This study aims to characterize the ZVS condition of the LCC resonant converter in the above-resonance operation mode. For this purpose, a two-step-based ZVS analysis is carried out, incorporating the partial steady-state analysis and the dead-time analysis. The outcome of this analysis is the derivation of a set of three necessary conditions that define a sufficient ZVS condition model of the LCC resonant converter in the above-resonance operation mode. According to the analytical dead-time analysis, a discriminator \Delta representing the ZVS performance of the LCC resonant converter is demonstrated, and the ZVS condition can only be achieved when \Delta > 0. Moreover, the analysis of the sign of \Delta reveals that the LCC resonant converter exhibits a weaker ZVS condition when G_{o} > 1 than when G_{o} \leq 1. On the basis of the proposed ZVS condition model, a design method is proposed to illustrate the influence of the ZVS condition on the output of the step-up LCC resonant converter. Finally, experimental resul