Research ZCS Synchronous Rectification of Resonant Converter

摘要

In this study, the application of ZCS synchronous rectification for the IPT resonant converter is researched. A novel control method that AC-DC section of the resonant converter works in ZCS SR state is proposed by using the characteristic of resonant tank current. First, the ZCS working operation of SR is presented, analyzed and equivalent circuits for each operation mode are also given, respectively. Then, the novel control method of ZCS SR for resonant converter is proposed. According to the ZCS working operation of SR and the differential equations of equivalent circuit, a steady-state mathematical model of the circuit is established. On that basis, the calculation method for ZCS operating point of SR is deduced by solving the fixed point function about resonant tank current. Moreover, the specific flow chart for calculating ZCS operating point of SR and the steady-state waveforms of each state variable is also presented and operating principle of control circuit for ZCS SR is described in detail. Finally, experimental results verify the effectiveness of control method proposed in this study.