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.