[Objective] BUCK circuits are widely used in new energy vehicle on-board power systems
industrial motor drives and other scenarios. In the application and realization of doubly-fed linear motor (DFLM)
it is necessary to design a BUCK circuit for level shifting between the on-board battery pack and the DC bus capacitor of the motor to realize its contactless feeding function. However
the ringing of this BUCK circuit introduces high-frequency noise to the DC bus capacitor
which affects the current control of the driver side of the DFLM. To address this problem
this paper proposes a ringing simulation method and suppression strategy
aiming at suppressing high-frequency ringing to provide a basis for the current control of the driver side. [Methods] Firstly
the causes of high-frequency ringing of silicon carbide metal-oxide-silicon field effect transistor (SiC MOSFET) with Kelvin source in a BUCK circuit topology were analyzed. Then
specific values of each parasitic parameter were obtained by fitting the experimental data. Finally
for the ringing suppression objective
the selection of RCD snubber circuit was optimally designed through simulation to reduce the time cost of experimenting with different selections. [Results] The error of the system simulation results obtained through parameter identification was reduced by about 20% compared to the error caused by empirical value selection. According to the proposed value selection method
the turn-off ringing overshoot voltage was reduced by 83.0% and the turn-on ringing overshoot voltage was reduced by 83.6%. [Conclusion] In this paper
a method to optimize the snubber circuit selection is proposed. Simulation and experimental results show that this method can accurately obtain the circuit parasitic parameters through a small amount of experimental data
and select components to meet the requirements for SiC MOSFET switch ringing suppression
so that the spike voltage and device switching speed are operated in the system optimal range.