Motor Drives and Inverters
Technical Dialogue Session
Motor Drive and Inverters
WBG device, Soft switching, three-phase, modeling
To achieve zero voltage switching (ZVS), triangular conduction-mode (TCM) generate a reverse current which discharges the junction capacitance before a MOSFET turns on. Such a method is extended to three-phase applications by operating the other two-phase into two different conduction-modes; discontinuous conduction mode (DCM) and clamp-mode similar to a discontinuous PWM (DPWM) scheme. However, the presence of a three-phase coupling and transitions of the conduction-modes along the line-cycle arise complexity in the modeling and control. In this paper, a decoupled modeling is presented for three-phase TCM inverters utilizing three different conduction-modes for ZVS operation. Under the condition that the DCM phase does not affect the zero-crossing instant of TCM phase current, the modeling and analysis for an equivalent single-phase TCM and DCM inverter can be directly extended to the three-phase counterpart. This significantly simplifies the analysis under three-phase coupling. The proposed modeling is verified by SIMPLIS simulation and an experiment with the prototype three-level three-phase TCM inverter.