Modeling of a Three-Phase ZVS Mixed Conduction Mode DC–AC Inverter Into Equivalent Single-Phase DC–AC Inverters

To achieve zero-voltage switching (ZVS), triangular conduction mode (TCM) delays the turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> time of SiC <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> s to generate a reverse current that discharges the junction capacitance–voltage before a <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> turns <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> . In the literature, TCM has been combined with discontinuous conduction mode (DCM) and discontinuous pulsewidth modulation to achieve ZVS in three-phase inverters. However, the coupling between the three phases, and transitions between the different modes cause complexity in the modeling and current control. This article presents a simple modeling approach where the modeling and analysis for an equivalent single-phase TCM and DCM inverter can be directly extended to this mixed conduction mode. Thanks to the simplicity, not only the impact of the three-phase coupling can be compensated, but also small signal gains for current control can easily be derived. The proposed modeling approach has been verified by SIMPLIS simulation and experimental tests with a three-phase PV inverter.