Optimal Trajectory Control for a Fully Soft Switching Single-Stage Isolated Three Phase AC to DC Series Resonant Converter

Three phase AC to DC and DC to AC conversion is experiencing a growing demand for various applications such as e-vehicle charging and grid coupling of renewable energy sources. To address this demand efficiently, single-stage converters can offer cost effectiveness, higher power density, and improved efficiency compared to their two-stage counterparts. Hence, a single-stage isolated three phase AC to DC series resonant converter has been proposed. Although various control techniques for this converter have been studied, a technique that can provide unity power factor and ensure fully soft switching is still lacking. This paper proposes a control technique, that ensures zero voltage switching and explicitly includes the effect of the switching node capacitance for single-stage isolated three phase AC to DC series resonant converters. The control technique is verified with simulations and experiments.