Minimum Dead Time for Complete ZVS in Bidirectional Isolated DC/DC Converters for More Electric Aircraft

Dual-Active-Bridge (DAB) and Active-Bridge-Active-Clamp (ABAC) converters are the most promising power converter topologies for More Electric Aircraft (MEA) applications. These bidirectional isolated DC/DC converters are commonly used to interface the High-Voltage DC (HVDC) grid with the Energy Storage Systems (ESS). The utilization of wide bandgap semiconductors in MEA applications is leading to an increase of the switching frequency in these converters, inherently reducing the dead time of the power devices. Therefore, the analytical models to determine the minimum required dead time to fully discharge the output capacitance (C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">oss</inf>) of the power devices in DAB and ABAC is derived in this work. Afterwards, these models are validated through a simulation model developed in LTSpice. Furthermore, an analysis of the impact that incomplete ZVS (iZVS) behavior has on the power losses of these converters is carried out.