Mild-hybrid traction system based on a bidirectional half-bridge interleaved converter and a three-level active NPC inverter-fed PMSM

In this paper a practical and original solution for a mild-hybrid traction system is proposed. It is based on a surface permanent magnet (SPM) synchronous motor drive supplied by a three-level active neutral point clamped (NPC) inverter and a bidirectional half-bridge interleaved converter on the battery side. Design issues, optimization (especially from the efficiency point-of-view) and advantages of the considered system architecture are analyzed through simulation and preliminary experimental results. A prototype hybrid traction test bench controlled by multiple digital signal controllers is proposed.