Novel Integrated Charger Concept Using an Induction Machine as Transformer at Standstill

A novel isolated integrated charger concept based on a six-phase electrical machine is reported in this paper. Previously reported concepts using the electrical machine as a transformer in the charging process are reviewed and used as a basis for a new concept, in which the efficiency is improved compared to state of the art, while keeping the rotor at standstill. This is achieved by disconnection of the rotor windings so that no shaft torque is generated in charging mode. Efficiency levels up to 88% are reported, which is an improvement of 8% compared to state of the art.