An Integrated EV Battery Charger with Retrofit Capability

摘要

A new type of fast integrated on-board charger for the electric vehicles (EVs) is proposed in this paper. This proposed charging scheme utilizes the components of the existing EV drive train for charging and driving modes of operation with minimal modification to the machine. One commonly followed scheme for fast on board charger is the use of a multiphase machine (more than three phases). Multiphase machines are modulated such that the leakage inductances of the machine serves the purpose of grid interface inductance while producing zero electromagnetic torque during charging. In the proposed method this is achieved by reconfiguration of windings of a split phase motor. The dual stator windings of the split three-phase motor have a 30° displacement in space, effectively making it an asymmetric six-phase motor. The machine can be used as a three phase machine for driving mode, and reconfigured as grid interface inductance producing zero torque during charging mode. Furthermore, in the proposed scheme available three phase traction inverter can be utilized for charging mode as well as driving mode. This reduces the cost-to-change of the existing system.