Boris Bouchez

A combined multiphase electric drive and fast battery charger for Electric Vehicles

Currently, the main technical weaknesses of Electrical Vehicle (EV) are the limitation of the on-board energy storage and the time to recharge it. Despite of recent improvements in batteries, these drawbacks as well as the cost make the EV not yet attractive. Real challenges for Power Electronics engineers are not only the cost reduction through new system optimizations but also the autonomy increase through the global efficiency improvement and the introduction of a cheap fast on-board charger. This paper deals with a new concept of electric powertrain system which is configurable as a battery charger without additional power components. The interest of this particular solution is the full magnetic decoupling between the rotor and the stator during the charging mode which avoid a clutch system, and prevent the rotor from vibrating. The traction system solution is presented, the feasibility of this combination topology is studied and the effect of the electrical machines windings configuration is analyzed. Some simulation results show the propulsion efficiency is also improved.

A multiphase traction/fast-battery-charger drive for electric or plug-in hybrid vehicles: Solutions for control in traction mode

For Electric Vehicles (EV), the charger is one of the main technical and economical weaknesses. This paper focuses on an original electric drive [1]–[3] dedicated to the vehicle traction and configurable as a battery charger without need of additional components. This cheap solution can outfit either electric or plug-in hybrid automotive vehicles, without needing additional mass and volume dedicated to the charger. Moreover, it allows a high charging power, for short duration charge cycles. However, this solution needs specific cares concerning the electrical machine control. This paper deals with the control of this drive [1], focusing on traction mode. In introduction, a review is done about topologies of combined on-board chargers. Then, the studied topology is introduced; using a 3-phase brushless machine supplied with a 6-leg Voltage Source Inverter (VSI). A model for its control is defined in the generalized Concordia frame, considering the traction mode. Then, an analysis of this model is established using a multimachine theory and a graphical formalism (the Energetic Macroscopic Representation denoted EMR). Using EMR, a description of energy flows shows specific control constraints. Indeed, numerical simulations illustrate the perturbations on the currents and the torque when controlling the machine with standard control methodologies. An improved control, deduced from the previous analysis, shows good performances, strongly reducing currents and torque ripples.