A computationally efficient design technique for electric vehicle traction machines

This paper describes a new design technique for electric vehicle (EV) traction machines in order to achieve high efficiency against a defined driving cycle such as the New European Drive Cycle (NEDC), while satisfying the required torque-speed operating range and other volumetric and thermal design constraints. The work is undertaken as a part of the EU funded P-MOB (Personal Mobility) project. By analysing the energy distribution of a given driving cycle, the energy efficiency of the traction machine over the driving cycle can be characterized against a number of representative points and the design optimization can be carried out with respect to these points. This dramatically reduces the computation time of the design optimization process, while improving the energy efficiency of the traction machines. The utility of the design technique has been illustrated through design case studies and its effectiveness validated by experimental results.