Strategy for improving electric propulsion system efficiency with weight method considering vehicle driving schedule

This paper presents a method of improving efficiency of the electric propulsion system over specific driving schedule. The electric propulsion system's usage profile is firstly mapped on its efficiency map with the hardware-in-the-loop (HIL) test over emulated urban dynamometer driving schedule (UDDS). Then the usage ratings of specified operating ranges could be calculated and represented in terms of weighting factors. Based on the weighting results, regions that highly sensitive to the efficiency over UDDS could be identified and the efficiency in those regions could be the targets for the optimal design. A case study is given in this paper, the dimensions of a 50-kW permanent magnetic motor is redesigned with the proposed method. The results show that the average motor efficiency over UDDS cycle has been improved 2.6% compared to the original level.