Calculating the tractive power and power conversion efficiency of battery electric vehicles using a global navigation satellite system and a road elevation database

The energy conversion efficiency of battery electric vehicles (BEVs), which is an essential index in the development of motor systems, remains unknown during real driving. This paper presents a calculation method of the tractive power and energy conversion efficiency of BEVs during driving. The progress of the global navigation satellite system (GNSS) and the widespread use of road elevation database enable a tractive power measurement during driving. We have developed the calculation method to evaluate an advanced motor-drive for BEVs under development without using chassis dynamometers. The calculation method showed almost the same energy conversion efficiencies on the three different routes. The results demonstrate the universality of the method and raise the possibility of benchmarking of the power conversion efficiency of any of various BEVs.