Functional modeling of an electric machine used on road vehicles

Recent years bring new European Union regulations concerning harmful emissions for road vehicles. The hybrid electric and electric mobility is a technology revolution for the automotive industry. In response to the stringent regulations and requirements enforced, vehicle manufacturers are developing new strategies, using hybrid electric or electric powertrain solutions. In order to obtain the goal of using alternative powertrain solutions, it is important to integrate from the early beginning different devices and to optimize their behavior. However, with a minimum of one electric motor architecture, a hybrid electric powertrain triggers more concerns about energy flows. During operation, there are energy losses caused by heat generation. Generated heat, emphasized as losses, is having a negative effect on motor efficiency. Using simulation, the electric motor, with both its functional model and its thermal model, were integrated in a mock-up virtual hybrid electric vehicle to study its behavior during a predefined cycle. The functional model is generating the data files, with regard to the voltage use and the torque generation. The functional behavior of the electric motor is the production of torque/rotational speed. The thermal model is using the data files in order to determine the energy losses. There will be possible to determine the electric motor efficiency, as part of the powertrain. Thereby, this paper aims to present the functional behavior of an electric motor in order to build the needed data files, which have to be used by the thermal model. An oriented electric motor was developed and the resulted data files were used by the electric motor that equips the virtual mock-up hybrid electric vehicle.