Potential of an electric brake resistor to increase the efficiency of electric vehicles

Electric brake resistors are well known in the domain of power electronics, railway or elevator technology to guarantee electric braking or to damp high electric power peaks. The generated heat energy, however, is usually dissipated. This work deals with the potential of an automotive application of the electric brake resistor to enable brake energy regeneration (recuperation) also at low temperatures and high state of charge when the charge performance of the traction battery is limited. By reusing the excess recuperation energy to support the vehicle's cabin heating, the overall energy efficiency can be increased. In this paper three classes of battery electric vehicles are simulated with different driving environments and start parameters to assess the influences on the efficiency potential of this application. It is shown that, depending on the start conditions and drive cycle, the total energy demand can be reduced by up to 12% with the use of a 6kW rated brake resistor.