Multi-objective optimisation for battery electric vehicle powertrain topologies

Abstract

Electric vehicles are becoming more popular in the market. To be competitive, manufacturers need to produce vehicles with a low energy consumption, a good range and an acceptable driving performance. These are dependent on the choice of components and the topology in which they are used. In a conventional gasoline vehicle, the powertrain topology is constrained to a few well-understood layouts; these typically consist of a single engine driving one axle or both axles through a multi-ratio gearbox. With electric vehicles, there is more flexibility, and the design space is relatively unexplored. In this paper, we evaluate several different topologies as follows: a traditional topology using a single electric motor driving a single axle with a fixed gear ratio; a topology using separate motors for the front axle and the rear axle, each with its own fixed gear ratio; a topology using in-wheel motors on a single axle; a four-wheel-drive topology using in-wheel motors on both axes. Multi-objective optimisation techniques are used to find the optimal component sizing for a given requirement set and to investigate the trade-offs between the energy consumption, the powertrain cost and the acceleration performance. The paper concludes with a discussion of the relative merits of the different topologies and their applicability to real-world passenger cars.

Optimum dog-leg angle for mass and bearing force optimization of multistage gear reduction

“…Here it is used that when designing EVs, there is more freedom as the new design does not have to fit into the old space or other requirements based on the old design. Different drive line arrangements are studied by for example Othaganont et al 22 and Cai et al 23 Throughout this work, it is assumed that a careful design choices have been made to the gear set, for example through optimizations as discussed above. Thus, only the dog-leg angle is altered in the study; all other parameters are left unaltered.…”

“…Here it is used that when designing EVs, there is more freedom as the new design does not have to fit into the old space or other requirements based on the old design. Different drive line arrangements are studied by for example Othaganont et al 22 and Cai et al 23…”

Multi-objective vehicle optimization: Comparison of combustion engine, hybrid and electric powertrains

“…Application to specific powertrain layouts are provided for ICEV, 18,19 HEV 20,21 and battery electric vehicle (BEV) 22 where for the works with HEV and EV scalable approaches are applied for the powertrain’s components definition in order to handle design variations. A method for developing scalable models of the combustion engine and the electric motor (EM) can be found in Angerer et al 23 and further techniques referring to data mining are described in detail in Karahoca.…”

“…8 Current research activities addressing this topic are under development at Politecnico di Milano regarding the optimization of several powertrain architectures, [9][10][11] at TU Munich focusing on EV, [12][13][14] and at TU Wien in the field of optimization strategies. [15][16][17] Application to specific powertrain layouts are provided for ICEV, 18,19 HEV 20,21 and battery electric vehicle (BEV) 22 where for the works with HEV and EV scalable approaches are applied for the powertrain's components definition in order to handle design variations. A method for developing scalable models of the combustion engine and the electric motor (EM) can be found in Angerer et al 23 and further techniques referring to data mining are described in detail in Karahoca.…”

Comparing battery electric vehicle powertrains through rapid component sizing

“…Some recent studies related to the design of BEV powertrains consider different layouts for the system (Hofman and Dai, 2010;Ruan et al, 2016). Various solutions employing both in-body and in-wheel motors have been studied (De Novellis et al, 2013;Othaganont et al, 2016). Although the latter solution optimises efficiency and energy consumption, it should be noted that in-wheel motor configurations are more difficult and expensive to engineer for passenger cars than the in-body solutions (Chen et al, 2016;Huang et al, 2017).…”