Hybrid Powertrain Technology Assessment through an Integrated Simulation Approach

Global automotive fuel economy and emissions pressures mean that 48 V hybridisation will become a significant presence in the passenger car market. The complexity of powertrain solutions is increasing in order to further improve fuel economy for hybrid vehicles and maintain robust emissions performance. However, this results in complex interactions between technologies which are difficult to identify through traditional development approaches, resulting in sub-optimal solutions for either vehicle attributes or cost. The results presented in this paper are from a simulation programme focussed on the optimisation of various advanced powertrain technologies on 48 V hybrid vehicle platforms. The technologies assessed include an electrically heated catalyst, an insulated turbocharger, an electric water pump and a thermal management module. The novel simulation approach undertaken uses an integrated toolchain capturing thermal, electrical and mechanical energy usage across all powertrain sub-systems. Through integrating 0-D and 1-D sub-models into a single modelling environment, the operating strategy of the technologies can be optimised while capturing the synergies that exist between them. This approach enables improved and more informed cost/benefit ratios for the technologies to be produced and better attributes by identifying the optimum strategy for the vehicle. The results show the potential for CO2 reductions in the range of 2-5% at no additional cost, through co-optimisation of the technologies in a single simulation environment. The simulation work forms part of the THOMSON project, a collaborative research project aiming to develop cost effective 48 V solutions, in order to reduce the environmental impact of the transportation sector.