A performance optimisation-based e-CVT design method and analysis of representative HEV/PHEV powertrains

Abstract

An electronically controlled continuous variable transmission (e-CVT) which consists of planetary gears and electric machines plays a key role in advanced hybrid powertrains of HEV/PHEV/EREVs. Design of these e-CVTs for best performance is a challenging task due to the complexity of these e-CVTs and hybrid powertrain system derived from them. In this work, a performance modelling and optimisation-based design method is introduced to automatically identify the best performance of an e-CVT or other complex hybrid vehicle powertrain system. The complex design optimisation problem for peak powertrain performance is solved using a unique two-stage search method to significantly reduce needed computation and assure the accuracy of the optimisation. Four representative e-CVT powertrain designs of representative HEV/PHEV/EREVs were used as case studies. Test results are calibrated using verified data to reveal the performance characteristics and potential of each powertrain designs. Application of this method to produce new e-CVT and gear-train designs with enhanced performance is demonstrated.Keywords: peak powertrain performance; powertrain design; model-based design; electronically continuous variable transmission; e-CVT; optimisation; hybrid electric vehicle; HEV; plug-in hybrid electric vehicle; PHEV; extended range electric vehicle; EREV.Reference to this paper should be made as follows: Zhou, L. and Dong, Z. (2011) 'A performance optimisation-based e-CVT design method and analysis of representative HEV/PHEV powertrains', Int.