Impact of Hybrid Powertrain Architectures on Commercial Vehicle Performance

Abstract

To investigate the impact of hybrid powertrain architectures on the dynamic performance and fuel economy of light commercial vehicles, the study takes a Chinese domestic light commercial vehicle as the research object. A forward simulation model is established in Matlab/Simulink to compare the performance of two hybrid configurations: series-parallel (P13) and power-split (PS). Multi-factor sensitivity analysis is conducted to quantify the influence mechanism of key parameters, and the simulation model accuracy is verified through real-vehicle tests following GB/T 27840-2021. First, the engine direct-drive gear ratio of the P13 configuration is optimized to reveal its trade-off relationship between medium-high speed constant fuel consumption and acceleration performance. Second, sensitivity factors including driving cycles, motor efficiency, motor no-load loss, and transmission ratios are decomposed to identify the core causes of simulation-test deviation. Finally, the fuel consumption of the two configurations under the CHTC-LT cycle and multi-speed constant conditions is systematically compared. The results show that the optimal engine direct-drive gear ratio range for the P13 configuration is 0.6-0.65, which achieves the best balance between dynamic performance and fuel economy. Driving cycle type and motor efficiency are the dominant factors causing simulation-test deviation, contributing 12.3% and 9.6% to the total error respectively. The PS configuration concentrates engine operating points in the high-efficiency region, achieving a fuel consumption of 8.37L/100km under the CHTC-LT cycle, which is 4.3% lower than the P13 configuration (8.75L/100km). Its fuel-saving advantage reaches 7.7% at a constant speed of 40 km/h. This study provides direct engineering guidance for hybrid powertrain architecture selection and parameter optimization of light commercial vehicles.