Series and IMMD+: Performance Comparison and Analysis of Hybrid Vehicles with Additive Clutches

The series-parallel hybrid system has become an important development route for hybrid vehicles. To enhance energy efficiency of series-parallel hybrid system, this paper investigates and compares the effects of increasing the clutch or adding the gear ratio at different power source position on the performance of the vehicle. Firstly, the effect of adding clutches or gears at different is analyzed，and the possible working modes with the addition clutch or gear ratios of different power source positions are investigated. Secondly, multi-objective particle swarm optimization (MOPSO) algorithm is used to solve the transmission ratio of the new gears of the improved configuration with fuel consumption and acceleration time as the design objectives, which provides a foundation for the subsequent comparative study of different configurations. Moreover, the fuel economy performance of the producing series-parallel configuration was evaluated using a rapid dynamic programming approach with the objective function of minimizing fuel consumption during power transfer. Finally, on the basis of the aforementioned research, the acceleration performance and economic performance of different configurations were compared quantitatively. The comparative analysis shows that for series-parallel hybrid powertrain, increasing the driving motor direct drive gear had a significant effect on improving the dynamic performance, the 100 km acceleration time increased by 14.09%. increasing the clutch had a significant effect on improving the economy under UDDS, the fuel consumption was reduced by 4.76% on average, increasing the engine direct drive gears had a significant effect on improving the economy under HWFET, the fuel consumption was reduced by 2.16% on average.