Simulation studies of hybrid powertrain for urban vehicles

The powertrain of an urban vehicle was subjected to detailed simulations. This study was conducted with the aim of getting to know the operating principle, verification of assumptions adopted during its design and determination of most effective control procedures to be applied with regard to its powertrain. However, the most important aspect involved the aspect of the power distribution between the engines, electrical machine and vehicle wheels in the particular operating modes of the powertrain. A study was conducted in the MATLAB/Simulink environment with the purpose of finding a configuration of an electrical machine coupling with a combustion engine that offers the greatest advantages in terms of the range of the speed ratio, demanded performance of the electrical machine and maximum power output. The simulations indicated that control of the speed ratio of the vehicle could be gained by application of an electrically controlled planetary gear. The range of the transmission ratio is relative to the ratio of the planetary gear, speed range of the combustion engine as well as electrical machine. The efficiency of the battery charging in the hybrid mode is mostly relative to the operating point of the engine. The optimization of the process of power generation by the electrical machine requires that the operating point of the engine be maintained at a range at which its high performance is guaranteed.