HYBRID POWERTRAIN PARAMETER OPTIMIZATION AND HIGH EFFICIENT AREA MATCHING OF ENGINES EXCLUSIVE TO HYBRID COMMERCIAL VEHICLES

The growing issues of energy shortage and the environmental crisis have resulted in new challenges for the automotive industry. Conventional commercial vehicles such as refuse trucks and delivery vehicles consume significantly more energy than other on-road vehicles, and emit more emissions. It is important to make these vehicles more fuel efficient and environmentally friendly. Hybrid powertrains provide a good solution for commercial vehicles because they not only provide optimum dynamic properties but also substantially reduce emissions. For most commercial vehicle powertrains, the IC engine is the only power source that provides power to the driveline. The emission reduction faces a limit since a high-powered engine is required to meet the dynamic properties of those heavy-duty vehicles. Also, the high-powered engine cannot avoid operating in low efficient areas due to the fact that these vehicles continually drive at low speeds on designated city routes. However, hybrid powertrains allow commercial vehicles to select lower powered engines because they are equipped with multi-power sources to supply torque together to the driveline. Therefore, hybrid powertrains are a natural fit for commercial vehicles. This paper mainly discusses the advantages that the combination of highly efficient engine selecting and powertrain optimization can provide to improve fuel economy for hybrid commercial vehicles. The research is based on the study of the efficiency area of hybrid engines to propose the technical parameters for hybrid engines. These include the rpm range and torque range in order to guarantee both the engine and the motor output work within the range of the high efficiency area on the premise of the reliable dynamic properties. Moreover, further optimization of the powertrain is included to make sure the whole drive train is functioning at high efficiency together with transmission and final drive reducer. The powertrain simulation models were executed before and after optimization to demonstrate their reliable dynamic performance, improved driving distance, and emission reduction. Finally, the powertrain cost analysis and current related energy products such as engine, motor, and battery will be indicated along with the challenges and opportunities of hybrid powertrain system.