چكيده به لاتين
The aim of this PhD thesis is to design and introduce a new kind of the power-split transmission, and to present a systematic approach to achieve an optimal mechanism for application in hybrid electric vehicles. In order to do so, the performance of two commercial and one conceptual power-split powertrain systems were studied and modeled. Then, a hybrid electric power-split powertrain was built in the MATLAB environment by using the obtained dynamic equations of the power-split mechanisms and by having the real data of the power sources as well. This model was used for the controller design, simulations and studying the performance of the power-split configurations.
Considering the studied systems’ operation and to achieve a system with better performance than the available ones, a new dual-mode power-split powertrain was designed and presented; and its performance was analyzed and compared with respect to the available power-split systems in terms of efficiency and power. Furthermore, for identifying the optimal configurations in family of the designed powertrain, all possible configurations were calculated according to the introduced mechanism and then, based on a screening process, four potential systems were chosen for application in the hybrid electric vehicle.
To compare and evaluate the performance of the chosen mechanisms, the dynamic programming method was used. This method, as a global energy management strategy, has the ability to provide the best possible solutions for optimal performance of the hybrid powertrain system. By using this optimal control method, it was seen that among the four selected systems, two had better performance, in terms of fuel economy and drivability, than the commercial ones and the two other mechanisms had close but a little lower performance. Finally, the best system, among the four, was recognized and chosen.
The Pontryagin’s Minimum Principle was used for real evaluation of the power-split powertrain system. The obtained results of this instantaneous optimal control method showed fuel consumption reduction of 7 to 14 percent (depending on the driving cycle) in comparison to the Toyota Prius while satisfying the power demands. This showed that the designed power-split powertrain is highly capable of being used in the hybrid electric vehicles.
