Design and control of a novel uninterrupted dual input powertrain system for electric vehicles

University of Technology Sydney. Faculty of Engineering and Information Technology.The automotive powertrain is one of the most important subsystems of any vehicle whose major function is to convert the stored energy to kinetic energy and deliver it as tractive load to the road. In order to reduce the harmful emissions and the dependence on fossil fuels, the development. The new technology will improve the overall efficiency, the drivability and the driving comfort, and reduce the tailpipe emissions. However, the inclusion of electric machines alone does not guarantee these improvements, proper transmission structure design and adequate control strategy should be designed to fully exploit the potential of the whole system, thereby maximizing the benefits to end users. In order to achieve the aforesaid benefits of electric vehicle, a novel dual input clutchless transmission configuration is proposed which consists of an automated manual transmission (AMT) and a fixed gear pair. It has the merits of low manufacturing cost, robustness and easy implementation. With the proposed gear shift control strategy, the novel configuration could eliminate the torque interruption of conventional AMT systems, improving the drivability and driving comfort. To fully exploit the efficiency improvements of the proposed system, a real time power sharing control strategy is proposed to balance the load distribution between the two motors. By adequately choosing the gear position and distributing the power demand, the overall efficiency could be improved by more than 10%. The proposed power sharing strategy has the disadvantage encountered by many other energy-oriented energy management strategies which is high gear shifting frequency. To keep a high overall efficiency and at the same time significantly reduce the shift frequency, a shifting stabilizer is proposed and embedded in to the control strategy. At last, a modified hybrid configuration based on the proposed concept is developed for mining trucks. The hybrid system could satisfy the specific requirements of mining trucks and present high overall efficiency and drivability. To evaluate the effectiveness of the proposed approaches, various detail mathematical models have been built and tested in sets of driving conditions which could reflect the practical implementations