The Research On Energy Assembly Controller And Promotion Motor's Vector Control For Hybrid Electric Vehicle

Due to the increasingly serious environmental issues and exhausted petroleum resources, Hybrid Electric Vehicles (HEV) are becoming an increasingly popular alternative to conventional Internal Combustion Engine (ICE) driven vehicles owing to their better fuel economy and lower pollutant emissions. The whole work of this thesis surrounds the HEV subproject of the"985 Project"in Hunan University.The propulsion system of a HEV comprises both an ICE and an Electric Motor (EM). Selection of an appropriate propulsion system structure is very critical to the performance of a HEV. On the basis of the characteristics analysis of various propulsion system structures coupled with the propulsion system selction strategies, this thesis selects the sigle-shaft parallel structure as the propulsion system structure of choice for the HEV subproject.Energy Assembly Control System (EACS) is the most important part of a HEV. The purpose of designing the EACS is to realize the optimal control of the power produced by the ICE and EM. Therrfore, the ICE and EM of a HEV can run at its high efficiency region respectively all the time so as to improve the fuel economy of the vehicle and minimize the ICE's emissions. Based on the functional requirements analysis of the Energy Assembly Controller (EAC), Digital Signal Processor (DSP) is choosed as the CPU of the EAC, and the hardware platform of it using TMS320F2812 is designed. The thesis also introduces the detailed hargware circuit design of each module in the EAC, besides the introduction of the software system of the EAC and the control strategy of HEV.Electric Motor and its control is one of key technologies of a HEV. The motor of choice for the EM in the HEV project is the induction motor, owing it to its robustness, its virtually free maintenance and its low cost. For the realization of high performance control of induction motor, the thesis investigates the mathematical model of the induction motor built upon the idea of the vector control. Based on the model, a Field Oriented Control (FOC) strategy using fuzzy logic is presented in the thesis, and the performance analysis of the proposed control strategy is carried out on the basis of the simulation results obtained by Matlab/Simulink. The simulation results show the preferable dynamic and static behaviors of the fuzzy logic controller compared to a classical PI-based controller. Accurate knowledge of the induction parameters especially the rotor time constant is critical for the high performance vector control algorithms. Since the rotor time constant varies considerably during the process of the motor control, a rotor time constant adaption strategy based on fuzzy-logic for vector control is presented in this thesis.