Research On Dual Rotor Machine And Its Control System In Hybrid Electrical Vehicle

As the energy problem getting more and more serious and the calling of energy saving and lower consumption is becoming stronger and stronger day after day, the research of electrical vehicle is a worldwide hot spot in nowadays. As a transition solution, hybrid electrical vehicle has got the fundamentals and marketing condition to be commercialized. It has become a very important research area. Electrical variable transmission is a newly developed hybrid vehicle transmission system. With its special advantages, it has attracted worldwide concentration. This paper mainly works on the mathematical model, control strategy, control system, additional system such as bidirectional DC/DC converter, system cooperation relationship of electrical variable transmission and the dual rotor machine which is the kernel of it.As the fundamental of later analyze such as the mathematical model and control strategy, a dual synchronous coordinate is built. Considering an ideal machine, the voltage equation, flux equation, electro-magnetic torque expression and motional equation in both static coordinate and dual synchronous coordinate are given out. The detailed inductance calculation and coordinate transformation are carried out, as well. For transient analyze, the state equation model is given. To get a more specific mathematical model which is much closer to a real machine, the coupling effect is taken into consideration. The voltage equation, flux equation, electro-magnetic torque expression and motional equation in both static coordinate and dual synchronous coordinate with the coupling effect are given. Similarly, the inductance calculation the coordinate transformation and the state equation model for transient analysis are carried out. Based on a controlled voltage source, the equivalent circuit of dual rotor machine is given.The control strategy and working mode of hybrid electrical vehicle using the electrical variable transmission system are discussed. According to the vehicle control strategy, the dual rotor machine control strategy is confirmed. To satisfy the demand of machine controlling in all working condition in the four quadrants working process and the maintaining of high working efficiency of internal combustion engine, the speed-speed control mode and torque-speed control mode of dual rotor machine is discussed and analyzed. To expand to velocity range of dual rotor machine, field-weakening control strategy of it is given out. The prototype hardware design and software design is carried out. In a dual rotor machine control system, bidirectional DC/DC converter take great importance in energy exchange between battery and power circuit and stability of DC bus voltage. A new type bidirectional DC/DC converter based on phase shift control is introduced in the paper. The working principle, soft switching condition and power transfer expression of it is analyzed. The DC/DC converter prototype machine hardware and software design is carried out.By simulation and experiment, the theory and strategy discussed in the paper is tested and verified.Lastly, the new technology of dual rotor machine is discussed. The brushless dual rotor machine which is a modified structure of traditional dual rotor machine is introduced and the working principle and structures of it is given in the paper. Base on the study of coupled machine mathematical model, a decoupling control strategy of dual rotor machine is discussed and it has been analyzed and verified theoretically.