The Algorithm Research Of Dual-motor Coupling Control For Electric Vehicle

As the world’s energy shortage, countries continue to exploit oil resources’, resulting in oil production is not balanced and the soaring price of fuel and the car too much dependence on oil resources, leading to the energy crisis highlights. Therefore, to promote the use of electric vehicles is our inevitable choice to achieve sustainable development. At present, China’s electric car with a small load mainly for large load of electric vehicles, single-motor running slow response speed, the higher the chances of locomotive shake, use double shift occurs when the motor is running, the electric car speed at startup relatively fast, relatively smooth shifting. And when approaching the target, single-motor operation is to slow down, slide the long distance between the stalls, not short-term effective control of speed, dual-motor electric vehicle deceleration run faster glide short distances. Especially in the rainy weather conditions, the advantage is more obvious dual-motor operation. Modern electric vehicle drive solutions have focused on driving, drive axle, dual-motor drive and wheel motor drive and other means. For large load of electric vehicles, due to limitations of space and a separate motor vehicle performance, the use of dual-motor coaxial drives more appropriate.To ensure the running speed of synchronization, the project usually with a rigid shaft will link up both sides of the motor. But the affected materials, manufacturing processes and manufacturing precision and other factors, the parameters cannot be exactly the same as the two asynchronous motors, running easily due to load imbalance leads to burn out the motor distribution. Therefore, the study of the theory and methods of connecting the hard axis dual-motor synchronous transmission, to ensure that such machinery safely and reliably synchronized operation, has a very important practical significance.Through extensive literature review and data analyzed coaxial dual-motor coupling system power imbalance causes through formula derivation, the power balance condition. According to the actual parameters of electric vehicles, matching the appropriate power and motor parameters, and the establishment of AC induction motor model by MATLAB, the establishment of a coaxial dual-motor coupling system model for simulation of the power imbalance. Launched a study of two mathematical algorithms:1. Coaxial coupling system for dual motor power tracking algorithm using vector control theory, the current model from the spindle motor decoupled from the motor model inside. The problem is reduced to the current track from the motor shaft problem, namely fuzzy adaptive control and iterative algorithm were simulated and compared, reflecting their superiority. Fuzzy self-tuning control current track time is 0.5s, and iterative algorithm needs 2s. The fuzzy self-tuning is faster.2. Conduct rese0 arch coaxial dual-motor coupling system power balance algorithm, using a dual motor master-slave control, and the use of direct torque control principle established model of the whole system, and are designed PID controller and fuzzy self-tuning PID control parameters device. Two motors run at speed 1950 rpm and 1550 rpm process, start the process, speed changes during the transition, the output torque fluctuations were 0N.m achieve power balance. The system simulation respectively, reflecting the advantages of fuzzy parameter self-tuning PID controller.