Algorithmic Research On Vector Control Of Asynchronous Motor Of Electric Vehicle

In engineering, vector control (VC) is called as filed orientation control (FOC). The principle of FOC is to divide stator current into two DC components .One of them is oriented to the rotor magnetic flux, another is oriented to the torque. The operating process can be carried out by transforming coordinate in magnitude flux and torque keeping consistent conditions. As a result, the magnetic flux and torque can be decoupled and controlled.In the paper, the principle and actualizing means of spatial vector control have been systemically discussed and the control software has also been designed. The magnitude of both the rotor flux and the current in torque component have been estimated by using a flux observer, which is developed based on field orientation control principle. The results show that the observer has a good feature due to its speed being calculated without speed sensor or additional hardware. Mathematical model of sensorless induction motor and corresponding control algorithm have also been setup.In the paper, a new variable voltage variable frequency system has been developed based on the study above, and digital signal processor, TMS320LF2407, which is specially designed for motor drive system in practice, is also used to debug the system.The results show that the system can be use to control the motor successfully.