The Application Study Of Vector Control In Hoister System

Based on the wide investigation on variable frequency variable speed methods, this thesis adopts vector control to take the place of traditional rotor series connecting resistance and thyristor cascade methods, according to the state that speed-adjusting methods of many coal-mines' hoister systems lag behind.The system adopts the flux open-loop slip-frequency vector control variable frequency variable speed scheme. The thesis elaborates the design method of the speed-current dual closed-loop digital control system which includes microchips and frequency inverters on the foundation of mathematical modeling of the systems' control method, applies MATLAB to model and simulate to the system, and gets satisfied results. Meanwhile, the idea that applies fuzzy-control theory to track the speed of hoister systems, that is taking the fuzzy controller instead of the PI speed-controller, is put forward in this thesis. The results of simulation show that fuzzy control strategy can make the system response rapidly and possess small steady-state error, and the system is insensitive to the parameters' changes which led by outer factors and have stronger robustness. The new method can make the system's dynamics and static characteristics better and make the hoister systems possess better flat layer feature and comfortableness.