Study On Vector Control Of External Rotor Permanent Magnet Synchronous Motor For Coal Mine Belt Conveyor

At present,most coal mine belt conveyors use asynchronous motors with reducer and belt rollers.The mechanical loss of this driving method is very large.Therefore,this thesis adopts a method that uses an external rotor permanent magnet synchronous motor(PMSM)to directly drive the coal mine belt conveyor.The direct drive mode realizes a highly efficiency and energy saving mechatronics zero transmission structure.Through the research and analysis of the special application environment and control strategy of this kind of motor,this thesis proposes to adopt a vector control strategy based on the combination of active disturbance rejection technology and sensorless control to improve the speed regulation performance of the belt conveyor under variable load frequently.The main research contents are as follows:Firstly,this thesis summarizes the development trend of external rotor permanent magnet synchronous motors and its application in coal mine belt conveyors,and conducts an in-depth study on working principles of this structures.According to the characteristics of the external rotor permanent magnet synchronous motor direct drive system,mathematical models in different coordinate systems are derived,and the commonly used vector control methods are analyzed and compared.Secondly,through the analysis of the characteristics and requirements of the application conditions of this type of motor,aiming at the problem that the vector control system of PMSM cannot guarantee the response speed and overshoot at the same time,this thesis designs a compensating active disturbance rejection controller(ADRC)for PMSM to replace the traditional PI speed regulator in vector control to improve the performance of permanent magnet synchronous motor.Then,in order to realize sensorless control system,this thesis analyzes the shortcomings of the traditional sliding mode observer(SMO)in the control system.This thesis proposes an improved scheme of sliding mode observer under rotating coordinates,and uses the saturation function sat to replace the switching function in the traditional observer,and introduces a phase-locked loop(PLL)to obtain the rotor position estimated value to reduce the estimation error.In order to verify the feasibility of the proposed control algorithm in this thesis and the speed regulation performance of the driving control,this thesis carries out modeling and simulation analysis on the Matlab/Simulink simulation software platform,and compares with the traditional vector control system and the traditional vector control system.Simulation results show that the vector control system using compensating ADRC has better anti-disturbance ability,no overshoot under starting at the load,and when the load torque changes suddenly,the system responds quickly and shortens the adjustment time.The improved SMO can effectively improve the rotor position estimation accuracy and tracking performance,so it verifies the algorithm is effective.