Study On Transient Characteristics Of Double Roller Permanent Magnet Drive Belt Conveyor Separately

At present is developing towards the direction of large-scale belt conveyor,aiming at the existence of the traditional belt conveyor transmission type transmission efficiency is low,the starting and braking performance is relatively poor,permanent magnet direct drive mode is put forward,the transmission pattern which can effectively improve the transmission efficiency,starting and braking performance,shorten the transmission chain,so the choice of permanent magnet direct drive transmission ways.Large due to the large power belt conveyor,often adopt double drum drive,to improve the work of the permanent magnet direct drive belt conveyor system performance and ensure the stability of a belt conveyor and good starting and braking performance,with double drum permanent magnet drive belt conveyor respectively as the research object,first of all,the research object to construct dynamic model,Then the transient electromagnetic field,starting and braking characteristics of permanent magnet synchronous motor are studied.The main research contents of this paper are as follows:Taking the head double-drum permanent magnet drive belt conveyor as the research object,the minimum tension method,equal power distribution method and other methods are adopted to distribute the power of the driving drum.Based on the classical viscoelastic model,the double-drum belt conveyor with head was discretized,and the dynamics model and state equation of the whole machine were obtained.The demagnetization model is adopted to determine the relationship between the magnetic remanence density and coerced force of permanent magnet synchronous motor.The finite element method is used to calculate the model of permanent magnet synchronous motor.Considering the influence of environmental temperature factors,a two-dimensional model of permanent magnet synchronous motor is established based on the Ansoft-Maxwell software platform.Combined with the influence of environmental temperature factors and the actual operating conditions of the belt conveyor on the permanent magnet synchronous motor,the influence of the belt conveyor under various operating conditions and environmental temperature factors on the transient electromagnetic field of the permanent magnet synchronous motor is obtained,and the comparative analysis is made.The results show that the influence of ambient temperature on the transient electromagnetic field of PMSM is small,while the influence of load on the transient electromagnetic field of PMSM is great.Coordinate transformation of permanent magnet synchronous motor,build a transient mathematical model of permanent magnet synchronous motor,and then through traditional PI vector control,vector control based on sliding mode speed controller and based on the typical second-order system of vector control of permanent magnet synchronous motor starting and braking,pulling the prototype test platform to validate starting and braking characteristics of vector control.The results show that the vector control based on the typical second-order system has a better effect on the starting and braking control of the motor.The simulation test data of the prototype is similar to the simulation data,which verifies the correctness of the vector control research on the starting and braking.For double drum permanent magnet drive belt conveyor system structure and hardware circuit system,and its starting and braking,comprehensive protection and power balance control scheme design,and then choose the right means of starting and braking of permanent magnet synchronous motor with belt conveyor,electromechanical coupling simulation working condition of random load,for example,The output torque and speed curves of PMSM under this working condition are obtained.The results show that the motor output speed of the double-drum permanent magnet drive belt conveyor system is almost the same as the given speed,and the torque changes accord with the given trend,which indicates that the power balance design of the electromechanical coupling model is correct to some degree.Figure 53 table 8 reference 268...