Research On Multi-motor Control Strategy Of Belt Conveyor Permanent Magnetic Direct Drive System

As a medium and long distance material conveying equipment,belt conveyor is widely used by major factories and enterprises because of its advantages of simple structure,low transportation cost,high reliability,strong transmission capacity,convenience and efficiency,etc.With the continuous improvement of the entire social industrial structure,the production scale of major enterprises has gradually increased.The research of high-power belt conveyors has gradually become a hot spot.Belt conveyors are also constantly developing in the direction of high speed,long distance,high power,and intelligence.Aiming at the shortcomings of the traditional belt machine drive system,this paper deeply studies the multi-motor control scheme of belt conveyor based on permanent magnet direct drive technology.The thesis is organized as follows:First of all,this paper summarizes the structure and characteristics of the belt conveyor,then analyzes and compares several commonly used driving devices of the belt conveyor system.Finally,the permanent magnet motor frequency conversion driving method is selected as the driving scheme of this paper.According to the viscoelastic characteristics of the conveyor belt,the Kelvin-Voigt model is used to dynamically analyze the belt conveyor.This paper studies the start-up characteristics of the belt machine and selects the S-shaped curve as its start-up curve.Secondly,according to the simplified model of the belt conveyor,This thesis studies the friction drive theory of belt conveyors,explores the problem of traction distribution in multi-motor drive systems,and analyzes the power imbalance factors in multi-machine systems.In this thesis,the permanent magnet motor is used as the driving motor of the belt machine.The power balance control structure is designed for the two different working conditions including the rigid connection and the flexible connection.For the three-machine double-drum drive belt conveyor,this thesis combines the deviation coupling control structure to perform power balance control.Through the torque current coupling compensation method,the speed current power balance control method is used to achieve the power balance of the three-motor system under the premise of ensuring the same speed of each motor.Furthermore,the mathematical model of permanent magnet synchronous motor is established,and the principle of its vector control system is analyzed.Building the corresponding simulation model and analyzing the results.In view of the shortcomings of the traditional PI control strategy,the ADRC algorithm is introduced.Combined with fuzzy control theory,this paper designs a fuzzy auto-disturbance suppressor,then simulates and verifies its performance.Then,according to the established multi-motor power balance control model in this article,this paper builds the corresponding simulation model,and verifies the effectiveness of the power balance strategy.Finally,the belt conveyor based on the permanent magnet direct drive system in the coal mine is used as the research object.The power balance control system is briefly introduced.Through the field experiment,the performance of the control scheme in this paper is verified.The paper has 75 pictures,3 tables,and 89 references.