| The belt conveyors are the main conveying equipment in mining,metallurgy,power plants and other industries.With the continuous expansion of the production and manufacturing scale of enterprises,belt conveyors are developing in the direction of long distance and large capacity,but the number of driving devices in the conveying system is also increasing.With the increase,there are problems such as low transmission efficiency,unbalanced power distribution of multiple machines,and large starting impact,which not only increases the extra production cost,but also poses a certain threat to the safe and reliable operation of the belt conveyor.Compared with the traditional asynchronous motor combined with the reducer,this paper adopts the outer rotor permanent magnet motor to directly drive the belt conveyor,cancels all the intermediate transmission equipment,and analyzes the starting performance and power balance strategy of the multi-motor control system.The self-adaptive speed regulation system of belt conveyor is analyzed and designed,and the main research contents are as follows.According to the design requirements of the belt conveyor drive device,the electromagnetic design of a surface-mounted external rotor permanent magnet synchronous motor is carried out.In order to improve the reliability and torque density of the drive motor,a formed winding structure is adopted.In view of the difficulty in rolling off the rectangular slot shape of the outer rotor motor and the large cogging torque,a new type of winding between parallel slots and parallel teeth is designed.The trapezoidal slot structure of the motor is adopted,and the Taguchi method is used to optimize the cogging torque,torque ripple and electromagnetic cost of the motor with the slot width,slot depth,slot bottom width and air gap as optimization factors.Meta-simulation to verify.Aiming at the multi-point driving problem of long-distance belt conveyor,the running resistance of the belt conveyor is analyzed,and the power distribution of each driving motor and the determination method of driving position are given.The constant acceleration,triangular acceleration and sinusoidal acceleration starting curves are compared and analyzed,and the S-shaped starting speed curve is designed based on the actual working conditions and starting performance,which can realize smooth and heavy-load starting;for the multi-machine power of the belt conveyor when the load changes Unbalance problem,this paper designs a bias-coupled multi-machine control system.When any drive motor has different output power,based on the torque current compensation method,the influence of the load change is shared to the rest of the motors to reduce the impact on a single motor.,and can quickly restore to the power balance state.Finally,the multi-machine control system model of the belt conveyor is built in Matlab/Simulink,and the simulation verification is carried out.Due to the uneven distribution of coal seams,the belt conveyor often appears in the running state of high belt speed and low load,resulting in unnecessary waste of electric energy.In this paper,an adaptive speed control method of belt conveyor based on magneto-caloric analysis is designed.The output current of the drive motor and the internal temperature adjust the belt speed of the belt conveyor,so that the belt conveyor system can always maintain a high load operation,so as to achieve the effect of speed reduction,energy saving and speed increase protection.The method for determining the parameters of the adaptive speed control system is given,and the prototype loading test platform is completed,which verifies the accuracy of thermal simulation analysis. |
PDF Full Text Request