Research On Key Technology Of Belt Conveyor Permanent Magnet Motor Direct Drive System

Belt conveyors are widely used in the material transportation industry,such as coal mine,petroleum,building materials and other fields,because of their diverse types,high power,high performance and other advantages.With the increasingly mature coal mining technology,daily output of belt conveyors increases simultaneously,and therefore,the high-power and high-performance belt conveyors have become a research hotspot.They should not only adapt to various working environments,but also minimize energy consumption on the premise of ensuring the largest amount of coal transported per unit time.In order to improve the transmission efficiency and energy saving of belt conveyor system,the key technology of belt conveyor's permanent magnet direct drive system is studied deeply in this paper.To begin with,the magnetic circuit structure of permanent magnet synchronous motor(PMSM)are analyzed briefly.In order to facilitate research,the dynamic mathematical model of PMSM is established,the traditional high-performance control strategy(vector control)are analyzed detailedly,and a PMSM vector control system with voltage decoupling is set up,whose effectiveness has been verified by simulation.Next,the Kelvin-Voigt model is selected as the viscoelastic model of the belt conveyor and the dynamic model of the belt conveyor is established.The s-shaped curve is designed as the starting curve of the belt conveyor.In order to increase the current response,the current loop PI controller in the vector control system is replaced by the model predictive controller.On this basis,a rigidly connected driver is designed and verified by simulation.In addition,the driving force distribution during system operation is analyzed,and a flexible connected driving controller is designed.Considering the influence of power imbalance on the system,a multi-machine power balance controller with annular coupling is designed for the whole system to avoid multi-machine power imbalance during system operation.Meanwhile,the sensorless control algorithm is introduced in detail,the sensorless technology based on sliding mode observer is studied,and the first-order sliding mode observer is then designed,which is verified by simulation.Finally,under the background of the belt conveyor PMSM direct drive project in Jinjiaqu coal mine,the control scheme proposed in this paper is verified,and has been successfully applied in engineering practice.