Study On Auto-disturbance Fault Tolerant Control Strategy Of Shearer Cutting Drive System Driven By Permanent Magnet Motor

Drum shearer is an important component of the three machine supporting equipment in the comprehensive mining face,and it is a complex system integrating mechanical and electrical integration,which is mainly used for cutting coal seam.The load of shearer cutting transmission system is fluctuant and strong impact when cutting coal seam.In this paper,the permanent magnet synchronous motor is used to drive the transmission system by semi direct drive.By improving the structure of traditional cutting transmission system,abandoning planetary gear system,reducing the failure rate of the system and improving the transmission efficiency.However,due to the shortening of the transmission chain,this places higher requirements on the stability and fault tolerance of the system speed control.In this paper,by establishing models,numerical simulations,and building experimental platforms,combined with the load characteristics of the shearer cutting transmission system,this paper proposes an active disturbance rejection fault-tolerant control based on the shearer's permanent magnet semi-direct drive cutting transmission system.The main work content includes:(1)The permanent magnet synchronous motor is selected as the power source of the cutting drive system of the shearer,and the structure of the traditional shearer is improved.According to the cutting mechanism when the shearer cuts the coal seam,the force condition of a single pick is analyzed,and combined with the force condition of the drum,the overall instantaneous load mathematical model of the cutting drum is obtained.On the same time,getting the relationship among average load traction,speed and drum speed.From the simulation results,the cutting drum presents regular and periodic waveforms when cutting pure coal seams;when cutting coal seams containing gangue,the load fluctuation is greater,the impact force is stronger,and it has a certain degree of randomness.(2)Combined with the load characteristics of the shearer's permanent magnet semi-direct drive cutting transmission system,this article combines the motor mathematical model of the permanent magnet synchronous motor,and through coordinate changes,obtaining the voltage equations and electromagnetic torque equations of the permanent magnet motor in two-phase coordinate system.The frequency conversion control of the permanent magnet motor is carried out based on the vector control method,a speed controller using a speed loop sliding mode controller is designed,and an improved genetic algorithm is used to obtain the optimal parameters of the controller.System speed control simulation based on MATLAB/Simulink simulation platform.The simulation results show that the designed speed controller has good anti-interference performance under the condition of the load with severe disturbance and when the internal parameters change.(3)A sensorless control strategy based on a non-singular fast terminal sliding mode observer is designed to realize the fault-tolerant control of the shearer's permanent magnet semi-direct drive system.A non-singular fast terminal sliding surface is used to achieve the rapid convergence of the sliding surface,and the phase-locked loop technology is used to extract the rotor speed and position information.The simulation results show that no matter the shearer cutting drum is cutting pure coal seams with relatively stable media or cutting more complex coal seams containing gangue,which compared with traditional control strategy,the PMSM sensorless control strategy with Non-singular Fast Terminal Sliding Mode Observer has better stability and estimation accuracy.(4)According to the similarity principle and dimensional analysis method,a set of highly reliable permanent magnet semi-direct drive system experiment platform was built in a laboratory environment.Combining the actual working conditions of coal seam cutting underground,a magnetic powder dynamometer is used to simulate the load of the shearer cutting drum in a laboratory environment,and a permanent magnet synchronous motor is selected as the power source for system speed control.The experimental results show that after scaling,the magnetic powder dynamometer used in this paper simulates the load characteristics of the permanent magnet semi-direct drive cutting drive system when it under laboratory conditions.At the same time,the system has a certain anti-disturbance ability when dealing with sudden load changes,which verifies the reliability of the active disturbance rejection fault-tolerant control strategy in this paper in practical applications.There are 55 pictures,4 tables and 92 references.