Design And Research On Auxiliary Lifting System Of Super Large Bucket Based On Permanent Magnet Linear Motor

With the strategic adjustment of national coal resources,coal mining is developing towards the direction of large-scale,depth and intellectualization.The application of superlarge skip in coal mine main shaft lifting has the advantages of large lifting volume and high efficiency.However,due to the physical characteristics of the traditional hoisting wire rope itself,skip capacity can not continue to increase,especially in the case of ultra-deep wells and ultra-large loads,its service life and safety performance will be greatly reduced.Aiming at the insufficiency of current research and technical requirements,an innovative design scheme of assistant driving of super-large skip by permanent magnet linear motor was proposed,and detailed design calculation and analysis were carried out.The research results have important theoretical significance and practical value for further increasing lifting load,lifting depth and service life of large skip hoisting system.At the same time,it has a certain forward-looking guiding value for the future development of new lifting technology in ultradeep mines.Taking 1000 m deep mine as engineering background,aiming at the largest 50 t superlarge coal-lifting skip in China at present,and taking the skip’s additional load of 20% as design objective,the scheme demonstration,design calculation and simulation test of the auxiliary lifting system of permanent magnet linear motor were carried out.Firstly,based on the analysis and research of the driving principle of permanent magnet linear motor,according to the design requirement of adding 10 t additional coal lifting capacity,the overall design of the mine layout,sectional power supply,linear guide selection and explosion-proof structure of the auxiliary lifting system of skip linear motor was carried out.Secondly,according to the auxiliary lifting scheme,40 linear motors on both sides were synchronously driven,and an atmospheric gap permanent magnet linear motor with a single thrust of 5500 N is designed.Ansys Maxwell was used for electromagnetic static and transient simulation to optimize the structure parameters of the motor.Thirdly,the single-motor and multi-motor control strategies of the auxiliary drive system were studied.The vector control of single motor id=0 and the master-slave control strategy of multi-motor speed follow were selected.The coordinate transformation,SVPWM control and PMLSM were studied and the mathematical model was established.Finally,the simulation model of unit motor of auxiliary hoisting system is established by using MATLAB Simulink,and the simulation experiments under no-load and sudden load change were carried out respectively.In order to verify the master-slave control scheme,the master-slave control simulation model of the motorassisted hoisting system was established with three motor units,and the performance indexes of the system,such as speed following,load stability,speed mutation and auxiliary braking,were simulated.The results show that the speed following delay is 0.16 s,the thrust lag is 0.08 s,the speed error after stabilization is 0.96%,the thrust fluctuation is 0.2%,the stabilization time after speed mutation is 0.19 s,and the motor following lag is 0.05 s under the master-slave control of the auxiliary hoisting system,and the auxiliary braking and speed regulating effect is good,which shows that the control strategy has excellent synchronization following and control stability.According to the simulation results and the actual lifting scheme design,the master-slave control of the permanent magnet linear motor across two unstable motors to transfer the speed of the next motor can meet the multi-motor control requirements of the auxiliary lifting system.