Research On Dynamic Characteristics Of Winding Permanent Magnet Outer Rotor Hoist

As a new generation of mine hoists,permanent magnet outer rotor hoists are gradually used in mine hoisting systems with the advantages of low speed,large torque,low energy consumption and less infrastructure construction.Its efficiency and reliability are directly related to the production efficiency and safety of mines.In the actual production of mines,the hoisting load of the winding permanent magnet outer rotor hoist has the characteristics of large tonnage and time-varying.As a direct drive mechanism,the load of the outer rotor drum will act directly on the drum,so its load is a nonlinear,strong coupling,multi-objective complex stress problem.The time-varying load causes the load characteristics of the key bearing bodies such as the outer rotor drum to change,which has a certain impact on its safety and reliability.In view of the above problems,this dissertation comprehensively uses theoretical analysis,numerical simulation and experimental methods to study and analyze the dynamic characteristics of the winding permanent magnet outer rotor hoist.Firstly,according to the deployment structure and load analysis of the single rope winding permanent magnet outer rotor hoist,the principle and composition of the vector control drive system of the permanent magnet outer rotor hoist are analyzed.Combined with the actual working conditions of mine hoisting,the bearing characteristics of permanent magnet outer rotor drum and stator spindle are analyzed theoretically.Secondly,the dynamic operation characteristics of the permanent magnet outer rotor hoist under different loads are studied.Based on the mine hoisting system dynamics theory and vector control principle,the electric control-mechanical co-simulation model of the permanent magnet outer rotor hoist was established by using the electromechanical hydraulic co-simulation software Simulation X,and the dynamic changes of the permanent magnet outer rotor hoist speed,electromagnetic torque,dynamic tension of wire rope and three-phase current under the actual working conditions of no-load and heavy load were studied.The research shows that the speed and electromagnetic torque of the high-power permanent magnet outer rotor hoist based on vector control system can quickly realize closed loop,with smooth current response,large starting torque and stable operation.Then,aiming at the nonlinear,strong coupling and other complex forces of the permanent magnet outer rotor drum in operation,the transient dynamic analysis model of the permanent magnet outer rotor drum was established by comprehensively considering the dynamic load of the wire rope end,the pull reduction factor,the multi-layer winding factor,the electromagnetic torque and other factors under the heavy lifting condition;Combined with the radial deformation of the cylinder wall,the electromagnetic model of the permanent magnet outer rotor hoist is established by Ansoft,and the electromagnetic torque variation under different air gap deformation is studied through air gap parameterization;The isolation ring or reinforcing rib is used to separate the steel wire rope winding drum from the rotor yoke to complete the structural improvement.The results show that the maximum equivalent stress and deformation of the outer rotor drum wall increase nonlinearly under the whole heavy lifting condition,and the maximum stress and deformation occur in the drum area on both sides of the rotor yoke.The air gap deformation caused by the deformation has a certain influence on the electromagnetic torque,and the optimization method of separation treatment can effectively reduce the air gap deformation.Finally,the dynamic characteristics of the permanent magnet outer rotor hoist are studied.The modal and harmonic response of the permanent magnet outer rotor hoist are analyzed by numerical simulation.The amplitude frequency response of the whole structure of the permanent magnet hoist under different frequency ranges is determined,and the vibration characteristic test of the permanent magnet outer rotor hoist is completed.The results show that the sensitive frequency range of permanent magnet external rotor hoist is about 14 Hz and83hz;In the acceleration and deceleration stage,the vibration signal fluctuates greatly,and in the constant speed stage,the vibration signal is relatively stable.