Research On Key Technology Of Mining Permanent Magnet Roller

In recent years,a new type of permanent magnet roller has gradually entered the market.Compared with the ordinary three-phase AC asynchronous motor,it has the advantages of low energy consumption,small floor space and high efficiency.It has a good development prospect in coal mining and other industries.At present,the permanent magnet roller still has some problem to be improved.For example,the cogging torque generated during the operation of the permanent magnet roller is one of the important factors affecting the operation stability of the permanent magnet roller.Too high cogging torque will cause rotation jamming and even shutdown;In addition,the electromagnetic load of the permanent magnet roller is high,and the long-term operation is easy to directly lead to the increase of temperature,so as to reduce the electromagnetic performance of the permanent magnet,appropriately reduce the peak value of cogging torque,reduce the thermal effect of the roller,and optimize the structure of the heat dissipation channel of the permanent magnet roller,which is of great significance to maintain the torque performance of the permanent magnet roller and ensure the normal operation of the equipment.Firstly,the structure of permanent magnet roller is designed,and the influence of permanent magnet material,permanent magnet arrangement and winding arrangement on electromagnetic performance is analyzed.Secondly,because the numerical calculation method of the cogging torque has the defects of complex calculation process and inaccurate results,this paper uses the finite element analysis method to build a two-dimensional electromagnetic model of the permanent magnet drum.Through the simulation and analysis of the cogging torque,the curve laws of the air gap,slot depth,pole slot ratio,the number of rotor auxiliary slots and the cogging torque are obtained,which provides a more accurate basis for the optimization of the cogging torque.Then,the thermal effect of the permanent magnet drum is analyzed,the copper loss is analyzed and optimized theoretically,and the iron loss of the permanent magnet drum is simulated based on the finite element method,and the change law of the iron loss with the stator tooth structure is obtained and optimized.Fourthly,in view of the insufficient heat exchange and poor heat dissipation function between the traditional one-way cooling channel structure and the water jacket,this paper proposes a new out of phase parallel water channel cooling structure,establishes the roller model,simulates the temperature field of the permanent magnet roller through fluent finite element software,and obtains that the cooling effect of the new out of phase parallel water cooling pipe structure is improved by 12.5%compared with the traditional one-way channel.Finally,the accuracy of the simulation results of the temperature field under the two heat dissipation modes is verified by the temperature rise experiment of the permanent magnet roller.