Calculation Of Temperature Rise And Analysis Of Cooling System Of Permanent Magnet Motor For New Driving Device

The difference between the new driving device for crane and the traditional lifting mechanism is that it adopts the outer rotor structure and has a higher degree of integration,so the stator winding is difficult to dissipate heat,especially for high-power equipment.Special hoisting machinery is widely used in various complex working conditions,which puts forward higher requirements for its sealing and insulation.It is different from the intermittent working system of traditional electrical equipment,which puts forward new problems in the calculation of temperature rise.The above problems are discussed in this paper through the following aspects:Firstly,the physical model and mathematical model of an external rotor permanent magnet synchronous motor for a high-power 90 kw driving device are established in this paper.The relevant loss and heat source are determined according to the characteristics of the equipment.The different working levels of the crane mechanism are listed,and the temperature rise algorithm of the equipment is studied.The finite volume method and thermal network method are used to calculate according to the same experimental conditions,and the results are compared with the experimental data to prove the correctness of the relevant algorithms,so as to provide a method for the selection of cooling structure in the following paper.Through the simulation calculation of the selected cooling structure model,the obtained temperature rise structure is used to verify whether it meets the requirements of equipment insulation.Secondly,the air cooling structure of hollow shaft is selected and designed through the air cooling characteristics of different structures.Based on the basic principles of hydrodynamics and heat transfer,a fluid structure coupling mathematical model is established.Through the computational fluid software and its embedded user-defined function,the programming and simulation are carried out according to the working level of the mechanism required by the design of traditional hoisting machinery.Through the adjustment of different cooling structures and relevant dimensions in the structure,the rationality of the selected cooling structure is designed and analyzed.The calculation results under different load levels are compared.The final conclusion is used as a reference in the subsequent research on the heat dissipation of crane driving device.Finally,by using the external rotor permanent magnet motor direct drive,compared with the traditional crane mechanism,it has a great improvement in structure simplification and equipment efficiency.Therefore,the temperature rise under extreme working conditions is discussed according to the operation mode of the equipment.In this paper,the cooling mode of the axial water channel in the rotating shaft is designed,and the temperature rise structure is verified by the thermal calculation method,so as to prove the applicability of this mode to the operating conditions of the equipment.