Analysis And Research On Electromagnetic Loss And Thermal Characteristics Of Self-ventilated Low-voltage Asynchronous Electric Motor

With the modernization of industrial development and the continuous application of new technologies,motors,as an indispensable power component of the industry,will also continue to make technological improvements and improve performance to adapt to the development of the industry.The service cycle of the motor is very long,which requires the motor to be able to run stably for a long time,and the temperature rise of the motor is an important factor affecting the long-term stable operation of the motor.There are many types of motors with different characteristics.Among them,self-ventilated low-voltage asynchronous electric motor are widely used in all walks of life because of their simple structure and sufficient reliability,as well as a wide range of adjustable speed and low maintenance costs,whether it is household appliances or self-ventilated low-voltage asynchronous electric motor can be seen in heavy industrial machines.According to statistics,70% of the country’s total annual power generation is consumed by various motors.It can be seen that motors consume a very large proportion of electricity.Under the background of environmentally friendly development,how to reduce motor losses to reduce motor heating Thereby saving electric energy and improving the running stability of the motor are issues that many scholars need to explore continuously.Aiming at the temperature rise of the motor,this article takes two aspects of reducing the electromagnetic loss of the motor and improving the heat dissipation efficiency of the motor as the starting point to study and improve the temperature rise of the self-ventilated low-voltage asynchronous electric motor.The main work is divided into the following aspects:(1)Establish a two-dimensional finite element model of the self-ventilated low-voltage asynchronous electric motor,and analyze and study the harmonic losses of the induction motor.The Rmxprt module in the Ansys module software is selected to carry out parametric modeling of the motor,and the motor stator,stator slot,rotor,rotor slot,geometric model of the shaft and motor winding winding form are established.Then import the motor geometry model into the Maxwell module,add excitation,set boundary conditions and mesh division,and perform finite element analysis to calculate motor losses.Analyze the motor loss characteristics,start from the mechanism of motor loss,redesign the winding distribution form,compare and analyze the harmonic loss characteristics of the optimized winding and the original winding.(2)Establish a three-dimensional model of the motor’s heat dissipation components,conduct a numerical simulation analysis of the motor’s heat dissipation flow field,and optimize the characteristics of the blade structure to improve the heat dissipation efficiency of the motor.The Solidworks 3D modeling software was selected to establish the equivalent model of the prototype casing,stator and rotor,centrifugal fan and windshield components,and the model was optimized to adapt to the numerical simulation analysis of the fluid field.The Fluent module in the Ansys module software is selected for the numerical simulation of the fluid field,and the appropriate algorithm is selected according to the simulation boundary conditions and simulation requirements.Through the Fluent software,the external air flow field of the entire motor is simulated and analyzed to obtain the speed characteristics of the external flow field,pressure characteristics,streamline characteristics and other parameters,and then the flow characteristics of the internal flow field of the centrifugal fan hood are analyzed.By optimizing the structure of the centrifugal fan,the flow rate of the flow field is increased,and the heat dissipation of the motor is optimized.(3)The calculated total loss of the motor is used as the heating source of the motor and applied to the corresponding position of the three-dimensional model of the motor.Combined with the analysis of the external flow field of the motor,the fluid-structure coupling heat dissipation simulation analysis is performed in Fluent.Through the temperature monitoring of the characteristic points of the motor casing,the influence of the original structure cooling fan and the optimized structure cooling fan on the temperature of the motor casing is compared.The optimized structure of the centrifugal fan was printed out through 3D printing technology,and the practice workshop was arranged to conduct a motor temperature rise test to verify the optimization of the motor temperature rise.After the group,the full text is summarized,the engineering practicality of the optimization scheme is summarized,the remaining problems in the research content are proposed,and the follow-up research is prospected.