Research On Temperature Rise And Operating Characteristics Of Asynchronous Motors Under Different Operating Systems

With the gradual improvement of the use efficiency of motors,the motor of S1 working system is usually operated in S2 or S3 working system.As the load multiple of the motor increases,the temperature of the motor will rise too high,which will affect the safety performance of the motor.Therefore,in order to ensure the safe operation of the motor,it is important to study the relationship between the temperature rise and the operating characteristics of the motor under these working systems.This paper conducts major research in several aspects described below.Firstly,the effect of different loads on motor losses is studied.The twodimensional finite element model of the asynchronous motor is established.The magnetic field distribution diagram,the magnetic density distribution diagram under rated load are obtained,as well as the stator winding current,stator winding copper loss,rotor bar copper loss,and core loss curve.Based on the torque and speed curves of the motor at different loads,the overload capacity of the motor is obtained,and the loss of the motor is calculated and analyzed when the load changes.Secondly,the temperature rise limit of S1 working system motor is determined.A three-dimensional transient temperature field calculation model is established.The temperature field distribution and the temperature rise curve of the S1 working system motor when it reaches the thermal stable state under the rated load is obtained.And through the experimental test data and simulation results for comparison and verification.The highest temperature rise is taken as the temperature rising limit of the S1 working system motor in other working systems.Then,the operating characteristics of the S1 working system motor in the S2 working system is analyzed.Take different loads as the operating capacity of the motor in the S2 operating system,calculate the time required for the motor temperature rise to reach the temperature rise limit and the minimum re-running time,and the output power of the motor under the four standard short-term operatingsystems.Provide a theoretical basis for the motor running time under different operating capacities.Finally,the operating characteristics of the S1 working system motor in the S3 working system is studied.The effect of starting current on the temperature rise of the motor is considered,calculate the running time,running capacity and load duration when the temperature rise of the motor reaches the temperature rise limit under different operating capacities,then obtain the operating capacity when the S1 working system motor can run safely in the S3 working system.