Analysis On Key Parts Of Generator In Magnetic-Thermal-Solid Coupling Field Under Rotor Winding Interturn Short Circuit

As important energy equipment,the normal operation of the generator set affects all aspects of daily life.During the operation of the generator,it is in a complex environment composed of multi-physical fields such as magnetic field and temperature field.Therefore,it is very important to analyze the characteristics of the key parts of the generator such as stator core and armature winding insulation in the multi-physics coupling field.This paper analyzes the temperature rise characteristics and thermal response characteristics of key parts such as the stator core and winding of the generator through theoretical derivation,finite element simulation calculation and experimental verification.The main work and achievements are as follows:(1)In this paper,based on the air-gap flux density,the analytical expressions of the generator phase current and loss are sorted out,and the variation laws of phase current and loss under different rotor interturn short-circuit faults and composite faults are obtained.The results show that after the strong excitation action occurs,the core loss and copper loss of the generator will increase with the deepening of the fault degree.Compared with the core loss,the copper loss increased more obviously.(2)Then,Ansys Electromagnetics,Ansys Workbench simulation software and Solidworks 3D modeling software are used to establish the simulation model with winding insulation,analyzed the temperature rise characteristics of the generator in the magnetic-thermal-solid coupling field and the thermal response of the stator winding insulation,and made a preliminary verification of the theoretical analysis.The results show that with the aggravation of the fault degree,the temperature rise of the generator is more obvious,and the temperature is higher,and the highest temperature appears in the straight section of the stator winding insulation.The occurrence of the eccentricity fault makes the temperature distribution of the generator not uniform,and the side with the smaller air gap is higher than the side with the larger air gap.The maximum position of the total deformation of the stator winding insulation occurs at the nose,and the position of the maximum thermal stress and thermal strain occurs at the junction of the involute and the straight segment.(3)Finally,experiments are carried out on the CS-5 fault simulation unit,and the temperature rise curves of the generator stator winding insulation under different fault conditions are obtained,and the theoretical analysis and finite element simulation calculation results are further verified.This paper studies the temperature distribution and thermal response of the key parts of the generator under the complex operating conditions of the rotor interturn short-circuit fault,and provides a theoretical reference and basis for the subsequent winding insulation damage analysis and failure prevention.