The Research For Numerical Simulation And Structure Optimization Of Roof Insulator In The Process Of Manufacturing

As an important high-voltage insulation device, the train roof insulator was related to normal safe operation of the electrified locomotives. With the development of the construction work of electrified railway in our country, the safety problem of the roof insulator is increasingly outstanding, and how to effectively improve the mechanical and electrical performance of the roof insulator has become a important project. This paper aiming at the pollution flashover in the process of service and the sintering incomplete problem in the process of sintering for the roof insulator, optimizes the structure of insulator which includes shape structure and microstructure,and improves the overall mechanical and electrical performance and quality stability of the roof insulator, which is based on the numerical simulation method. The main conclusions as follows:(1) This paper studies electric field distribution of the roof insulator with the aid of MAXWELL software. Through the analysis and compare of electric field distribution characteristics of roof insulators of different sheds structure, it is found that the electric field distribution on the surface of the insulator can be effectively homogenized by selecting reasonable sheds arrangement and setting up suitable sheds angle and sheds spacing, and this kind of homogenization can prevent the occurrence of flashover. It also further discusses the effect of improving electric field distribution of the roof insulator for coating method of the semiconductor coating, and analyzes the impact of the coating material properties for electric field distribution of the insulator.(2) According to the actual environment around the roof insulator in the process of train running, three-dimensional model of the roof insulator airflow field has been built. It studies the distribution and change rule of the airflow field around the insulator in the process of serving with the aid of CFX software. Furthermore, combined with field investigation, it analyses the relationship between the pollution accumulation law and the airflow field distribution change law of the insulator. Based on the airflow field distribution characteristics of the roof insulator, this paper proposes a kind of pollution deposition prevention structure for the roof insulator. And in this paper, the new structure insulator is Compared with the ordinary structure insulator in the airflow field distribution and pollution accumulation characteristics using the method of simulation analysis, which proves that the structure can effectively improve the pollution resistance of the roof insulator.(3) In this paper, the failure roof insulator samples of the certain factory in the routine test is observed by using scanning electron microscope, and the phenomenon of incomplete sintering have been found. In this situation, with the aid of finite element simulation method,this paper analyzes the temperature distribution and temperature change rule for kiln and porcelain billet in the process of sintering; proposes to improve the microstructure of porcelain billet by improving the sintering temperature or extending the holding time under the original sintering temperature; quantitatively determines the increase of sintering temperature and the extension of heat preservation; combining the SEM observation with the measure of the porosity. And in the end, it has verified the simulation results.