Research Of Railway Integrated Grounding System Reflow Index

With the increasing speed of high-speed railway and operating mileage,the stability and reliability requirements of the railway power supply,communications,signal equipment are also rising.In order to avoid the impact of electromagnetic field and potential changes on the railway power supply,communication and signal devices,which is caused by the traction current generated by electric locomotive operation,the short-circuit current,thunder and lightning,China high-speed railway grounding system adopts integrated grounding technology,the railway traction power supply reflow system,power supply system,signal communication and other electronic information systems connected together through integrated ground wire formation a grounding system.In order to verify the high-speed railway integrated grounding system to satisfy the design and the technical requirements,the testing and commissioning and dynamic testing for the high-speed railway is required before the opening.The ratio of the return paths in the integrated grounding system can reflect whether the construction quality of the integrated grounding system conforms to the design requirements,and then provides the basis for the dynamic acceptance of the project.At present,China railway industry does not have reflow index standards and technical requirements,dynamic acceptance,testing and commissioning lack of standards.This research mainly studies evaluation of the integrated grounding system as the background,makes a theoretical analysis of the traction reflux proportion,and uses the analysis results to guide the test.The large data obtained from the tests is statistically analyzed,the analysis result is used for dynamic detection.This research makes full use of the large amount of data obtained from the dynamic detection,through statistical analysis and theoretic calculation on past data,to provide the evaluation index of the reflow index which meet the needs of field test,guidance and basis for the testing and evaluation of the quality of integrated grounding system in high-speed railway dynamic detection.The main research contents are as follows:Firstly,according to our characteristics of the high-speed railway integrated grounding system,it is necessary to determine which parameters should be evaluated in the traction reflux evaluation index.Secondly,through the modeling and simulation of traction reflux system of high-speed railway,depending on the impedance characteristics of the various reflux paths,get the reasonable current distribution ratio,and guide the selection of the testing location according to the analysis result.Finally,based on the sufficient statistical samples obtained from the tests,the statistical analysis is made on the testing data of each traction reflux path in the integrated grounding system with different power supply modes and line modes,to determine if the data fit the normal distribution,if it has homogeneity of variance,and if it is necessary to develop different assessment indicators to different types of railway,and confirm the classification of assessment indicators of the traction reflux proportion and specific reference limit.In the course of dynamic acceptance,testing and commissioning of railways,such as Bao-Lan Railway,Hu-Zhang Railway and Xi-Cheng Railway,the reflow index were already used to evaluate the quality of the integrated grounding system of high-speed railway.And it has already achieved very good results when those were used to guide the rectification of the project.