Research On Intelligent Drainage System For Stray Current In Metro

The stray current corrosion protection measures applied in metro construction will gradually become ineffective due to the impact of pollution,humidity,water leakage and high ground stress,resulting in a large amount of current leakage to the ground,causing corrosion of buried metal structures and pipelines.Therefore,it is necessary to apply a drainage system to protect buried metal structures.During the operation of the drainage system,excessive drainage can lead to track voltage increasing,and then threatening passenger safety.At present,the drainage flow is usually manually controlled,which has potential risk in error.Therefore,this article studied the intelligence of metro stray current drainage system,proposed an intelligent drainage control strategy,and designed a web-based monitoring system to realize the real-time monitoring of stray current and drainage flow,which could provide technical support for effectively and reliably controlling drainage flow,improving the corrosion protection effect of stray current,and ensuring the safe operation of the metro.In the thesis,methods of theoretical model derivation,intelligent control model,and experimental verification were comprehensively applied to study and design the intelligent drainage system for metro stray current.The main content is as follows:(1)Constructed a three-layer resistance network model of track drainage network earth under bilateral power supply mode,derived mathematical analytical models of track potential,track current,and leakage stray current,and applied MATLAB to perform simulation analysis to obtain the distribution and variation of stray current before and after drainage;and verified the effectiveness of drainage method in solving the corrosion problem of stray current,meanwhile,analyzed the problems caused by excessive drainage flow.(2)Based on the principle of multi-point evaluation of drainage control and fuzzy control theory,the drainage flow fuzzy controllers for the overall roadbed drainage circuit and the tunnel sidewall structural steel drainage circuit were designed,and a fuzzy query control table was developed,providing an intelligent drainage control strategy for the metro stray current drainage system.(3)An intelligent drainage system scheme that integrated stray current and drainage monitoring was proposed.A new intelligent drainage device with high-power switching device IGBT as the core was designed,and the drainage flow fuzzy control model was applied to control drainage.Under ASP.NET MVC framework,designed the web server software and database of the intelligent drainage system to realize real-time display of monitoring data and maintenance of equipment fault information.(4)Set up an intelligent drainage device simulation test platform and conducted experiments on design functions of the intelligent drainage system.This study mainly verified the drainage circuit function and the reliability of drainage flow control based on fuzzy control methods.The results indicated that adjusting the duty cycle of the gate drive signal of the IGBT module could realize the functions of regulating the drainage flow;the intelligent drainage control method based on fuzzy control model could be suitable for the drainage control of metro stray current.The effectiveness of the intelligent drainage scheme for metro stray current designed in this thesis has been verified.In conclusion,this thesis has conducted a detailed study on the intelligent drainage system of metro stray current,which can provide technical support for the intelligent control scheme of the drainage system applied in urban rail transit.