Research On Interference Mechanism And On-line Monitoring System Of Buried Pipelines In Grounding Of HVDC Transmission

With the rapid development of China’s economic construction,the laying of high-voltage transmission systems has also entered a high-speed development model.The concomitant phenomenon of high-voltage direct current(HVDC)lines and buried pipelines has become increasingly common,resulting in the HVDC power transmission system grounding the metal pipe.Corrosion interference is deepening.In China’s ongoing large-scale engineering projects,the problem of DC stray ground current interference is becoming more and more serious,mainly when the HVDC transmission system is in the initial stage of operation,maintenance and during the fault period.When the HVDC grounding electrode is unipolarly operated,it will induce voltages in nearby buried oil and gas metal pipes.Thousands of ampere-hours of stray current will break through the buried pipeline anticorrosion layer and interfere with the damage of electromagnetic valves and other electrical equipment.In addition,the problem of electrocorrosion and misoperation of the gas-liquid linkage switch is extremely prone to occur.In serious cases,the life safety of personnel is also impaired.In recent years,the potential detection of long-buried buried metal pipelines in China still uses the method of manual point-by-point detection.This method is not only time-consuming and labor-consuming,but also causes errors.Contemplated herein coating sheet resistance,the resistivity of the soil,the ground electrode to the three parameters from the conduit,establishing a metal pipe by ANSYS Simulation Model inductive coupling potential,increase of soil disturbance results resistivity increases linearly,with the pipe coating resistance increases exponentially,with a ground electrode to buried pipelines index decreases as the distance increases law.Detailed analysis of the basic mechanism of the pipeline corrosion,and applied to design a pipeline under normal operation,the wireless hardware and software acquisition system designed and constructed based on,online monitoring system ground tube is formed,the induction current for the DC interference.This paper introduces the overall design framework for wireless data acquisition system,and line monitoring system in the field of radio-bit hardware acquisition system designed for a detailed elaboration.Through laboratory simulation tests,this system has the characteristics of stability and high accuracy for the signal measurement work,achieving the design accuracy expected.And on this basis,to interfere law obtained by simulation for a simple verification.