Study On Stray Current Analysis Based On VMD Algorithm And Protection System Of Oil And Gas Pipelines

Buried steel pipelines are currently the main way of transport of oil and gas.However,the stray currents widely existing in the earth due to various reasons may cause corrosion and damage to buried steel pipelines.At the same time,oil and gas leakage may occur,and accidents such as fire and explosion may occur.Therefore,the monitoring and protection of stray currents are increasingly valued by oil and gas companies.Once the stray current is formed,it will easily affect the cathodic protection system and then corrode the pipe.Based on the causes and hazards of stray currents,this paper researches and analyzes the stray currents,and sets up a stray current protection system that integrates drainage and monitoring to provide effective protection and real-time monitoring of the normal operation of the pipeline.Firstly,the commonly used wavelet analysis methods are tested and analyzed for stray current signals,and there is a problem that it is difficult to determine the wavelet basis functions and the number of decomposition layers.A variational modal decomposition based on a combination of correlation coefficients and kurtosis values(Variational Mode Decomposition)algorithm is applied to stray current test analysis.After decomposing the potential signal into multiple modal components,VMD selects the effective component according to the correlation coefficient value and kurtosis value of each component,and then performs signal reconstruction to obtain the denoised real signal.Application Effect of Denoising and Wavelet Denoising Using VMD Algorithm on Denoising of Potential Signals.The results show that the VMD noise reduction algorithm based on the correlation coefficient and kurtosis value is more suitable for stray current test analysis.Secondly,starting from the stray current corrosion mechanism and characteristics,the stray current elimination technology is analyzed from both DC and AC stray currents.Due to the pipeline under the jurisdiction of Daqing Natural Gas Branch Company,which is mainly affected by high-voltage transmission lines and electrified railways,solid-state decoupler drainage technology is eventually used.Effectively solve the effect of stray current on the pipeline,and protect the normal operation of the pipeline cathodic protection system,and can effectively extend the service life of Daqing Natural Gas Branch Company.Finally,according to the fact that the pipelines under the jurisdiction of Daqing Natural Gas Branch Company are still required to manually collect cathodic protection data,a cathodic protection remote transmission system based on TMS320VC5509 A and GTM900 is studied and designed.The system is mainly divided into control module,data acquisition module,GPRS transmission module and monitoring software.Utilize Huawei GTM900 GPRS wireless transmission module,combined with DSP technology,design negative potential detection device to collect and upload the pipe potential,and design data monitoring center to receive the potential data transmitted by the data transmission module through GPRS,and save it to realize The intelligent management of the pipeline.And the use of solar energy to the system continued power supply,to achieve long-term operation of the system.