Metallic pipelines are protected from induced corrosion by the application of coating and Cathodic Protection (CP) systems. The latter is achieved by keeping the pipeline at a constant Direct Current (DC) voltage in relation to the surrounding soil. While this is conventionally meant to arrest corrosion, the Alternating Current (AC) interference from high voltage transmission lines has been a major problem to the CP potential systems of buried steel pipelines. Several research studies dealing with this problem have been published, and a lot of research work is still on going. This work focuses on assessing the stability of the CP potentials under the influence of AC interference. Seven different CP potentials varying from -800 mV to -1200 mV were applied on steel pipe specimen exposed to the AC interference with a varying AC voltage from 0-50 V. The results of the laboratory investigation revealed that CP potential of -1150 mV was more stable under the influence of AC interference, with just a minimal shift from the set value. The results from the corrosion morphology tests on the pipelines using Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) reveal the need for optimising the CP potential to provide adequate or optimum protection to the pipelines. Thus, more research studies involving simulation and field studies may lead to a major breakthrough in improving protection potentials.
1. Brena, A., L. Lazzari, M. Pedeferri, and M. Ormellese, "Cathodic protection condition in the presence of AC interference," La Metallurgica Italiana, Vol. 6, 29-34, 2014.
2. Christoforidis, G. C., D. P. Labridis, and P. S. Dokopoulos, "Inductive interference on pipelines buried in multilayer soil due to magnetic fields from nearby faulted power lines," IEEE Transactions on Electromagnetic Compatibility, Vol. 47, No. 2, 254-262, 2005. doi:10.1109/TEMC.2005.847399
3. Satsios, K. J., D. P. Labridis, and P. S. Dokopoulos, "The influence of nonhomogeneous earth on the inductive interference caused to telecommunication cables by nearby AC electric traction lines," IEEE Transactions on Power Delivery, Vol. 15, No. 3, 1016-1021, 2000. doi:10.1109/61.871368
4. Qi, L., H. Yuan, Y. Wu, and X. Cui, "Calculation of overvoltage on nearby underground metal pipeline due to the lightning strike on UHV AC transmission line tower," Electric Power Systems Research, Vol. 94, 54-63, 2013. doi:10.1016/j.epsr.2012.06.011
5. Ponnle, A. A., K. B. Adedeji, B. T. Abe, and A. A. Jimoh, "Planar magnetic field distribution underneath two-circuit linear configured power lines in various phase arrangement," Proceedings of the 12th IEEE AFRICON Conference, 777-781, Ethiopia, Sep. 14–17, 2015.
6. Ponnle, A. A., K. B. Adedeji, B. T. Abe, and A. A. Jimoh, "Variation in phase shift of multi-circuits HVTLs phase conductor arrangements on the induced voltage on buried pipeline: A theoretical study," Progress In Electromagnetics Research B, Vol. 69, 75-86, 2016. doi:10.2528/PIERB16062308
7. Ponnle, A. A., K. B. Adedeji, B. T. Abe, and A. A. Jimoh, "Variation in phase shift of phase arrangements on magnetic field underneath overhead double-circuit HVTLs: Field distribution and polarization study," Progress In Electromagnetics Research M, Vol. 56, 157-167, 2017. doi:10.2528/PIERM16110304
8. Adedeji, K. B., A. A. Ponnle, B. T. Abe, and A. A. Jimoh, "Analysis of the induced voltage on buried pipeline in the vicinity of high AC voltage overhead transmission lines," Proceedings of the 23rd Southern African Universities Power Engineering Conference, 7-12, Johannesburg, Jan. 28–30, 2015.
10. Adedeji, K. B., B. T. Abe, and A. A. Jimoh, "Low frequency induction simulation of power transmission lines and pipelines: A comparative study," Lecture Notes in Engineering and Computer Science: Proceedings of the World Congress on Engineering and Computer Science, 265-270, San Francisco, USA, Oct. 25–27, 2017.
11. Southey, R., F. Dawalibi, and W. Vukonich, "Recent advances in the mitigation of AC voltages occurring in pipelines located close to electric transmission lines," IEEE Transactions on Power Delivery, Vol. 9, No. 2, 1090-1097, 1994. doi:10.1109/61.296294
12. Tachick, H., "AC mitigation using shield wires and solid-state decoupling devices," Materials Performance, Vol. 40, No. 8, 24-27, 2001.
13. Gregoor, R., A. Pourbaix, and P. Carnentiers, "Detection of AC corrosion," CEOCOR Congress, Paper No. 2, 1–14, Biarritz, France, Oct. 2–5, 2001.
14. Markovic, D., V. Smith, and S. Perera, "Evaluation of gradient control wire and insulating joints as methods of mitigating induced voltages in gas pipelines," Proceedings of the Australasian Universities Power Engineering Conference, 2001-Hobart, Australia, Sep. 2005, 2006, 2005.
15. Shwehdi, M. and B. Al-qahtani, "Cost effective mitigation study of electromagnetic interference by power lines on neighbouring gas pipeline," CIGRE C4 Colloquium on Lightning and Power System, 11-17, Kuala Lumpur, May 16–19, 2010.
16. Adedeji, K. B., B. T. Abe, Y. Hamam, A. M. Abu-Mahfouz, T. H. Shabangu, and A. A. Jimoh, "Pipeline grounding condition: A control of pipe-to-soil potential for ac interference induced corrosion reduction," Proceedings of the 25th Southern African Universities Power Engineering Conference, 577-582, Stellenbosch, South Africa, Jan. 30–Feb. 1, 2017.
17. Ouadah, M., O. Touhami, and R. Ibtiouen, "Diagnosis of the AC current densities effect on the cathodic protection performance of the steel ×70 for a buried pipeline due to electromagnetic interference caused by HVPTL," Progress In Electromagnetics Research M, Vol. 45, 163-171, 2016. doi:10.2528/PIERM15101103
18. Ouadah, M., O. Touhami, and R. Ibtiouen, "Diagnosis of AC corrosion on the buried pipeline due to the high voltage power line," Journal of Electrical Engineering, Vol. 16, 76-83, 2016.
19. Beavers, J. A. and N. G. Thompson, "External corrosion of oil and natural gas pipelines," ASM Handbook on Corrosion: Environments and Industries, Vol. 13C, 1016-1025, 2006.
20. Xu, L., X. Su, and Y. Cheng, "Effect of alternating current on cathodic protection on pipelines," Corrosion Science, Vol. 66, 263-268, 2013. doi:10.1016/j.corsci.2012.09.028
21. CEN/TS12954, "Cathodic protection of buried or immersed metallic structures: general principles and application for pipelines," European Technical Specification, Germany, 2001.
22. CEN/TS15280, "Evaluation of AC corrosion likelihood of buried pipelines-application to cathodically protected pipelines," Technical Specification, European Committee for Standardization, Germany, 2006.
23. Shabangu, T. H., K. B. Adedeji, B. T. Abe, and P. A. Olubambi, "A study on the impact of ac interference on the cathodic protection potentials of buried pipelines," 25th Southern African Universities Power Engineering Conference, Stellenbosch, South Africa, Jan. 30–Feb. 1, 2017.
24. Isogai, H., A. Ametani, and Y. Hosokawa, "An investigation of induced voltages to an underground gas pipeline from an overhead transmission line," IEEJ Transactions on Power and Energy, Vol. 126, 43-50, 2006. doi:10.1541/ieejpes.126.43
25. Isogai, H., A. Ametani, and Y. Hosokawa, "An investigation of induced voltages to an underground gas pipeline from an overhead transmission line," Electrical Engineering in Japan, Vol. 164, No. 1, 43-51, 2008. doi:10.1002/eej.20465
26. Djekidel, R. and D. Mahi, "Calculation and analysis of inductive coupling effects for HV transmission lines on aerial pipelines," Przegl¸ad Elektrotechniczny, Vol. 90, No. 9, 151-156, 2014.