| Title | Measurements of higher harmonics in AC interference on pipelines
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| Author | Boteler, D H ;
Croall, S J; Nicholson, P |
| Source | Proceedings, CORROSION 2010; 2010, 11 pages |
| Image |  |
| Year | 2010 |
| Alt Series | Earth Sciences Sector, Contribution Series 20100274 |
| Meeting | CORROSION 2010; San Antonio; US; March 14-18, 2010 |
| Document | book |
| Lang. | English |
| Media | paper |
| Subjects | soils science; engineering geology; pipelines; pipeline feasibility studies; soil types; soil studies; soils; soil properties |
| Illustrations | graphs; plots |
| Program | Public Safety Geoscience Targeted Hazard Assessments in Northern Canada |
| Released | 2010 01 01 |
| Abstract | Recordings of alternating current (AC) pipe to soil potential (PSP) variations have been made using fast-sample (2000 samples/sec) dataloggers. This sampling rate is fast enough to show the waveform of
the AC potential variations. The recordings were made on two sections of a pipeline sharing a right-of-way with an AC transmission line. Global Positioning System (GPS) timing on the dataloggers allows the PSP variations to be recorded accurately
enough to determine the phase relation between the AC potential variations at different places along the pipeline. A notable feature of the recordings is that they show significant PSP variations, not only at the fundamental AC frequency (60 Hz) but
also at the third harmonic (180 Hz). This prompted a comparison of the factors affecting the size of the fundamental and third harmonic PSP variations in a typical pipeline. It is shown that the pipeline can be many hundreds of times more sensitive
to the third harmonic than to the fundamental. This suggests that more attention should be paid to the size of the third harmonic AC currents in power lines adjacent to pipelines. |
| GEOSCAN ID | 287163 |
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