Hybrid method to calculate GICs in pipelines and its application to the gas pipeline in China

摘要

A hybrid method to estimate Geomagnetically-Induced Currents (GICs) in pipelines based directly onmagnetic recordings is presented. The method in this paper includes two steps. First, a model is used inwhich the geomagnetic variation field propagates as a vertical plane wave (VPW) in the earth and theearth is a half-space, to determine the electric field on the earth's surface for the calculation of GICsbased on available magnetic data. Secondly, if the external geoelectric field and the geometry andelectromagnetic properties of the pipeline are known, we introduce a general method which can be usedto determine voltage and current profiles for buried pipelines. The method makes it possible to use thedistributed source transmission line (DSTL) theory, which is based on the analogy between pipelinesand transmission lines. Lastly, a particular attention is paid to the China natural gas pipeline networkand the hybrid method is used to calculate or predict GICs and voltages on pipelines of the First GasPipeline from West to East in China. Obtained results show that GICs and voltages on pipelines shouldbe paid to great attention.