Abstract

The electromagnetic interference caused by overhead power lines on nonparallel underground pipelines is assessed in “A numerical model for the calculation of electromagnetic interference from power lines on nonparallel underground pipelines” (Popoli et al., 2020 [1]) by segmenting the pipeline path in a number of traits parallel to the power line. The analysis requires a multi-port electrical component to be extracted for each pipeline segment by means of finite element 2D analysis; circuit analysis can then be applied to the network composed of the cascade of the multi-port electrical components in order to calculate the induced voltages and currents on the pipeline. The data in this paper consist of matrices which represent the multi-port electrical components corresponding to the segments in which the pipeline has been subdivided. These matrices can then be used as constitutive relations in network analysis, as detailed in (Popoli et al., 2019 [2]), in order to find the induced pipeline voltages and currents for different intersection angles between the pipeline and overhead power line routings.

Abstract

This work proposes a numerical methodology for the calculation of currents and voltages induced on underground pipelines by nearby overhead power lines. A previously developed quasi-3D methodology is extended, allowing the investigation of nonparallel routings of the pipelines with respect to the power lines. The proposed technique is based on a discretization of the pipeline path into several segments parallel to the power line. The section of the corridor corresponding to each pipeline segment is regarded as an electrical multi-port component, whose electrical parameters are extracted via finite element 2D analysis. Then, the obtained components are integrated into a network embodying the physical characteristics of the whole corridor. In this way, the circuital analysis is used to extend the capabilities of a standard two-dimensional field analysis. The proposed methodology is employed to simulate a pipeline running parallel to a power line for a distance of 12km. Afterwards, several nonparallel configurations – consisting of crossings between a pipeline and a power line – are assessed. The physical consequences of the crossing are discussed and a convergence study is performed to investigate the optimal pipeline subdivision procedure to be adopted for a set of different crossing angles.

Abstract

In this paper, a novel quasi-three dimensional technique for the study of electromagnetic interferences induced by overhead power lines on buried metallic pipelines located in the same corridor is proposed. The aim of the method is to provide an inherently three dimensional solution to the problem, by using a two dimensional finite element approach. According to the proposed methodology, a bidimensional quasi-magnetostatic analysis is performed on a section of the considered corridor. The three dimensional extension is obtained by using a circuital approach to consistently couple the analysed section with the rest of the system. The analysis of the obtained equivalent circuit finally provides the actual values of the longitudinal electric fields acting on the studied section, and thus allows the solution of the problem. The results obtained from the described procedure have been compared for a few simple interference cases with those obtained using Carson’s analytical formulas for the calculation of mutual impedances. Finally, a study on the effects of a non-homogeneous soil structure has been carried out.