Eur. Phys. J. Appl. Phys. (2012) 58: 30902 DOI: 10.1051/epjap/2012110462 THE EUROPEAN PHYSICAL JOURNAL APPLIED PHYSICS Regular Article Electromagnetic ﬁeld model for the numerical computation of voltages induced on buried pipelines by high voltage overhead power lines C. Munteanu a , G. Mates, M. Purcar, V. Topa, I.T. Pop, L. Grindei, and A. Racasan Department of Electrical Engineering, Technical University of Cluj-Napoca, 400020 Cluj-Napoca, Romania Received: 9 December 2011 / Received in ﬁnal form: 28 March 2012 / Accepted: 9 May 2012 Published online: 5 July 2012 – c  EDP Sciences 2012 Abstract. This paper proposes an innovative, generally applicable numerical model for the calculation of the three-dimensional (3D) electromagnetic ﬁeld generated by high voltage (HV) overhead power trans- mission lines (OHL) on the buried metallic structures (e.g., pipeline networks). The numerical analysis is based on a coupled ﬁnite element-boundary element model (FEM-BEM) designed to calculate the induced potential on buried pipelines for complex geometrical structures of HV OHL networks working on normal or fault conditions. The one-dimensional (1D) FEM technique based on pipe elements is used to discretize the mathematical model that describes the interior of the pipe and is coupled with the mathematical model that describes the exterior of the pipe using 3D-BEM integral equations. The full electromagnetic ﬁeld model gives the ﬂexibility to calculate the potential distribution in any point of the soil, providing useful information for the step and touching voltages. The computation accuracy of the numerical algorithm implemented is veriﬁed through two test problems by comparing the numerical results with those obtained using a software package based on the Transmission Line Method (TLM) and CIGRE formulae. Last part of the paper presents calculations of the induced potential on buried pipeline in the vicinity of a complex HV OHL working on normal and fault condition. The inﬂuence of the currents’ direction and magnitude ﬂowing on the HV OHL on the induced pipeline potential distribution is analyzed. 1 Introduction The sharing of common corridors by fuel transportation pipelines and HV OHL is becoming quite common nowa- days. As the electrical energy can be transferred from the OHL to pipelines through inductive, conductive and ca- pacitive coupling, when an OHL runs in the vicinity of a pipeline for a considerable distance, important induced AC voltages can appear on the pipeline. Stray currents due to these induced voltages can cause corrosion of the metallic structures, although the amount of metal loss is less than an equivalent amount of DC current discharge would produce. The magnitude of the AC stray current is often large: hundreds of amperes for the steady-state elec- tromagnetic induction and thousands of amperes during the power line faults. These faults can lead to shock haz- ard for personnel and can damage the structure or related equipment. The international regulation practices [1] state that potentials exceeding 15 V should be considered haz- ardous and actions should be taken to reduce the potential level. A signiﬁcant number of papers and research studies have been published both on the mechanisms and model- a e-mail: calin.munteanu@et.utcluj.ro ing of the AC-induced voltages and their mitigation in the pipelines. A comprehensive overview of these researches developed so far is presented below. The initial attempts to study the AC interferences were based on the widely known Carson’s formulae [2]. At the same time Pollaczek presented in reference [3] the induc- tive coupling between parallel conductors in the presence of the earth. Twenty-three years later Sunde extended Carson’s work toward multi-layered earth in reference [4] and he studied conductors in the vicinity of current sinks. Takashima et al. proposed in reference [5] a method for calculating complex ﬁelds between electrodes in con- ducting media. They demonstrated that there exist dual relationships between a complex ﬁeld generated by an al- ternating current source in a conducting medium and an electrostatic ﬁeld due to a charge in a dielectric medium. Grcev built a computational model [6] for the transient analysis of a large grounding system and above-ground conductors. He recalled the complex image ﬁeld theory de- veloped by Takashima et al. in reference [5] and combined with an electromagnetic ﬁeld theory. The model works for either parallel or perpendicular conductor conﬁgurations. Taﬂove and Dabkowski used the transmission line (TL) theory [7] to calculate the induced voltages on gas pipelines by a 60 Hz AC power transmission line. Afterwards they 30902-p1