The magnetic field of underground 330 kv cable line and ways for its reduction

This paper discusses the mitigation of the cable line magnetic field by the two-point bonding of shields of cables. We produce a two-dimensional mathematical model of the cable line with two-point bonded cable shields based on the Maxwell-Ampere equation. The calculation of induced shield currents and magnetic field is carried out by the computer simulation using the finite element method. This allows to take into account a nonuniform shield current distribution and therefore to obtain the most accurate solution, as evidenced by the coincidence with the experimental research. We consider the most common case of the flat cable line and tabulate the dependence of the magnetic shielding factor from the cross-sectional area, the diameter of shields, and the distance between cables.

Magnetic field calculation of cable line with two-point bonded shields

Purpose . Preparation of short scientifically-historical essay about creation and development of the National Academy of Sciences (NAS) of Ukraine. Methodology. Known scientific methods of collection, analysis and analytical treatment of scientific and technical information, touching creation and development of NAS of Ukraine and resulted in scientific monographs, journals and internet-reports . Results. A short scientifically-historical essay is presented about creation and development of NAS of Ukraine. The main scientific achievements of NAS of Ukraine in various fields of science are presented. It is pointed that a large scientifically-organizational contribution to these achievements brought by present President of NAS of Ukraine, Academician B.Ye. Paton, his 100th Birthday (27 November, 2018) coincides surprising appearance with the 100th anniversary of NAS of Ukraine. An important role of NAS of Ukraine in the development of society and international scientific and technical cooperation was noted. The results of scientific research, achieved over the past few years by the Institute of Technical Problems of Magnetism of the NAS of Ukraine (Kharkiv), as well as by the Institute of Ionosphere of the NAS and Departments of education and science (DES) of Ukraine (Kharkiv) are briefly presented. The research cooperation in the field of electrical engineering of NTU «KhPI» with scientific institutions of the NAS of Ukraine is highlighted. Originality. Certain systematization is executed of known from scientific journals and other mass of scientific and technical materials, touching the results of activity of research workers of institutes of NAS of Ukraine in the last few years. Practical value. Scientific popularization and deepening for the students of higher school, engineer-technical and scientific workers, working in the different sectors of economy of country, scientific and technical knowledge in an area of physical-technical and mathematical sciences, chemical and biological sciences, and also social and humanitarian sciences, extending their scientific range of interests and further development of scientific and technical progress in society.

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To the 100th anniversary of the National Academy of Sciences of Ukraine – the cradle of domestic science and technology

The work is devoted to the study of stray fields of cable lines to ensure electromagnetic compatibility, with different connection of screens. The influence of the electromagnetic field (EMF) on the flow of currents in the shielding layers, the occurrence of leakage currents in the main insulation of power cable samples has been studied. The issues of electromagnetic compatibility of power cables are considered. A computational model of PCL has been developed in the COMSOL Multiphysics software pack-age. The conducted experimental studies of the magnetic field induction level B(I) of power cables will reveal the dependence of the change in the magnetic field on the distance to the current-carrying core, the presence of shielding grounding, and the presence of defects in the insulation of power cables. A technique has been developed for numerical simulation and calculation of EMF B(I), H(I) depending on the distance from the cable and on the magnitude of the current of the cable core. The novelty of the work is aimed at developing a non-destructive method of complex diagnostics based on the analysis of data obtained as a result of experimental studies and the developed three-dimensional physical model of a power cable line. The development of three-dimensional objects (PCL) enables the most detailed modeling of the physical processes of PCL. It was revealed that the electric field formed around the current-carrying wires contributes to the development of partial discharges (PD) in the inhomo-geneities of the insulating layers. 

Investigation of Electromagnetic Field in Problems of Electro-Magnetic Compatibility of Power Cable Lines

The unified approach to modeling the propagation of electric and magnetic fields of power lines and electrical machines with the use of modern software tools has been developed. The results obtained make it possible to rationalize the ratio of the parameters of the field sources and minimize its propagation in space. This reduces energy losses and the impact on people. 

The Propagation of Electromagnetic Fields of Energy Facilities Modeling in the Context of Energy Saving and Public Safety

The study tested the process of the magnetic field (MF) mitigation in the HV three-phase power cable lines (CL) made of single core cables in two-ends bonding of their shields. Developed the technique of numerical simulation and calculation of the MF of CL based on its axisymmetric calculation model using the finite element method that allowed to describe the condition of closing the cable shields at the both ends of the CL and solve the problem in two-dimensional formulation. The authors show the possibility of MF mitigation of the three-phase CL by increasing the cross-section of closed cable shields, which in some cases may be an alternative to external electromagnetic shields. Obtained and experimentally validated in laboratory and field conditions with an accuracy of no more than 5 % the value of mitigation coefficients of MF of three-phase three-wire CL in two-ends bonding of their shields depending on the technical parameters of the cables and the geometry of their installation, which is important for the design of new cable power lines. Their values are in the range from 0.99 to 0.32 when the cross sections of cable shields are from 25 mm2 to 200 mm2 and the distance between the axes of the cables are from 0.1 to 0.5 m. The results show the ability to execute design of cable power lines in residential areas, taking into account both the sanitary standards of the MF, as well as to energy efficiency.

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Исследование магнитного поля трехфазных кабельных линий из одножильных кабелей при двустороннем заземлении их экранов

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A. A. Kvytsynskyi

Papers

Исследование магнитного поля трехфазных кабельных линий из одножильных кабелей при двустороннем заземлении их экранов

Double-circuit passive shielding of the magnetic field of high-voltage cable lines in junction zones