Dziuba K. Electromagnetic field generated by conductors with current near conducting body with strong skin-effect

Object of research: electromagnetic systems with conductors, located near the conducting body, which manifests a strong skin effect. Purpose: further development of analytical methods for calculating three-dimensional quasi-stationary electromagnetic fields under conditions of strong skin effect in an electrically conductive body with a plane surface in the direction of taking into account the spatial configuration of circuits with current, determination and analysis of composite fields in dielectric and electrically conducting environments. Methods of research: Solving the problems formulated in the dissertation work is achieved using electromagnetic field theory, partial differential equations, vector and tensor analysis, fundamental positions of electrodynamics and theoretical electrical engineering. The reliability of the results obtained in the work is ensured by the correctness of the formulation of the boundary value problems of mathematical physics, the consistency of the results with the data obtained with the help of independent numerical methods. Theoretical and practical results and novelty: it was first established that the normal component of the electric field strength on the surface of the dielectric medium and the surface electric charge density do not depend on the properties of the conductive medium and are determined only by the normal component of the induced electric field of the current circuit, which makes it possible to simplify the mathematical models of the calculation three-dimensional field, neglect for these components of the field of currents induced in the conductive medium; for the first time on the basis of the general analytical solution it has been proved that the inhomogeneous alternating electromagnetic field at penetration into the conducting half-space always decays faster than homogeneous; An approximate method for calculating an electromagnetic field using asymptotic series has been further developed; got the scientific substantiation of using the mathematical model of a locally two-dimensional field for the spatial current circuit near the conducting half-space by estimating the errors of field determination; In the conditions of strong skin effect, the method of asymptotic decomposition was first used to determine the pulsed electric field in a dielectric half-space for the contours of arbitrary spatial configurations. Subject and degree of implementation: the results of the dissertation work on the application of methods for calculating the current density and electrodynamic forces under strong skin effect have been used to substantiate the method of contactless treatment of welds of aluminum alloy structures at the Institute of Electric Welding. E.O. Paton of the National Academy of Sciences of Ukraine. Implementation efficiency: further development of analytical methods for calculating three-dimensional quasi-stationary electromagnetic fields under conditions of strong skin effect in the conductive half-field in the direction of taking into account the arbitrary spatial configuration of circuits with current, determination of both magnetic and electrical component fields in the dielectric and electrically conductive regions, development of effective approximation methods calculation of harmonic and pulsed fields. Scope of application: development of experimental devices of contactless treatment of welded seams of structures made of aluminum alloys; pulsed systems for the processing of metal constructions and the determination of electrophysical processes using electrodischarge circles; use in the educational process of higher technical educational institutions of the Ministry of Education and Science of Ukraine.