Features of field modeling of electromagnetic processes of trolley busbar
Authors: Kotsur М.І. , Yarymbash D.S. , Bezverkhnya Yu.S. , Divchuk T.Yu. 
Published: July 2021

Purpose. Research and analysis trolley busbar’s parameters in condition of higher current harmonic actions, with taking into account the structural features of nonlinearity of magnetic and electrical properties of materials, proximity effects, surface and external surface effects.

Methodology. The researches were carried out using the electromagnetic field theory methods, the electrical circuit theory, mathematical physics, finite elements, interpolation, approximation and regression analysis.

Findings. The mathematical spatial model of electromagnetic processes in a steel trolley busbar in time statement of a problem of distribution of an electromagnetic field is developed. The dependences of the distribution of equipotential lines of the resulting z-component of the magnetic potential vector along the busbar, as well as the distribution of the resulting normal component of magnetic induction and magnetic field strength in the transverse (XY) cross section at non-sinusoidal current in busbar trolleys is obtained. Along the length of the busbar, in their cross section, the magnetic field tends to a plane-parallel shape it is proved. The error of the modulus of the vector magnetic potential along the length of the busbar does not exceed 0.9-1.2%. To reduce the dimension of the problem, computational resources and calculation time, a two-dimensional plane-parallel mathematical model in the frequency setting of the electromagnetic field distribution is proposed. To take into account the nonlinear magnetic properties of steel trolleys, to determine the effective magnetization curve for the nonlinear two-dimensional problem of the electromagnetic field of the busbar it is proposed. The verification results, according to the calculated voltage drop, confirm the high accuracy of the calculation and the reliability of the obtained results (error does not exceed 1.88% ÷ 2.06%) of the two-dimensional model in the frequency setting relative to the spatial model in the problem of time-dependent electrical -magnetic field is obtained.

Originality. A mathematical two-dimensional model of electromagnetic processes in the frequency formulation of the problem of electromagnetic field distribution in a trolley busbar is proposed, which takes into account design features, nonlinearity of magnetic and electrophysical properties of materials, proximity effects, surface and external surface effects, influence of harmonic current components power transmission, which allows with high accuracy and efficiency of numerical implementation to determine the parameters of the bus trolls for the corresponding values of the amplitudes and frequencies of the frequencies harmonics of the current.

Practical value. Verification of the calculated voltage drop confirms the high accuracy of the calculation and the reliability of the results (error does not exceed 1.88% ÷ 2.06%) of the two-dimensional model in the frequency reference relative to the spatial model in the problem of time-dependent electromagnetic field distribution is performed.