Аналіз впливу вихрових струмів на динамічні та енергетичні характеристики лінійної електромеханічної системи

Abstract

На основі розробленої вісесиметричної інтегро-диференційної математичної моделі нестаціонарного електродинамічного процесу в електромеханічній системі з постійними магнітами та алгоритму сумісного чисельного розв’язку електромагнітної та механічної задачі було проведено перевірку на адекватність математичної моделі шляхом порівняння з результатами фізичного експерименту. Розглянувши різні варіанти конструкції було досліджено вплив вихрових струмів на динамічні та енергетичні характеристики електромеханічної системи.

Purpose. The study of electromechanical systems of reciprocating motion was most often limited to devices with nonconducting or non-ferromagnetic elements of the structure and, in most cases, were of an applied nature. The analysis shows that in some problems that have been solved, the features of the operation of linear electromechanical systems are not fully taken into account. Within the framework of the research, methods for calculating the associated non-stationary electromagnetic and mechanical processes in systems with massive ferromagnetic elements with axial symmetry under various operating conditions have been developed; in the presence of permanent magnets as non-consuming sources of magnetic field. On the basis of the stepping method, an algorithm for calculating the non-stationary electrodynamic process in an electromechanical system with axial symmetry has been developed. This algorithm makes it possible to transform a nonlinear problem with respect to the speed of motion of the armature, the density of the eddy currents in the cross section of conductors, and the density of the magnetization currents at the boundary of the magnetic circuits into two linear ones shifted in time. The algorithm was implemented in the FORTRAN programming language, the reliability of the obtained results was proved by comparison with the models built in the Comsol Multiphysics 3.5 a software package and the adequacy of mathematical models by comparison with previously published experimental research results. A study was conducted to identify the effect of eddy currents in moving massive ferromagnetic elements of the electromagnetic system on the electrodynamic process. The dampingeffect of eddy currents was shown, which leads to a decrease in the amplitude of the natural oscillations of the system. The calculated heat losses do not exceed 11%. A decrease in the amplitude of the higher harmonics of the current is shown, which affects the power quality indicators. As a practical application, the electromechanical system of reciprocating action is proposed to be used as a drive for the crystallizer of a continuous casting machine to ensure the optimal law of motion of the mold.