Method for computing electromagnetic force of transformer iron core based on finite element method

Abstract

The invention discloses a method for computing electromagnetic force of a transformer iron core based on a finite element method. The method comprises the steps that structural parameters of a winding, the iron core and a fuel tank of a transformer are collected, and then a three-dimensional geometric grid model of the transformer is established; the three-dimensional geometric grid model is input into software, sinusoidal currents with a phase different of 120 DEG are applied to the cross section of the three-phase low voltage winding respectively, and Dirichlet boundary conditions are applied to the outer side of the structural grid model; and an instant electromagnetic field is solved by a virtual displacement method, magnetic field energy is computed, a virtual work method is used to compute instant electromagnetic force borne by the transformer iron core and the winding, FFT is conducted to the instant electromagnetic force, and frequency domain distribution of the electromagnetic force of the iron core can be obtained. The computation method disclosed by the invention is direct and convenient; electromagnetic vibration and force bearing situations of the transformer iron core can be analyzed from the perspective of energy; each influential factor on force bearing of the iron core is considered comprehensively; and computation results are accurate and reliable.

Description

technical field [0001] The invention relates to the technical field of transformer electromagnetic vibration noise analysis and control, in particular to a method for calculating electromagnetic force of a transformer iron core based on a finite element method. Background technique [0002] Too much vibration of the iron core of the transformer may lead to deformation, loosening of the iron core, and increased temperature rise. These conditions will seriously affect the ability of the transformer to resist the impact of short-circuit current, affect the normal operation of the transformer, and may even cause damage to the transformer. At the same time, it will also affect the normal operation of the AC power grid. run. The transformer noise mainly comes from the electromagnetic vibration of the transformer core. The study of the electromagnetic force of the transformer core can provide a basis for the vibration control and structural optimization design of the transformer. ...

AI Technical Summary

Problems solved by technology

This method mainly considers the influence of DC bias on the vibration of the transformer iron core, and the research on other factors affecting the vibration of the iron core is not comprehensive enough.

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