Winding stress assessment method based on three-dimensional electromagnetic coupling model of transformer

Abstract

The invention discloses a winding stress assessment method based on a three-dimensional electromagnetic coupling model of a transformer. The method is characterized by comprising: establishing the three-dimensional electromagnetic coupling model of the transformer and solving the model; calculating a leakage magnetic field of the transformer based on a vector magnetic potential node finite element method; and by simulating magnetic field distribution in the transformer, performing calculation and analysis on a stress on a winding. After the winding deforms, a geometric structure of the winding is no longer regular and a magnetic structure coupling model programmed by utilizing a current loading principle is not applicable, so a winding stress value is calculated from a two-dimensional model corresponding to a three-dimensional model and then the stress value is loaded into the corresponding three-dimensional model through a related program to calculate the stress on the winding. The deformation of the winding is reflected through a difference of the sunken degrees of the winding between two supporting strips, so that the conditions of stresses on the model in different accumulation situations are observed. The method provides a basis for judging the structural stability of the winding of the transformer, and has the advantages of being scientific, reasonable, real, effective, high in practical value and the like.

Description

technical field

[0001] The invention is a winding stress evaluation method based on a three-dimensional electromagnetic coupling model of a transformer, which is applied to force analysis and structural stability evaluation of power transformer windings. Background technique

[0002] Power transformer is one of the most important equipment in power grid and power transmission. The ability of its winding to withstand short circuit directly affects the safe and reliable operation of the power grid. Under the action of a single short-circuit impact, the stability of the winding depends on the setting value and the actual force value. When the setting value is greater than the actual force value, the winding is stable. In actual operation, the transformer may be subjected to multiple short-circuit impacts, and the short-circuit resistance of the winding may decrease with the increase of the number of short-circuit impacts. At the same time, the stress of the wire may increase, s...

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