Analysis method of relationship between transformer winding deformation and short-circuit impedance change

Abstract

The invention provides a transformer winding deformation and short-circuit impedance change relationship analysis method which comprises a step of using a finite element method to establish a finite element simulation model of transformer winding displacement, wherein each pillar in the finite element simulation model comprises high, middle and low transformer windings, and disc modules are employed by the transformer windings, a step of using a middle-low voltage winding operation mode lower field circuit coupling model to process a winding in a finite element area as an inductor in a circuit, wherein the lower field circuit coupling model is obtained by coupling an electromagnetic field and a circuit generated by the electromagnetic field generated in the operation of a transformer, and a step of simulating the change trend of transformer short-circuit impedance when the transformer windings have radial displacement and axial displacement based on the field circuit coupling model. By using the method, a transformer winding deformation and short-circuit impedance change relationship can be accurately analyzed, a winding deformation security risk is timely found, the elimination of a possible sudden failure of the transformer in a maintenance cycle is facilitated, and an accident is prevented.

Description

technical field [0001] The invention relates to transformer technology, in particular to a method for analyzing the relationship between transformer winding deformation and short-circuit impedance change. Background technique [0002] The safe, stable and economical operation of power transformers is of great significance to the entire power grid. It is one of the most important and expensive equipment in the power system. When the transformer is subjected to a short-circuit impact, the winding may be distorted, dislocated, bulged and other deformations. The deformation of the winding does not necessarily cause an accident immediately, but in the operation of the transformer, the vibration caused by the electromagnetic force will further damage the winding insulation. If the maximum relative deformation of the winding is greater than 1.5%, the inter-turn insulation is prone to rupture and cause inter-turn insulation. Short circuit, but the transformer can still operate, but...

AI Technical Summary

Problems solved by technology

The low-voltage pulse method is basically no longer used because it is susceptible to interference from the on-site electromagnetic environment; the frequency response method has high sensitivity, but it cannot be applied to online monitoring projects, so it does not have real-time performance, and it is difficult to detect potential safety hazards of winding deformation in time. There may be sudden failures between maintenance cycles, causing accidents

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