A calculation method for comprehensive evaluation coefficient of transformer direct-mounted bushing cooling performance

Abstract

The invention discloses a method for calculating a comprehensive evaluation coefficient for the cooling performance of a direct-mounted casing of a transformer, comprising the following steps: establishing a comprehensive test platform for the cooling performance of the direct-mounted casing of a transformer, obtaining the cooling coefficient of the casing under the condition of natural convection, and obtaining a crosswind The cooling coefficient of the casing under the conditions, the comprehensive evaluation coefficient of calculating the cooling performance of the direct-mounted casing of the transformer, and the evaluation of the cooling performance of the direct-mounted casing of the transformer. The beneficial effect of the invention is that: the index for judging the cooling performance of the direct-mounted bushing of the transformer is proposed for the first time, and the cooling effect of the direct-mounted bushing under natural convection and forced convection can be comprehensively considered scientifically and reasonably, and the direct-mounted bushing of the power transformer can be realized. Scientific evaluation of the cooling performance of the casing to reduce the consumption of manpower and material resources.

Description

technical field [0001] The invention relates to the field of on-line detection and fault diagnosis of electrical insulation, in particular to a method for calculating a comprehensive evaluation coefficient for the cooling performance of a direct-mounted bushing of a transformer. Background technique [0002] Large-scale power transformers are the core equipment in the power transmission and transformation system, and their reliability is the key to the safe operation of the power grid. The bushing is one of the important components of the power transformer. It not only guides and supports the outgoing wires of the windings to pass through the transformer box and connects to the external power grid, but also ensures the insulation between the outgoing wires and the transformer body. When the transformer is running, the central conductor of the bushing will generate heat under the Joule effect of the current, which will cause the temperature of each part of the bushing to rise...

AI Technical Summary

Problems solved by technology

The cooling performance of the bushing mainly depends on the convective heat transfer characteristics of the outermost shed of the porcelain bushing. However, due to its complex structure, the structure of the shed among different types of bushings is quite different. The cooling performance evaluation in some specific situations, or the bushing cooling performance can only be estimated roughly based on empirical parameters, and there is a lack of a universal evaluation method for bushing cooling performance that can fully consider the convective heat transfer characteristics of the porcelain shed shed.

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