On-site overhaul process of oversize transformer

Abstract

A technique for complete overhauling large-size transformer comprises the following steps including (1) conducting whole leak test for the transformer, (2) demounting the assembly and components of the transformer and conducting maintenance, (3) conducting the preparation work before hoisting the upper fuel tank and behavior respecting the machine body, (4) hoisting the upper fuel tank and behavior respecting the machine body, (5) vacuum oiling and replacing the assembly and components, and (6) finishing and acceptance testing. The invention is characterized in that at the same time of conducting step (4), exerting axially quantitative quantification hold-down for the windings and executing vacuum hot oil spraying and drying for the machine body, the vacuum hot oil spraying and drying system comprises a transformer, which is characterized of comprising a spraying, heating and cleaning return circuit, a processing oil self-circulating return circuit, a gas-changing device, measuring device and a vacuum device. The invention has the advantages that (1) the efficiency is high, the hold-down is stable, (2) the process has characteristics of high flow capacity and self-filtering of the processing oil, the flow capacity of the processing oil reaches 70m3 / h and (3) the whole noise level of the transformer is decreased, the ability of resisting short circuit and impact of the transformer is improved.

Description

(1) Technical field: [0001] The invention relates to a transformer overhaul process, in particular to an extra-large transformer on-site overhaul process. (two) background technology: [0002] At present, the on-site overhaul of domestic power transformers is carried out in accordance with DL / T573-95 "Guidelines for Maintenance of Power Transformers" (hereinafter referred to as "Guidelines") and State Grid Biotechnology [2005] No. 173 "Notice on Printing and Distributing Maintenance Specifications for Power Transmission and Transformation Equipment" Attachment 2 "110(66)kV-500kV oil-immersed transformer (reactor) maintenance specification" (hereinafter referred to as the specification), the traditional overhaul of the transformer on site, the fastening of the pressure nail is only carried out with a hand wrench, hand-tight, no pressure Quantitative value, at the same time, the pressure plate cannot be pressed down at the same time, and the coil as a whole is not under pressu...

AI Technical Summary

Problems solved by technology

[0002] At present, the on-site overhaul of domestic power transformers is carried out in accordance with DL / T573-95 "Guidelines for Maintenance of Power Transformers" (hereinafter referred to as "Guidelines") and State Grid Biotech [2005] No. 173 "Notice on Printing and Distributing Maintenance Specifications for Power Transmission and Transformation Equipment" Attachment 2 "110(66)kV-500kV oil-immersed transformer (reactor) maintenance specification" (hereinafter referred to as the specification), the traditional transformer overhaul on site, the fastening of the pressure nail is only carried out with a hand wrench, hand-tight, no pressure Quantitative value, at the same time, the pressure plate cannot be pressed down at the same time, and the coil as a whole is not under pressure at the same time, sometimes causing the pad to shift from the effective area or even the insulation is crushed, especially for the inner coil, which cannot be detected in time, leaving hidden dangers for future operation. Insufficient pre-pressure means that the pre-pressure is small, the winding is loose, and cannot withstand the mechanical force of the short-circuit. If the pressure is too high, the wire insulation will be crushed.

[0003] However, the overhaul process of the transformer in these two technical documents does not have quantitative axial compression of the coil and high-efficiency high-efficiency insulation and drying of the body, so it cannot effectively improve the insulation performance of the transformer and enhance the short-circuit resistance of the transformer.

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