Model coil of interturn insulation test of oil-immersed power transformer and manufacturing method of model coil

Abstract

The invention relates to a model coil of an interturn insulation test of an oil-immersed power transformer and a winding method of the model coil. Specification parameters of the coil and a category of insulation paper are the same as those of the transformer. The coil is divided into an upper cake and a lower cake, wherein each cake is subjected to parallel winding by two paper wrapped wires A and B; two first tangling positions of a connecting part of the two cakes are wrapped with at least six layers of insulation paper; the two first tangling positions are located on an inner ring of the coil; a distance between the two first tangling positions is half perimeter of a lead wire of the inner ring; the head end and the tail end of each paper wrapped wire are connected together; the two paper wrapped wires serve as a high-voltage outgoing wire and a low-voltage outgoing wire respectively; an ellipse is defined by four leading-out terminals of the paper wrapped wires; the high-voltage outgoing wire and the low-voltage outgoing wire of the coil are arranged at the two ends of a long axis respectively; a short axis is coincided with a straight line formed by the two first tangling positions of the two paper wrapped wires and is equal to the diameter length of an excircle of the coil; and each of the paper wrapped wires from tangent points to end points of the leading-out terminals is additionally wrapped with at least six layers of crepe paper to reinforce insulation. The coil can effectively simulate breakdown characteristics of an interturn oil paper compound insulation system and a development process of electrical aging and thermal aging under a working condition of the large transformer, and is simple to manufacture.

Description

technical field [0001] The invention relates to an oil-immersed power transformer turn-to-turn insulation test model coil. The present invention also relates to a manufacturing method of the model coil. Background technique [0002] As the core equipment of the power grid, large-scale oil-immersed power transformers, whose operating conditions determine the operational reliability of the power grid, and their investment also account for the largest proportion of power grid construction, operation and maintenance costs. At present, under the influence of the world economic situation, the domestic economic development is slowing down, and the problem of waste of resources caused by excessive investment is becoming more and more prominent. The research on key technologies for extending the life of power transformers based on full life cycle management is imminent. The service life of domestic power transformers is often insufficient or close to 30 years, so re-investment in po...

AI Technical Summary

Problems solved by technology

At present, there are many tests on the breakdown and aging of the inter-turn insulation of motors, but there are few related research results on the inter-turn insulation of transformers.

The coil model coils of the inter-turn insulation of the motor are mostly pig-tail model coils made according to the method specified in the standard IEC60034-18-42. The structure of the model coil is similar to the actual motor coil structure, but there is a large gap with the actual transformer coil. difference

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