A d-connected high-voltage coil

Abstract

The invention discloses a high-voltage coil by a D connecting method. The high-voltage coil comprises a basic section and a tapping section, the basic section is continually wound, the axial size of the basic section is B, the tapping section is provided with four tapping portions, the tapping section is parallelly and continually wound by the aid of a plurality of wires, the number of the wires for winding the tapping section is twice that of the wires for winding the basic section, the cross section area of each wire for winding the tapping section is one half that of each wire for winding the basic section, the total cross section area of the tapping section is as same as that of the basic section, the four tapping portions of the tapping section are eight cakes, the height of each cake is 0.5B, and the total height of the eight cakes is 8*0.5B=4B. Compared with the prior art, winding modes of the tapping section of the high-voltage coil is adjusted, safe operation of products is ensured, filling rate of the coil is increased, winding is convenient, winding difficulty is reduced, production efficiency is improved, height sizes of the soil, an iron core and an oil tank can be reduced, the size, the weight and the loss of a transformer are reduced, and material cost is reduced.

Description

technical field [0001] The invention relates to a transformer coil, in particular to a D-connection high-voltage coil. Background technique [0002] Usually the high-voltage coil of a 35kV power transformer is Y-connected, and the tap range of off-excitation voltage regulation is ±2×2.5%. There are 4 taps. In order to improve the filling rate of the coil, the basic section is continuous winding. The sections are tangled winding, each of them has the same number of turns, 4 taps and 4 cakes, that is, 1 tap / cake (see attached figure 2 ). [0003] The turn insulation thickness of the 35kV class coil is δ=0.45mm, and the field strength limit between turns of the coil is E=2000 V / mm; [0004] The inter-turn voltage of the basic section is between 18 and 90 V, and the inter-turn field strength Et=(18~90V) / 0.45=40~200 V / mm is much smaller than the limit value E of the inter-turn field strength of the coil. [0005] The inter-turn voltage of the tap section is the voltage of each...

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Problems solved by technology

[0008] The disadvantage of this method is that the filling rate of the tap section is greatly reduced, and the gap in the tap pie needs to be filled with paper pads, which increases the difficulty of winding; the tap section is changed from 4 pies to 8 pies, and the high and low voltage coils are enlarged. The ampere-turn imbalance between them increases the height of the coil, iron core, and oil tank, which increases the volume, weight, and loss of the transformer, reduces product performance indicators, and increases costs.

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