Introduction To The Winding Of Dry-type Transformer

Introduction to the winding of dry-type transformer
The winding is an important part of the dry-type transformer. It is composed of transmission lines and insulation layers. The transformer engineering calculation is inseparable from the winding. The electric control system of the dry-type transformer composed of primary and secondary windings. The structure and structural size of the winding determine the characteristics of the transformer. When measuring the winding, it is necessary not only to achieve the technical performance such as transmission capacity, voltage ratio, characteristic impedance, but also to ensure that the winding has sufficient insulation strength, high temperature resistance and impact toughness.

The cross-section of the core transformer winding is generally circular. The structural forms of the winding are circular, spiral, rotary, worry or mobile phone screen. For electric furnace transformers and low-voltage transformers with transformers, when the voltage regulating transformer and the transformer are installed in the same oil tank, the low-voltage winding also uses an 8-shaped winding. Some special transformers also use double-talk and low-voltage windings with bare copper coins. When measuring the winding, first select the structural form of the winding reasonably according to the winding capacity, working voltage and its transformation method.

1.1 Barrel Winding of Dry-Type Transformer

Barrel winding is generally made of low-cost transmission wire or conductor wire, which is wound on one side without gaps. This type of winding has weak impact toughness and small heat dissipation area, so it is generally used for small-capacity transformers. It also has single-sided barrel type, two-layer barrel type, double-layer barrel type and segmented barrel type.

Single-sided barrel winding has only one layer of turns, and the head and tail of the winding are led out at both ends of the winding. Two-layer barrel winding has only two layers of turns. The head and tail of the winding are both led out at the same end of the winding. The solid layer is set with main oil channel (or air pipe) or padded with solid insulation according to the insulation layer and heat dissipation requirements. Because the single-layer and two-layer barrel windings can accommodate less wire bands, they are generally used for low-voltage windings of small-capacity transformers of 630kVA and below.

Double-layer barrel has more than two wire bands. The first can also be connected to the same lake of the winding, and the tap used for transformer can be drawn from the middle of the group. According to the insulation and heat dissipation requirements, one or more layers are placed in the main oil channel or channel), and the other layers are placed in the solid insulation. Because the double-layer enclosed simple winding can accommodate more wires, it is generally used for small-capacity transformers of 630KVA and below, as 3035W high-voltage windings.

The section-area simple winding is composed of several radially arranged multi-layer medical cylindrical windings, and each double-layer circular simple winding is called a section. The sections are separated by paper or

. Because the section-area cylindrical winding can accommodate more wires, it can be used as: 2000kVA and below small-capacity transformers as 60kV and below high-voltage windings.

1.2 Dry-type transformer spiral winding

Spiral winding is made by connecting and winding multiple flat wires, just like the single-sided simple winding: but the adjacent coils are separated by pads, and each section is a junction. This type of winding has higher impact toughness than the national cylindrical type. The heat dissipation area is also very large: but it can accommodate fewer thin wires, so it is generally used for low-voltage windings of transformers of various capacities. Spiral windings can also be divided into single-spiral, double-spiral and quad-spiral types.