10kV SC(B)10-14 cast resin transformer

Product Overview:

A Dry-Type Transformer is a transformer that does not use liquid insulating media (such as transformer oil). Its insulation and cooling mainly rely on air or other non-liquid media. This type of transformer usually uses solid insulating materials such as epoxy resin, insulating cardboard, cable paper, etc.

Structure of dry-type transformer

1. Core

The core of a dry-type transformer is the magnetic circuit part, which consists of two parts: the core column and the iron yoke. The winding is mounted on the core column, and the iron yoke closes the entire magnetic circuit.Core structures are generally divided into two types: core type and shell type:

①　Core core: The iron yoke is against the top and bottom surfaces of the winding, but does not wrap around the sides of the winding. The core core has a simple structure, and the arrangement and insulation of the winding are also relatively easy. Therefore, my country's power dry-type transformers mainly use core cores.

②　Shell core: The iron yoke not only wraps around the top and bottom surfaces of the winding, but also around the sides of the winding. The shell core has a complex structure and is suitable for some special dry-type transformers (such as electric furnace dry-type transformers).

2. Winding

The winding is the circuit part of the dry-type transformer, usually wound with insulating varnish, paper-wrapped aluminum wire or copper wire.According to the different arrangements of high and low voltage windings, the winding can be divided into concentric and overlapping types:

Concentric winding: The low voltage winding is close to the core column, which is convenient for the insulation of the winding and the core.Overlapping winding: The low voltage winding is close to the iron yoke to reduce the insulation distance.

3. Insulation

The main insulating materials inside the dry-type transformer include epoxy resin, insulating cardboard, cable paper, corrugated paper, etc.The insulation structure formed by epoxy resin pouring has good insulation performance and mechanical strength.

4. Tap changer

In order to supply stable voltage, control power flow or adjust load resistance current, dry-type transformers need to adjust voltage.At present, the method of adjusting voltage of dry-type transformers is to set taps on one side of the winding, and change the number of turns of the winding by cutting or adding some turns of the winding, so as to achieve step-by-step voltage adjustment.The circuit in which the winding is tapped for voltage regulation is called a voltage regulation circuit, and the switch used to change the tap for voltage regulation is called a tap changer.

In general, the tap changer is set on the high-voltage winding, because the high-voltage winding is often sleeved outside, it is convenient to lead out the tap, and the current on the high-voltage side is small, the cross-section of the tap lead and the current-carrying part of the tap changer is small, and the direct contact contact of the switch is also easier to manufacture.

The voltage regulation of the dry-type transformer without load resistance on the secondary side and the primary side is also disconnected from the power grid (no power excitation) is called no-excitation voltage regulation; the voltage regulation with load resistance to change the winding tap is called on-load voltage regulation.

Application fields

Widely used in power transformation and distribution of urban power grids, high-rise buildings, commercial centers, airports, offshore drilling platforms, ships, tunnels, large hydropower stations, railway stations, etc.