The coil of a power transformer

January 02, 2025

The coil is an important and complex part of the power transformer, which is wound by copper (or aluminum) wire and composed of special insulating parts.

1, spiral coil

The main feature of the spiral coil is that the number of parallel wires is more, the wire cake is wound into a spiral, and a coil of the wire cake is a turn. Spiral coil has good mechanical stability, good heat dissipation and good technology, and is widely used in transformer low voltage and high current coil.

According to the size of the current, the spiral coil can be wound into a single helix, double helix and four helix three structures.

2, continuous coil

When the coil is composed of a number of axial distribution, and by each other do not need to be connected to the line segment of the coil, called continuous coil.

The end of the continuous coil has large supporting surface, large axial force, strong short-circuit resistance, and large dispersion capacity on each line segment. This coil is widely used in both voltage level and capacity range.

3, tangled coil

The entangled coil is composed of several entangled segments (cakes). The coils that are all entangled segments (cakes) are called fully entangled coils, which are widely used in transformers of 220kV and above voltage. A coil composed of a part of the tangled line segment (cake) and a part of the continuous line segment is called the tangled continuous coil, which is used in transformers with a voltage of 66kV and above.

Because it inserts non-adjacent turns between the adjacent turns of the coil, forms a staggered entangled line segment and forms a entangled coil, so that the longitudinal capacitance of the coil is increased, making the impact voltage distribution characteristics along the axial height of the coil good, so it has been widely used in a variety of high-voltage coils.

4, inside type coil

The inner plate continuous coil achieves the purpose of good impulse voltage distribution by means of series capacitors between large line segments. The structure features that the additional capacitor turns are directly wound inside the continuous line segment, and the end of the capacitor turns is wrapped in insulation and suspended in the line segment. The capacitor turns do not carry current and only work under the impulse voltage.

The inner plate continuous coil has two segments, four segments, eight segments and segment connections in structure.

Author:

Ms. Vivian Chai

E-mail:

chinatransformer@isxftransformer.com

Phone/WhatsApp:

+55 19981089637