Continuously Transposed Cable which also names CTC, refers to the combination of a certain number of enameled copper flat wires into two rows in which the wide surfaces are in contact with each other, and the transposition of the same direction is made on the top and bottom of the two rows of enameled wires along the narrow surface as required, and is covered with electrical insulating paper. The tape is composed of multiple layers of continuous tight wrapping.
The windings of large-scale power transformers use CTC, which can greatly reduce load loss, reduce the temperature rise of winding hot spots, improve the mechanical strength of the windings, make the structure more compact, and make the coil processing easier. Widely used in winding design and manufacture.

Compared with ordinary flat wires, CTC has many advantages, and at the same time, due to their relatively small dimensions, the manufacturing cost of transformers is reduced.
1. Since a plurality of small-section single wires are used instead of a large-section flat wire, the loss of discrete fields is reduced.
2. Compared with multiple parallel self-insulated single wires, since the CTC is an enamelled single wire, the thickness of the paint film is much thinner than that of the previous paper insulation, but the withstand voltage is several times that of the paper insulation, plus The insulation thickness of the public paper insulation is relatively thin, so the volume of the winding is obviously reduced, and the utilization rate of the space is effectively improved.
3. Due to the transposition between single wires, the winding has high mechanical strength.
4. Because the insulation thickness is relatively thin, it has high heat dissipation.
5. Due to the thin paint film and insulation thickness, it has better heat dissipation, so it has higher thermal stability.
6. Due to the reduction of manual transposition, the winding process becomes simple and the processing time of the winding is shortened. For the CTC, winding one turn of the transposed wire is equivalent to winding multiple turns of a single parallel flat wire.