Winding

 

The windings, generally, are cylindrical and are arranged concentrically. The advantages of concentric windings are simplicity, symmetry, good mechanical resistance to short-circuit forces and ease of arrangement of cooling ducts.

Various type of windings made by us are helical winding, layer winding, spiral winding, continuous disc winding and interleaved disc winding. Foil winding is used for high current medium power transformers. Our standard practice is to use a separate tapping winding for transformers. The outside tapping barrel ensures that the voltage adjustment taps do not upset the ampere-turn balance seriously in any position, as the tappings are distributed over the entire height of the coils.

Generally, the low voltage coils are wound on an automatic foil winding machine. The high voltage coils are wound on microprocessor controlled winding machines. Using these winding machines ensures proper control on manual inputs. Controlled tensioning of the conductor & insulation, as well as precision wire laying, result in accurately dimensioned coils, which are in conformance with the design parameters.

To minimize the forces developed during short circuit, careful attention is paid to the design employed for the coils and the materials used. The prudent selection of insulating material, in addition, prevents radial and axial movements of the conductors and the coils, which usually are the primary contributing factors leading to the failure of the transformers in operation. The LV windings for distribution transformers are made out of Copper Foil or Paper or Enamel insulated Conductor. The HV windings are made of round / rectangular copper conductors insulated by enamel or paper. The inter-layer paper is epoxy diamond dotted paper, to give proper adhesion to the layers. The winding process is carried out in a climatically controlled environment, thereby also eliminating the possibility of ingress of dust.