The disk-shaped windings may involve a single bundle or several bundles of interlaced and isolated conductors in a series-parallel orientation of interconnected horizontal discs. Each disc contains several turns, one on top of the other, with alternating intersections between interior and exterior.
The life of a transformer is related to its insulation system, its insulation material and the process of producing the material. The characteristics of the insulation system depend on the conductor geometry, the dielectric composition, temperature gradients and the characteristics of all the combined materials that have been applied. LOR400SAP44
Most transformers with this type of winding belong to the voltage class of 25 kV, and are usually of the core type involved. Given the high voltages studied in the tests and their operation, we must pay special attention to prevent high mechanical stresses between the disks and the ends of all the turns when subjecting the equipment to transient voltage peaks. Several techniques have been developed to support an allowable voltage distribution throughout manufacturing under these conditions.