A Study of Application of Cable Lapping Theory to EHV Cables

Two categories of lapping theory for paper-insulated cable are reviewed. The first category, old and established, analyzes the structure of the paper lapping which influences the electric strength of the cable in terms of the paper registration only, e.g. 65/35 registration. The second category, recently developed and based on the mathematical theory of elasticity involving both the paper dimensions and its physical properties, aimed to obtain correct paper tensions for lapping. The result was the elimination of creases and wrinkles, which are always potential sources of dielectric weakness.