The effects of cellulose insulation quality on electrical intrinsic strength

Cellulose serves as raw material for various electrical insulating materials, for instance, insulation paper and electrical pressboard. The practical application of these insulating materials involves situations where a reduction in strength may occur due to impurities, structurally inhomogeneous features, and ageing of the cellulose, or by boundary layer phenomena. The insulating capacity is restricted by such effects. In addition to knowing the factors that cause a reduction in strength, it is also important to know the intrinsic strength of pure cellulose insulation. Knowledge of dielectric imperfections is necessary in order to take advantage of the higher intrinsic dielectric strength and thus to achieve an optimal application of the insulating material. Based on the cellulose structure, material and structural influences and their relation to dielectric properties are investigated, and suggestions are given for better implementation of electrical intrinsic strength of cellulose insulation.<>