Mechanical and electrical performance of polypropylene paper laminates versus cellulose paper for power cables

The authors present the results of laboratory evaluation of polypropylene paper laminates manufactured by Japanese, European, and North American suppliers and their performance as compared with conventional cellulose paper dielectric. The physical properties of the laminates, and the mechanical and the electrical performance of model cables constructed from them were evaluated. All three laminates had similar loss characteristics, which were significantly lower than those of cellulose paper. The impulse strength of the Japanese and European laminates was approximately 20% higher than that of cellulose paper, whereas the North American laminate exhibited only 10% higher impulse strength. The effect of perforations on the impulse strength of the laminates was also investigated, the idea being that perforations would improve drying and impregnation. Results indicate that perforation geometry significantly influenced breakdown strength