Synthetic polymer papers suitable for use in EHV underground cable insulation

This relates to the applicability of Tenax
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paper made of poly(2,6-diphenyl-p-phenylene oxide) fibers to EHV cable insulation. Tenax paper shows excellent thermal stability in DDB impregnant even at 150° and its impulse strength has been improved significantly. Long-term dielectric test on model cable suggests that Tenax paper insulation may provide an EHV cable capable of operating at 25 kV/mm and 120°. Some experimental 275 kV cables are manufactured and offer much valuable imformation. Additional calculation based on the data available indicates that Tenax paper insulated oil-filled cables rated at lOO0 KV may offer much power capability advantage.