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Experimental investigation of ageing effect on the dielectric performance of FRP sticks

The dielectric performance of FRP insulator sticks, which have been in power system maintenance service for 15, 24 and 25 years respectively, have been investigated experimentally. The factors causing the deterioration of the samples are discussed. The dielectric current method was used to evaluate their performance. A homogeneous electric field was obtained by a properly designed electrode system. The experiments were conducted in a humidity controlled chamber. The results illustrate that the mechanical factor had a stronger impact on the deterioration of FRP sticks than the chemical one. The pretence of moisture caused accelerated deterioration and the hydrophobic property of FRP sticks changed with time.