of the EPDM surge arrester (Fig. 8a) show the effects of
ageing in the level of erosion at different test time. The
electrical stress and the aggressive environment simulated
in laboratory have promoted degradation of the polymer
matrix in the housing composite. As indicated by the rows
in Fig. 8a, filler microparticles on EPDM insulating
material are seen after 2500 h until the end of the test,
while on the shed micrographs of the SiR surge arrester
(Fig. 8b), fillers are showed after 4150 h of test.
The replica technique has the advantage of making a
surface analysis of the sheaths which is almost impossible
by other methods. Figs. 8c and d show microstructures
observed by replication of EPDM and SiR sheaths at
4150 h of accelerating ageing. The environmental and
electrical stresses are more aggressive on this side of the
surge arresters because more eroded areas were observed on
the replica. In the case of SiR material, the degradation
process was caused mainly by corona activity, according to
results obtained from the measurement of visible corona
after 2500 h of testing, as it can be seen in Fig. 8d.
of the EPDM surge arrester (Fig. 8a) show the effects of
ageing in the level of erosion at different test time. The
electrical stress and the aggressive environment simulated
in laboratory have promoted degradation of the polymer
matrix in the housing composite. As indicated by the rows
in Fig. 8a, filler microparticles on EPDM insulating
material are seen after 2500 h until the end of the test,
while on the shed micrographs of the SiR surge arrester
(Fig. 8b), fillers are showed after 4150 h of test.
The replica technique has the advantage of making a
surface analysis of the sheaths which is almost impossible
by other methods. Figs. 8c and d show microstructures
observed by replication of EPDM and SiR sheaths at
4150 h of accelerating ageing. The environmental and
electrical stresses are more aggressive on this side of the
surge arresters because more eroded areas were observed on
the replica. In the case of SiR material, the degradation
process was caused mainly by corona activity, according to
results obtained from the measurement of visible corona
after 2500 h of testing, as it can be seen in Fig. 8d.
การแปล กรุณารอสักครู่..
