Aging and related phenomena in modern electric power systems [comment and reply]

For original paper see ibid., vol. 28, no. 5, p. 826-844 (1993). Of all the highly interesting aspects of insulation aging which have been studied in this paper, we would like to comment on the detection of cavities in epoxy samples with the aid of the X-ray technique. The cavity irradiation must not be too weak since this may lead to intermittent partial discharges (PD). A too strong irradiation, on the other hand, may lead to quenching of the PD through pressure rise in the cavity. A reply is given.<
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