Abstract :
The principal factors limiting the safe working electric strength of modern low-loss insulation are electrochemical deterioration and breakdown caused by internal or surface discharges. In the paper the mechanisms of deterioration and breakdown by discharges are discussed in detail. Special consideration is given to the effects of the amplitude, frequency and waveform of the applied voltage on the discharge sequence and on the rate of dielectric deterioration. Suggestions are made for supplementary industrial tests to assess the resistance of materials to internal and surface discharges.
