The relation of capacitance increase with high voltages to internal electric discharges and discharging void volume

Historically, power factor “tip up” or increase with voltage as a result of internal discharges has been a sort of qualitative indication of internal discharges and of an insulation quality. In European countries, the slope of the rising power factor voltage curve has been used in specifications of high voltage generator insulation. It is the purpose of this paper to emphasize the value of considering the capacitance increase associated with internal discharges at high voltages.