Obtaining the electrical parameters of the predischarge in air by using digitized voltage waveforms

Important information about the physics of the discharge process can be obtained by analyzing the dynamic behavior of the circuit electrical parameters voltage, current, resistance and energy. However, the normalized testing procedures ignore these parameters and the breakdown probabilities of the insulation are presented only in terms of a breakdown probability voltage (mainly 10% or 50%), or in terms of a discharge probability function. To use the enormous amount of information obtained during an impulse voltage test procedure and to take advantage of the use of computers in high-voltage laboratories, the Single Stress Method -SSM- has been proposed. As it is explained in the present paper, the captured oscillographic digitized voltage waveforms obtained during the application of the SSM test procedure were processed. Numerical methods were used to derive the non-measured parameters of the circuit: current, resistance and energy dissipated in the discharge path.