Development and Application of a Programmable Partial Discharge Calibrator

A programmable partial discharge (PD) calibrator composed of an arbitrary waveform generator that is series connected to a capacitor is described. The voltage waveform supplied by the generator is software controlled. The characteristics and capabilities of the calibrator are presented, and the procedures used for its characterization are discussed. The calibrator can reproduce different types of pulses, which include both the corona and PDs of random amplitudes and the predetermined phase relationship with respect to the high-voltage (HV) supply. Examples of the actual discharges measured in the laboratory are compared with the corresponding pulse sequences generated by the calibrator. Finally, by means of this developed instrument, the performances of four partial-discharge-measuring systems equipped with analog and digital measuring instruments are investigated and compared by generating suitable pulse charge sequences.