PROJECT TITLE :

Enhanced distinction of surface and cavity discharges by trapezoid-based arbitrary voltage waveforms

ABSTRACT:

Identification of different partial discharge (PD) sources could be improved by the utilization of non-sinusoidal waveforms of the testing voltages. For instance, surface discharge (SD) and cavity discharge (CD) are not continuously simple to directly distinguish from the part resolved PD pattern at traditional fifty or 60 Hz alternating sinusoidal voltage. This study compares PD patterns stimulated by sinusoidal voltage and by several forms of trapezoid-wave voltage, as well as the limiting cases of triangular and approximately square-wave voltages. Trapezoid-based mostly voltage waveforms are thought of as a possible new off-line diagnostic technique for PD sources. Partial discharge measurements were performed with each completely different waveform in two test cells representing canonical cases of SD and CD, with polycarbonate plates because the solid insulating material. The results show that the applied voltage of arbitrary waveform might additional clearly distinguish between these PD sources' behavior than traditional sinusoidal voltage. The constant-voltage period of peak value in trapezoidal and sq. voltage waveforms played an necessary role in the distinction of the 2 discharge sources. Compared with the cavity discharge's symmetric options, surface discharge made within the uneven test cell shows robust uneven behavior during the constant-voltage period between two polarities underneath trapezoidal and sq. voltage waveforms. A faster rise time and increased duration of the constant peak-voltage part of the waveform caused a lot of obvious asymmetry of the surface discharge.