Partial Discharge Characteristics in Bushing Under Dry and Wet Configuration

The unwanted condition known as partial discharge (PD) shortens the lifespan of power system equipment and permanently damages it. PD typically occurs in defect locations like voids, cavities, cracks, and joints. In most cases, PD does not result in an abrupt breakdown. It is possible to assess the damage caused by a discharge based on the type of discharge, such as electrical treeing, surface or internal discharge, corona, etc. PD noise reduction PD indicators and diagnosis The two main fields of study in the analysis of PD are sources. For power apparatus to operate safely and to be monitored for malfunctions, the PD signal must be measured and identified. Transistor bushings are insulators that make it easier for a current-carrying, energized wire to pass through the grounded transformer tank. Draw-lead bushings are also referred to as bushings with built-in conductors, such bottom-connected bushings, or bushings with holes for a separate conductor to be drawn through the center of the bushing. Bulk or solid type and capacitance-graded (also known as condenser type) bushing construction are the two main varieties. The low voltage winding(s) of a transformer's solid bushings is often encased in an epoxy or porcelain insulator. Transformer high voltage windings employ capacitance-graded bushings since they are made for higher voltage ratings. Transformer asset owners place a high value on bushing quality because they are frequently cited as one of the main reasons for transformer failures. Typical bushing failure modes include a damaged tap connection, corrosive sulfur, and moisture infiltration. Electrical field testing provides information on the integrity of the bushings.