Partial discharges are electrical discharges occurring in the insulation layer of electrical equipment (cables, switchgears, circuit breakers, etc). They are called partial, as they do not completely bridge the space between the two conducting terminals.
Partial discharge can occur in many parts of an electrical grid, where high voltage exists and is surrounded by some type of insulation (solid, liquid, air). Due to their localized and repetitive characteristics, they build over time and result in insulation breakdown in transformers, power cables, and cable accessories.
Learn more about how high-performance digitizers are used in partial discharge monitoring for maintenance and preventive replacement planning in power grids.