How is partial discharge (PD) monitored in transformer bushings?

Partial discharge (PD) in transformer bushings is monitored using specialized sensors that detect electrical discharges within the bushing insulation. These sensors measure the transient electrical pulses generated by PD events. Monitoring systems can be permanently installed on the bushing or used for periodic inspections. PD analysis is often combined with other diagnostic techniques, such as infrared thermography or acoustic emission monitoring, to detect insulation degradation. Early detection of PD helps prevent insulation failure by allowing maintenance teams to take corrective action before a breakdown occurs.