Partial Discharge Monitoring

Partial discharge monitoring detects small electrical discharges within insulation systems before they develop into major faults. It provides early warning of insulation deterioration in HV equipment such as switchgear, transformers, GIS and cables.

Partial discharge activity can indicate developing defects that may lead to equipment failure, unplanned outages or safety risks. Monitoring helps asset owners identify problems early, plan maintenance and extend the life of critical electrical assets.

Online partial discharge testing is carried out while equipment remains in service, providing condition data without planned shutdowns. Offline testing is performed when equipment is isolated and can be useful for detailed investigation, commissioning or fault diagnosis.

HV switchgear is a common source of partial discharge activity due to ageing insulation, contamination, poor connections or installation defects. Monitoring helps detect early warning signs before failures affect safety, reliability or continuity of supply.

Partial discharge in transformers can indicate insulation weakness, winding issues, bushing defects or internal degradation. Monitoring supports condition-based maintenance and helps reduce the risk of costly transformer failure.

Gas Insulated Switchgear can develop partial discharge due to particles, insulation defects, voids or installation issues. UHF and other monitoring techniques can help identify developing faults in sealed GIS systems before they become critical.

Partial discharge monitoring for HV cables helps identify insulation defects, joint problems, termination issues and ageing-related deterioration. Early detection supports targeted maintenance and reduces the risk of cable failure

Partial discharge monitoring can use a range of sensor technologies, including TEV, ultrasonic, HFCT, UHF and acoustic sensors. We can help identify the most suitable monitoring approach based on asset type, risk profile and operational requirements.

We provide UK partial discharge survey services to help assess the condition of HV assets and identify early signs of insulation deterioration. Surveys can support maintenance planning, risk reduction and decisions on permanent monitoring.