Nonintrusive partial discharge measurements on high voltage switchgear

Partial discharges in high voltage metal-clad switchgear can result in catastrophic failure of the individual plant and in some cases of the substation. There has been a need for detection and location of the damaging discharges without the plant or substation being taken out of service. The conventional partial discharge detection technique requires direct connection to the high voltage busbars and therefore is limited in application. The EA Technology Partial Discharge Locator and Partial Discharge Monitor are designed to fulfil this important requirement. These instruments are complemented by ultrasonic detection to provide a comprehensive service to both Regional Electricity Companies and industry. The Partial Discharge Locator and Partial Discharge Monitor both use the Transient Earth Voltage (TEV) measurement technique. The Partial Discharge Locator is a portable instrument used to survey switchrooms taking approximately an hour to survey a ten panel switchboard. The Partial Discharge Monitor is installed for a week monitoring a switchboard and provides a means of detecting intermittent partial discharge activity which may be missed by a survey with the Partial Discharge Locator