Partial-discharge detector for in-service cables and joints under normal network operating conditions

An evaluation of commercially available partial-discharge detectors was undertaken at IREQ to find a safe device for splicers working in manholes on underground 25 kV electrical distribution networks. Laboratory and field tests were conducted to compare different devices from the standpoints of sensitivity, resolution and equipment characteristics. The radio-frequency approach was then adopted as the underlying principles for a new design of PD detector using different types of probe. A second-generation device has been built, calibrated and successfully tested both in the IREQ High-Power Laboratory and on Hydro-Quebec´s 25 kV underground distribution network for measuring PDs on cables and joints under normal network operating conditions