Partial Discharge Measurement and Cable Length: Meaning and Limits

Optimum detector bandwidth selection for partial discharge testing of high voltage power cables is discussed in this paper. The analysis is based on analytical models already described in literature, whose parameters have been validated by lab tests. The results indicate that when testing cables system on an accessory-per-accessory basis a detection bandwidth of few tens of MHz ensures: (a) large sensitivity to PD that could originate in the accessories as well as in the cable, (b) the capability of separating pulses coming from different parts of the power system and, thus, providing an approximate location of PD sources.