Using the CNAIM methodology for 10-20 kV PILC cables

An increasing number of Danish distribution systems operators (DSO) are implementing the CNAIM methodology develop and used in Great Britain in their risk management of distribution assets as a part of their asset management. The methodology is used to calculate the condition-based risk for distribution assets. One asset group important for Danish DSO’s is 10 kV (MV) PILC cables, which are not included in the CNAIM methodology. In this paper focus will be on calculating the CNAIM methodology’s PoF (probability of failure) parameter for 10 kV (MV) PILC cables based on Danish failure statistic for PILC cables and their age distribution. The calculated PoF are then compared to the observed age dependent failure rate for MV PILC cables in Denmark to see how well the PoF based on the CNAIM methodology fits the observed failure rates.