The objective of this project will be to identify solid cable assets operating at 33kV, 66kV and 132kV where it would be cost beneficial to customers to replace, as opposed to carrying out multiple fault repairs. By carrying out this analysis a cost benefit can be proven for the replacement of old cables to ensure best value for customers.
The specific objectives are:
- Collation of historic faults with asset registers in place (linking to the fault to cable information)
- Analysis of faults and trends for cables operating at 33kV, 66kV and 132kV, leading to identification of factors that affect the likelihood of failure of solid cables
- Collation of all sources of information into a model to allow identification of cables at increased risk of fault
- Output of model to identify cables where replacement would be beneficial to customers
The project will review fault history of solid cables to identify how prioritisation of investment can be made to reduce CIs and CMLs. It is planned this will be carried out by:
- Collation of all recorded faults on the network
- Extraction of all data on cables (GIS, asset registers, cable loading history)
- Analysis of faults against cable type (construction type, location, voltage, age, type of lay, historic loading)
- Identification of factors that affect the likelihood of failure of solid cable
- Following analysis of historic faults and identification of solid cable failure factors
- Development of model to input all current data on cables (construction type, location, voltage, age, etc.) to calculate prioritisation of replacement for cables.
The above analysis will be based on faults at EHV voltages, to enable sufficient data to be collected for statistical analysis.
Learning that will be shared with other DNOs is expected to include:
- An improved understanding of causes of failure of solid cables;
- A method by which other DNOs prioritise replacement of solid cables; and
- A method to reduce CI and CMLs that is cost beneficial to DNOs and customers.