Operational flexibility in distribution networks: application of CNAIM to facilitate planned outages

This paper explores how Common Network Asset Indices Methodology (CNAIM) was used to value risk during a practical demonstration of flexibility services in response to a series of planned outages. A model is developed which looks at a range of health indices and explores their effect on the probability of failure. Results from this analysis showed that probability of failure is directly proportional to the overall health index of the circuit. The implementation of this methodology showed that in situations where data is limited, this model is a valuable estimation tool however it does possess some limitations. For Distribution Network Operators (DNOs), this method presents an option to justify the use of operational flexibility and offers a perspective on the effect of mitigating Customer Interruptions (CI) / Customer Minutes Lost (CML) penalties through the use of flexibility services. This paper concludes that a model utilising CNAIM can be used to estimate the financial risk associated with network outages, providing justification for the procurement of flexibility services.