Incorporating health indices into a composite distribution network risk model to evaluate asset replacement major projects

The use of condition based risk management (CBRM) to prioritise asset replacement on electrical distribution networks has become widespread, typically through the calculation of health indices for each asset. A separate methodology has also been developed for evaluating network risk on both simple and complex EHV networks. By combining this risk methodology with CBRM techniques, a composite model has been developed to predict the consequences of replacing, or of not replacing, individual assets or combinations of assets. This model can be used to inform the distribution network operator's asset replacement decisions, enabling them to become more cost effective. The present paper describes the model, and applies it to regions of the actual distribution network in the North of England.