Network reliability framework integrating demand response and flexible OHL ratings

The need for flexible power networks has become an emerging challenge for network operators. The utilisation of emergency loadings and probabilistic thermal ratings for overhead lines (OHLs) are vital flexible options to the network operators. So far, the impact of the ageing risks associated with such OHLs operation on reliability and the operators' managing actions to mitigate this impact, have not been thoroughly investigated. This study presents a novel methodology for optimising the available demand response in the network at emergency conditions for minimising the network ageing risks and network expected energy not supplied considering the criticality of an individual line's ageing. This methodology facilitates the analysis of the trade-off between ageing and reliability. An index, defined as expected equivalent Line ageing, is also formed to quantify the network ageing; this associates the OHL ageing directly with the available demand response at the network busses. A case study on the IEEE RTS-96 indicated a reduction on the network expected energy not supplied and expected interruption costs by almost 42 and 34%, respectively, while reducing the overall network ageing risk by 58%, enabling operators to extend the end-of-life of critical OHLs.