Incorporating Line Security Constraints within Network Planning for Dynamic Line Rating Systems

In order to maintain system security levels against a backdrop of generation and demand growth, network planners may require grid expansion and/or line modification measures. Traditionally, this has been achieved by uprating existing lines and constructing new lines. However, technical, environmental, cost and timeliness concerns can encourage the adoption of dynamic line rating (DLR) systems, as part of enhancing the utilisation of the existing network. Hence, a novel approach is presented here for planning reconductoring and DLR systems, relating to the implementation of security constraints. A multi-year stochastic mixed integer linear model for line N-1 short time security is developed, incorporating a unit commitment stage, which is later solved using Benders decomposition. An additional pre-optimisation stage, which can be efficiently parallelised, is introduced to largely support the burden of incorporating the security constraints. In addition, staged investments for individual lines, including applying DLR before later reconductoring, is investigated. The effectiveness of the proposed approach is shown for the IEEE RTS 24 bus system.