Sensitivity Factors Report

The TRANSITION[1] project is an Ofgem NIC funded 5-year project from 2018-2023, led by SSE-Networks, that aims at further developing DSO experience and capability with deploying local flexibility markets. Part of the objective of the work is to design several new commercial processes for flexibility markets, but also the suite of technical tools and systems required to support and deliver them. Two of the TRANSITION technical tools in particular focus for this specific report are called the Select and Dispatch (S&D) tool, and the Power System Analysis (PSA) tool.

The PSA tool (built around the core engine of the DIgSILENT PowerFactory product) has the task of evaluating where any constraints exist on the network, and the S&D tool has the role of contracting for flexibility responses from customers to mitigate them. Because the location of the flexible assets may be far from the point of the constraint, and because electricity networks may have complex topology conditions, then these two tools need a way to communicate the relative impact of flexibility action from a given market actor to relieving congestion at a distant point of constraint in the network.

That paired impact of a given flex asset dispatch action on a specific network constraint element is encapsulated in a metric called the “Sensitivity Factor” (SF), and this report summarises the TRANSITION work to both define this metric, and also to design a robust numerical procedure to calculate it in a practical setting of a real DNO network.