UMBRELLA Deliverable D 2.2 "Report on methods for system state forecasting"

The energy landscape of Europe has been altered heavily in recent years, especially due to an increase in power generation from variable renewable energy sources (RESs). Infeed from RESs and other uncertainties complicate the daily operational planning process and real time operation of transmission system operators (TSOs). Additionally, the uncertainties resulting from RESs are compensated by conventional power plants. The respective quantities are traded on intraday markets, which adds additional uncertainty to the decision making process in operational planning. The modelling of those uncertainties, which has been a major contribution of the UMBRELLA project is described in the project deliverable D2.1. Here, it is shortly recapitulated and a description of modelling reactive load and cross-border flow uncertainty is added. However, the main focus of the deliverable at hand is the translation of the additional information into measures that are directly usable by TSOs. This includes the computation of system state parameter distributions and the forecasting of critical system states. Therefore, system state parameters are defined and the merging of uncertainties is described in detail. How this information in combination with a security analysis can be used to forecast critical system states is elaborated as well.