Defining the Simulation Scope for Extreme Events

This report investigates extreme events through the means of using three large, recent reports into different types of extreme event to determine what constitutes an extreme event, what data is likely to be necessary to model it, and what compromises are likely necessary to make such modelling possible. The discussions consider the use of weather data in power system analysis, the modelling of cascading outages within the power system, and the potential of attacks on the cyber-physical system which constitutes the power system. Recommendations are then made in terms of how weather data should be used, what types of power system simulations are necessary, and what metrics are likely to be useful in such analyses. It is suggested that an extreme event be defined as “any event that, without suitable mitigating actions, would cause, as a result of conditions arising from that event: interruptions to a large number of end users’ supply of energy, beyond those that could be expected due an outage of any single item of energy system plant; extraordinary energy market conditions, or; interruptions of energy supply to significant elements of critical national infrastructure ”. This captures all potential extreme events that are likely to be simulated; those associated with correlated weather events; those associated with an extended abnormal weather or operational conditions; those incurred by cyber-physical attacks on the power system. Different scenarios are proposed which would be appropriate to simulate to help define a clearer scope of what simulations to undertake, for example modelling an extreme windstorm similar to Storm Arwen.