Blackout Probabilistic Risk Assessment and Thermal Effects: Impacts of Changes in Generation

Renewable energy integration and deregulation imply that the electric grid will be operated near its limits in the future, and that the variability of cross-border flows will increase. Therefore, it is becoming more and more crucial to study the impact of these changes on the risk of cascading failures leading to blackout. We propose in this paper to emphasize important factors leading to blackouts, to review methodologies which were developed to simulate cascading failure mechanisms and to study specifically the impact of thermal effects on the risk of blackout for several changes in generation (variations in cross-border flows, wind farms penetration, shut-down of power plants). This is studied by applying to a test system the first level of a dynamic probabilistic blackout risk assessment developed previously. We show that taking into account thermal effects in cascading failures is important not only to have a good estimation of the risk of blackout in different grid configurations, but also to determine if a specific change in generation has a positive or a negative impact on the blackout risk.