An Integrated Approach to Improving Power Grid Reliability: Merging of Probabilistic Risk Assessment with Resilience Metrics

The resilience of a system is often disconnected from its reliability. For many types of systems the sacrifice of nonessential processes may be acceptable for maintaining a resilient set of core operations. For the electric grid, however, this often translates to load shedding. Combining Idaho National Laboratory’s probabilistic risk assessment tool SAPHIRE and adaptive capacity measurement software PowDDER can provide insights for improving the electric grids ability to absorb disturbances. A quick survey of major power outages revealed that high wind related storms causing toppled power lines and failed transformers were most commonly associated with major power outages. These findings validated SAPHIRE’s output of most critical components for the IEEE 14 bus model during a windstorm scenario. SAPHIRE provided the probabilities of critical equipment being unavailable, providing insight into the likelihood a particular threat scenario would play out. An analysis of PowDDER revealed sensitivities within the system’s overall resilience could be improved by reducing the reliability of Load 10 (via load shedding). Combining information from both PowDDER and SAPHIRE enables one to consider preemptive strategies that would improve system resilience and system wide reliability simultaneously.