A study of the impact of peak demand on increasing vulnerability of cascading failures to extreme contingency events

The vulnerability of large power systems to cascading failures and major blackouts has become evident since the Northeast blackout in 1965. PNNL developed Dynamic contingency analysis tool (DCAT) provides a framework to accurately simulate cascading outages of power system using both dynamic and steady state analysis including protection simulation. Using this tool, a study to investigate the impact of peak loading on grid stress and potential cascading is presented in this paper. To examine loading effect, multiple base cases corresponding to different load levels are developed with the IEEE bus 300 system and dynamic PSS/E models with protection schemes for generation, transmission, and load integrated with base cases. The impact of several extreme contingencies under different loading conditions is simulated using DCAT as hybrid dynamic and steady-state simulations to mimic the cascading outage process. Analysis is then performed to show how the increase in loading condition increases the vulnerability of cascading failures occurrence. From the simulation results, it is observed that increasing peak load demands lead to more cascading failures than uniformly distributed loads.