The effects of load demand uncertainty on cascading overload failures in power systems

In contemporary power systems, the potential for cascading failures and subsequent blackouts looms large, particularly under significant system stress. This stress often stems from uncertainties in renewable power generation and fluctuations in load demand, both of which pose formidable challenges to grid stability. This paper presents a comprehensive analysis of the impact of load demand uncertainty on cascading failures, addressing a notable gap in existing literature. We propose a novel analysis methodology that integrates load demand uncertainty modeling with stress assessment techniques based on Line Outage Distribution Factors. Leveraging an alternating current power flow model, simulations are conducted to gauge system vulnerability and identify critical contingencies, with cascading severity assessed using metrics such as the relative frequency of load shedding and disconnected lines. Importantly, the methodology pioneers the exploration of two risk measures in the context of cascading failures: Probable Maximum Loss and Spectral Risk Measures. To demonstrate the applicability of the proposed methodology, a detailed analysis is conducted on the IEEE 39-bus system, serving as a representative model of the 345 kV New England power system. The findings underscore the significance of load demand uncertainty and its impact on cascading failures, providing valuable insights for enhancing system resilience and risk management strategies. Through this comprehensive approach, the study contributes to advancing understanding in the field and offers a robust framework for addressing the complex challenges posed by cascading failures in power systems.