Adaptive under‐frequency load shedding scheme for power systems with high wind power penetration considering operating regions

Abstract

Abstract With the ever‐increasing penetration of wind power into power systems, wind turbine generators (WTGs) are required to provide frequency regulation services to maintain the system frequency stability. For variable‐speed WTGs, the adaptability of dissimilar frequency control strategies to different operating regions is distinct, which impacts the system frequency response. However, existing under‐frequency load shedding (UFLS) schemes do not take that impact into account, causing improper load shedding after a loss of generation. To this end, this paper proposes an adaptive UFLS scheme for power systems with high wind power penetration considering operating regions. Based on the WTG operating characteristics in different operating regions, the appropriate frequency control strategy for each operating region is elaborated. The simplified frequency response model of the power system considering WTGs participating in frequency regulation is then established. According to the WTG active power response characteristics in different operating regions, the impact of WTGs participating in frequency regulation on UFLS is analysed. Accordingly, the method of accurately estimating the magnitude of the power deficiency and calculating the amount of load to be shed is proposed. Finally, the feasibility and effectiveness of the proposed UFLS scheme are verified through simulations on the IEEE 39‐bus test system.