Underfrequency load shedding scheme for systems with large penetration renewable variable generation

Under-frequency load shedding (UFLS) is well-known and widely used emergency control scheme to prevent system instability under disturbances that cause large imbalance between load and generation. A properly design UFLS scheme should be able to shed the minimum amount of load necessary for a safe and smooth transition of the system from emergency condition to a normal operation state. As penetration of renewable generation increases, the dynamic behavior of power system changes, and consequently, the performance of the UFLS is affected. This paper presents an analysis of the impact of renewable generation integration on the optimal design of a UFLS scheme. The analysis is performed in a generic power system model implemented in PSS-E software. Several scenarios with different levels of wind generation are evaluated for the analysis. For each dispatch scenario, various combinations of generation disturbances are simulated.