Abstract：As more and more wind farms are integrated in to power system, risk assessment based on enumeration method may take too much time to meet the computation time requirement of system operation because the enumeration method has combination explosion problem. With consideration of forecasting errors of multiple wind farms, this paper proposes a fast computation method for risk assessment. The paper clusters the input samples based on K-means. Cumulant and Gram-Charlier series expansion theory are applied to compute the cumulative distribution of node voltage and branch flow. According to the cumulative distribution, the probability of over-limit can be computed. Risk indices are computed by the product of the over limit probability and the impact. Case study on a practical power system demonstrates that the proposed method meets system operation's accuracy and time requirements.
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2021, Vol. 36 
