Dynamic Operational Risk Evaluation of Power Systems Considering Renewable Energy Generation Variability

The continuous and rapid development of renewable energy generation (REG) has led to significant changes in the operating characteristics of power systems. Power system operation is increasingly threatened by multi-source uncertainties, such as equipment failures and REG fluctuations. Thereby, the operational risks of power systems which include the load shedding risk, REG curtailment risk, and transmission line overloading risk, are rising. This paper proposes a framework that evaluates the operational risks in a comprehensive and dynamic manner. First, a set of systematic evaluating indicators are developed to measure the operational risks. Then, an elaborate method is proposed to address the computation burden of operational risk evaluation due to the massive system states that need to be analyzed by the complicated OPF model. On one hand, the uniform design method is customized to reduce the sample size of system states for operational risk evaluation. On the other hand, the cheap-to-evaluate surrogate models are constructed to replace the original complicated system state analysis models. Based on the proposed methods, the dynamic operational risk evaluation is achieved, i.e., the evaluation results can be updated timely when the REG output or load demand changes. Simulation results verify the effectiveness of the proposed methods.