Comprehensive decision-making method considering voltage risk for preventive and corrective control of power system

This study proposes a comprehensive decision-making method considering voltage risk to coordinate preventive and corrective control for voltage stability of power system. The voltage risk is quantified in the form of economic index with considering the uncertainty of postulated contingencies. Then, a non-linear optimisation model with the objective of minimising voltage risk is performed to coordinate the preventive and corrective control. The positive constraint relaxation algorithm (PCRA) is presented to determine the integrated countermeasures. Based on the principle of PCRA, the failure with the smallest severity factor in the set of preventive fault is selected as an emergency fault. With the changes of the fault sets, the voltage risk and the countermeasures are recalculated until that the risk is no longer reduced for the expected contingencies. The proposed method is significant not only to achieve the optimum balance between the security and economy of stability control, but also improve the decision efficiency. Finally, the proposed method is demonstrated on the New-England 39-bus system, and the results validate the effectiveness of the proposed method.