Probabilistic assessment of voltage sags in power systems

A systematic set of indices for probabilistic assessment of critical power system voltage sags, including the customer-orientated and global system-orientated indices is established. The indices systems is concise and complete. The authors also develop a practical approach, named step by step analysis, and the corresponding software tool for addressing the calculations of these indices. This is a novel analytical method in which conventional short-circuit tools have been associated with failure rates of transmission line and in advanced probabilistic calculus. The probabilistic prediction methodology allows both the utility and end-users to, objectively and quantitatively assess the impact of voltage sags on electric systems. It is the first important step in determining the correct and economically feasible mitigation measures.