Overview of methods for voltage sag performance estimation

Voltage sags may cause malfunction of customer equipment and interruption of customer processes. Voltage sag performance should be quantified to incite informed decisions from utilities, customers, and regulators. This paper describes existing voltage sag performance estimation methods and classifies these as either model- or measurement-based, depending on the data required for implementation. Model-based performance estimation is classified either as mean performance estimation or Monte Carlo approach. The methods of fault positions and critical distances, as well as derivatives of these, fall under the first group, while Monte Carlo techniques applied either to short-circuit calculations or EMTP models fall under the second group. Measurement-based performance estimation includes regression based on site and system characteristics, and conventional state estimation formulation.