Interval Evaluation of Voltage Sag Magnitude and Frequency in Distribution System

Aiming at the uncertainties of voltage sag evaluation and integrating the interval algorithm to existing stochastic evaluation methods, a interval-based method and approaches for the evaluation of voltage magnitude and sag duration were proposed. In this method, the interval characteristics of reliability parameters of components in distribution system and the variation of customer loading were considered and a interval evaluation method is proposed in order to assess the voltage magnitude and sag frequency in the distribution system based on existing fault location method. For the typical configuration of distribution system, the mathematical model and approaches were researched in detail on the basis of the algorithm of interval power flow. The proposed method was performed on RBTS-2 standard testing distribution system and compared with existing method with certain parameters. It is proved that it needs only one time of interval iteration process. The simulation results indicate that this method is reasonable and effective.