Research On Propagation Regularity And Simulation Assessment Of Voltage Sags In Distribution System

The characteristics of voltage sags in PCC are analyzed firstly. Then the paper presents the influence of different types of transformer winding connections on the propagation of sags caused by symmetrical and asymmetrical faults in the power system. A simulation modeling of voltage sags is studied in this paper. Based on EMTDC/PSCAD, the paper founded Lang fang development zone distribution system. According to Monte-Carlo method, the random number is produced to simulate fault occurrence. By using Visual Basic.net, this study made up a simulation data processing system to carry out the analysis of the mass simulation data. Then the probability distribution of voltage sags on every PCC and the load profile and the assessment index were gained. The paper also studies the factors influence on the exposed areas of sags, and the law how to get exposed areas from one phase to another. At last, the exposed areas of this distribution system are plotted, and the best operation mode and sensitive load connection rules are proposed to reduce the loss caused by sags.