Voltage Sag Assessment for Distribution Network Containing Distributed Generation

The voltage sag of distribution network containing distributed generation(DG) is assessed.Simulation models for synchronous machine-based DG and inverter-based DG are built respectively;then based on EMTDC/PSCAD and by use of Monte Carlo method the typical distribution network containing DGs are simulated,and the system average root mean square frequency index are utilized as the indices to evaluate voltage sag at different nodes.Based on a lot of simulation examples,the influences of the types,control strategies,output power and grid-connected positions of DGs on voltage sag are analyzed.Simulation results show that connecting inverter-based DG to power grid can decrease the frequency of occurrence of voltage sag in distribution network;the control strategy,output power and grid-connected position of DGs exert influences on voltage sag.This conclusion is available for reference in the configuration of DGs and the mitigation of voltage sag.