Studies on Voltage Sag in Distribution Network Containing Distributed Generations

The operational state of distribution network will be changed when a large number of distributed generations (DGs) is installed in, which may cause power quality problems. In this paper, a voltage sag analysis model of distribution network containing DGs is built and simulated based on EMTDC/PSCAD. The voltage sag characteristics are extracted precisely from the simulation results by the Moving Window Method. Simulation results show that interconnecting inverter-based DG to distribution network can mitigate the voltage sag to some extent. The control strategy, installed position and output power and of DGs also exert certain influences on voltage sag. All these conclusions are available for reference on mitigating voltage sag with DGs installed in the distribution network.