Research of islanding detection and islanding protection based on WAN phase comparison

Study PQ control mode of the inverter-based distributed energy resources(DER), and analyses its system characteristics while DER operating connected with distribution network. When the point of common coupling (PCC) between DER and distribution network is broken and the island formed, analyzed change characteristics of frequency and voltage phase and the influence of unbalanced power in islanding system, especially remarkable phase difference changes will occur between large power bus side and DER side voltage. Based on this the islanding detection and islanding protection method based on WAN phase comparison is proposed, the islanding detection criterion is the voltage phase difference between distribution network bus side and DER side, the synchronous measurement and calculation of voltage phase on both sides are completed by the feeder automation terminals (FTU), and realize information exchange through the rapid communication system. Based on Matlab, established the islanding detection simulation model, experimental results verify the reliability and applicability of the method..