Research on close-loop simulation for centralized coordination of protection settings

Distributed energy resources (DERs) pose great technical challenges in control, protection and energy management. To mitigate the effect of DERs and network configuration changes on the sensitivity and selectivity of protection system, a solution for an on-line re-coordination of the protection relays in the active distribution grid based on advanced communication, on-line DER and network connectivity information and results from off-line fault analysis was proposed. A close-loop simulation system is proposed to test the centralized adaptive protection system. Some technical requirements for close-loop simulation are discussed in the paper. With introduction of the testing platform, this paper analyzes the coordination between protection and wind turbine LVRT profile. The testing results show the feasibility and validity of close-loop simulation for adaptive protection for active distribution grid.