Wide-area protection scheme for active distribution networks based on phase comparison

The massive penetration of distributed generations (DGs) into electric distribution networks may reshape it from a passive system to an active network with bi-directional power flows, and have a serious impact on the system contribution to fault current. These effects may cause severe troubles for the coordination of existing current protection system. Phase comparison differential protection serves as a better option for active distribution networks (ADNs) due to its simplicity, sensitivity and selectivity. This paper proposes a new wide-area protection scheme for ADNs based on phase comparison. Wide area measurement system (WAMS) is used for time synchronous measurement and communication. An active distribution network model with high amount of DGs is established in PSCAD/EMTDC. Theoretical analysis and system simulation results validate the effectiveness and feasibility of the proposed method.