Resilient protection scheme preserving system integrity during stressed condition

During stressed system condition, power flow in transmission lines may substantiate and affect seen impedance of distance relay resulting in maloperation. Such a situation may initiate cascaded tripping leading to blackout. Proper coordinated blocking and tripping schemes of distance relays become essential to avoid such a relay malfunction and thus preserving system integrity. In this study, a resilient protection scheme is proposed employing adaptive zone‐1 setting, thereby preventing relay maloperation during stressed system condition. The scheme uses a prefault data of both end distance relays to accomplish the proposed adaptive relay setting for the purpose. The performance of the proposed scheme is tested on the IEEE 118 bus system using PSCAD/EMTDC simulation data and is found to be accurate.