Adaptive impedance‐based out‐of‐step detection of synchronous generator without any network reduction

An adaptive technique for out-of-step (OOS) protection by modifying the impedance-based method is proposed in this study. Impedance-based methods are powerful and are operational in the power system as the main protection of OOS conditions. The setting of these relays depends on some parameters of the generator and power system that should be updated for the setting. The presence or absence of generator units in a power plant and transient conditions directly affects the machine dynamic parameters. Service or not in service of power lines and power system configurations can change the impedance of the power system at the generator terminals. Furthermore, to use the methods in a multi-machine power system, an equivalent two-area system is needed that is a complicated and time-consuming procedure. It should be made clear that these complexities limit the application of the impedance-based methods. Therefore, to remove these complexities, all factors that influence the relay setting are considered together in this research. The simulation results show that the proposed adaptive technique overcomes some of the problems and difficulties associated with impedance-based methods as well.