Supervision of power swing blocking using model-based distributed intelligence relaying framework

Abstract

The power swing phenomenon is characterized by oscillations in power flow between two areas of a power system due to an abrupt imbalance in mechanical and electrical power. Unintentional operation of distance relays during power swings can propagate a disturbance and result in a cascading outage. It is therefore critical that relays operate securely under such conditions. Modern distance relays can provide a function for power swing blocking (PSB). However, the PSB settings can be difficult to calculate without extensive stability studies and may fail to block if the slip frequency is too fast. In this work, we investigate the application of a model-based relaying framework applied to power swing blocking. The framework is named Model-Based Distributed Intelligence (MBDI) because it integrates, at the relay level, real-time knowledge of the network structure and system state in the form of simulation circuit models. We investigate the efficacy of a relay equipped with MBDI to supervise PSB operation during power swing and fault scenarios.