Cascading Failures Caused by Frequency Collapse in Coupled Oscillatory Power Network

Power network is one of the critical infrastructures, aiming to supply a reliable power. In general, some accidental and/or deliberate attacks may lead to large losses of power supply with severe social consequences. This paper considers a coarse-grained model of power networks using a swing equation depending on the synchronous machine. Furthermore, we investigate the dynamical cascades failure, which is induced by power flows exceeding the capacity threshold of the transmission line. Therefore, a simple and flexible condition for synchronization is derived, which provides a new perspective for preventing cascading failure in oscillatory power network. The developed control approach is applied to several power network models to demonstrate its capability for suppressing cascading failures. In addition, it is found that the control effect strongly depends on the choice of control law. The study might be useful for enhancing the robustness of the power network or providing a more robust power supply.