Partitioning of power networks and applications to security control

The performance of power-system application programs, such as online contingency analysis and security control, VAR control, etc., can be significantly improved by partitioning a power network into strongly connected subnetworks, and by using only the most appropriate subnetworks. Unreferred portions of the network can be modelled by an external equivalent that reduces each unreferred subnetwork to a single PV busbar. A network partitioning algorithm based on the electrical distances among the system busbars is proposed. Results are also presented on the use of the partitioning technique in a security-control algorithm for alleviating system emergencies (thermal overloads and voltage violations) by transmission branch and shunt device switching, and real and reactive power generation rescheduling