On the Persistence of Dominant Inter-Area Oscillation Paths in Large-Scale Power Networks

This article discusses the degree of persistence of dominant inter-area oscillation paths: the passageways containing the highest content of inter-area oscillations in large-scale power networks. To this aim, a number of contingency studies are carried out: faults being imposed on the lines connecting to the dominant inter-area path. The path persistence is then examined using the relationship between sensitivities of network variables (i.e. voltages and current, magnitude and angle), and mode shapes describing the contribution of the oscillations among the generators variables (e.g. speed and angle). This relationship is termed network modeshape. The larger in magnitude and the lesser the variation the network modeshape is, the more observable and the more robust the signals measured from the dominant path becomes. The outcome is a proposed signal combination to be used as inputs to the damping controller for mitigation of inter-area oscillations in large-scale power systems.