Proactive Defense Strategy Against Uncertainty Induced Voltage Disturbance Propagation in Deregulated Market Oriented Greener Grids

Renewable resource proliferation results in clusters with reactive power interdependence within emerging deregulated power grids. The clusters generally form as balancing areas (BA) and the reactive power interdependence is endured through voltage-controlled areas. In such grids, renewable generation uncertainty could manifest as propagating voltage disturbances towards the relatively weaker clusters. Operational and topological constraints of locally optimized conventional reactive support systems limit their capability in alleviating the propagation. This work demonstrates voltage disturbance propagation between BAs and proposes a framework to defend and mitigate them. The framework comprises a proactive resource procurement followed by a proactive first line of defense and a two-stage mitigation strategy. The strategy intelligently utilizes distributed resources through wide area supplementary control. The strategy avails the cyber-physical features of the grid to formulate the multi-criterion decision logic and associated defense as well as mitigation plan. This complex process is realized by an analytical hierarchical process (AHP). Extensive case studies conducted on modified IEEE 68 bus system illustrates the vitality of this decision logic and validates the effectiveness of defense plan and real-time mitigation strategy. The proposed approach also leads to better utilization of available reactive resources and facilitates improved participation in the deregulated market.