A distributed solution approach to centralized emergency voltage control

Voltage control and stability issues typically involve large networks with structurally diverse components extending over considerable areas and interconnecting different system grids and operators. In such a setting it is of the utmost importance to be able to effectively coordinate the control actions among the various operators whilst preserving sensitive local system data that regional operators are not willing to disclose. In view of these two discording factors centralized and decentralized control schemes respectively yield advantages and drawbacks, as the former require the global system data to be accessible whereas the latter may prove to be difficult to effectively implement if realistic performance requirements and constraints are imposed. The present paper therefore proposes a centralized control scheme that is solved however in a distributed fashion, thus reaping the benefits of both approaches: the control problem is global, therefore intrinsically more reliable and comprehensive, but only local information is employed to achieve the overall optimum control input