Risk-based var allocation considering both voltage profile and security margin

This paper proposes an optimal Var resource allocation framework for power transmission system in such a manner that both voltage profile and security margin for future operation is considered. The risk index is used to represent the uncertainty in this framework. The conception of Var gap is proposed to cover the voltage profile issue and the security margin issue when the Var allocation is performed. This problem is formulated as a mixed integer nonlinear programming problem, and the generalized Benders decomposition method is used to solve it. The approach is illustrated using the AEP 14-bus test system.