Power system contingency analysis-an improved technique based on Tellegen theorem

In the paper, an improved algorithm based on Tellegen theorem is proposed for power system contingency analysis. The main feature of the improved algorithm is calculation of post-perturbation nodal variables utilizing a fast non-iterative procedure. For that purpose, new modeling of voltage controlled (PV) nodes is introduced to account for PV bus response to a given perturbation. The improved adjoint network method was tested on several test systems and its results were compared to those obtained with other power flow based techniques, i.e. fast decoupled power flow and 1P1Q method. The tests show that the improved adjoint network method performs faster for large power systems while keeping the accuracy of post perturbation solution on the same level as widely accepted 1P1Q method.