Improvement of SNB points, weaker buses and line losses using reconfiguration and modified CPF

The Saddle-Node Bifurcation (SNB) is one of the most popular voltage stability indexes by which weaker buses or lines can be determined. Gradually increasing the load, the SNB point is determined using the modified Continuation Power Flow (MCPF) algorithm considering the practical security constraints. The three different sets of the security limits (i.e. three cases) are judged for the voltage stability analysis. The weakest and the weaker buses are detected from the power flow solution at the SNB point for the all cases. The three different reconfiguration are implemented on the identified weaker lines. For the all cases and for the all test systems, the loading margin or the SNB point is enhanced and the voltage stability is improved as the voltage magnitudes of the weaker buses are increased. The line loss of each reconfigured line is significantly reduced. The overall network line losses are also minimized for the all cases. The optimal location and the suitable lines for the reconfiguration are demonstrated with the results. Simulation results show that by using the network reconfiguration, the SNB points, weaker buses, line losses for the different cases are significantly improved.