A New Voltage Stability Control Model Considering Active Power Constraints on Weak Branches

A new voltage stability control model was presented to guarantee the static voltage stability of power system using the active power constraints of weak branches as the static voltage stability margin constraints. A local index for voltage stability was used to recognize the key contingencies, the weak branches and their maximum active power. Based on DC power flow equations, a static security analysis method was adopted to deduce the active power flow expressions on weak branches under every key contingency. According to the active power flow expressions and maximum active power on weak branches, the static voltage stability margin constraints were established. The proposed voltage stability control model was quadratic, and the predictor-corrector primal dual interior method was used to solve the proposed model. The simulations of the IEEE14-bus system and IEEE118-bus system proved that the proposed voltage stability control model was correct and effective.