An Optimal Power Flow (OPF) Method with Improved Voltage Stability Analysis

Voltage stability is given very high importance in the power system studies, In the present studies, the voltage stability is determined by a method of on line monitoring of power system based using measurements like voltages, active power and reactive power etc. This is proposed with the aim of detection of the voltage instability.An indicator is derived from the fundamental kirchoff-laws. Since in the transient process, at any time point, the electrical power of the system is in balance, and Kirchoff-laws is obeyed, this indicator still works during transient process. From the indicator, it is proposed to predict the voltage instability or the proximity of collapse.The advantage of the method lies in the simple numerical calculation and strong adaptation in steady state and transient process. Through the indicator of voltage stability, it is to find the impacts of other loads, areas and power transactions.An IEEE 9-bus system is taken as a study case to test the efficacy of the proposed systems. The optimal load flow studies for the given bus data are conducted using Newton Raphson method. An IEEE 6-bus system is taken as a study case to test the efficacy of the proposed systems. The optimal load flow studies for the given bus data are conducted using PSAT tool.