A novel method for online voltage stability assessment based on PMU measurements and Thevenin equivalent

From the power systems security point of view, determining voltage stability margin is essential for operation systems. An inaccurate determination maximum loading factor or collapse in a system may cause instability and blackout system. So, applying proper method with high accuracy speed vital analysing This article presents novel based on Thevenin equivalent to accurately determine load-ability using phasor measurement units (PMUs) data. The proposed fact that at point, characteristic curves ‘the reactive receiving end’ load’ weakest bus are tangential each other. Furthermore, online application requires accurate estimation ‘ZIP load model’ ‘Thevenin equivalent’ designed margin, ZIP model system, simultaneously. makes it possible be applied assessments. To demonstrate effectiveness method, simulation results IEEE 14-bus, 39-bus New England 300-bus presented analysed.