Voltage Stability Protection and Control Using a Wide Area Network of Phasor Measurements

This paper presents a concept for local monitoring of the onset of voltage collapse and protective and emergency control in the presence of voltage sensitive loads. The onset of voltage collapse point is calculated based on the load characteristics and simulated voltage and current phasors measurements, which are provided by a network of phasor measurement units. If the stability margin is small and the reactive power reserves nearly exhausted, then controls to steer the power system away from the critical point will be activated.