Wide-Area Voltage Monitoring and Optimization

As the power demand becomes higher all over the world, transmission lines are often carrying electric power near their limits, which can cause power systems to be operated under serious stress. Voltage collapse is one of the more critical problems that impacts power system operational security and many of the recent major blackouts were caused, at least partially, by voltage collapse. Therefore, a fast and accurate voltage stability monitor is necessary for the modern system, together with a fast calculation of possible remedial actions. The development and application of wide-area measurement systems established the foundation of online assessment of voltage stability in large-scale power systems. In this paper, a voltage stability (QV) index based on phasor measurements is used to identify the weak buses and a new parallel optimization method that increases this voltage stability margin is introduced. Results on the IEEE standard systems show the accuracy and efficiency of the methods.