| The rapid progress of synchrophasor technology greatly promotes many applications of wide-area measurement systems. Traditionally, contingency analysis is based on off-line studies conducted long in advance. This is becoming increasingly unreliable for real-time operations. New technologies, which rely on accurate, high resolution, and real-time monitoring of actual system conditions using phasor measurements are needed to support the real-time operations. In this research an algorithm is developed, using phasor measurements, that allows real-time analysis and correction of contingencies in power systems. The focus is specifically on overloaded lines. An off-line study performed with POWERWORLD software is used for contingency analysis, and contingency indicative phasor limits are investigated using current magnitude and voltage angle. These limits are applied to a rotating phasor chart. An algorithm which predicts sensitivity is applied in the off-line analysis in order to determine the buses that need to be monitored. An actual system with available real-time PMU data is used to verify the phasor chart obtained using off-line data. The chart is completed for on-line data, and the off-line and on-line charts are compared for further verification. |
