Power System Monitoring and Control

4Graphical Tools for Stability and Security Assessment

Power system dynamic analysis and control synthesis is becoming more significant today due to the increasing size, changing structure, emerging renewable energy sources and new uncertainties, environmental constraints, and the complexity of modern power systems. In response to this crudity, the present chapter introduces new analytic graphical tools for studying the power system dynamics, stability evaluation, and security assessment.

These graphical tools could be useful in developing new control schemes in normal, predictive, and emergency states. The proposed graphical tools employ well-known power system indices, that is, frequency, voltage, and angle deviations in proper multidimensional planes. The presented planes are angle–voltage deviations, voltage–frequency deviations, frequency–angle deviation, and wave propagation graphs.

4.1 Importance of Graphical Tools in WAMS

The power system is the largest man-made system with numerous unpredictable events and disturbances that may often be characterized by instability phenomena, leading to the triggering of component protections, resulting in a widespread interruption or blackout, where it is difficult to anticipate the affected region. Instability phenomena related to severe events are mainly large-disturbance voltage, rotor angle, and frequency instability [1].

Due to the growing size and complexity of power systems, monitoring-based and graphical analysis tools are ...