A comprehensive long term dynamic simulation for power system recovery

The long term dynamic system behavior under severe frequency and voltage changes, and the logics of automatic control actions (e.g., underfrequency load shedding and underfrequency generator separation) are discussed. The long term power system dynamic simulation is devised as a tool for studying the coordination of emergency control techniques in order to prevent significant deviations in power systems variables. A modification of the fast, decoupled power flow technique is considered for the quasi-stationary power flow solution. This approach is enhanced by the trapezoidal rule integration algorithm and the Runge-Kutta fourth order method for the solution of power system dynamic equations. Typical scenarios for the system recovery after power outages are discussed, and recommendations for the implementation of these techniques in large-scale power systems are provided. These topics are illustrated by two practical-examples for modern power systems