The effects of speed variations on transient stability - simulation study and mechanism analysis

Transient stability simulation is an important aspect of dynamic security assessment (DSA) in power systems. In the deregulated environment, simulation results are more sensitive to models and parameters. In this paper, based on many simulation cases, the effects of neglecting speed instantaneous changes in generator modeling on transient stability are discussed. Based on extended equal area criterion (EEAC), a method is provided to analyse the mechanism of the influences. Numerical simulation results have proved the method´s validity. Based on digital simulation and theory analysis, suggestions on choosing appropriate simplifications of speed variations in transient stability calculations are given.