Transient Stability of a Synchronous Generator Under Conditions of Bang-Bang Excitation Scheduling

Bang-bang excitation scheduling, applied to a synchronous generator returning from load rejection, has been investigated and the results are reported here. Such control increases the generator´s degree of transient stability and terminates its mechanical oscillations. The criterion for control is developed from observations of generator response to return from load rejection, and pulse variations in the excitation. Using the instantaneous frequency deviation as a characteristic quantity, the generator´s response is discussed, and results are presented in equation and graphical form. From these, the switching criterion is developed to obtain bang-bang excitation scheduling, experiments with which verify the method.