A Hybrid Method for Generator Tripping

Generator tripping is one of the most effective approaches to enhance the transient stability of a power system. An online prediction method of transient stability and an offline analysis method of generator tripping are studied, respectively. Firstly, a polynomial curve fitting technique is employed to improve the online prediction accuracy of system stability. Then a shell program is developed to automatically generate and update lookup tables for generator tripping. Based on these, a hybrid method is proposed. It uses the lookup tables to determine generator tripping requirements, and before sending out generator tripping signals, instability is confirmed by online prediction of system stability. Simulation results show this hybrid method can avoid unnecessary generation shedding.