Power system out-of-step dissection section searching method and system

The invention provides a power system out-of-step dissection section searching method and system. The method comprises the steps that the along-line voltage of a line is calculated according to the head and tail voltage of the line; whether an oscillation center is located on the line or not is determined according to the along-line voltage of the line; when the along-line voltage of the line is greater than a head and tail phase difference critical value of the line and the oscillation center is located on the line, the line is an out-of-step dissection section. According to the technical scheme, the line phase difference and trend change features are used, so that the cross section where the system oscillation center is effectively searched, influences of the system operation mode and the fault form are avoided, the oscillation center can be accurately grasped, and the advantages that the calculation amount is small, the speed is high, and the adaptability is high are achieved. 本发明提供的一种电力系统失步解列断面搜索方法及系统，包括：