A Practical Transient Stability Margin Algorithm Based on Information-Driven and Fine Fault Information

At present, the transient stability control adopts the uniform cutting stability control measure and asymmetric faults are treated with three-phase short circuit, called event-driven analysis, which ensures the reliability of the system stability, but the accuracy is not enough. Taking three-phase short circuit as a benchmark, this paper analyzes the relationship of limit cutting time between the three-phase short circuit and various asymmetric faults in different fault positions, presents the angle-time curve of four kinds of short-circuit faults with a unified expression and obtains the limit cutting time directly according to the limit cutting angle, which turns event-driven into information -driven. The single-machine infinite bus model is built in matlab and the analysis of asymmetric faults is verified. It is found that the maximum difference of limit cutting time between asymmetric faults and three-phase short circuit is 500ms. Therefore, it is of great significance to obtain the accurate limit cutting time of asymmetric faults.