Power system critical circuit identification method

The invention relates to a critical branch circuit identification method in the technical field of electric power and particularly relates to a power system critical circuit identification method. The power system critical circuit identification method comprises the following steps of 1, determining generator-branch circuit power distribution factors; 2, determining branch circuit absolute tide factors; 3, determining branch circuit weight factors; 4, determining branch circuit absolute tide betweenness; 5, determining critical circuits of a system in a static state; 6, determining the distribution factor correlation degree between branch circuits; and 7, determining critical circuits of the system in a dynamic state. According to the generator-branch circuit power distribution factors, the absolute tide betweenness is invented and is calculated through simple change in an impedance matrix, the complex tide calculation is not required, and the critical circuit identification is accelerated. In order to accelerate identification of the critical circuits of the system in the dynamic state, the invention also defines an index of the distribution factor correlation degree to describe the correlation degree between circuits, so that new critical circuits can be rapidly found out after system faults occur.