Research on limit power flow state for cascading overload in power network

Based on the method of direct current flow, this paper studies the limit conditions under which cascading overload events may happen in the power system in N-1 mode, and proposes a practical method for obtaining the limit power flow state. In this method, the limit power flow state can be directly obtained by the power increment equation after an initially faulted branch is removed, which helps to avoid a large amount of computations with special optimized techniques and searching methods that may need much time. An example in 22-bus system of Chinese Electric Power Research Institute proves that this method is reasonable.