Identification of critical components in power grid based on state vulnerability and structural importance

A synthesis identification method for critical components of power grid is proposed. Considering different roles nodes and branches serve as in power grid, the proposed method focuses on the evaluation of node voltage support ability and branch power flow transmission capacity. In terms of state, based on the node static energy function and the distribution rule of branch transfer power flow, the sensitivity of voltage to load fluctuation and the corresponding stability redundancy when other components disconnect are considered, which are defined as the state vulnerability. Structurally, the network impedance matrix is used to evaluate the relevance of node voltage with grid voltage level and the impact of branch tripping on grid electrical connection degree, which are defined as electrical structure importance degree of components. Finally, the structure and state indices are combined as comprehensive indicators to identify the critical components in power grid.