The black start of power grids is a complex process consisting of the startup

the dispatch and the operation of plants and power grids. For the dispatchers and operators

how to determine the startup paths and the closedloop points are the most difficult problems. In order to implement the quantitative analysis of the above problems

the transient energy function (TEF) is introduced into this domain and a novel auxiliary decision-making system is developed. The system has been successfully applied to several local power grids in South China. Two practical cases presented by the paper demonstrate the methodology of the proposed method.