Flexible Evaluation Method and Its Application in Smart Grids

Considering the demand of multiple indices such as economy,safety and flexibility for coordinated optimization in the process of planning,operating and managing of the next-generation smart grids,this paper proposes and defines a multi-scale flexible evaluation and analysis method,and divides the power system flexibility into four respects,including property flexibility,constraint flexibility,load flexibility,and structure flexibility.To address the constraints from system operation safety on flexibility,the current study defines the constraint flexibility evaluation index under steady state,providing self-explanatory evidences for power system dispatchers to evaluate the safety margin of the gird operation state.Finally,a case study of node voltage flexibility evaluation and its application in the analysis is conducted on an IEEE 30 bus test system.The results show the rationality and validity of the flexible evaluation and analysis method proposed.