The generalized short-circuit ratio helps effectively reflect the strength of the receiving end power grid.The calculation of the generalized short-circuit ratio is based on Thevenin's equivalent admittance matrix of the receiving end power grid at DC feeder node,in which the influence of dynamics of all components on the strength of receiving end power grid is ignored.In this paper,a time-varying generalized short-circuit ratio calculation method is proposed based on Thevenin's equivalent parameter identified through transient data.The voltage of infeed buses and the power injected into infeed buses are used to identify the time-varying admittance matrix of receiving end AC system based on multi-port Thevenin equivalent model and least-squares method.Then time-varying generalized short-circuit ratio is calculated based on Thevenin's equivalent admittance matrix,which can accurately reflect the influence of the system dynamics on the strength of the receiving end AC system.Finally,the accuracy of proposed method is verified by case studies on single infeed system,and the practical effect of this proposed method is verified by case study of provincial system,and the effect of dynamic load characteristics of on time-varying generalized short-circuit ratio is analyzed.
关键词
广义短路比/多馈入直流系统/多端口戴维南等值/时变参数辨识/暂态数据
Key words
generalized short-circuit ratio/multi-infeed HVDC system/multi-port Thevenin equivalent/time-varying parameter identification/transient data
维普
万方数据