Dynamic short-circuit ratio calculation method based on Thevenin equivalent parameter tracking

The invention provides a dynamic short-circuit ratio calculation method based on Thevenin equivalent parameter tracking. The method comprises the following steps that when an AC/DC system has a fault, a current-conversion busbar is selected as a monitoring object; Thevenin equivalent AC system dynamic potential and impedance monitored through the current-conversion busbar are found; the dynamic short-circuit ratio of the AC/DC system is calculated; the strength of the AC/DC system is judged in real time according to the dynamic short-circuit ratio. In the dynamic short-circuit ratio calculation method based on Thevenin equivalent parameter tracking, the supporting capacity to DC by an AC system after the fault is reflected by monitoring the change of the short-circuit ratio of the AC/DC system after the fault. The dynamic short-circuit ratio calculation method based on Thevenin equivalent parameter tracking can be applied to online analytical control and offline simulation analysis of an electric system, so that the operation of the AC/DC system is facilitated, analysts can take effective measures in time, and the safe and stable operation level of a large grid is improved.