Real-time estimation of short-circuit capacity under operational conditions holds significant practical value for assessing the stability level of distribution grids under various disturbance conditions. This paper employs the two-point method to solve circuit equations and evaluate load-saving operational states. Based on non-disturbance technology—weighted adaptive recursive least squares—the short-circuit capacity provided by connected power sources is calculated. Through simulation analysis and verification, taking a 110 kV substation in the Su North region as the research object, it can be observed that the nighttime operating mode is relatively small, while the daytime operating mode is relatively large. The non-disturbance method proposed in this paper for measuring short-circuit capacity shows that if the ratio of load capacity to actual short-circuit capacity exceeds 15%, the error will reach 10%. Therefore, this method can be further extended to address grid safety issues and holds significant research value.
