In order to solve the problems of grid stability, security and vulnerability arising from large-scale access to distributed power sources. This paper constructs an assessment method for distribution network vulnerability based on considering the short circuit capacity change. The method is based on analyzing the strength of the electrical connection relationship between nodes, followed by accurately capturing the power system weak links. Then the jellyfish search algorithm is combined with the improved butterfly optimization algorithm to design a multi-objective optimization model for distribution networks based on the consideration of indicators such as active loss, voltage offset and system vulnerability. The results show that this method makes the power system vulnerability and network loss decrease by 30.3% and 37.63%, respectively, and the voltage offset decrease by 33.5%. This study not only provides a reference for the dynamic change of short-circuit capacity and vulnerability analysis of distribution networks, but also provides a reasonable explanation for the optimal design and operational security of active distribution networks.
