With the continuous improvement of energy storage technology and the increasingly strict power quality requirements of power grids

large-scale access to distributed energy storage systems in distribution networks has become a development trend. First of all

for the actual complex industrial process

the process immune time(PIT)is used as the voltage sag tolerance evaluation method to analyze the effect of energy storage access on the voltage.Secondly

considering the economics of system operation and considering the quality of the voltage

energy storage location and capacity double-layer optimization model is established

and the fuzzy comprehensive evaluation(FCEM) method is used to determine the target weight. Finally

an example analysis of the IEEE-33 node model is performed. The results show that

the model built can effectively increase the voltage quality and economic benefits of the distribution network

and plays a role in peak cutting and valley filling.