Abstract: With the widespread application of electrochemical energy storage, it has become one of the popular solutions for the integration of renewable energy. However, the switching of charging and discharging modes and different operation control strategies of energy storage stations will lead to more complex fault characteristics of the power grid. In order to comprehensively and deeply analyze the grid-connected fault characteristics of energy storage stations, a simulation model of electrochemical energy storage stations is established based on the actual topology and operation control strategy of energy storage stations. The model simulates the dynamic response process of energy storage stations in different operation conditions such as conventional charging/discharging, fault ride-through, and overcharging/overdischarging. On this basis, the differences in fault characteristics of energy storage stations in conventional charging/discharging and overcharging/overdischarging scenarios are clarified, and the determinants for the differences are analyzed. Finally, the functional verification of the proposed model is completed based on the PSCAD/EMTDC simulation platform. The research results provide the reference for understanding the working principle of energy storage stations, studying grid-connected control strategies and protection schemes of energy storage stations.