Energy Storage System and Multi-Stage Short Circuit Protection System Thereof

An energy storage system and a multi-stage short circuit protection system thereof are provided. The multi-stage short circuit protection system includes N stages of fuse units. Each battery pack is connected to a corresponding first-stage fuse unit, a direct-current side of a power conversion device is arranged with a third-stage fuse unit, and at least one second-stage fuse unit is arranged between multiple battery packs and the power conversion device. In a case that a short circuit fault occurs at a position on the direct-current side of the power conversion device, only a fuse unit at a stage preceding the position and a fuse unit at a stage following the position are broken, thereby avoiding a problem of a high maintenance cost in the conventional technology due to that all fuses are broken.