Energy storage system and control method thereof, and power consumption system

A power consumption system, comprising an energy storage system electrically connected to a power grid, wherein the energy storage system comprises:

• a first energy storage sub-system, comprising a first battery system and a first battery management system, the first battery management system being electrically connected to the first battery system;
• a second energy storage sub-system, comprising a second battery system and a second battery management system, the second battery system comprising a first battery sub-cluster and a second battery sub-cluster, the second battery management system being electrically connected to the first battery sub-cluster and the second battery sub-cluster, and the second battery management system being communicatively connected to the first battery management system;
• and
• a power conversion system, electrically connected to the first battery system and the first battery sub-cluster or the second battery sub-cluster, and communicatively connected to the first battery management system;
• wherein the first battery management system performs coordinated charge and discharge control on the first battery sub-cluster.