Large-scale energy storage systems can be divided into the following types according to the electrical structure:
Centralized: This system adopts a low-voltage, high-power boost-type centralized grid-connected energy storage system. Multiple battery clusters are connected in parallel and connected to the power conversion system (PCS), pursuing high power and high efficiency. At present, the 1500V solution is being promoted.
Distributed: A low-voltage, low-power distributed boost-type grid-connected energy storage system. Each battery cluster is connected to a PCS unit and adopts a low-power, distributed layout.
Smart string type: Based on the distributed energy storage system architecture, it adopts battery module-level energy optimization, battery single cluster energy control, digital intelligent management and full modular design technologies to achieve more efficient applications.
High-voltage cascade high-power energy storage system: A single battery cluster is inverter, directly connected to the 6/10/35kv or above voltage level grid without a transformer, and the capacity of a single unit can reach 5MW/10MWh.
Distributed type: Multiple branches are connected in parallel on the DC side, and a DC/DC converter is added at the battery cluster outlet to isolate the battery cluster. The DC/DC converters are then connected to the centralized PCS DC side.