Requirement analysis and development of MW-range PCS for substation-scale battery energy storage systems

The paper analyzes the requirements for the power conditioning systems (PCSs) applied to substation-scale battery energy storage systems (BESSs). Then, the hierarchical parallel technology and the 3-level convertor technology are discussed considering the requirements. Based on the discussion a large capacity PCS rated at 800kW is developed. The developed PCS is evaluated by full power tests at the factory simulating the large capacity battery bank. The PCS also shows excellent performance for substation application as expected. The PCSs have already applied to an actual BESS.