Study of Charging Current Ripple Suppression for Battery Energy Storage Converter Under Distorted Grid Voltages

This letter proposes a charging current ripple suppression strategy for battery energy storage T-type three-level converter. Under distorted grid voltage scenarios, the harmonic contents of grid voltage lead to current ripple during battery charging. Theoretical analysis and mathematical derivations of the charging current ripple are presented. Based on the analysis, a control scheme for suppressing the charging current ripple is proposed by simplified calculating to obtain the amplitude and phase of harmonic reference current, and adding a charging current suppression loop. The suppression performance is verified via a 100-kW three-phase three-wire T-type three-level converter with battery. The experimental results prove that the charging current ripple can be effectively eliminated with the proposed strategy.