Comparative analysis of losses in converters for battery energy storage using EMT simulations

The paper presents a comprehensive analysis of losses in several battery energy storage system (BESS) converters using EMT simulations. The work is motivated by the critical need to determine converters’ semiconductor losses, particularly due to the high-frequency dc-dc converters that interface batteries. Two general classes, namely modular multilevel and two-level converter topologies, are considered. A simulation-based, computationally efficient, and accurate loss calculation method, which utilizes device data sheet loss curves, is used to estimate semiconductor losses based upon post-processing of EMT simulation results of the converters. The paper quantifies the impact of switching frequency and circulating current suppression controller on the losses. Comparative assessments of the merits of each topology are also presented.