PROJECT TITLE :

Enhancement of Performance, Availability, and Flexibility of a Battery Energy Storage System Based on a Modular Multilevel Cascaded Converter (MMCC-SSBC)

ABSTRACT:

This paper provides a theoretical and experimental discussion regarding the performance, availability, and suppleness of a battery energy storage system (BESS) using a modular multilevel cascaded converter based on single-star bridge cells (MMCC-SSBC). The SSBC-based BESS produces 3-phase multilevel voltage waveforms, and eliminates both harmonic filters and a sophisticated zig-zag transformer from the ac facet. The circuit modularity of the SSBC enables the usage of multiple individual low-voltage battery modules. Along with management strategy based on zero-sequence-voltage injection, this modularity enhances the supply and adaptability of the BESS. A three-part laboratory downscaled system rated at 140 V, 10 kW, and 21 kW·h is intended, created, and tested to verify the operating principles and performance. The tested BESS produces a current total harmonic distortion (THD) of three.zero% even when it operates with totally different active-power commands for individual bridge cells. Also, zero-voltage ride-through capability is verified for the severest single-phase, 2-section, and three-section voltage sags. Mathematical analysis and experimental verification validate the downscaled system and performance, making the BESS prospective.