A novel photovoltaic battery energy storage system based on modular multilevel converter

作者:Zhang, Dan*; Li, HongLiang; Jiang, JianGuo
来源:Journal of Renewable and Sustainable Energy, 2018, 10(5): 053508.
DOI:10.1063/1.5045526

摘要

Modular multilevel converters (MMCs) have been widely applied in photovoltaic battery energy storage systems (PV-BESSs). In this paper, a novel topology of PV-BESS based on MMC is proposed, where the batteries are connected to the sub-modules through DC-DC converters. It is necessary to analyze the control strategies of both DC-DC converters and MMC. Specifically, the capacitor voltage balancing and the modulation mode are important. The sorting method is proposed to balance the capacitor voltages in this paper. Moreover, carrier phase shift-square wave modulation with the highest voltage utilization ratio and the highest power transfer capability is proposed to generate PWM singles for MMC-PV-BESS. In order to verify the availability of the proposed control strategy, a simulation model is built and related experiments are carried out. The simulation results and experimental results are consistent with the theory. As a result, the voltages of all capacitors could be balanced, and the MMC-PV-BESS could reliably work. Published by AIP Publishing.