Power management with BMS to modified interlinking converter topology in hybrid AC/DC microgrid

Abstract

This paper presents a battery management system (BMS) for a modified interlinking converter in a hybrid AC/DC microgrid. The power management strategy (PMS) employs the BMS to avoid the battery operation in harmful conditions, increasing the battery banks’ life cycle. Besides, techniques for power-sharing, power quality mitigation, and grid formation are also presented in the PMS. This study proposes the PMS for a hybrid microgrid operating in the grid-connected and standalone mode. The modified interlinking converters are composed of an interlinking converter (ILC) and a two-stage interlinking converter-energy storage device (TSILC-ESD), acting according to the operation mode. The ILC works as a grid-forming to the DC microgrid in the grid-connected mode, while the TSILC-ESD acts as a grid-supporting unit for both microgrids. In this case, when the BMS actuates, the TSILC-ESD is disabled. For standalone mode, the ILC is responsible for forming the AC microgrid, while the TSILC-ESD forms the DC microgrid. Moreover, the TSILC-ESD also renders support to the AC microgrid. To maintain the formation of both grids, the BMS applies a load or source selectivity, according to SoC conditions. To evaluate the performance of the proposed BMS, PMS, and interlinking converters, simulations are performed in the Matlab/Simulink software. The results show an appropriate performance for the hybrid microgrid in the grid-connected and standalone modes, while a satisfactory BMS response is achieved during the operation restrictions.

Keywords

• Battery management system
• Power management
• Interlinking converter
• Energy storage system
• Hybrid microgrid
• Power quality