A Robust Controller for Battery Energy Storage System of an Islanded AC Microgrid

A battery energy storage system (BESS) can play a critical role in regulating system frequency and voltage in an islanded microgrid. A mu-synthesis-based robust control has been proposed for dc link voltage regulation of BESS for achieving frequency regulation and voltage quality enhancement of islanded microgrid. Variation in the operating condition of ac microgrid affects the operating condition of the BESS' converter. This controller synthesis accounts for such uncertain variations as parametric uncertainty. The stability and performance of the proposed controller can be guaranteed for bounded parametric variations. The bounds on parameters are selected based on practical limitations of BESS. In this article, the proposed controller's performance is tested on an islanded CIGRE TF C6:04:02 benchmark low voltage ac microgrid system. The importance of dc link voltage regulation is analyzed based on performance comparison with a benchmark controller. The controller performance is also validated using a real-time Typhoon HIL emulator.

Automated summary

A mu-synthesis-based robust control method is proposed in this paper for the dc link voltage regulation of BESS in an islanded microgrid, aiming to achieve frequency regulation and voltage quality enhancement. The proposed controller takes into account the variations in the operating condition of the ac microgrid and the parametric uncertainty of the BESS converter, ensuring stability and performance under bounded parametric variations.