Linear Robust Discharge Control for Flywheel Energy Storage System With RLC Filter

• Published in: IEEE transactions on industry applications Vol. 58; no. 5; pp. 6175 - 6189
• Main Authors: Liang, Yang, Liang, Deliang, Kou, Peng, Jia, Shaofeng, Chu, Shuaijun, Wang, Hao, Liang, Yongtao
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.09.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Active control; Discharge; Discharges (electric); Energy storage; Flywheel energy storage system (FESS); Flywheels; Frequency modulation; Harmonics; High speed; linear extended state observer (LESO); Magnetic bearings; Mathematical models; Observers; Passive filters; Power harmonic filters; Power system dynamics; reduced-order Luenberger observer; Robust control; Robustness; State observers; two degree of freedom internal model control (TDOF-IMC)
• ISSN: 0093-9994; 1939-9367
• DOI: 10.1109/TIA.2022.3189967

High speed becomes an important development direction of flywheel energy storage system (FESS) for higher energy storage density. However, the high speed leads to a wide-range and rapid speed variation (tens of thousands of revolutions in seconds) and a limited frequency modulation index, both of which aggravate the current harmonics and deteriorate the robustness of the discharge control, and even lead to instability. To address this issue, this article proposes a robust and practical discharge control strategy for high-speed FESS with RLC filter, which realizes speed adaptation and harmonic suppression. In this scheme, the linear extended state observer and two-degree-of-freedom internal model control (TDOF-IMC) are applied to FESS in the framework of linear active disturbance rejection control (LADRC). Besides, considering that high-speed FESS usually require sensorless control due to magnetic bearings, a reduced-order Luenberger observer for the investigated FESS is proposed. The salient feature of this strategy is to introduce the TDOF-IMC containing FESS dynamic information into LADRC, so that the discharge control is both practical and robust. Experiments and simulations verify the effectiveness of the control strategy.