Title: A control method for uninterruptible power supply in weak current systems based on virtual impedance

Authors: Yalei Shang

Addresses: School of Electronic Information Engineering, Hebi Polytechnic, Hebi, 458030, Henan, China

Abstract: If there is a significant voltage control error in the uninterruptible power supply (UPS) of weak current systems, it will seriously reduce the stability of the power supply. Therefore, a virtual impedance based UPS control method for weak current systems is proposed. Firstly, analyse the basic structure of weak current systems and uninterruptible power supplies. Secondly, an inverter output inductor current feedback is added outside the voltage and current dual loop control of the UPS to form a virtual impedance loop. Finally, virtual impedance is used to suppress the inverter circulating current of the UPS in the weak current system, thereby completing the control of the UPS. The experimental results show that the maximum voltage control error of the proposed method does not exceed ±0.331 V. Therefore, it indicates that the UPS control performance of this method is good.

Keywords: virtual impedance; weak current system; uninterruptible power supply control; UPS; circulation suppression.

DOI: 10.1504/IJETP.2023.134167

International Journal of Energy Technology and Policy, 2023 Vol.18 No.3/4/5, pp.275 - 285

Received: 27 Apr 2023
Accepted: 03 Jul 2023
Published online: 12 Oct 2023 *

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