Control delay compensation scheme based on non‐instantaneous loading and pulse‐width equivalence for active damping of LCL‐type inverters. Issue 9 (15th July 2019)

• Record Type: Journal Article
• Authors: Zhu, Kunlong; Sun, Pengju; Wang, Lin; Zhou, Luowei; Du, Xiong
• Is Part Of: IET power electronics. Volume 12:Issue 9(2019)
• Page Start: 2389
• Page End: 2399
• Publication Date: 2019-07-15
• Subjects: delays -- feedback -- compensation -- power grids -- power filters -- invertors -- PWM invertors -- capacitors -- damping -- electric current control -- digital control; control delay compensation scheme -- noninstantaneous loading -- pulse‐width equivalence -- active damping -- LCL‐type inverters -- capacitor current -- effective solution -- resonance peak -- LCL‐type grid‐connected inverters -- damping performance -- pulse‐width modulation delays -- digital control system -- poor system robustness -- phase lag -- control delays -- constrained bandwidth -- low‐frequency gain -- control loop -- novel compensation method -- computation delay -- 3 kW single‐phase grid‐connected inverter -- LCL filter -- power 3.0 kW; Power electronics -- Periodicals; 621.31705
• DOI: 10.1049/iet-pel.2019.0359
• Languages: English
• ISSNs: 1755-4535

Abstract

Abstract : Active damping (generally by the feedback of capacitor current) is an effective solution to the resonance peak of LCL ‐type grid‐connected inverters. However, the damping performance is significantly affected by the computation and pulse‐width modulation delays in the digital control system, which results in poor system robustness. Moreover, the phase lag would be introduced by these control delays, leading to the constrained bandwidth and low‐frequency gain of control loop. In this study, a novel compensation method based on non‐instantaneous loading and pulse‐width equivalence is proposed to completely eliminate the computation delay without any reliability problem. Moreover, compared to the traditional strategies, the proposal can be extended to most two‐level converters because of its simplicity. Finally, the validity of the proposed method is confirmed by the experimental results from a 3 kW single‐phase grid‐connected inverter with an LCL filter.