Title: Research on control strategy of grid-connected inverter based on three-loop structure

Authors: Yan Geng; Yingjun Ju; Bo Hu; Jianwei Ji

Addresses: College of Information and Electrical Engineering, Shenyang Agricultural University, Shenyang 110886, China; Department of Automotive Engineering, Liaoning Provincial College of Communications, 110122, China ' Development Planning Department of Liaoning Electric Power Co. Ltd., 110006, China ' College of Information and Electrical Engineering, Shenyang Agricultural University, Shenyang 110886, China ' College of Information and Electrical Engineering, Shenyang Agricultural University, Shenyang 110886, China

Abstract: A grid-connected inverter system is deeply researched based on the two-stage single-phase PV grid-connected inverter. Full bridge structure is adopted in the backend inverter circuit. In order to realise the balanced flow of power, to improve the system's response speed and to eliminate the influence of the resonance peak of LCL filter, the three loop control strategy is adopted in the inverter system. At the same time, the reason of generation of the dead-time and its influence on the output of the grid-connected inverter are analysed in detail. And an improved dead-time compensation method is proposed for zero-current clamping phenomenon. The output voltage error of inverter is extended from two to seven in this method, which effectively solves the problems, such as zero-crossing distortion of the grid-connected current, additional odd harmonic content, higher distortion rate and lower amplitude of fundamental wave.

Keywords: grid-connected inverter; dead-time compensation; PV.

DOI: 10.1504/IJITM.2022.126707

International Journal of Information Technology and Management, 2022 Vol.21 No.4, pp.405 - 422

Received: 04 Oct 2019
Accepted: 05 Mar 2020
Published online: 03 Nov 2022 *

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