Adaptive current harmonics suppression strategy for grid-tie inverters

Zhifeng Pan; Xiaohong Wang; Quanxue Guan; Yangquan Chen; Lianfang Tian

doi:10.1016/j.isatra.2021.08.045

Adaptive current harmonics suppression strategy for grid-tie inverters

ISA Trans. 2022 Sep;128(Pt A):698-710. doi: 10.1016/j.isatra.2021.08.045. Epub 2021 Sep 2.

Authors

Zhifeng Pan¹, Xiaohong Wang², Quanxue Guan³, Yangquan Chen⁴, Lianfang Tian⁵

Affiliations

¹ School of Automation Science and Engineering, South China University of Technology, Guangzhou, 510640, China. Electronic address: p.zhifeng@mail.scut.edu.cn.
² School of Automation Science and Engineering, South China University of Technology, Guangzhou, 510640, China. Electronic address: xhwang@scut.edu.cn.
³ School of Intelligent Systems Engineering, Sun Yat-Sen University, Guangzhou, 510006, China. Electronic address: guanqx3@mail.sysu.edu.cn.
⁴ School of Engineering, University of California, Merced, 5200 North Lake Road, Merced, CA, USA. Electronic address: ychen53@ucmered.edu.
⁵ School of Automation Science and Engineering, South China University of Technology, Guangzhou, 510640, China. Electronic address: chlftian@scut.edu.cn.

PMID: 34563336
DOI: 10.1016/j.isatra.2021.08.045

Abstract

Since the observed angle of a phase-locked loop (PLL) is relatively accurate even under distorted grid conditions, the mathematical model of the voltage errors caused by the switching modulation and the dead-time effect are derived as a function of the grid voltage angle in this paper. Based on the model analysis, an adaptive compensation algorithm is proposed to suppress the grid-side current harmonics in three-phase converters. The proposed algorithm fits the unmeasurable voltage errors by a truncated Fourier series expansion, and then takes it as an equivalent disturbance in the current control loop to achieve harmonic compensation. By the feed-forward compensation, the design and tuning of the controller parameters are simplified and separated from the dynamic performance. In addition, the controller can adapt to the grid frequency variation by updating the grid voltage angle with the PLL block. To reduce the computational burden, a simplified version of the proposed method is also presented. Simulation and experiment results show that the proposed methods can suppress the current harmonics and achieve better performance in terms of total harmonic distortion, strong robustness and insensitivity to the grid frequency variations, compared with the traditional PI control or repetitive control strategy.

Keywords: Adaptive compensation; Frequency variation; Grid-connected inverter; Harmonic suppression.