Open AccessStability and robust performance analysis of grid‐connected inverter with high‐order filter: Resonances beyond the Nyquist frequency
Author(s) -
Koiwa Kenta,
Kuribayashi Toru,
Zanma Tadanao,
Liu KangZhi,
Natori Kenji,
Sato Yukihiko
Publication year - 2021
Publication title -
iet control theory and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.059
H-Index - 108
eISSN - 1751-8652
pISSN - 1751-8644
DOI - 10.1049/cth2.12162
Subject(s) - harmonics , control theory (sociology) , nyquist stability criterion , nyquist frequency , robustness (evolution) , nyquist plot , nyquist–shannon sampling theorem , filter (signal processing) , anti aliasing filter , computer science , electronic engineering , physics , low pass filter , mathematics , band stop filter , engineering , voltage , artificial intelligence , dielectric spectroscopy , chemistry , biochemistry , control (management) , quantum mechanics , electrochemistry , computer vision , parametric statistics , statistics , electrode , gene
Filters are inevitable for grid‐connected inverters to attenuate the current harmonics caused by the pulse width modulation which is usually used in power conversion systems. High‐order filters have attracted much attention because they attenuate the current harmonics effectively. Nevertheless, the high‐order filters have some resonances which cause instability of the system. In addition, the resonance frequencies shift to high as the inductors and capacitors are smaller. It implies that the resonance frequencies may be beyond the Nyquist frequency in downsizing the filter. This complicates the stability and performance analyses of the system. This paper investigates rigorous input–output stability and analyses a robust performance based on the sampled‐data control theory regardless of whether the resonance frequencies are beyond the Nyquist frequency or not. Our analysis contributes to downsizing the filter synthesis while the stability and the robustness are guaranteed even if the resonance frequencies are beyond the Nyquist frequency. The effectiveness of the proposed method is verified through simulations and experiments.