Open AccessMagnetic integrated LLCL filter with resonant frequency above Nyquist frequency
Author(s) -
AlBarashi Maged,
Wu Siqi,
Liu Zhigang,
Meng Xiangyu,
Tasiu Ibrahim Adamu
Publication year - 2022
Publication title -
iet power electronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.637
H-Index - 77
eISSN - 1755-4543
pISSN - 1755-4535
DOI - 10.1049/pel2.12313
Subject(s) - nyquist–shannon sampling theorem , harmonics , filter (signal processing) , nyquist frequency , nyquist plot , nyquist stability criterion , engineering , pulse width modulation , electronic engineering , control theory (sociology) , computer science , electrical engineering , physics , mathematics , voltage , parametric statistics , statistics , control (management) , electrode , quantum mechanics , artificial intelligence , dielectric spectroscopy , electrochemistry
This paper presents a design technique of magnetic integrated LLCL filters for grid‐tied inverters. With the proposed design technique, the LLCL filter's resonant frequency can be higher than the Nyquist frequency. Furthermore, the proposed concept was only reported for the LCL filter in the previous research works. In addition, the modulation process will produce dominant switching harmonics for unipolar PWM H‐bridge inverters at the double switching frequency. Thus, putting the resonant frequency beyond the Nyquist frequency will increase the stability zone. The proposed design methods maximize the filter inductors' utilization and resist the grid impedance variations under weak grid conditions, depending on the improved stability zone. Comparative simulation and HIL experimental results are presented to confirm the effectiveness of the proposed magnetic integrated LLCL filter design. The HIL experimental results and the simulation results agree well with each other.