Predictive Adaptive Filter for Reducing Total Harmonics Distortion in PV Systems

Energies

Ching-Ming Lai¹  Liqaa Alhafadhi²  Jiashen Teh²  Mohamed Salem² 

[1] Department Electrical Engineering, National Chung Hsing University (NCHU), 145 Xing Da Road, South District, Taichung 402, Taiwan;School of Electrical and Electronic Engineering, Engineering Campus, Universiti Sains Malaysia (USM), Nibong Tebal, Penang 14300, Malaysia;

关键词: adaptive filters;    converter;    harmonics;    inverters;    photovoltaics;    PV;   

DOI  :  10.3390/en13123286

来源: DOAJ

【 摘 要 】

This paper presents a new method for reducing the total harmonic distortion (THD) of photovoltaic (PV) systems by using an adaptive filter based on a predictive model. Instead of reducing the produced THD at each stage of the PV system, a one-step process is implemented at the end stage. The connection topology of the adaptive filter is similar to normal active and passive filters. The main difference is its ability to adjust the filtering coefficients while others cannot. The proposed method is applied to a single-phase standalone PV system by adopting least mean square (LMS), normalized LMS (NLMS) and leaky LMS algorithms to verify the validity of the proposed method. Various values of filter length and step size are evaluated, and results indicate that the proposed method can reduce THD in the current signal of the PV system significantly by using all of the mentioned algorithms. Different step sizes and filter lengths directly influence the effectiveness of the THD reduction, with small step sizes and long filters being the most effective. Amongst the algorithms, NLMS reduces THD the most, and LMS reaches the peak current value the fastest.

【 授权许可】

Unknown