Table of Contents Author Guidelines Submit a Manuscript
Mathematical Problems in Engineering
Volume 2014, Article ID 501781, 10 pages
Research Article

PLL Based Digital Adaptive Filter for Detecting Interharmonics

1Department of Electrical-Electronics Engineering, Sakarya University, Esentepe, 54187 Sakarya, Turkey
2Turgutlu Vocational High School, Industrial Automation Department, Celal Bayar University, 45000 Manisa, Turkey

Received 18 March 2014; Revised 21 May 2014; Accepted 25 May 2014; Published 23 June 2014

Academic Editor: Xia Huang

Copyright © 2014 Ayhan Özdemir and Mehmet Taştan. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Studies on the PLL (phase locked loop) based interharmonic measurements have been considerably increased recently. The method proposed in this study is a hybrid method based on the frequency analysis. The proposed method presents solutions for the leading problems about the interharmonic measurement, such as fundamental frequency shifting, spectral leakage, and picket-fence effect, using digital PLL and adaptive notch filter. In addition, a new approach is presented to solve the multizero crossing problem encountered in the analysis of the harmonic-interharmonic. Both simulative and field data tests have been performed to verify the effectiveness of the proposed method.