Abstract—In this paper, among different methods of signal processing, wavelet transform is chosen due to its advantages over other methods. To show wavelet transform capabilities, first an HVDC system which has noise on its output current is simulated. In the first step noise is removed by applying discrete wavelet transform. In the next steps, harmonic problem is resolved thorough appropriate passive filters. In this paper, we suppose that not only low order harmonics exist in the output current, but also high order ones. The results indicate that we can obtain a good passive filter design for harmonic reduction by decomposing a signal into its harmonic components via applying discrete wavelet transform.
Index Terms—Wavelet multi-resolution decomposition, passive filter for harmonic reduction, harmonic detection, wavelet-based threshold de-noising method.
H. R. Esfahani is with the Department of Electrical Engineering, Young Researchers Club, Najafabad Branch, Islamic Azad University, Najafabad, Isfahan, Iran (e-mail: Rahimi_ham@yahoo.com)
R. Amirfattahi is with the Digital Signal Processing Research Lab, Department of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran (e-mail: Fattahi@cc.iut.ac.ir)
F. Kiyoumarsi is with the Department of Computer Engineering, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran (e-mail: Kumarcifirstname.lastname@example.org)
E. Borzabadi is with the Department of Electrical Engineering Najafabad Branch, Islamic Azad University, Najafabad, Isfahan, Iran (e-mail: email@example.com)
Cite: Hamid Rahimi Esfahani, Rasoul Amirfattahi, Farshad Kiyoumarsi, and Ebrahim Borzabadi, "Designing Passive Filters for Harmonic Reduction in a Noisy System Based on Discrete Wavelet Transform," International Journal of Computer Theory and Engineering vol. 4, no. 5, pp. 802-806, 2012.