The increased use of nonlinear devices in industry has resulted in direct increase of harmonic distortion in the industrial power system in recent years. The significant harmonics are almost always 5th, 7th, 11th and the 13th with the 5th harmonic being the largest in most instances. Active filter systems have been proposed to mitigate harmonic currents of the industrial loads. The most important requirement for any active filter is the precise detection of the individual harmonic component's amplitude and phase. Fourier transform based techniques provide an excellent method for individual harmonic isolation, but it requires a minimum of two cycles of data for the analysis, does not perform well in the presence of subharmonics which are not integral multiples of the fundamental frequency and most importantly introduces phase shifts. To overcome these difficulties, this paper proposes a Multilayer Perceptron Neural Network trained with back-propagation training algorithm to identify the harmonic characteristics of the nonlinear load. The operation principle of the synchronousreference- frame-based harmonic isolation is discussed. This proposed method is applied to a thyristor controlled dc drive to obtain the accurate amplitude and phase of the dominant harmonics. This technique can be integrated with any active filter control algorithm for reference generation.

Meeting Name

32nd Annual Conference on IEEE Industrial Electronics, 2006. IECON 2006


Electrical and Computer Engineering


Duke Power Company
National Electric Energy Testing Research and Applications Center

Keywords and Phrases

DC Motor Drives; Fourier Transforms; Active Filters; Harmonic Distortion; Multilayer Perceptrons; Neurocontrollers; Power Engineering Computing; Power Harmonic Filters; Thryistor Applications; Back propagation (Artificial intelligence); Phase shifters

Document Type

Article - Conference proceedings

Document Version

Final Version

File Type





© 2006 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Nov 2006