A New Strategy to Step-Size Control of Adaptive Filters in the Harmonic Detection for Shunt Active Power Filter

This paper presents a new strategy to improve the applicability of adaptive filters for harmonic detection in shunt active power filters (SAPF). The final objective of the strategy is improving the speed of convergence of the adaptive filter and reduces the steady- state error. Two cases are presented and discussed, one with a Finite Impulse Response (FIR) adaptive filter with 32 coefficients and another with an adaptive notch filter. The Least Mean Square (LMS) algorithm was used to adjust the coefficients in the both cases. Simulations using Matlab are presented to clarify the algorithm. Also practical implementation is performed using the DSP Texas Instruments TMS320F2812 and the results depicted. Important aspects concerning the calculation time of the adaptive filter, convergence speed during changes in the load and the steady-state error, are presented.

[1]  Jiangzi,et al.  Application of Adaptive Filtering in Harmonic Analysis and Detection , 2005, 2005 IEEE/PES Transmission & Distribution Conference & Exposition: Asia and Pacific.

[2]  Raymond H. Kwong,et al.  A variable step size LMS algorithm , 1992, IEEE Trans. Signal Process..

[3]  Subhashish Bhattacharya,et al.  Active filter system implementation , 1998 .

[4]  G. Lambert-Torres,et al.  DSP Implementation of Three-Phase PLL using Modified Synchronous Reference Frame , 2007, IECON 2007 - 33rd Annual Conference of the IEEE Industrial Electronics Society.

[5]  Seppo J. Ovaska,et al.  Delayless method to generate current reference for active filters , 1998, IEEE Trans. Ind. Electron..

[6]  Yihan Yang,et al.  Harmonic detection using fuzzy LMS algorithm for active power filter , 2007, 2007 International Power Engineering Conference (IPEC 2007).

[8]  Seppo J. Ovaska,et al.  Reference signal generator for active power filters using improved adaptive predictive filter , 2005, IEEE Transactions on Industrial Electronics.

[9]  Hui Li,et al.  A Novel Variable Step size Adaptive Harmonic Detecting Algorithm Applied to Active Power Filter , 2006, 2006 IEEE International Conference on Industrial Technology.

[10]  B. Widrow,et al.  Adaptive noise cancelling: Principles and applications , 1975 .

[11]  W. Y. Chen,et al.  A variable step size LMS algorithm , 1990, Proceedings of the 33rd Midwest Symposium on Circuits and Systems.