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.