An enhanced sliding window Fourier analysis with a time delay compensation for single-phase active power filter

The performance of an active power filter (APF) to eliminate the harmonic in the power system depends, firstly, on the harmonic detection process. An accurate reference current calculation and time delay compensation for the harmonic detection process are therefore focused. This paper introduces the enhanced sliding window Fourier analysis (SWFA). The proposed technique is to combine the SWFA with Lagrange’s equation. Herein, the amplitude-phase calculation of the SWFA method and the reference current prediction at two sampling times are the key techniques to improve harmonic detection for digital implementation. The hardware-in-the-loop simulation on an eZdsp™ F28335 board is used to verify and evaluate the performance of the proposed harmonic detection technique. The testing results indicated that the APF with the enhanced SWFA approach can compensate the time delay and calculate the harmonic and reactive currents. After compensation, it would also improve the power factor and reduce the percentage of total harmonic distortion within the IEEE standard 519 even though the voltage source is in sinusoidal or distorted conditions.