Evaluation of Harmonic Detection Algorithms for Active Power Filter based on Voltage and Current Detection Methods

This paper compares four filtering algorithms implemented in Shunt Active Parallel Filters (SAPF) based on current and voltage detection. The dq reference frame, the dq harmonic reference frame, the Power Theory, and the Fast Fourier Transform (FFT) are compared. First, the filtering methods are studied decoupled from SAPF structure to reveal the time response and accuracy of filtering algorithms. Later, they are coupled to the SAPF structure to study the effect of the detection method (current or voltage) in the harmonic compensation. The results indicate the choices of filtering and detection methods are fundamental for obtaining good accuracy in the harmonic compensation.