Research on the detection algorithm for fundamental active current

The key technology of effective compensation in Active Power Filter (APF) is the exact and fast detection for fundamental active current. In this paper, the detection methods of fundamental active current are researched, a new algorithm is presented. By subtracting a serial of prestored sine from a sampled current signal sequence, a new data sequence is attained. Using any existing methods to detect the fundamental amplitudes of these two data sequences, the fundamental active current can be calculated according to the fundamental amplitudes and the relationship between the fundamental amplitude of original signal and initial phase angle. The simulation and calculation results are carried out to verify the validity of the algorithm.