A new single-phase specific harmonic detection algorithm without phase-locked loop

In single-phase harmonic current detection algorithm of active power filter (APF), phase-locked loop (PLL) is always used to detect the frequency and phase of grid voltage. As a result, the harmonic detection result is directly affected by the performance of PLL. In order to solve this problem, combined with the demand for specific harmonic compensation, a new specific harmonic detection algorithm without PLL is proposed. Then the algorithm is analyzed theoretically. Finally, a simulink model of single-phase active power filter with the new algorithm is built. Simulation result proves the effectiveness of the new algorithm.