Harmonic Detection Based on Adaptive Digital Filtering

In modern electric power system, harmonics by nonlinear loads deteriorate power quality and decrease the security and economy of power delivery.In recent years, a novel apparatus, active power filter (APF), is developed. It is an effective measure to eliminate harmonic currents produced by nonlinear loads in system. The key technique to realize its function is the fast and precise detection of load currents' harmonic components. The harmonic detection methods used in APF are introduced, a new method to obtain the harmonic currents based on adaptive digital filtering is presented. It can be simply implemented with DSP to meet the requirement of harmonic detection by APF. Simulation results verified its feasibility.