Improved Control Strategy for APF based on Three-Phase Direct Matrix Converter

Active power filter (APF) is a new type of power electronic device that can dynamically suppress harmonics and compensate reactive power. To address the shortcomings of inverter-based APFs, a new matrix converter-based APF is proposed, which avoids the need for energy storage devices on the DC side and the problem of large capacitance on the intermediate DC side in AC-DC-AC conversion. Aiming at the problem that the traditional $p-q$ harmonic detection algorithm cannot be applied to complex working conditions, an improved $p-q$ harmonic detection algorithm is proposed, which can accurately detect harmonics under a variety of working conditions and can effectively reduce harmonic distortion. The feasibility of the topology and the effectiveness of the control strategy are verified by simulation results.