Control Method of the Current Injection Bridge in Hybrid Active Front-End Matrix Converter

Proper control of the third-harmonic current injection bridge is critical for hybrid active third-harmonic injection matrix converter (H3IMC), because both the sinusoidal input currents and controllable power factor are realized by synthesizing the suitable third-harmonic current. This paper shows an analytical work concerning the working conditions of the conventional control method and discusses the applicability of this method for H3IMC. Furthermore, the paper proposes two improved control methods derived in different ways, which set the outputs of proportional-integral (PI) controllers to be the variation of the third-harmonic current and the voltage across the injection inductor respectively. In addition, the two proposed methods are proved to have the same effect through theoretical derivation, and can be both utilized to track the third-harmonic reference current and eliminate input current harmonics. Finally, simulation and experimental results verify the feasibility and validity of the proposed methods.