Active Damping Control Strategy of Hybrid Active Third-Harmonic Injection Matrix Converter via Modifying Third-Harmonic Injection Reference Current and Output Reference Current

In this paper, an active damping control strategy based on modifying third-harmonic injection reference current and output reference current is proposed for hybrid active third-harmonic injection matrix converter (H3IMC) to improve system instability. First, the system stability when H3IMC adopts no damping methods and passive damping method is analyzed through small-signal modeling and root locus analysis. Then, the active damping method based on virtual damping branch is applied to H3IMC. A specific implementation method based on the modification of reference third harmonic injection current is proposed, which can realize active damping control strategy directly and effectively by injecting the damping signal into the reference third harmonic injection current, and avoid the problem of reducing the control freedom of the output side. Finally, simulation results illustrate that, under the condition of the same parameters, the proposed active damping control strategy performs the same as passive damping control in damping at source side and better in filtering.