抄録
This paper presents a design procedure for output current and damping controls of a matrix converter to suppress the LC filter resonance and to improve the transient current response. With a conventional design method that provides preference to stability, the damping control leads to a large output current overshoot and a large error of the cut-off frequency of the output current control between the desired and the actual values. Thus, in order to obtain a desired transient response with maintaining a stable operation, this paper describes a modified control block diagram in which a reference filter is added to suppress the output current overshoot. In addition, a design flowchart using Bode diagrams is also presented to reduce the error of the cut-off frequency of the output current control and to ensure a desired gain margin. From the experimental results, it is verified that the damping control designed with the proposed method suppresses the filter resonance. As a result, the damping control reduces the input current THD (total harmonic distortion) by 52.3% compared to the result without the damping control. In addition, the proposed design method reduces the output current overshoot of 67.6% and an error between the desired and the obtained cut-off frequencies to less than 1/6 compared with the conventional method because of the proposed reference filter and the design flowchart. Finally, the effects of discretization and a voltage-type commutation sequence for the cut-off frequency of the output current control are analyzed.
