Damping Control of Filter Resonance Focusing on Output Stage for Multi-Modular Matrix Converter

Abstract

This paper discusses a damping control that is applied to multi-modular matrix converters in order to suppress the oscillation due to the LC resonance of the input filter. The multi-modular matrix converter connects a multiple winding transformer and several modules. The module consists of a three-phase to single-phase matrix converter and filter capacitors. It is found that the multi-modular matrix converter has a resonance problem between the leakage inductance of the transformer and the filter capacitors in the modules. In this paper, a damping control combined with the output current control of the multi-modular matrix converter is proposed to suppress the resonance and to achieve better input current quality. The proposed damping control can divert the output current sensors for an ACR (auto current regulator), which is generally used in the adjustable speed drive system of a motor. Therefore, the proposed damping control does not require additional sensors, which is an advantage over the conventional damping control applied to the input stage of the multi-modular matrix converter. From the experimental results, the proposed damping control improves the input current THD (total harmonic distortion) by 75.5%. In addition, the proposed damping control obtains a higher damping performance than the conventional damping control.