The direct three-phase-to-single-phase Modular Multilevel Matrix Converter (M3C) encounters challenges in rapid control of submodule capacitor voltages due to variable coupling under identical input-output frequency conditions in active arc suppression applications for distribution networks

which compromises the stable operation of M3C and its capability for rapid fault arc elimination. To address this issue

a feedforward decoupling active voltage arc suppression control method is proposed. First

a three-phase-to-single-phase direct M3C circuit model is established using ΣΔ-αβ0 coordinate transformation

revealing the underactuated characteristic of M3C under identical frequency operation. Subsequently

full actuation is achieved by injecting multi-frequency combined circulating currents and common-mode voltages. Analysis of the average power across each arm reveals that the capacitor voltage balancing control system constitutes a multivariable

coupled

multi-input

multi-output (MIMO) system. Based on the coupling relationships

the feedforward decoupling principle is applied by feeding the coupling terms into corresponding channels

thereby transforming the original MIMO system into multiple fully decoupled single-input single-output (SISO) systems. This enhancement significantly improves the dynamic response speed of the voltage balancing control system and the rapid fault arc suppression capability. MATLAB/Simulink simulations and hardware-in-the-loop (HIL) experimental results demonstrate that the proposed method effectively achieves rapid capacitor voltage balancing across all M3C arms and reliable arc suppression during single-phase grounding faults in distribution networks.