Independent Control of Input Current, Output Voltage, and Capacitor Voltage Balancing for a Modular Matrix Converter

This paper presents a novel control scheme for the modular matrix converter (MMxC), in terms of balancing capacitor voltages in addition to controlling output voltage and input current along with a comprehensive mathematical model. The proposed technique has been designed based on a fully decoupled current control of the positive-, negative-, and zero-sequence components of each MMxC subconverter in addition to the feedforward instantaneous power control to suppress the capacitor voltages fluctuation. The frequency of the zero-sequence is the output frequency for the load. Therefore, the positive-sequence current component is used to control the input current to achieve unity input power factor, the negative-sequence current component is used to balance the capacitor voltages among all MMxC arms, and the zero-sequence current component is used to control the output voltage. The effectiveness of the proposed control scheme for controlling the MMxC has been verified theoretically, using simulation software, and experimentally, using a laboratory prototype based 3 kVA, 200 V.