Direct model predictive current control for matrix converters

Abstract

This paper proposes a direct model predictive current control (MPC) strategy for matrix converters (MCs). The proposed method aims to regulate the output current of the MC while minimizing the input reactive power at the same time. In addition, in order to reduce the switching losses, the MPC adjusts the average switching frequency of the converter. The MPC scheme uses the discrete-time model of the MC to predict the future trajectories of the controlled variables of concern. Then, a cost function is formulated to include all the control objectives, i.e. the output current, input reactive power, and switching frequency. Subject to the system dynamics, the cost function is minimized in order to find the optimal control action that can be applied to the converter at the next time-step. In order to examine the proposed control strategy with the MC, simulations based on MATLAB/Simulink are conducted. The simulation results show the effectiveness of the proposed scheme in steady-state and transient operations. The results show that the proposed MPC strategy offers a very good steady-state behavior as well as very fast dynamic responses during transients. Moreover, the switching frequency can be highly reduced which in turn results in low switching losses.