System implement of voltage-current dual closed-loop control model of AC-AC matrix converter

Based on analyzing the control principle of AC-AC matrix converter (MC), the voltage-current dual closed-loop control strategy of MC with PI regulator and current following technology is introduced in this paper. The PI regulator of the outer-voltage-loop makes the output voltage follow the reference one, and the hysteresis-loop current control is used in the inner-current-loop to determine the switch states of MC. Comparing the measured currents with the reference ones, we get three current factors H_i(i=A,B,C) that can represent 8 different cases of the three-phase current. Combining the current factors with the six intervals of three-phase input voltage, totally, 48 switching modes of MC are derived in this paper. Small computation task, quick response and good stability can be achieved in the solution. The simulation and experimental results have demonstrated the validation of the theory analysis and equivalent circuit models