Virtual Capacitors and Resistors Control for Isolated AC-DC Matrix Converter

The LC filter of the isolated AC-DC matrix converter (IAMC) on the input side decreases the power factor and has some distortion in the grid current. Here, a novel IAMC control strategy with virtual capacitors and virtual resistors is proposed to address this issue. Under different load conditions, the virtual capacitor current can fully or partially compensate phase difference between the grid voltage and current, so that the IAMC works in the unit power factor or the maximum achievable power factor (MAPF) state on the grid-side. Meanwhile, Active damping control based on virtual resistance is proposed to suppress the resonance of the LC filter without increasing the extra loss, which improves the efficiency of the system. A simulation is established to demonstrate the validity of the proposed approach. Under different load conditions, simulation results show that the proposed approach controls the input power factor with high precision and reduce the grid current harmonics effectively.