A Control Scheme for a Quasi-Z Source Three-Phase Inverter

This paper presents a novel control scheme for a three-phase quasi-z source inverter (qZSI) using a capacitor voltage and input current-based sinusoidal pulse width modulation (SPWM) technique. The proposed scheme combines the advantages of both qZSI and SPWM techniques to achieve improved performance. The SPWM technique utilizes a sinusoidal modulation signal, which is compared with a high-frequency triangular carrier wave and two shoot-through (ST) references to determine the switching states for the three-phase qZSI. The positive and negative ST references are obtained from the capacitor voltages and input current, allowing for control of the DC bus voltage and ST states of the inverter. Additionally, the proposed control scheme generates the three-phase modulation signal through decoupling control in the dq reference frame. The detailed analysis of the control scheme includes its operating principle, transient state, steady-state responses, and the effects of parameter variations. Simulation studies are conducted using MATLAB/Simulink to assess the performance of the three-phase qZSI under the proposed control scheme. The simulation results demonstrate the effectiveness of the control scheme in terms of output voltage quality, DC bus voltage control, and robustness against reference variations. Overall, the proposed capacitor voltage and input current-based SPWM control scheme for the three-phase qZSI shows promising performance improvements and robustness, as confirmed through comprehensive simulation studies.