Space Vector Modulation Method-Based Common Mode Voltage Reduction for Active Impedance-Source T-Type Inverter

In recent years, many pulse width modulation techniques have been explored for three-level impedance-source inverters. Among them, a space vector modulation (SVM) technique using upper/lower shoot-through (UST/LST) insertion provides high voltage gain and satisfactory output voltage quality. This paper further introduces a new SVM control method to reduce the magnitude of common-mode voltage (CMV) without affecting the output voltage quality and voltage gain. With this approach, only small vectors with low magnitudes of CMV are adopted to synthesize an output voltage vector. The UST and LST states are also inserted to these small vectors to boost the DC-link voltage in high voltage gain and high modulation index. The comparison of CMVs between this strategy and other schemes is presented to demonstrate the effectiveness of the proposed method. The simulation and experiments are conducted to verify the accuracy of the theory.