A Novel Modulation Method to Eliminate Leakage Current and Minimize Capacitor Voltage Ripple for Grid-Connected Three-Level T-Type Inverter

This paper presents a modulation method for Three-level T-type inverter (3LT
²
) in grid-tied renewable systems (PV systems, wind turbines), PFC converters and V2G technology. Many modifications for space vector pulse width modulation have been proposed such as Medium-voltage Vector PWM, SVM Eight-segment or SVM Six-segment, etc. However, MVPWM is only able to eliminate leakage currents (LC) but cannot balance neutral point (NP) voltage, while SVM Eight-segment and SVM Six-segment are the opposite. A modulation method has been proposed to reduce leakage current by keeping the Common-mode Voltage (CMV) constant in each modulation cycle and selecting the right modulation modes to balance neutral point voltage. The simulation results analysis of the proposed method and SVM Eight-segment or SVM Six-segment is presented.