In order to reduce the switching loss of the inverter and control the neutral-point potential balance, a novel discontinuous space vector modulation are proposed for the typical two stage TL-Boost converter and three-level inverter. Firstly, the fluctuation of the neutral-point potential of the inverter is analyze. The charge compensation of the TL-Boost converter is quantitatively calculated based on charge balance principle. Then the adjustment of duty ratio is deduced, aiming at controlling the total amount of charge flowing through the neutral-point to zero. Through the coordinated control strategy, it can not only take advantage of the low-switching loss of the discontinuous modulation, but also suppress the neutral-point potential fluctuations. The strategy is applicable to the two stage three-level inverter, which can obvious y improve the system efficiency while guaranteed output waveform quality.
