Abstract: An optimized discontinuous space vector pulse width modulation（DPWM） scheme was studied with the advantages of low switching losses and neutral-point（NP） voltage balance capability. The NP voltage was regulated by redundant clamping modes, and both of the redundant clamping modes and switching states sequence were presented. Moreover, a novel Fourier analysis algorithm was proposed for the three-level modulation scheme. The proposed harmonic analysis algorithm was based on the combination of digital control and Fourier analysis. The AC side voltage harmonics was calculated by the way of piecewise accumulation. Finally, a 10 kW three-phase Vienna-type rectifier prototype was built. Experimental results show that the proposed scheme can regulate the NP voltage balance effectively, and the efficiency of the proposed DPWM is higher than that of the conventional SVPWM. Further, the accuracy of the proposed voltage harmonic analysis algorithm was verified by simulation results.