The traditional three-level space vector pulse width modulation (SVPWM) algorithm is hard to implement for the numerous trigonometric functions contained. What’s more

the traditional method of acquiring output voltage harmonic of three-level inverter is susceptible to noise

step size and accuracy of simulation. Based on the distribution characteristics of three-level voltage space vector

an analysis is made of the essential relation between three-level inverter SVPWM and sinusoidal pulse width modulation (SPWM) algorithm under the 120° coordinate system. The three-phase modulation wave and pulse duration ratio are obtained just by simple linear calculation

simplifying the three-level SVPWM algorithm. According to the characteristics of digital circuits

the fundamental and harmonic amplitudes of the output voltage are obtained by Fourier analysis

providing a theoretical basis for the filter design

comparison of different modulation algorithms

further theoretical analysis and computation. The results of theoretical analysis are consistent with digital signal processor (DSP) hardware based experimental results. This work is supported by National Basic Research Program of China (973 Program) (No. 2014CB046306).