Research of Three-level PWM Rectifier Based on Improved SVPWM Algorithm

Topdogical structure of neutral-point-clamped three-level rectifier was analyzed. A mathematical model of the rectifier was established based on switching function in d-q frames. On the basis, current d-q decouple control was realized by means of dual closed loops control, so dynamic performance of the rectifier was improved. In view of shortcoming that there are a large number of trigonometric calculations in determining sector and solving action time of space vector in traditional SVPWM algorithm, a SVPWM algorithm based on non-orthogonal 60°coordinate system was proposed. The algorithm optimizes vector calculation of the three-level rectifier. The results of simulation and experiment valified correction of the algorithm.