The Study of Three-level PWM Rectifier

In the high-power applications,the switching frequency of the two-level rectifier is twice higher than the three-level rectifier in the situation of the same performance,and it’s difficult to reject the heat,besides the two-level rectifier requires a higher voltage of IGBT,therefore,a mid-point clamp-type three-level PWM rectifier is researched.By researching of the topology and back to back three-level converter system,the SVPWM control strategy based on virtual flux-oriented line voltage is proposed.Through simulation and experimental results indicate that the mid-point clamped three-level rectifier-type can improve the stability of the DC bus voltage and the power factor of rectifier,fur-thermore,the current harmonics is inhibited.