A Multimodulation Times SVPWM for Dead-Time Effect Elimination in Three-Level Neutral Point Clamped Converters

In order to improve the speed regulation performance of induction motors, a multimodulation times space vector pulsewidth modulation (MMT-SVPWM) is proposed for the three-level neutral point clamped (NPC) converter. This method can eliminate the dead-time effect (DTE), which is caused by the addition of the dead time (DT) in the SVPWM. This article first analyzes the deviation of the output voltage that is caused by the DTE in the SVPWM, and then proposed the MMT-SVPWM. The generation of driving signals in this method is different from the ideal SVPWM. According to the directions of three-phase currents, the driving signals of a pair of complementary power switches are obtained by comparing a pair of multiple modulation times with the triangular carrier. Thus, this method directly eliminate the DTE, which is different from the SVPWM with DT. The output voltage vector is the same as that of the ideal SVPWM, and there is no zero-current clamping effect. Finally, the simulation and experimental results show that the proposed method effectively eliminates the DTE and improves the output currents of the three-level NPC converter.