A Dead-Time Effect Elimination Method for Three-Phase Dual Inverters

In response to the issue of significant distortion in transformer current caused by the dead-time effect in three-phase dual inverters, a method for eliminating the dead-time effect is introduced. The dead-time elimination pulsewidth modulation (PWM) approach assigns complementary drive signals alternately based on current polarity, thereby fundamentally preventing shoot-through failures. However, this method heavily depends on the accuracy of current polarity detection, and inaccuracies in current polarity determination can lead to notable distortion in zero-crossing zones. To mitigate current zero-crossing distortion while preserving the benefits of dead-time effect elimination, this paper suggests a double-modulation-wave PWM as an enhancement to the dead-time elimination PWM. By utilizing two modulation waves of varying amplitudes to create an underlap period between complementary drive signals, shoot-through failures can be avoided, and the dead-time effect can be circumvented. A real-time simulation platform is employed to validate the efficacy of the proposed method. In comparison to the dead-time elimination PWM, the double-modulation-wave PWM proves adept at reducing current distortion in zero-crossing zones.