Online Dead-Time Compensation Method Based on Harmonic Model for Voltage-Source Inverters

The dead-time effect, while necessary for preventing shoot-through faults in voltage-source inverters (VSIs), introduces significant harmonic distortion and voltage errors that degrade system performance. Traditional dead-time compensation methods typically rely on detecting the polarity of the phase current to estimate and compensate for the voltage error. However, these approaches suffer from inaccuracies, particularly near zero-crossing points of the current, where sampling noise and sensor resolution limitations lead to erroneous polarity detection and ineffective compensation. To address this issue, this article proposes an improved dead-time compensation strategy that enhances estimation accuracy by leveraging the sixth-order harmonic characteristics inherent in permanent magnet synchronous motors (PMSMs). By analyzing the relationship between dead-time-induced voltage distortion and the sixth-order harmonic component in the motor current, the proposed method formulates an error voltage estimation model that is less sensitive to current polarity misjudgment. This approach not only improves compensation precision under lowcurrent conditions but also reduces dependency on noisy current measurements, thereby enhancing overall inverter performance. Experimental validation confirms the effectiveness of the proposed method in suppressing dead-time effects while maintaining robustness against measurement disturbances.