A Novel Narrow‐Pulses Elimination Strategy Based on Dead‐Time Elimination PWM for NPC Three‐level Inverter

ABSTRACT In three‐level neutral‐point‐clamped (NPC) inverter, dead‐time elimination PWM has advantages such as high voltage utilization, reduced switching loss, and avoid the dead‐time effect (DTE). However, this modulation method has the issue of narrow pulses, which may affect the switching states and potentially lead to a short circuit in the inverter. To address this issue, this paper first analyzes two mechanisms and ranges of narrow pulse generation in a single‐phase NPC inverter. Then, a novel narrow‐pulses elimination strategy is proposed. The proposed strategy predicts the narrow pulses in advance and adjusts switching period to eliminate them. Additionally, the SOGI‐PLL is used to predict the current phase angle to solve the narrow pulses and distortion in the current zero‐crossing. Compared to existing narrow‐pulse elimination methods, the proposed strategy can completely eliminate narrow pulses, ensuring reliable circuit operation while maintaining high‐quality output waveform. Finally, the effectiveness of the proposed strategy is validated through simulations and experiments.