Impact of Deadband on a Three-Phase Three-Level NPC Inverter for Induction Motor Drive utilizing a Innovative Deadband Circuit

This paper proposes an innovative dead band circuit designed to be utilized in multilevel converters. Multilevel con-verters are workforce of industrial drive. Especially neutral point clamped (NPC) is very popular, and it has very high efficiency. To drive a three-phase three-level NPC (TTNPC) inverter, deadband circuits are utilised to avoid shoot-through between two switches in same leg of an inverter. In this article, Modelling and hardware implementation of an NPC inverter are carried out, and a fully controlled dead-band circuit is proposed using digital logic gates and RC circuits. Hardware is tested with carrier-based Pulse Width Modulation (PWM) Techniques, In-Phase Sinusoidal PWM (IPSPWM), and Phase Opposite SPWM (POSPWM). Experimental results demonstrate that deadband circuit exhibits minimal oscillation during dead band time, improving converter performance. Furthermore, performance of proposed deadband circuit is evaluated based on voltage and current total harmonic distortion (THD), and typical results are presented.