A novel variable hysteresis band current control of three-phase three-level rectifier with constant switching frequency

A simple and novel variable hysteresis band current control technique for three-phase three-level front-end rectifier of an adjustable speed drive (ASD) is proposed in this paper. The hysteresis band is controlled as variations of input voltage and output dc link voltage to achieve constant switching frequency at any operating conditions. The rectifier has the characteristic of drawing nearly sinusoidal current with unity power factor. Theoretical results of its analysis are verified initially through digital simulation, and confirmed by using an experimental prototype.