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

A Simple and novel variable hysteresis band current control technique for three-phase three-level unity power factor (PF) rectifier is proposed in this paper. The hysteresis band is controlled as variations of the rectifier input voltage and output dc link voltage to achieve constant switching frequency at any operating conditions, i.e., at rated and below and above the rated conditions. The rectifier has the characteristic of easy implementation, and draws a nearly sinusoidal current at unity input PF. Theoretical. and predicted results of its analysis are verified initially through digital simulation, and confirmed by using an experimental prototype.