Single-phase three-level rectifier with high power factor

A new control scheme for the single-phase rectifier with three-level voltag e pattern is proposed. A power-factor corrector to improve the power qualit y is presented. A hysteresis current control (HCC) is adopted to control th e line current with high power factor and low harmonic distortion. The line current command is derived from a DC link voltage regulator and an output power estimator. The major advantage of using three-level instead of two-le vel voltage pattern is that the blocking voltage of each power device is cl amping to half of the DC link voltage. Based on the region detector of the line voltage, capacitor compensator and hysteresis comparator, the proposed control scheme is used to drive the line current with high power factor an d low current distortion. The proposed scheme is verified by software simul ations and experimental results from a laboratory prototype.