Single-phase three-level PWM rectifier with power-factor correction

A novel control strategy for single-phase undirectional switching-mode rectifier (SMR) that draws a sinusoidal nar line current in phase with the supply voltage is proposed and discussed in this paper. In the adopted circuit topology: two AC power switches are placed between the AC side of the SMR and the center-tapped terminal of the DC-link capacitors. The control schemes are based on the hysteresis current control (HCC) tech technique and the simple look-up table. The control schemes, stored in a programmable army logic (PAL), are implemented such that the line current is driven to follow the current command. There are three voltage levels (u(DC), U-DC/2.0) on the AC sine of the rectifier in each half cycle. The blocking voltage of each AC power switch is clamping to half of the DC-link voltage. Software simulations and experimental circuits are implemented and measured to verify, the proposed control strategy.