Implementation of a three-level rectifier for power factorcorrection

摘要

In this paper, a new single-phase switching mode rectifier (SMR)nfor three-level pulse width modulation (PWM) is proposed to achieve highninput power factor, low current harmonics, low total harmonic distortionn(THD) and simple control scheme. The mains circuit of the proposed SMRnconsists of six power switches, one boost inductor, and two DCncapacitors. The control algorithm is based on a look-up table. There arenfive control signals in the input of the look-up table. These controlnsignals are used to control the power flow of the adopted rectifier,ncompensate the capacitor voltages for the balance problem, draw ansinusoidal line current with nearly unity power factor, and generate anthree-level PWM pattern on the AC side of adopted rectifier. Thenadvantages of using three-level PWM scheme compared with two-level PWMnscheme are using low voltage stress of power switches, decreasing inputncurrent harmonics, and reducing the conduction losses. The performancesnof the proposed multilevel SMR are measured and shown in this paper. Thenhigh power factor and low harmonic currents at the input of thenrectifier are verified by software simulations and experimental resultsnfrom a laboratory prototype