Improvement of Nonlinear-carrier Control for High-power-factor Boost Rectifiers

Improved nonlinear-carrier (NLC) control is presented herein for high-power-factor boost rectifiers. In such control, the switching duty ratio is determined by comparing a signal derived from the main switch current with a periodic nonlinear carrier waveform. Most of all, a feedforward control technique is additionally applied not only to reduce the total harmonic distortion of the line current but also to increase the corresponding power factor. In this paper, the theorem of nonlinear-carrier control is briefly derived and some simulation results are provided to demonstrate the proposed control topology.