Symmetrical dynamics of peak current-mode and valley current-mode controlled switching dc–dc converters with ramp compensation

Abstract

The discrete iterative map models of peak current-mode (PCM) and valley current-mode (VCM) controlled buck converters, boost converters, and buck–boost converters with ramp compensation are established and their dynamical behaviours are investigated by using the operation region, parameter space map, bifurcation diagram, and Lyapunov exponent spectrum. The research results indicate that ramp compensation extends the stable operation range of the PCM controlled switching dc-dc converter to D > 0.5 and that of the VCM controlled switching dc–dc converter to D < 0.5. Compared with PCM controlled switching dc–dc converters with ramp compensation, VCM controlled switching dc–dc converters with ramp compensation exhibit interesting symmetrical dynamics. Experimental results are given to verify the analysis results in this paper.