Control of bifurcation in current-programmed DC/DC converters: a reexamination of slope compensation

Abstract

This paper reexamines the conventional current-mode control strategy as applied to DC/DC converters in the light of "avoiding bifurcation". This alternative viewpoint permits convenient selection of parameter values to guarantee stable operation. Slope compensation is viewed as a means to keep the system sufficiently remote from the first bifurcation point. It is shown that excessive bifurcation clearance is accompanied by undesirably slow dynamical response. A variable ramp compensation is proposed to dynamically adjust the slope magnitude such that the system is kept clear of bifurcation yet responds sufficiently fast during transients.