Visible to the public Fast Unloading Transient Recovery of Buck Converters Using Series-Inductor Auxiliary Circuit Based Sequence Switching Control

TitleFast Unloading Transient Recovery of Buck Converters Using Series-Inductor Auxiliary Circuit Based Sequence Switching Control
Publication TypeConference Paper
Year of Publication2018
AuthorsZhao, Z., Lu, W., Ma, J., Li, S., Zhou, L.
Conference Name2018 IEEE International Power Electronics and Application Conference and Exposition (PEAC)
ISBN Number978-1-5386-6054-6
Keywordsbuck converter, Buck converters, capacitor-charge balance principle, control systems, equivalent inductance, fast transient regulation, fast unloading transient event, fast unloading transient recovery, Inductance, Inductors, load transient response, low-voltage high-current synchronous buck converter, output current ripple reduction, power convertors, pubcrawl, resilience, Resiliency, sequence switching control (SSC), sequence switching control scheme, series inductor auxiliary circuit based sequence switching control, series-inductor auxiliary circuit, SSC control scheme, Steady-state, Switching circuits, switching systems (control), switching time sequence, System recovery, time-optimal control scheme, Transient analysis, transient response, unloading transient response, variable inductance circuit, voltage 12 V to 3.3 V, voltage overshoot

This paper presents a sequence switching control (SSC) scheme for buck converters with a series-inductor auxiliary circuit, aiming at improving the load transient response. During an unloading transient, the series inductor is controlled as a small equivalent inductance so as to achieve a fast transient regulation. While in the steady state, the series inductor behaves as a large inductance to reduce the output current ripple. Furthermore, on the basis of the proposed variable inductance circuit, a SSC control scheme is proposed and implemented in a digital form. With the proposed control scheme the unloading transient event is divided into n+1 sub-periods, and in each sub-period, the capacitor-charge balance principle is used to determine the switching time sequence. Furthermore, its feasibility is validated in experiment with a 12V-3.3V low-voltage high-current synchronous buck converter. Experimental results demonstrate that the voltage overshoot of the proposed SSC scheme has improved more than 74% compared to that of the time-optimal control (TOC) scheme.

Citation Keyzhao_fast_2018