Effects of the input filter on the stability of a voltage-mode controlled buck converter

摘要

This letter presents a favorable effect of the input filter on the stability of a filter-converter system, which employs a cascade configuration of a voltage-mode controlled buck converter and a third-order input filter. Such an effect can enlarge the stable region of the stand-alone buck converter when appropriately selecting the damping resistor of the input filter. Effectively, the frequency-domain model based on the extra element theory is used to analyze and illustrate the input filter interaction regarding this favorable effect. Our work provides a supplementary view for engineers to deal with input filter interaction.