Common-mode and differential-mode loop gains of paralleled buck converters

Based on the time-domain decomposition of small-signal model in paralleled buck converters, two equivalent low-order loop gains, namely, common-mode and differential-mode loop gains, are derived to analyze and design the stability of the system with N converter modules. Specifically, the proposed loop gains are applied to two voltage-mode controlled buck converters under active current-sharing control. Experimental verification is performed to validate the effectiveness of the proposed loop gains on locating the stability boundary of design parameters.