Unified Equivalent Modeling for Stability Analysis of Parallel-Connected DC/DC Converters

A unified equivalent modeling approach is proposed for enabling simple and effective analysis of stability of parallel-connected buck converters. Two kinds of active current-sharing schemes are considered, i.e., the master-slave scheme and democratic scheme. By applying elementary transformation to the Jacobian of the averaged model, two decoupled subsystems (which determine common-mode and differential-mode stabilities, respectively) have been found, irrespective of the specific type of active current-sharing scheme. From the decoupled subsystems, the parameters of interest that affect different stability issues are clearly identified. Results from this work greatly simplify the stability analysis and design of parallel-connected dc-dc converters.