Calculation of steady-state solution of parallel-connected buck converters with active current sharing and its parameter sensitivity

In this paper, the effect of active current-sharing control on the steady-state operation of parallel-connected buck converters is investigated. The system under study consists of N voltage-mode-controlled buck converters connected in parallel. Three kinds of active current-sharing schemes are considered, namely, master-slave scheme with automatic master, master-slave scheme with dedicated master, and democratic scheme. Using the principle of charge balance, the mechanism of the operating point drift arising from active current sharing is examined. A general formulation of the steady-state solution under active current sharing is derived. Moreover, detailed parameter sensitivity analysis is performed to evaluate the effect of parameters variation on the operating point. The results from sensitivity analysis can be used to categorize parameters for facilitating practical design. Computer simulations are presented to verify the analytical results. © 2010 John Wiley & Sons, Ltd.