The purpose of this paper is to develop a novel power conversion circuit for cost-effecfive battery-fuel cell hybrid systems. First of all, the various reduced parts power conversion systems (PCS) are overviewed and an advanced dc-dc boost converter and a bidirectional dc-dc converter are proposed. Theoretical explanation and informative simulation and experimental results are provided, along with the evaluation of the developed topologies in performance points of view. (c) 2005 Elsevier B.V. All rights reserved.