A systematic framework for reliability assessment and fault-tolerant design of multiphase dc-dc converters deployed in photovoltaic applications is presented. System-level steady-state models allow a detailed specification of component failure rates, and in turn establish the effects of ambient conditions and converter design on reliability. Markov reliability models are derived to estimate the mean time to system failure. Case studies applied to two-and three-phase, 250-W converters demonstrate that topological redundancy does not necessarily translate to improved reliability for all choices of switching frequency and capacitance. Capacitor voltage rating is found to be the dominant factor that affects system reliability.
Bibliographical noteFunding Information:
Manuscript received July 12, 2010; revised October 28, 2010; accepted December 10, 2010. Date of current version January 9, 2012. This work was supported by the Grainger Center for Electric Machines and Electromechanics. Recommended for publication by Associate Editor J.-L. Hanen. S. V. Dhople and A. D. Domínguez-García are with the Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA (e-mail: firstname.lastname@example.org). A. Davoudi is with the Department of Electrical Engineering, University of Texas, Arlington, TX 76019 USA. P. L. Chapman is with the SolarBridge Technologies, Austin, TX 78758 USA. Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TPEL.2010.2103329
- Markov reliability modeling
- maximum power point tracking (MPPT)
- switch-mode dc-dc converters