Open-Circuit Switching Fault Analysis and Tolerant Strategy for Dual-Active-Bridge DCDC Converter Considering Parasitic Parameters

摘要

The dual-active-bridge (DAB) is a typical topology of dc-dc converter for bus connection, voltage conversion, power transmission, and electrical isolation in dc power grids. The opencircuit switching fault (OCSF) may threaten the safe operation of DAB and should be eliminated in time. However, the researches on parasitic parameters mainly focus on traditional dc-dc converters, and there are still few discussions on parasitic parameters in the high-frequency dc-dc converter such as DAB. The power components are usually considered without parasitic parameters inOCSF analysis and tolerant control, leading to deviations inmodality analysis and practical control for DAB. To solve this issue, themodality analysis considering parasitic parameters during OCSF in DAB is investigated, and the sneak circuits and electrical characteristics with parasitic parameters are discussed in this article. Besides, to realize fault tolerance for DAB during OCSF considering parasitic parameters, a new fault tolerance control strategy including modeling, topology transformation principle, and practical control architecture are also proposed. Compared with conventional fault tolerance strategy, the proposed strategy will be more efficient, rapid and feasible forDABduringOCSFprocess. The experimental results in DAB prototype verify correctness and effectiveness of analysis and proposed strategy.

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