This paper focuses on the typical fault of the series resonant dual-active-bridge (SRDAB) converters which are widely used in active DC distribution systems. Firstly, two fault tolerant control methods including duty-cycle regulation and topology reconfiguration of full-bridge converter, are analyzed and detailed compared on their characteristics and inherent drawbacks. Based on these analyses, a control method of hybrid fault tolerant is proposed. In this method, the output voltage is real-time monitored and can be recovered quickly through duty-cycle regulation if voltage sag appears. Secondly, the circuit automatically reconfigures to realize highly efficient operation if open-circuit fault is identified. By implementing this proposed method, the system acquires self-fault-diagnosis and self-recovery capabilities. Comparing to conventional fault tolerant methods that employ massive hardware redundancy and complex fault detection circuit to identify particular faults, this hybrid control method can realize highly efficient and reliable fault tolerant operation without any additional hardware. Thirdly, the proposed method has favorable transient and steady-state performances, and prevents defects of conventional methods such as current surge and voltage sag appearing when operation mode changes. Finally, experimental results are provided to validate the effectiveness of the proposed method on fault tolerant control for dual-active-bridge interfacing converters.
|Translated title of the contribution||Control Method of Hybrid Fault Tolerant for Series Resonant Dual-active-bridge Interfacing Converters in DC Distribution Systems|
|Journal||Dianli Xitong Zidonghua/Automation of Electric Power Systems|
|Number of pages||8|
|Publication status||Published - Oct 2018|