直流配电系统SRDAB接口变换器的复合容错控制方法

Control Method of Hybrid Fault Tolerant for Series Resonant Dual-active-bridge Interfacing Converters in DC Distribution Systems

针对广泛应用于主动直流配电网的串联谐振型双有源桥(SRDAB)接口变换器典型故障开展研究。首先分析了基于占空比调节和基于全桥变换器拓扑结构重组的容错控制方法,并详细比较了两种方法的容错特性及其固有缺陷。在此基础上,提出了一种复合容错控制方法,该方法实时监测输出电压,在出现电压跌落后通过占空比调节快速恢复电压,并自动重组拓扑结构,实现高效运行,使电路具有故障自主辨识能力和故障后自主恢复能力。相比于传统的容错方法需要大量的硬件冗余和复杂的故障检测电路来检测具体故障,该方法无须增加任何硬件且无需复杂的故障定位方法,通过复合控制即可实现高效可靠的故障容错运行。此外,所提出的方法具有良好的暂态和稳态控制特性,克服了传统容错控制在运行模式切换时刻带来的电流冲击、电压跌落等缺陷。实验证明了所提方法对双有源桥接口变换器容错控制的有效性。

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.