基于故障树分析法的全光纤电流互感器可靠性研究

全光纤电流互感器(FOCT)具有体积小、绝缘简单、无磁饱和等优点，可以更好地兼容现代数字控制和保护系统，是电流互感器的重要发展方向。目前FOCT长期运行可靠性较低，严重制约了其在数字化变电站中的推广应用。为此，文中从电路和光路两方面开展FOCT的故障树模式分析，建立覆盖FOCT整体结构的故障模式分析体系。首先，分析FOCT的结构及工作原理，并根据其回路组成划分故障；其次，提取FOCT在长期运行过程中出现的主要故障模式，对其进行原因分析和排查；然后，从方案设计、元器件筛选和施工工艺方面提出可靠性提升措施；最后，结合实际案例，利用故障树对某例光源故障开展原因分析，并提出其可靠性提升措施，验证文中所提方法的有效性。研究结果可为FOCT故障分析及运行可靠性提升提供理论依据。

Reliability research of fiber optical current transformer based on fault tree analysis

The fiber optical current transformer (FOCT) has distinguishing advantages of small size, simple insulation, no magnetic saturation, and can be better compatible with modern digital control and protection systems, which has become an important development direction of current transformer. However, at preasent the long-term operation reliability of FOCT is low, which seriously restricts its popularization and application in digital substation. In this paper, the fault tree analysis of FOCT is comprehensively carried out from both the circuit and the optical path, and a fault mode analysis system covering the overall structure of FOCT is established, the main fault modes oc-curring in the long-term operation of FOCT are extracted, and the complete FOCT fault tree is constructed. Then, the listed fault modes are investigated one by one, and the reliability improvement measures are proposed from the aspects of scheme design, component selection and construction technology, and the application of the pro-posed method is verified with an actual case. The research can provide a theoretical basis for FOCT fault analysis and operation reliability.