中文摘要：

随着基于IEC61850的数字化变电站系统的进一步发展，传统变电站内的信号和控制电缆将逐步被过程总线所代替．IEC已经将工作重心逐渐转移到过程总线上，结合制订IEC61850Ed2．0，IEC开始深入研究并制订诸如IEC62439—3、IEEE1588—2008等标准。阐述了IEC62439—3标准的典型技术特征，及其支持网络无扰恢复的技术原理。将IEC62439—3应用于过程总线，并与传统保护系统相比，分析采用不同过程总线的全数字化保护系统的结构，利用可靠性框图对不同结构的保护系统可靠性参数进行详细的计算和分析。针对过程层总线宜采用的网络结构给出了建议。

英文摘要：

With the further development of the substation automation system based on IEC 61850, the process bus will be widely used in the substation to replace the traditional signal and control cable. IEC has shifted its focus to the process bus. Combined with the formulation of IEC 61850 Ed 2.0, IEC begins to study and develops some standards such as IEC 62439-3, IEEE 1588-2008, etc. This paper describes the typical technical characteristics oflEC 62439-3 standard, and introduces the main technical principles of the network bumpless recovery. It applies IEC 62439-3 to the process bus. By comparing with the traditional protection system, the paper analyzes alternative all-digital protection systems which employs different process bus architectures. Finally, the reliability block diagrams are used to calculate and analyze the reliability indices of different protection systems, and network structure that fits for nrocess bus is pronosed.