备自投是电力系统中的主要设备之一。备自投可以有效的提高供电的可靠性和连续性。与传统的备自投相比，数字化备自投符合数字化变电站分层分布式布置的结构特点，它具有分布式采集、分布式计算等许多优点，最重要的是，各个保护测控装置能独立的进行保护计算和跳闸，将误动降到最低，大大的提高了供电系统的可靠性和实时性。本文是以符合IEC61850标准下的数字变电站备自投为研究对象，重点对备自投的功能分解建模以及语言配置、仿真研究过程总线网络延时、并对软件进行设计。 首先，对数字化备自投的工作原理分析，并且对两种自投方式的充电条件、放电条件以及动作条件进行研究，分析了备自投的部分功能。通过深入学习IEC61850标准体系结构和GOOSE通信模型，在此基础上，对数字化备自投的进行建模，并对逻辑节点信息模型进行了深入剖析，以及备自投功能实现的信息流向进行了分析，最后创建备自投配置语言。 其次，研究了不同拓扑结构的优缺点，并利用OPNET网络仿真软件对共享式和交换式网络进行了网络延时仿真，得出在100M以太网用于过程总线通讯对于共享式和交换式可以满足网络延时的要求，但交换式网络延时最大延时小于共享式。 最后，对备自投软件任务进行了分析，结合MMS-EASE-LITE软件包，完成符合IEC61850标准的备自投的采样值软件和GOOSE软件设计，并通过调试工具对软件进行验证。

Spare power automatic switching is one of the main equipment of the power system. It can effectively improve the reliability and continuity of the power supply. Compared with traditional spare power automatic switching, the digitizing spare power automatic switching comply with the digital substation hierarchical distributed arrangement structure characteristics, it has distributed collection，distributed computing and many other advantages, most importantly, each protection and monitoring device independent computing and tripping protection, and minimizing the malfunction, greatly improve the reliability and real-time of the power supply system. This article is according with the IEC61850 standard of the digital substation spare power automatic switching as the research object, focusing on the modeling spare power automatic switching of functional decomposition and language configuration, simulation study process bus network delay, and software design. In the first place, analysis the working principle of the digitize spare power automatic switching, and research on the discharge and charge conditions, well as operating conditions, analysis the spare power automatic switching features. Through in-depth learning IEC61850 standard architecture and GOOSE communication model, based on this, modeling to the digital spare power automatic switching, and anglicizing its functions to achieve of the flow of information, at last, create its configuration language. In the second place, to study the advantages and disadvantages of different topologies, and use OPNET network simulation software to emulate the shared and switched network delay. Use 100M Ethernet for process bus communication of the shared and switched network can meet the requirements of network delay, but the maximum delay time of the switched network is less than shared. Finally, analysis the task of spare power automatic switching, combined with MMS-EASE-LITE package, completed SMV software and the GOOSE software design of the spare power automatic switching in line with IEC61850 standard, and used debugging tools to verify the software.