基于Ethernet技术的变电站综合自动化系统研究

【作者】 苏渊；

【导师】 郝晓弘； 何如聪；

【作者基本信息】 兰州理工大学 ， 电力电子与电力传动， 2003， 硕士

【摘要】 本文首先针对变电站中通信协议标准不一，数据传输速率低的问题，提出了一种基于以太网的分层分布式通信网络模型。在该模型中，应用层协议采用Modbus协议，传输层协议采用TCP协议，介质访问控制协议采用IEEE802.3标准，上位机通过轮询的方式对测量数据进行采集。由于Modbus和以太网协议均已成为事实上的工业标准，并被大多数厂商所接受，因此Modbus/TCP通信协议可以实现不同厂商设备的互联互通。其次，未来的变电站不仅要向调度中心传输测量数据，还要传输图形、语音、视频等信息，而传统的RTU模式只能传输一些简单数据，这已不能适应技术发展的要求。本文就此提出了一种基于Web的变电站远程监控系统。该系统采用浏览器/服务器结构，实现了通过IE浏览器查看变电站的各种图形和数据信息。该方法具有编程简单，客户端免维护等特点。另外，针对传统的变电站安全自动装置可靠性低的问题，本文利用可编程控制器实现了自动重合闸等功能。模拟试验结果表明，可编程控制器具有使用灵活，安全可靠等优点，可以替代传统的安全自动装置。最后设计了变电站操作票专家系统。该系统采用产生式知识表示法和框架知识表示法，通过在数据库中分别建立规则库、状态库、网络拓扑知识库和设备属性库来完整表述变电站的全部信息。本系统采用基于规则的正向推理作为推理策略，通过比较初始状态和目标状态的不同完成开票。本系统的应用将解决手工开票速度慢、易出错等问题。更多还原

【Abstract】 First, a layered and distributed network model based on Ethernet is presented to solve following problems: there is no an uniform communication protocol applied in substation and the speed of data transmission is too slow. In the newly presented model, the application layer uses modbus protocol, the transmission layer uses TCP and the Media Access Control protocol uses IEEE802.3 standard. The monitoring computer collects measuring data by polling method. Modbus and Ethernet protocol have been the de facto standards in industry, and accepted by most companies, so the application of Mobus/TCP will make devices from different vendors to work properly together in the same network. Secondly, The future substation will transfer not only measuring data, but also information such as gragh, sound and video to the dispatching center. However, the traditional RTU mode can only transfer some simple information, it will not meet the requirements of the future substation. A web-based remote supervisory control system for substation is presented to solve this problem. The Browser/Server mode is applied in this system, various graph and data can be seen through Internet Explorer. The method has following advantages: simple in programming, maintenance-free for clients, etc. In addition, to improve the reliability of traditional automatic apparatuses, PLC is used to implement some functions such as automatic re-switch and automatic put-in of standby power source. The simulation test shows that PLC has advantages such as flexibility in programming ,safety and high reliability, it can replace traditional automatic apparatuses. At last, An expert system used to automatically generate switching sequences is also presented. Knowledge production and frame representation are used to build rule database, status database, topology database and property database, these databases can describe all information of a substation. Forward reasoning based on rules is used as reasoning strategy to generate switching sequences through comparing the differences between the initial status and the final status. The application of the system will solve folio whig problems: much time are consumed and easy to make mistakes when the operator writes switching sequences.更多还原