基于嵌入式以太网的电子式互感器数字输出口

数字输出口是电子式互感器对变电站通信网络的信息输入点,为实现变电站监视、计量、控制和保护装置的信息共享与系统集成提供了技术基础.电子式互感器的数字输出口负责将瞬时电流电压数字信号以指定帧格式封装,并传送给变电站的二次设备.根据IEC 60044-8标准,在数字输出口的设计中可采用以太网接入方案和点到点链接方案.文中提出了一种基于嵌入式以太网的电子式互感器数字输出方案.该方案采用基于386EX微处理器的嵌入式网络模块作为硬件平台,并通过Linux操作系统内置的TCP/IP协议实现数据传输.在分析实时性与可靠性的基础上,具体阐述了以太网通信的实现.此设计方案符合IEC 60044-8标准,能够满足变电站监测系统对实时性与可靠性的要求.

DIGITAL OUTPUT FOR ELECTRONIC INSTRUMENT TRANSFORMERS BASED ON EMBEDDED ETHERNET

The digital output is the information input point of electronic instrument transformers for the communication network of substations. It provides the technical basis for realizing information sharing and system integration of the monitoring, measuring, control and protection devices in substations. The digital output interface of electronic instrument transformers is responsible for encapsulating instantaneous digital current and voltage signals according to the specified frame format and transmitting the data stream to the secondary devices in substations. Based on IEC 60044-8 standard, either the scheme of Ethernet access or that of point-to-point link can be used in the design of the digital output. In this paper, an embedded Ethernet-based scheme adopting the embedded network module is proposed with a 386EX microprocessor as the hardware platform. Data transmission is realized through the in-line TCP/IP protocol of Linux operation system. From an analysis of the real-time character and reliability, the realization of Ethernet communication is expounded in detail. The scheme is in conformity with IEC 60044-8 standard and can meet the real-time and reliability requirements of substation monitoring systems.