Study Of An IP Based Substation Insulation Information Transmission System

On-line monitoring is the technical orientation of the electrical insulation monitoring of high-voltage electric power equipment in substation. In order to gather the insulation condition information of equipment quickly and accurately for on-line monitoring, it's necessary to build a real-time, credible insulation information transmission system with the capability of transfer bulk data.With the rapid advancement of Ethernet technology, Ethernet has been able to satisfy the requirement to be used in industrial environment. Compare to current employed fieldbuses, Ethernet can provide better performance with cheaper price. The prospect of industrial Ethernet is very bright.In this paper, discussion on using Ethernet and embedded technique to build substation insulation information transmission system is presented. Focusing on the real-time performance, the design of data transmission network and embedded data acquisition device is discussed. First the feasibility of using Ethernet in industrial environment is analyzed, using switched Ethernet as substation insulation information transmission network and using TCP/IP protocol suite as the protocols of higher layers is suggested. The factors affecting the real-time performance of data transmission network is presented and the method to improve the performance of IP protocol stack and reduce the traffic of network is focused. Next the design of embedded real-time operating system used in data acquisition device is discussed. The development of the architecture of operating system is presented. The conclusion that the new technical orientation of embedded operating system is the component-based, scalable operating system is given. The function design of embedded real-time operating system is discussed. Then the structure of hardware and software of the data acquisition device is introduced and the design and implementation of an IP protocol stack running on uC/OS-II is described in detail. The test shows that the IP protocol stack works well.