Application of Embedded Ethernet in Reley Protection Device

The development of communication technology of substation automation system was reviwed and the serial communication with fieldbus technology on communication distance.speed,nodes aspects was compared. The design method of software and hardware for interface circuits which arc used in Ethernet communication of relay protection was also given. It selected W3100A (the chip which includes Internet and Ethernet protocol) and reduced the work of compiling the software. The speed of communication is fast and flexible. All of the chips work on voltage of 3.3 V, having low power.