Switched Ethernet based online monitoring system for power transformer

In order to promote the construction of smart grid, a switched Ethernet based online monitoring system for the power transformer is presented. Following the standard IEC 61850, the system has three levels: process level, bay level and station level. An embedded TCP/IP protocol is presented for less occupying resources; the local data acquisition unit designed by using chips ATmega168A and ENC28J60 can transfer the data to the monitoring station in the bay level; the system can easily become a part of substation automation systems, and realize the remote monitoring based on Internet. The application case shows the online monitoring system works well, and can measure the parameters accurately.