Analysis Of Communication Between Substations Based On IEEE1588 Protocol

According to the development and expansion of the technical fields such as measurement, industrial automation and telecommunication, the communication both between the devices inside the specific application and devices in different applications has becoming more and more often. Whether the time in those devices of applications are the same, or if not, are their time standards sufficiently closer to each other, all of those factors would affect the performance of the communication. As a result, try to find as precise time synchronizing technology seems the best way to resolve the problem.There are mainly five standards to realize time synchronization, they are IRIG-B, Loran-C, NTP, GPS and PTP. Among the above standards, the GPS and PTP protocol could synchronize with a relatively higher precision, which could meet most requirements of the industrial application, and has been extensively researched. The GPS standard is the most widely used and developed technology, however, this method is based on the GPS satellites, and the satellites are controlled by the national defense department of the United States, so there is potentially political threat for the users. The IEEE 1588 PTP protocol provides a new method to acquire high level synchronizing precision, and this protocol depends on no satellites or political organization, the technology is totally independent and reliable. Although this standard has not been widely used in the industrial application, the bright future still deserves a deep in research on it.The IEEE 1588 protocol can also be universally applied in the electrical power industry, such as the telecommunication between intelligence substations. This paper focus on the precise synchronization between intelligence substations based on IEC 61850 protocol, and start with the introduction of the development history of the time measurement and synchronization technology, then introduced the functional principle of IEEE 1588, the format of the messages used in the standard and so on, analyzed the boundary clock, transparent clock and the BMC algorithm, which is the core algorithm of IEEE 1588.In this paper, the core IEEE 1588 module of the functional circuit in the experiment is the DP83640 chip, which is designed by the National Semiconductor Company of the United States. The features and the main function of the chip are also mentioned in this paper. By the practical testing of the synchronizing circuit used in the merging unit of current electronic transformer, the precision is no more than 1μs, which absolutely meets the requirement of the substation communication. In the end of this paper, a comparison between PPS and PTP has been given out, it also shows the advantage of PTP.