Research Of The Communication Protocol In Smart Grid Based On Bei Dou Satellite System

The development of modern society and people's lives is deeply dependent on the electrical power,and the reliable,secure,efficient and intelligent operation of electrical grid is becoming increasingly important.The timely collection and access of electricity information makes the electrical grid operate stablely.At present,The electric energy data acquire system adopt optical fiber,GPRS and other wireless public phone network to transmit data,but the above-mentioned means of communication and can not effectively cover remote areas,mountainous areas and other network blind spots.Fortunately,satellite communication is an effective solution to the above problems because of its wide coverage area.In China,the BD short message communication for populace is limited about communications frequency and communication traffic per times,so how to use this way of communication to transmit data in the electric energy data acquire system is important and research significant.This paper introduces the current domestic and international situation of the electric energy data acquire system and the common data transmission.After analyzing the features of BD short message,the article noted the following problems when applying Beidou short message communication to the smart grid.First,The transmission success rate of length packets will deduce along with the increasing of the number of the sub packets.Second,The channel utilization will decrease when we retransmit all the missing sub packets,especially when a large number of short data packets need to be transmitted,the sender will be block state for waiting the feedback and response of the peer point.The paper designed retransmission level ARQ mechanism by improving the existing ARQ mechanism.On the basis of data collection success rate of the smart grid,the paper accord to the number of split sub-data packet to determine whether the lost data packet retransmitting and set the maximum number of retransmissions reasonable.Then,the paper presents a complete communication protocol and protocol data format for interface and simulation the protocol by the OMNet++ simulation software.The paper verified the rationality of communication protocols through a large number of experimental data,and the BD short message can be used for the grid smart to solve the electricity information collection in remote areas.