Research And Implementation Of Precision Clock Synchronization For Distributed Power Monitoring And Control System

Nowadays,the power industry is developing rapidly,and the amount of automation equipment is increasing in the Distributed Power Monitoring and Control System,and the power equipment with the requirement of the accuracy of the time of the microsecond level also appears gradually.Traditional clock synchronization timing accuracy can only ensure the millisecond level,has been unable to meet synchronization accuracy requirement of the Distributed Power Monitoring and Control System.In order to reduce the deviation of the industrial automation network clock synchronization in measurement and control system,in 2002,IEEE1588 precision time synchronization protocol(Precise Time Protocol,PTP)has been promulgated.PTP protocol achieves clock synchronization between the nodes in distributed network by Ethernet.And its synchronization precision guarantee the submicrosecond,which can reduce the deviation of the clock synchronization,satisfying the microsecond time accuracy requirement of the Distributed Power Monitoring and Control System.Firstly,this article introduced the IEEE1588 precision clock synchronization protocol.Clock synchronization principle,clock type,network to pological structure,PTP message,clock synchronization algorithm and scheme of time stamp recording was studied.Then the factors influencing the clock synchronization precision of the distributed power monitoring system are summarized.Base on these factors,the solution of PTP protocol was analyzed.In order to solve the problem of the network latency is unstable,the clock synchronization algorithm of PTP protocol is proposed to improve.Using moving average algorithm reduce the impact on the accuracy of clock synchronization.At the end of this paper,according to the synchronization precision requirement of Distributed Power Monitoring and Control System,select recording hardware time stamp in physical layer to realize PTP protocol.Design and realize hardware clock synchronization platform which is based on "STM32F107+DP83640".STM32F107 as the MCU of hardware platform,DP83640 as the external PHY,responsible for hardware time stamp to record and modify the local clock.In the article,building IEEE1588 embedded hardware platform,transplantation of network protocol stack,driven development of DP83640,improvement of clock synchronization algorithm were completed.In the end,improvement of the embedded hardware platform of IEEE1588 time synchronization accuracy and the algorithm proposed in this paper is verified.Test results show that,the IEEE1588 precision clock synchronization protocol can reach submicrosecond synchronization accuracy,and the improved algorithm improve the stability of clock synchronization,fully meet the synchronization accuracy requirements of Distributed Power Monitoring and Control System.It is proved that the research idea and algorithm improvement strategy is feasible.