Clock Synchronization Technology In Distributed Feeder Automation

As an important part of distribution automation,Feeder Automation shoulders the heavy responsibility of real-time monitoring,coordination and control of distribution network equipment,and is an important part of realizing self-healing control of distribution network.The realization of self-healing control of distribution network is based on a unified time base.Only the time between devices is unified,and the real-time information feedback and command transmission of the line has practical significance.In order to maintain the clock consistency between the distribution terminals on the distribution line in the feeder automation,the general method is to use the terminal equipment installed in the substation as the standard clock source,and the distribution terminal on the distribution line uses the clock synchronization protocol and Keep the time consistent when performing clock pairing.The commonly used clock synchronization protocols include NTP/SNTP protocol and IEEE 1588 protocol.When clock synchronization is performed,the round-trip time of the clock synchronization command is inconsistent,which will cause a certain time error.This paper proposes to use the power frequency voltage on the same distribution line.The phase difference of the end frequency is not large.The phase signal of the power frequency voltage is used as the reference signal.The clock synchronization technology between the power distribution terminals in the feeder automation is optimized based on the AC sampling technology and the SNTP protocol.In general,this article mainly carried out the following aspects:1.Research and analyze the source of error between distribution terminals in distribution network feeder automation.2.Study and understand the existing method of timing.The analysis of different timing methods,considering the optimization of the more economical and convenient SNTP protocol,aims to improve its timing accuracy.3.Study the algorithm and accuracy of AC sampling technology,and propose the theoretical idea of using the power frequency voltage phase method.4.The theoretical analysis error range is combined with the actual phase difference of the first and last sections of the same distribution line.The feasibility of the theoretical determination method.5.Theoretical analysis and construction of the experimental system for experimental verification.When the time delay from transmission to reception is less than 20ms(a voltage cycle),the SNTP protocol is optimized by the power frequency voltage phase signal,and the clock error can be less than 1ms.Its purpose for time accuracy.Finally,this paper summarizes the results and shortcomings of the current work.