The Research Of High Precision Clock Synchronization System In Smart Substation

With perfection of the IEC61850standard, more requirements are put forward onprecision and stability of synchronous clock. In order to meet a higher level ofaccuracy and adapt to the characteristics of clock synchronization system in smartsubstation. High precision clock synchronization system in smart substation is studiedin the thesis.First, the application of clock synchronization techniques in power system isanalyzed and introduced. combing with the IEC61850standard and actualrequirements by smart substation. satellite synchronous clock for smart substation isstudied. Two application schemes on time synchronization network model of smartsubstation are built and theirs redundancy scheme are designed, one is based onSNTP+IEEE1588and the other is based on IEEE1588. Then, taking into account thecrystal oscillator clock is free from random errors and the satellite second clock isfree from cumulative errors, based on the principle of digital phased-locked loop it isproposed to implement the highly accurate clock by the synchronization of a crystaloscillator second clock with satellite second clock. Both simulation and experimentalresults show that the method not only correcting the random errors of the satelliteclock, but also eliminate the accumulated errors of the crystal oscillator clock. Theproposed clock system possesses high time accuracy and stability. Finally, the internalerror of IEEE1588clock is analyzed and studied. Online monitoring and correctingmethod of IEEE1588clock oscillator is proposed. IEEE1588synchronous messagetransmission path delay error is studied. Error correction method of synchronousmessage transmission based on DPSM algorithm is proposed. Realized thesynchronous message service rate control and timing sent preferentially by settingurgency mechanism and bandwidth adjustment factor. High-precision network clockhardware platform is built and tested.Theoretical analysis and experimental results show, this clock synchronizationsystem realizes the smart substation high precision clock synchronization, meet thedemand for stability and reliability of smart substation and promote operation level ofsmart grid. This research will lay theoretical and technical basis for it.