Application And Research Of Clock Synchronization System In Merging Unit Based On IEEE1588

With the development of the power grid and management level,the requirements of the electric power system operation are higher and higher.Especially in the background of intelligent grid,the power grid has to extract the key information from huge amount of data collection and make some dynamic analysis and decision.In the power grid planning,scheduling and real-time operation of different time periods,the power system makes analysis of grid static and transient state and makes real-time warning.These make a higher requirement for the unified time reference of each equipment in the power grid.The paper designs and practices slave clock based on IEEE1588 and tests its accuracy.An slave clock hardware circuit based on DP83640 is designed,and selects Stm32f407 which contains MAC layer as microprocessor.The work of hardware design includes: the connection mode between the processor and the physical layer,the configuration and the operation of the relevant pin of the Ethernet,the design of the power circuit,the design of the USB circuit of the serial port.Software design includes: slave clock software architecture design;BMC best master clock algorithm design;packet processing flow design;local clock synchronization mechanism and algorithm design;LwIP and MAC layer communication interface design;the packet processing flow in the stack design;slave clock system and PC communication program design.At first,use Wireshark software to test the master-slave clock message communication.The test results show that the master-slave clock can send and receive messages.Then test PTP messages synchronization accuracy.Observe the master-slave clock realtime deviation on the computer.The results show the deviation between master and slave clock is less than 100 ns.Finally test the PPS synchronization accuracy.Use the oscilloscope observing the deviation between master and slave clock's PPS.Two tests result both show that the synchronization accuracy can fulfill the requirements of intelligent substation.