NTP-Based Precision Time Synchronization Scheme for Differential Networks

The key to implementing longitudinal differential protection in the distribution network lies in high-precision time synchronisation. Due to the large synchronisation error of traditional longitudinal differential protection schemes, the protection effect is not satisfactory. This paper analyses the time synchronisation problem of longitudinal differential protection in distribution networks based on 5G networks and proposes a time synchronisation algorithm based on the NTP protocol. In order to reduce the synchronization error caused by network fluctuation, the Lagrangian interpolation method is used to estimate and compensate for the network delay; in addition, a synchronization timer is set in the differential protection terminal to avoid the loss of synchronization messages. Simulation results show that the proposed algorithm can greatly improve the real-time performance and reliability of time synchronisation in differential protection, and it can have good synchronisation performance in the environment of more differential protection terminals.