智能变电站中网络对时的优化设计

Optimal Design of Network Time Synchronization in Intelligent Substation

针对智能变电站中IEEE 1588对时信息与采样值共网传输时,IEEE 1588对时信息网络传输的往返延时不一致,造成同步精度降低的问题,对网络对时进行了研究。对本地时钟相偏进行了极大似然估计与最优线性无偏估计的推导,给出了本地时钟相偏的最优计算方法。试验表明,方法可以显著减小网络传输往返延时不对称对IEEE 1588网络对时精度的影响,为智能变电站实现广域信息同步实时采集提供了可行方案。

Aiming at the problem of the inconsistent round-trip delay occurred during the network transmission of time synchronization information according to IEEE 1588 Protocol when the time synchronization information and the sampled value transmitted on the common network in the intelligent substation,causing the synchronization accuracy to be reduced,the network time synchronization was studied.The maximum likelihood estimation and optimal linear unbiased estimation were derived for the local clock skew,and the optimal calculation method for the local clock skew was given.The experiments show that this method can significantly reduce the impact of the asymmetry of network transmission round-trip delay on the network time synchronization accuracy in the IEEE 1588 Protocol,and provides a feasible solution for intelligent substations to realize synchronous real-time collection of wide domain information.