Abstract:

Abstract:The synchronous data sampling and triping of the relay protection device must be independent on time synchronization system. The network sampling and the triping can not be used in intelligent substation due to random fluctuation of the network delay. The electric power private exchanger can control and calculate the delay time exactly, so it gives a technical direction to solve above difficulty. In appliation of the electric power private exchanger, according to the inherent delay of the intelligent substation merging unit (MU) and the total delay of the link circuit, the time of ocurrence of interval sampling data was restore, and the synchronization of multiinterval sampling was realized. When the time delay is longer than 5ms, the relay protection device will be locked out and an alarm will be given. Based on the network testing system, the functions, the performance and the reliability of the delay compensation, the data flow precise control and the sampling synchronous processing of protection devices were analyzed. The networking scheme and the key technical requirements were put forward.

Key words: Keywords:intelligent substation, network delay, compensation of time delay, exchanger