Research on sampling and network scheme of centralized protection based on tri-networks integration in process layer

According to the model of practical project, the key performance indicators of process layer based on tri-networks integration, including the network traffic, the transmission delay and the jitter of the delay, are analyzed. Based on the analysis result, the synchronous sampling principles in a substation and between substations are analyzed and the specific sampling schemes are given. Finally, the feasibility of the sampling schemes in normal conditions and abnormal conditions such as the master clock or the merging unit out of step is analyzed theoretically and tested actually. By analyzing the problems which are exposed during the test, an improved sampling scheme is put forward. The study is referential to other research and engineering practice of centralized protection.