| Along with the rapid development of social economy,energy shortages have attracted more and more attention,therefore,intelligent grid was brought up in this context.In recent years,with the development of green energy systems,the concept of establishing high quality and efficient intelligent grid was put forward,moreover,intelligent substation is an important element of intelligent grid.Due to the shortage of complex structure,poor real-time capability and reliability,the traditional intelligent substation communication system is unable to meet the growing system requirements.Therefore,based on the demand of intelligent substation communication network,this paper designs a dual optical fiber bidirectional optical switching network structure similar to EPON,combining the advantage of passive optical network.It also elaborates on the structure of busbar node,interval node and the process of delivering-receiving.Moreover,this paper also puts forward the method of WDM traffic segregation for the intelligent substation,achieving simultaneous transmission of two categories of traffic in the communication system.A simulation model of the transmission is established to analyze the performance of the system,focusing on power budget requirements from the perspective of power loss.Our results show that the ring distributed optical switching network structure can satisfy power transmission traffic,and the eye diagram is also very clear,indicating good quality of the transmitted signal.On the other hand,this paper designs the corresponding scheduling algorithm for two categories of traffic,namely GOOSE traffic and SV traffic in the intelligent substation.On the basis of overall clock synchronization,this paper designs the clock synchronization method for the cyclical traffic with the feature of period traffic and a slot polling scheduling strategy to achieve a non-conflict transmission of the heart traffic.Additionally,according to the characteristics of tripping traffic such as sudden strong,low traffic,combined with the idea of shared random access media and "1248" rule provided by IEC61850 protocol,we have designed a corresponding scheduling algorithm.To evaluate the performance of the algorithm,we have established a discrete-time simulation model.The results suggest that the scheduling algorithm can meet the needs of the application.In addition,the paper also designed a protection program when the optical link fails to ensure the reliability of communication.Next,this paper focuses on the scalability issues in the intelligent substation communication system from two perspective of bandwidth rate and power loss.The simulation results provide a basis for maximum number of access interval node and future expansion demand for capacity.Our research demonstrates that,through introduction EDFA to network,it could effectively increase the number of system access node.Last but not least,we find some application difficulties at present,and the foundations have been laid for future research. |
