Research On Cross-platform Simulation Based On Process Level Of Intelligent Substation

With the improvement of intelligent substation technology, the application ofintelligent substation will be more extensive. The three-level model of intelligent substationbased on the IEC61850protocol makes the structure clearer and modeling simpler. Thetransmission performance of the substations’ important information being transmittedbetween process level and bay level, will severely affect the reliability of the substationrelay and the stability of power system, while currently the research of process levelnetwork is short of effective measures. This thesis designs the joint simulation system onthe basis of PSCAD/EMTDC(Power Systems Computer Aided Design/ElectromagneticTransients including DC) and OPNET(Optimized Network Engineering Tool), which canbe used to conduct a comprehensive analysis on the primary system and secondary systemof intelligent substation, providing powerful tools for intelligent substation research.This thesis firstly puts forward the cross-platform simulation system, with detaileddescription of the composition and principle of the simulation system and brief introductionof design ideas and workflow. Cross-platform simulation system consists of three bigmodules, namely the PSCAD/EMTDC power system simulation, OPNET network systemsimulation and simulation coordinated control program. Among each module communicatewith others through TCP/IP protocal which based on Socket. PSCAD/EMTDC module isused to build a model of power system simulation for power system; OPNET is used tobuild communication network model, simulate the communication network behavior;Simulation coordinated control program used to implement the synchronization of twosimulation software.Afterwards, PSCAD/EMTDC power system simulation software is studied in detail,including the characteristics of the custom module and the key technology of the Clanguage program called in custom modules. Then OPNET communication systemsimulation software is studied, especially the event-driven principle of OPNET simulationproceeding is described detailedly and compared with the discrete time driving mode inPSCAD/EMTDC. In order to design joint simulation system, the co-simulation interfaceof OPNET is explored and how to call C language code to drive the interface is studied. Finally it comes to the pivotal component, that is the Socket modeling as well as how touse the Winsock API to create a Socket and realize the communication among all thesimulation software.Last but not least, conducts a detailed analysis on communication mode of IntelligentSubstation process level defined in IEC61850and compares three connection modes andcharacteristics in process level communication network, namely direct sampling direct tripmode, direct sampling network trip mode and network sampling network trip mode. It alsostudies on performance and characteristics of various network topological structures,analyzing the strengths and weaknesses respectively. Then this thesis models on datapackets through intelligent substation process level and analyzes on its statistical traffic.Based on the above researches, time delay characteristics of intelligent substation processlevel is studied, delay composition and exchange behavior of data package through theexchange network is introduced, and features of M/M/1queue based on Poisson Process isanalyzed, then the analysis is extended to network delay of intelligent substation, solvingthe problems of network average delay and maximum number of devices. In the end of thethesis, a typical model is tested on the cross-platform simulation system, verified its reliabilityand accuracy. The cross-platform simulation system can be applied to analyze on theprimary system and secondary system of Intelligent Substation.