Research On Protection Testing Method Based On The Simulation Of Fault Scenario In Intelligent Substation

The reliable work of the Intelligent Electronic Device(IED)in the intelligent substation is necessary to the security and stability operation of power systems.Compared with the regular stations,information exchange network makes the relay protection secondary circuit of intelligent substation invisible,and the difficulty of the implementation of the secondary security measures for relay protection and the protection testing is greatly increased.In recent years,protection testing methods is completely artificially simulated simple faults and manually set test parameters in the regular inspection of relay protection and the acceptance of infrastructure construction.The protection testing workload is large and cannot fully reflect the relay protection action performance under real fault scenarios.In view of the actual operation in the intelligent substations,this thesis develops a practical protection testing method suitable for intelligent substations.Firstly,the functions and test requirements of the main IEDs related to the relay protection in intelligent substation are explored,and the method of dividing the electrical compartment of the substation is studied from the perspective of the scope of equipment functions.On this basis,the thesis studies the hierarchical and network structure of the intelligent substation equipment,and analyze the operation mode of the intelligent substation according to the classification of the secondary system.Furthermore,the realization of intelligent substation line,main transformer and bus protection is analyzed.Then,in view of the difficulty in implementation of security measures caused by the unintuitive secondary circuit of the intelligent substation,the thesis studies IED virtual terminal,virtual circuit and method of information exchange,and proposes the determination method and determination process of IED virtual connection section based on the Substation Configuration Description(SCD).Combined with the method of dividing the electrical compartment,the method of determining the virtual connection section in the electrical compartment is studied.Combined the types and the formulation principles of the security measures implementation,a prioritization method of the secondary security measures which based on the type of virtual circuit and physical channel is proposed.Finally,based on the analysis of the existing protection testing principles,a protection testing method based on the simulation of the fault scenario is proposed.Considering that the execution result of the protection action will cause to the change of the system structure and power flow,the circuit breaker position feedback system is introduced in the test process.According to the position of the circuit breaker,the fault calculation program calculates and adjusts the output of the tester in real time,in order to ensure that the testing environment is basically the same as the environment after the system fails,and the protection action behavior is tested in cycle dynamically.Take a 220 k V line compartment of a certain intelligent substation in Luoyang as an example to verify and analyze the test method proposed in this thesis.The research results showed that the application of the method in this thesis can make targeted secondary measures based on the virtual connection section and virtual circuit.The protection testing based on the simulation of the fault scenario can be completed with one-touch operation without repeatedly setting the test parameters,and the test results can truly reflect the system status and the protection action behavior in the fault state.