The Development Of Distribution Terminal Emulator Based On IEC61850

Nowdays, the test of distribution terminal in the distribution automation systemsneeds external input for the distribution terminal through test instrument whichsimulates protection experiments. After the distribution terminal state changes, signalis uploaded to the client (master). The received signal is compared with the localsignal of distribution terminals by the client; communication behavior of distributionterminals is determined artificially whether it is correct, and uploading information ofseveral multi-distribution terminals is simulated through several avalanche tests,which is useful to learn the network load and signal accuracy. But this test method hasthe following disadvantages: the communication capability of the client (master) isnot tested completely; the ICD model which is provided by the manufacturer can onlybe verified through the point test of tester; the peak of network traffic load in thedistribution automation systems is not fully understood.In this paper, a distribution terminal emulator based on IEC61850is designedand developed to make up these shortcomings.This emulator can simulate thebehavior of all the distribution terminals to external communications in the station,which can make better use of IEC61850communication standard.The distributionterminal emulator which runs in the computer doesn’t need the test instrument device,can reduce the workload of staff and engineering debug time greatly.In this paper, the theory, the core idea and the current situation of IEC61850standard is analyzed. And the IEC61850standard is applied to distribution terminalemulator. After a number of classical literature in distribution field is studied andpractical production is investigated, according to the actual needs of the distributionterminals, the function of monitor and control is analyzed fully, in which the directcontrol of general security, enhance security control and time activation are included.On this basis, the mapping between IEC61850and MMS and the ASN.1encodingand decoding technology of MMS is analyzed deeply. Based on the informationcommunication model, the implementation examples of IEC61850specific service isgiven and the implementation process of GetDataValues service is introduced. Afterthat, the design diagram of SCLServerSimulator61850simulator, function modulesand software are given. Finally, a test platform of distribution terminal emulator isbuilt and TMW61850Test Harness tool is used to verify the feasibility ofSCLServerSimulator61850simulator.