The Study Of Protection-load Shedding Scheme In Intelligent Substation

Several domestic and foreign large area blackouts are due to the fault action ofbackup protection, which can not identify the overload and mistakenly remove theload line leading flow transferring, eventually developed into chain tripping accidents.If backup protection identified overload, and eliminate overload with load sheddingdevice. The chain tripping accidents may be stopped.the program of protecting-loadshedding is an effective way to prevent large blackouts. This article detailed studies indetail the development process of the blackout,and analyses the problem of lowtransferring overload identification,load shedding strategy links at the moment, andproposing solution to the problem.At present the program of low transferring overload identification is onlydistinctting beteewn overload and fault, but it did not consider the system oscillationand system structure which has not changed, resulting in a miscarriage of justice. Thisarticle specifically analyses the electrical characteristics between the overload、thepower swings and fault to identify the differences of the three characteristics ofelectrical quantities, formulating a new flow transferring overload identificationmethod.The load shedding strategy based on wide area Information、 domaininformation which have no selective load shedding location, often loading too muchshedding. This article uses the trend flow of factor search the transfer path of the flowand determined the load shedding location, and in accordance with the electricalcontact between the load shedding location, and formulating a new selective loadshedding, which is selective.Smart station can realize information sharing technology, and it can easily getthe station data panoramic able to complete the advanced applications of the functionsof the substation, so protection-load shedding program only can achieve in smartsubstation. This article according to the requirements of the IEC61850data modeling, creating the core logic node,collaboration diagram, time sequence diagram of theprotection-load shedding schemes, and the protection-load shedding function of smartsubstation is completed. Using of the PSCAD structures system model simulates theprogram of transfer overload recognition and the new shedding strategy, thesimulation results verify correctness and validity.