The Design Of Intelligent Substation’s Protection And Automation System Configuration Scheme

Power plays a crucial role in the development of national economy. Along with thedevelopment of smart grid, the intelligent power grid renovation was attentioned by moreand more people. In the smart grid construction, the construction of intelligent substation isparticularly important.Because the substation plays an important role in power grid.Intelligent substation provides data and control object for smart grid. Intelligent substationbased on DL/T860(IEC61850) standard of the automation system, station control layernetwork are designed according to the MMS,GOOSE,SNTP.An ultimate intelligentsubstation’s equipments should be intelligent, under the support of network to realizeinformation interaction, coordinated operation and ensure safety, economic and reliableoperation.So the research of intelligent substation is very important.This paper summarizes the deficiency of conventional substation and digital substation,introduce the technical characteristics of intelligent substation and the structure of thesystem, the construction of intelligent substation and the design requirements are given.Relay protection device’s safety and stable operation of the smart substation plays an vitalrole in smart substation, the third chapter of this paper expounds the basic requirementsand principles of conventional protection. Conventional protection configuration scheme ofthe smart substation and the centralized protection configuration scheme are introduced.wecan conclude that centralized protection configuration scheme provide favorable conditionsfor fault behavior analysis, and make the right judgment for all kinds of operation.On thisbasis,this paper design the centralized protection configuration’s software and hardware.In the smart substation, protection algorithm should be study to guarantee the accuracyof the relay protection device and the correct actions. This paper introduce the commonlyused algorithms: two sampling value algorithm, fourier algorithm, differential equations,differential filter algorithm, half cycle, the root mean square algorithm,then summary theiradvantages and disadvantages. We can see the new algorithm study is very necessary, laidthe foundation for RBF neural network.Due to the transformer plays the function of voltage transform, so the protection deviceof transformer is particularly important. The transformer’s main protection is the differentialprotection, and the correct operation rate of differential protection is far lower than the otherprotection devices, the paper analysis the causes of transformer excitation inrush current and the influence of excitation inrush current.Paper introduce the commonly used identifymethod of excitation inrush current: second harmonic brake principle, discontinuous angleprinciple, magnetic flux characteristics principle. This paper analysis the transformer’sstates based on the MATLAB simulation. We can conclude that the transformer’s excitationinrush current is different from the characteristics of the short circuit current.Because the second harmonic component of transformer’s excitation inrush current ismore than the short circuit current, we select the second harmonic excitation surge contentas the training sample, train the selected samples by using RBF neural network, concludediscriminant criterion of excitation inrush current and short-circuit current, improve theright action rate of the protection.