Structure Analysis And Simulation Research On Smart Substation Relaying Protection

Smart substation is a key link and important innovation point in the process of the smart grid, and relay protection technology is the first line of defense, there are three differences about relay protection technology of smart substation comparing with the traditional relay protection technology:The application of intelligent devices and ECT, has adapted to the needs of the development of the power system; The unified modeling based on IEC61850 standard has support the interoperability between different equipment and network peer-to-peer communication; The network communication of secondary system data has made sharing and interaction of informationcome true. Therefore, according to the characteristics of smart substation relay protection structure, this paper studied the main factors that influencing smart substation on relay protection in three aspects:the way of information collection, information transmission mode and protect logic. In order to provide the basis for the effectiveness of protection decision of power system relay protection.Firstly, take transient transmission characteristics of air-core coil current transformer of as the main line, analyzed characteristics of air-core coil current transformer and the key influence factor by Matlab/Simulink; The integral technology of air-core coil current transformer was brought up based on analog integrator and digital integrator which adapts the relay protection transient change request, and made a conclusive summary.Secondly, smart substation relay protection information flow model has been built based on OPNET, and analyse the characteristics of network delay in different net and a same net; Then Simulation experiments show effectiveness about sampling frequency meeting the protection and measurement device, etc; And made detailed analysis and research for the application of VLAN technology’s influence on the smart substation relay protection.Finally, established model of transformer differential-protection system by PSCAD/EMTDC, combined with the brake characteristics of differential-protection setting principle and the characteristics of air-core coil current transformer network communication characteristics. Came up with an improvement idea about ratio braking characteristic curve by setting different types of fault of transformer.This paper was completed successfully with the support of National Natural Science Foundation of China (51377026).