The Operating Reliability Analysis And Research Of Transformer Differential Protection Of35kV

Power transformer occupies a very important position in the power system, especially in distribution network, therefore, improving the working reliability of the transformer, to ensure the safety of the electricity system operation has the very vital significance. This paper analysises the characteristics of the county power grid, and puts forward the importance of transformer in the power grid of the county. Introduce the process of development of transformer differential protection, and the research situation of the differential protection is described. Analysis the basic protection device of transformer. The basic principle and methods of realization of differential protection are described;Analysis the protection principle and methods of realization of the type of microcomputer transformer. This paper analyzes the main reason of the impact to protection reliability of the transformer differential of35kV, including the unbalance current, excitation inrush current, connection error, protection device secondary equipment disconnected and so on. To improve the reliability, the differential protection scheme of35kV transformer are put forward. How to avoid and elimination the inrush current is one of the main research. Put forward the fuzzy recognition method and the second harmonic brake combination of scheme to improve the reliability of the differential protection. Analysis the application effect of fuzzy recognition method.By using the index to identify fault current and excitation inrush current, so as to improve the differential protection reliability of35kV transformer. Finally, in view of the actual problems and to improve the reliability of differential protection,this paper puts forward related suggestions for electric power department.