Research On Inrush Current Recognition Technology Of The Transformer Of Yujialiang Coal Mine

Coal mine,the important energy supply base of China,plays an important role in the energy security of our country.The security of the coal mine,which is dependent on the security of power supply,lays a f-oundation to the security and sta~bility of-the economy of China.Transformer is a very important electric device of the power system of the coal mine.The fault and the failure to operate of the relay protective of the transformer are adverse to.the security of the coal mine.Consequently,this paper study the inrush current and its recognition technology.The main contents of this paper are as follows:Firstly,the irrush current of the transformer of Shenjialiang coal mine of Yujialiang and its influence factors are studied.The simulation model of the transformer is built in Matlab/Simulink with the parameters of the transformer of the Yujialiang.The curve of the inrush current,which is analyzed in detail,is given.All of these lay a foundation to the contents of this paper.Then,the influence factors of inrush current of transformer are simulated.The main contents of this part focus on the impact of the switch angle and residual magnetism on the inrush current.As to the switch angle,the curve of inrush current with difFerent switch angle,from 0 degree to 180 cdegrees?is given.As to the residual magnetism,the curve of inrush current with different residual magnetism,from O to 0.8p.u is given.The curves with different switch angle and diff-erent residual magnetism are analyzed in detail.The influence laws of these two factors on the inrush current are summarized.Fiinally,the principle of relay protective of transf-ormer of Yujialiang coal mine is studied.An inrush recognition method is given to guarantee the coarrect operation of relay protective witlh inrush current.Tlhe simulation results verify the correct of the proposed method*Furthemmore,an improved recognition method of the inrush current of transfonmer based on...