Research Of Effects On Transformer Protection And Automatic Equipment By Harmonics And Negative Sequence Of Electric Railway

With the rapid development of the electric railway and the vast use of the electric traction engine,the non-liner load of the state grid along the railway line has increased largely.Therefore,harmonic and negative sequence problem of electric railway has been gaining wide attention.Starting from the digital simulation,based on a typical electric railway traction power supply system and public power grid,this paper presents the model of fault recorder and the differential protection of the transformer.Combinated with theoretical analysis,simulation research by PSCAD and pilot study by RTDS,it researches the effects on transformer protection and automatic equipment by harmonics and negative sequence of electric railway.Finally,the relevant conclusions and recommendations are given.