Study On Scheme And Performance Optimization Of Multiple Connection Modes Traction Transformer

With the development of electrified railway,the increase of traffic volume puts forward higher requirements for the power supply capacity of traction transformers.The existing traction transformers have to be replaced before reaching the design life.How to make full use of the design life of traction transformers is important to the economic operation of traction power supply system.In order to make full use of the design life of traction transformer and improve the operation economy of traction power supply system by expanding the application scope of traction transformer and reducing the operation loss,the basic structures,wiring modes,working principle and iron core flux of traction transformers were analyzed and compared.Based on the analysis of the distribution of iron core magnetic fields by the finite element simulation,a scheme of multiple connection modes traction transformer is proposed,and the feasibility,technology and economy of the scheme were analyzed.According to the scheme,the existing V-connection traction transformer could be changed to parallel single-phase connection as a single-phase traction transformer to alleviate the problem of insufficient capacity of single winding;and the new products could be used to form different connection modes.In addition,the new three-phase iron core could be used in Scott connection traction transformer.The scheme can effectively expand the scope of application of traction transformer and improve the flexibility of application.Then,the leakage magnetic fields of traction transformers with different connection modes and structures were analyzed and compared by building two-dimensional and threedimensional models of traction transformers,and the influences of connection modes and structures were determined.Through further analysis of the location of the flux density concentration,such as the eddy current fields of the pull plate,upper and lower clamps,and the wall of the oil tank,the eddy current loss densities were determined.In order to improve the distribution of the leakage magnetic field and reduce the running loss,the practical effects of the measures such as slotting the plate,installing the magnetic shield and increasing the distance were compared.And some suggestions on the optimization measures are put forward based on different structures of traction transformers.