Analysis Of Electromagnetic Characteristics Of A Locomotive Transformer With Split Types Of Multi-windings

With the rapid development of electrified railway in our country,Higher requirements is put forward about the operating performance of a locomotive.As one of the most important equipment of a locomotive,its performance is directly related to the safety,reliability,energy efficiency and environmental protection of a locomotive.Based on a detailed review about the development and research status of locomotive transformer,a thorough and comprehensive research was made about the electromagnetic characteristics of a transformer with four split type combined with magnetic field calculation and circuit analysis.The main contents are as follows:First,based on ANSYS software,the 3D magnetic field analysis model of transformer was established,and the model area includes the core,the winding,the oil tank and the outer layer air gap.On this basis,The inductance matrix of 8 windings for the four split locomotive transformer was calculated.Secondly,according to the four low voltage windings independent operation under four high voltage windings in parallel of the connection mode,the circuit equation with the inductance matrix was listed and the electromagnetic characteristics was analyzed,such as the current distribution of each high voltage winding branch.So it can test the degree of the tight coupling of the low-high voltage winding voltage;The equivalent circuit of single low voltage winding short circuit under four high voltage winding in parallel was derived,and the short circuit impedance was calculated.Then,based on the 8 winding inductance matrix and the winding connection by using the current controlled voltage source to equivalent a magnetic coupling branch with the concept of controlled power,a simulation circuit in MATLAB was established,and the simulation of sudden short circuit of single or multiple low voltage windings was conducted.So it can know about the effect of a sudden short circuit of a winding on the operation of the other winding.Finally,the short circuit impedance was calculated by the steady state value(voltage and current)of the simulation results.the result is very close to the analysis of the equivalent circuit and the manufacturers test results.Used the ANSYS to analyze magnetic field and the MATLAB to establish the simulation,the electromagnetic properties of locomotive transformer was analyzed by thecoupled magnetic-circuit method.The Analysis method is novel and the establishment of magnetic field and circuit analysis model reflect the actual truly.The theory is reliable and the results are reliable,which provides a reference for the theoretical research and the manufacturing design of the multi split locomotive transformer.