Research On The Transient Characteristics Of Double-System Electric Locomotive's Traction Drive System

Double-system electric locomotives,which can run under the AC or DC traction power system,and make full use of different power and voltage levels of traction power system in different regions,to meet the demand of switching power system without stopping.With the continuous development of basic traffic construction of urban and regional,the double-system electric locomotive are of great significance to solve the problem of interconnection and intercommunication between different rail transit systems.However,due to the influence of the construction of traction power system,the domestic research on double-system electric locomotive started late.At present,the main research is on the structure of the traction system,but the research on its operation characteristics is relatively less,which is not conducive to the development of doublecurrent system electric locomotive and limits its large-scale application.In this paper,the topology,control strategy,operation characteristics and system simulation of the traction drive system of double-flow locomotive are studied.This paper firstly introduced the main circuit topology structure of double-system electric traction drive system,which divided into input and output levels.Paper established the mathematical model of the traction drive system under different power supply system respectively,according to the mathematical model,and put forward the corresponding control strategy.The simulation model of input and output levels built based on Matlab/Simulink,and the results show that the design of the control strategy can make the system meet the requirements fast and stable.At the same time,the double-system electric traction drive system need achieve power balance under single power supply system and switching between different power supply systems.The different of power supply system can lead to the change of traction drive system,so the paper simplified the traction drive system reasonable,and established the equivalent model,to analyze the power balance process of different power supply system and switching of power supply mode,which can analyze the main factors affecting the power balance.Based on the mode,this paper proposes a transient energy balance control methods,in order to solve the power balance problems of DC side on switching of power system.In the simulation mode,the double-system electric traction drive system under the different power supply system and power balance control which simulated and verified.Finally,the paper analyzed several instability problems of traction drive system on DC side voltage.In view of the the ripple caused by transformer that was multipled as flat wave reactor on DC power supply mode,and excitation inrush current problems of switching process,the paper analyzed the connection method of winding,and put forward a kind of active demagnetization technique,in order to demagnetization fast and stable.Then paper analyzed the mechanism of instability on DC side voltage under constant power condition and proposed a dynamic decoupling active impedance stability control methods.Based on PLECS and Matlab/Simulink,demagnetization and constant power simulation model that were establishe respectively,and analysied the demagnetization and active impedance stability control.The results verified the feasibility and effectiveness of the active demagnetization technology and active impedance stability control proposed in this paper.