"Method of analysis, modelling and simulation
of a locomotive with asynchronus motors
with fluctating voltage in the contact line"
Authors:
A.Szeląg - University of Bath, UK
M.Lewandowski - Warsaw University of Technology
Abstract
AC or DC electrical energy supplied to the pantograph of an electric locomotive is converted into an appropriate source of power for the locomotive's traction motors. Analysis of the power circuits and traction motors of locomotives have been undertaken in which voltage fluctuations in the conatact line of the supplyung system have been taken into account. For quasi-steady state, locomotives with DC motors are usually treated as non-linear steady-state current loads, but for analysis of locomotives with asynchronus motors and its power electronic equipment time domain analysis is applied and more sophisticated models of traction motors and power converters are used.
A method of analysis of a locomotive with asynchronous motors, taking into consideration voltage fluctuation in the conatact line and bilateral interaction between locomotives drives and supplying system are presented in the paper.
Mathematical models of: asynchronous motors, DC/A inverter, DC/DC converter and its implementation are shown. An iterative algorithm is presented which evaluates the working conditions of locomotive's motors, simulatanously with analysis of the power electronic equiment. The instantanous power received by locomotive from DC contact line is then derived. Some simulation results are presented and discussed. The method is especially usefull for the analysis of weak DC traction supply systems when the voltage in the contact line is lower then the nominal level.
