Research On The Influence Of PWM Strategy For The Loss In Auxiliary Inverter

With the continuous development of our national economy, the construction of rail transportation, in major cities, were involved in the period of rapid development.People welcome it as the urban transport tool because of its many advantages. The auxiliary power supply system as a part of the vehicle electrical system, is the important security to normal working of traction and safe operation of train. However there is a problem of too high temperature, always appears on auxiliary inverter, needs to solve. Under this background, research selects the loss of auxiliary inverter as subject, hoping to effectively address the temperature problem of auxiliary inverter on urban rail transit vehicle by optimizing the control strategy, therefore, it has some practical significance.This paper introduces the background, significance and present situation of the problem what we study on; describe the function and structure of the auxiliary power supply system on Urban rail transit vehicle; analyzing the cause of the loss on auxiliary inverter; establishing a model for calculating the switching loss of inverter and finding out the influence factors of switching loss on inverter; based on the theory of space vector pulse width modulation, combining with the influence factors of loss, finding out the optimization of space vector width modulation, which can reduce the switching loss, and then giving the principle and algorithm of it.In this paper, through the MATLAB/Simulink software platform, completing the implementation of the space vector pulse width modulation strategy and its optimization, and the establishment of the model of switching loss on inverter; through comparison of simulated data, analyzing the impact of pulse width modulation parameters to the size of switching loss and output current harmonics under all kinds of optimization mode.This paper uses the method of combing theoretical analysis with data verification, Qualitative analyzing and quantitative verifying the correctness and feasibility of space vector pulse width modulation optimized methods, and through the analysis of the data, put forward my own proposal on the selection of optimized method in different conditions and requirements.