Translated Abstract
With the rapidly development of high-power electronic’s technology and device, laminated bus bar is more and more popular.This structure of bus bar has advantage of low inductance and well heat dispersion,however,it also has bigger size and completed structure.Analyzing the current distribution for converter’s DC-link laminated bus bar is helpful to find and solve the key problem of the asymmetry of capacitors’ current and circuit parasitic parameter.It is meaningful for promoting converter’s stability.Generally,the target of optimizing bus bar is its inductance as ignoring the internal property of bus bar itself.According to the features of power electronic circuit and the rule of FEM,the thesis combines circuit analysis and FEA to study the current distribution for converter’s laminated bus bar from following aspects：.
Firstly,this thesis analyzes the design principle and current distribution’s frequency characteristic of laminated bus bar.A series of design principle of laminated bus bar is concluded by studying the basic structure from the aspect of bus bar’s shape,hole’s shape and capacitors’ arrangement.By studying the influence of current source for a kind of simple bus bar,this thesis concludes the frequency characteristic of bus bar’s current distridution.
Secondly, the thesis proposes a method for analyzing the current distribution of laminated bus bar based on the capacitors’ current loop for the circuit with fixed link point.By modeling the mutual inductance circuit of the laminated bus bar of single phase half bridge circuit in hige power condition based on this method,the accuracy of the model is verified.The thesis modeling the detailed equivalent circuit of half bridge considering the parasitic parameters.Then,the thesis not only studys the parasitic parameter’s influence on current asymmetry,but also on the overvoltage for switches.
Thirdly,the thesis proposes a method for analyzing the current distribution of laminated bus bar used in multi-phase circuit.In the analysis on three-phase Voltage Source Rectifier,the thesis combines finite element and circuit analysis.According to the real waves of circuit,the thesis calculates the weighted value of the capacitors’ current,getting the current distribution of bus bar.And then,use this method to find the better location of DC-link conncetion,which leads to the symmetry of capacitors’ current distribution.
Finally,experiment platform of three phase bridge inverter is built,by detecting the current distribution using Near-field probe,the method proposed in the thesis is verified.
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