【作者】 杨帆；

【导师】 舒泽亮；

【作者基本信息】 西南交通大学 ， 电气工程（专业学位）， 2022， 硕士

【摘要】 电力电子牵引变压器前级所采用的单相级联H桥整流器具有高度模块化的结构,作为其核心器件的功率开关器件存在较高的故障率,对系统的可靠性造成极大的影响。本文以单相两电平H桥级联整流器为研究对象,针对其功率开关器件存在的开路故障问题,研究了一种基于解析模型的开关管开路故障诊断算法,以及针对开关管开路故障的容错均压空间矢量脉宽调制(Space Vector Pulse Width Modulation,SVPWM)算法,具体内容如下:首先,本文分析了单相两电平H桥整流器的拓扑结构和基本工作模态,并在此基础上拓展建立了单相级联整流器的数学模型。通过对单个模块内各个开关管发生开路故障时的运行模态进行分析,然后建立了级联整流器的电流误差变化率的数学模型。根据此数学模型准确的分析了单相两电平H桥级联整流器发生单管、双管开路故障时的电流误差变化率的特征,并在此基础上分析总结后提出并建立了开关管开路故障的诊断定位思路与具体的诊断算法流程。然后,根据一维SVPWM算法建立了一维空间矢量图,分析了级联整流器的均压原理和均压优先级排序的原则。在以上基本原理分析的基础上,提出了两模块和n模块级联整流器发生开关管开路故障时的均压和容错均压矢量选择策略,并给出容错均压SVPWM算法的具体实现步骤。最后,通过Matlab/Simulink仿真软件验证了两模块和六模块的单相级联整流器的开路故障诊断算法和容错均压SVPWM算法的可行性与有效性。同时,通过本文设计的基于FPGA的两模块级联整流器硬件实验平台和基于Verilog的软件平台,完成了逆变和整流实验,进而完成了系统在发生单管和双管开路故障时的故障诊断实验和容错实验,其结果也验证了本文所提的开关管开路故障诊断算法和容错均压SVPWM算法的可行性与有效性。更多还原

【Abstract】 The single-phase cascaded H-bridge rectifier used in the front of power electronic traction transformer has a highly modular structure,and the power switching device as its core component has a high failure rate,which has a great impact on the reliability of the system.In this thesis,to solve the problem of the open-circuit fault of its power switching device in the single-phase two-level H-bridge cascaded rectifier,an open-circuit fault diagnosis algorithm of power switching device based on analytic model and a fault tolerant voltage equalization space vector pulse width modulation(SVPWM)algorithm are studied.The specific content is as follows:Firstly,the topological structure and basic working mode of the single-phase two-level H-bridge rectifier are analyzed,and the mathematical model of the single-phase cascade rectifier is established on this basis.By analyzing the operation mode of each power switching device in a single module when the open-circuit fault occurs,a mathematical model of the current error rate of the cascaded rectifier is established.According to this mathematical model,the characteristics of the current error rate of the single-phase two-level H-bridge cascaded rectifier with single or double open-circuit faults are analyzed accurately.On the basis,the idea of diagnosis and location of open-circuit fault and the specific flow of diagnosis algorithm are established.Secondly,one-dimensional space vector diagram is established according to onedimensional SVPWM algorithm,and the principle of voltage equalization and priority of voltage equalization are analyzed.On the basis of the above analysis of basic principles,the selection strategy of voltage equalization and fault tolerant voltage equalization vector for two and n-module cascade rectifier with open-circuit fault is proposed,and the concrete implementation steps of fault tolerant voltage equalization SVPWM algorithm are given.Finally,the feasibility and effectiveness of the open-circuit fault diagnosis algorithm and the fault tolerant voltage equalization SVPWM algorithm for two-module and six-module single-phase cascade rectifiers are verified by Matlab/Simulink simulation software.And,through the FPGA based two-module cascade rectifier hardware experiment platform and Verilog based software platform designed in this thesis,the inverter and rectifier experiments are completed,and then the fault diagnosis experiment and fault tolerant experiment of the system in the case of single or double open-circuit faults are completed.The results also verify the feasibility and effectiveness of the open-circuit fault diagnosis algorithm and the fault tolerant voltage equalization SVPWM algorithm proposed in this thesis.更多还原