用于新型贯通供电系统的级联变换器研究

发布时间：2018-06-21 02:55

本文选题：贯通供电系统 + 三相-单相变换器　；参考：《西南交通大学》2015年硕士论文

【摘要】：针对现有供电系统的不足而提出的贯通供电系统能够完全取消电分相装置,较好地解决电能质量问题。同时,电力电子器件功率等级的不断提升使得该系统的优势日益突出。本文研究用于无输出变压器新型贯通供电系统的级联变换器,并从理论、仿真和实验三方面验证了系统的可行性。本文首先从工程实际出发,设计了用于新型贯通供电系统的三相-单相级联变换器结构及其控制系统。研究了三相三电平二极管钳位整流器的拓扑结构和工作原理,建立了整流器在dq坐标系下的数学模型,结合数学模型研究了dq解耦双闭环控制策略；研究了单相三电平二极管钳位级联逆变器的拓扑结构和工作原理,建立了逆变器的数学模型,在此基础上研究了单相级联逆变器的电压闭环控制策略；探讨了三相-单相变换器直流电压二次脉动产生机理,并设计了二次滤波电路来抑制直流侧电压二次脉动。结合多电平调制技术研究现状,重点研究了多载波SPWM调制策略。深入分析了载波层叠SPWM调制策略(Carrier Disposition SPWM, CD-SPWM)和载波移相SPWM调制策略(Carrie Phase-shifted SPWM, CPS-SPWM),对比了不同调制策略下变换器输出电压的谐波特性。根据各个调制策略的优缺点,结合三电平二极管钳位PWM变换器电路特点,设计了适合三相-单相级联变换器系统的调制策略,包括三相-单相PWM变换器模块内的同相层叠调制(Phase Disposition SPWM, PD-SPWM)和三相-单相PWM变换器模块间CPS-SPWM级联调制策略。在上述研究的基础上,利用Matlab/simulink仿真平台完成了三相-单相PWM变换器、单相PWM逆变器级联仿真验证,最终搭建了基于三相-单相级联变换器的新型贯通供电系统变电所仿真模型,在启动、空载、带载等工况下分别对系统三相电网侧、直流侧、单相牵引网侧仿真结果进行分析,并分析了三相电网侧电压电流和单相输出电压的谐波特性。仿真结果表明系统在多种工况下均能正常稳定工作,工况发生改变时,系统能快速响应,超调小,调整时间短。在带载情况下,系统网侧功率因数为1,网侧电压电流谐波含量低,单相牵引网输出电压波形质量高,动态响应好。仿真验证了理论分析的正确性和本文所设计的三相-单相级联变换器系统结构、控制策略、调制策略的可行性和有效性。最后,本文搭建了基于FPGA的小功率实验平台,设计了实验方案和实验系统结构及参数。在实验平台上完成了三相-单相PWM变换器实验、单相PWM变换器级联实验,三相-单相级联变换器系统实验。实验结果证明,本文所研究的级联变换器能够有效扩大系统容量,同时进一步验证了本系统的主电路结构、控制策略和调制策略的可行性。综上所述,本文在理论分析的基础上,设计了用于新型贯通供电系统的三相-单相级联变换器结构、控制系统及其调制策略,通过仿真和实验验证了基于三相-单相级联变换器的新型贯通供电系统可取消输出升压变压器,降低系统电力电子器件的耐压要求；输出电压电平数可倍增,使得开关频率可降得更低,开关损耗随之降低；当电平数足够高时,谐波含量很低,可取消滤波电路；可根据工程需求增减变换器级联级数,方便扩容；系统动态响应好,能够适应多种工况。
[Abstract]:In view of the shortage of the existing power supply system, the connected power supply system can completely cancel the electric separation device and solve the problem of the power quality. At the same time, the continuous improvement of power electronic device power level makes the advantage of the system increasingly prominent. This paper studies the cascade converter used in the new type of power supply system of the non output voltage regulator. The feasibility of the system is verified from three aspects of theory, simulation and experiment. In this paper, the structure and control system of a three-phase to phase cascade converter for a new type of connected power supply system are designed in this paper. The topology and working principle of the three-phase three level diode clamp rectifier are studied, and the rectifier is set up in the DQ seat. The mathematical model in the standard system is used to study the DQ decoupling double closed loop control strategy with the mathematical model. The topology and working principle of the single-phase three level diode clamped cascaded inverter are studied, and the mathematical model of the inverter is established. On this basis, the voltage closed loop control strategy of the single-phase cascade inverter is studied. The two pulse generation mechanism of the DC voltage of the phase change converter is produced, and the two filter circuits are designed to suppress the two pulse of the DC side voltage. The multi level modulation technology is studied and the multi carrier SPWM modulation strategy is studied. The carrier cascaded SPWM modulation strategy (Carrier Disposition SPWM, CD-SPWM) and the carrier phase shift SPWM modulation are deeply analyzed. The Carrie Phase-shifted SPWM (CPS-SPWM) compares the harmonic characteristics of the output voltage of the converter under different modulation strategies. According to the advantages and disadvantages of each modulation strategy and the characteristics of the three level diode clamp PWM converter, a modulation strategy suitable for the three-phase to single-phase converter system is designed, including the three-phase to single-phase PWM transform. The CPS-SPWM cascaded modulation strategy between Phase Disposition SPWM (PD-SPWM) and three-phase to single phase PWM converter module is used in the module. On the basis of the above research, the three-phase to single-phase PWM converter is completed with the Matlab/simulink simulation platform, and the single-phase PWM inverter cascaded simulation verification, and finally built on the three-phase to single phase. The simulation model of a new type of connected power supply system of cascade converter is used to analyze the simulation results of the three-phase grid side, the DC side and the single-phase traction network under the starting, no-load and load conditions. The harmonic characteristics of the voltage current and the single-phase output voltage of the three-phase grid are analyzed. The simulation results show that the system is in a variety of conditions. The power factor of the system network side is 1, the harmonic content of the network side voltage and current is low, the output voltage waveform of the single phase traction network is high and the dynamic response is good. The correctness of the theoretical analysis and the design of this paper have been verified by simulation. The structure of three-phase to single-phase cascade converter system, control strategy, modulation strategy feasibility and effectiveness. Finally, this paper built a FPGA based small power experiment platform, designed the experimental scheme and experimental system structure and parameters. On the experimental platform, the three-phase to single-phase PWM converter experiment, the single-phase PWM converter cascade experiment, three phase - Experimental results show that the cascaded converter can effectively expand the capacity of the system, and further verify the structure of the main circuit, the control strategy and the feasibility of the modulation strategy. On the basis of the theoretical analysis, this paper designs a new type of through power supply system. The three-phase to single-phase cascade converter structure, control system and its modulation strategy, through simulation and experiment verify that the new type of connected power supply system based on the three-phase to single phase cascade converter can cancel the output boost transformer, reduce the pressure requirement of the system power electronic device, the output voltage level can be doubled, so that the switching frequency can be reduced more. Low switching loss is decreased; when the level is high enough, the harmonic content is very low, can cancel the filter circuit; according to the engineering requirements or converter cascade, convenient expansion; good dynamic response, can adapt to a variety of conditions.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM46

【参考文献】