混合级联多电平逆变器的结构与控制方法研究
发布时间：2018-07-14 10:41
【摘要】：多电平变换器以其电能质量高、效率高、功率大等特点被广泛应用在高压大功率领域,但随着该领域对变换器的性能和功能需求的不断增加,传统的结构的变换器越来越显现出其不足,比如所需功率器件较多、结构较为复杂、功能性不足等问题。混合逆变器能够采用更少的功率器件实现较多的输出电平,从而可以简化变流器结构,降低成本,减小体积。混合逆变器主要是指由不同电压等级、不同结构的功率单元或不同功率等级的开关器件组合成的电力电子变换器,这种组合可以使混合逆变器继承原始功率单元的某种特性,从而达到改善其工作特性的目的。本文以两种混合逆变器为研究对象,对其各自的工作特性与控制方法做了研究,一种是混合级联7电平逆变器和另一种是混合级联多电平静止同步补偿器。混合级联7电平逆变器使用较少的开关器件实现了较高的电能质量,但是混合调制法会使其低压单元直流侧发生电流倒灌问题,不利于其实用化。混合频率载波调制法可以解决电流倒灌问题,但是其高压单元运行频率过低,对其电能质量有很大影响,因此提出了改进混合频率载波调制法。改进后的方法利用单极倍频调制使高压单元在开关频率不变的情况下等效载波频率加倍,即提高了输出电能质量,又保留了混合频率载波调制法可消除功率环流的优点。对装置的多重化整流电路进行了研究,并证明了其不存在功率环流。最后,在MATLAB/Simulink下进行了仿真,验证了所提出的方法。混合级联多电平静止同步补偿器(HCMC-STATCOM)结合了三相桥逆变器结构简单与级联H桥逆变器输出电能质量好的优点。由于三相桥单元存在公共直流侧,其可进行相间能量交换,因此具有一定的不平衡电流补偿能力。对HCMC-STATCOM的补偿原理进行了研究,首先推导了HCMC-STATCOM整形电路直流侧平衡所需的零序电压,然后求出了HCMC-STATCOM可补偿电流的不平衡度范围。与相同输出电压水平的链式星形STATCOM相比,HCMC-STATCOM的补偿范围更广。研究了HCMC-STATCOM的控制系统,通过正、负序分开解耦的方法完成了对补偿电流的控制,并且给出了其三相桥单元与整形电路的直流侧平衡控制策略。最后,对HCMC-STATCOM在MATLAB/Simulink仿真平台下搭建了模型,仿真结果与理论分析基本一致。
[Abstract]:Multilevel converters are widely used in high-voltage and high-power fields because of their high power quality, high efficiency and high power. However, with the increasing demand for the performance and function of the converters in this field, Traditional converters have more and more disadvantages, such as more power devices needed, more complex structure, insufficient function and so on. The hybrid inverter can use fewer power devices to achieve more output levels, which can simplify the converter structure, reduce cost and reduce the volume. Hybrid inverters mainly refer to power electronic converters composed of different power units with different voltage levels, different structures or switching devices of different power levels. This combination can enable the hybrid inverter to inherit some characteristics of the original power unit. In order to achieve the purpose of improving its working characteristics. In this paper, two hybrid inverters are studied, and their respective working characteristics and control methods are studied. One is a hybrid cascaded 7-level inverter and the other is a hybrid cascade multilevel static synchronous compensator. The hybrid cascaded 7-level inverter uses fewer switching devices to achieve high power quality, but the hybrid modulation method will cause the DC side of the low voltage cell to produce current backflow problem, which is not conducive to its practicality. The hybrid frequency carrier modulation method can solve the problem of current backflow, but its high voltage unit has low operating frequency, which has great influence on its power quality. Therefore, an improved hybrid frequency carrier modulation method is proposed. The improved method uses unipolar frequency doubling modulation to double the equivalent carrier frequency of the high voltage unit under the condition of constant switching frequency, which not only improves the output power quality, but also retains the advantage that the hybrid frequency carrier modulation method can eliminate the power circulation. The multiplex rectifier circuit of the device is studied, and it is proved that there is no power circulation. Finally, simulation is carried out in MATLAB / Simulink to verify the proposed method. Hybrid cascaded multilevel static synchronous compensator (HCMC-STATCOM) combines the advantages of simple structure of three-phase bridge inverter and good output power quality of cascaded H-bridge inverter. Because of the common DC side of the three-phase bridge element, it can exchange energy between phases, so it has a certain compensation ability of unbalanced current. The compensation principle of HCMC-STATCOM is studied. The zero-sequence voltage required for DC side balance of HCMC-STATCOM shaping circuit is derived, and the unbalance range of compensating current of HCMC-STATCOM is obtained. The compensation range of HCMC-STATCOM is wider than that of chain star Statcom with the same output voltage level. The control system of HCMC-STATCOM is studied. The compensation current is controlled by decoupling the positive and negative sequence, and the balance control strategy of the three-phase bridge unit and the shaping circuit is given. Finally, the model of HCMC-STATCOM based on MATLAB / Simulink simulation platform is built, and the simulation results are in good agreement with the theoretical analysis.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM464
本文编号：2121386
[Abstract]:Multilevel converters are widely used in high-voltage and high-power fields because of their high power quality, high efficiency and high power. However, with the increasing demand for the performance and function of the converters in this field, Traditional converters have more and more disadvantages, such as more power devices needed, more complex structure, insufficient function and so on. The hybrid inverter can use fewer power devices to achieve more output levels, which can simplify the converter structure, reduce cost and reduce the volume. Hybrid inverters mainly refer to power electronic converters composed of different power units with different voltage levels, different structures or switching devices of different power levels. This combination can enable the hybrid inverter to inherit some characteristics of the original power unit. In order to achieve the purpose of improving its working characteristics. In this paper, two hybrid inverters are studied, and their respective working characteristics and control methods are studied. One is a hybrid cascaded 7-level inverter and the other is a hybrid cascade multilevel static synchronous compensator. The hybrid cascaded 7-level inverter uses fewer switching devices to achieve high power quality, but the hybrid modulation method will cause the DC side of the low voltage cell to produce current backflow problem, which is not conducive to its practicality. The hybrid frequency carrier modulation method can solve the problem of current backflow, but its high voltage unit has low operating frequency, which has great influence on its power quality. Therefore, an improved hybrid frequency carrier modulation method is proposed. The improved method uses unipolar frequency doubling modulation to double the equivalent carrier frequency of the high voltage unit under the condition of constant switching frequency, which not only improves the output power quality, but also retains the advantage that the hybrid frequency carrier modulation method can eliminate the power circulation. The multiplex rectifier circuit of the device is studied, and it is proved that there is no power circulation. Finally, simulation is carried out in MATLAB / Simulink to verify the proposed method. Hybrid cascaded multilevel static synchronous compensator (HCMC-STATCOM) combines the advantages of simple structure of three-phase bridge inverter and good output power quality of cascaded H-bridge inverter. Because of the common DC side of the three-phase bridge element, it can exchange energy between phases, so it has a certain compensation ability of unbalanced current. The compensation principle of HCMC-STATCOM is studied. The zero-sequence voltage required for DC side balance of HCMC-STATCOM shaping circuit is derived, and the unbalance range of compensating current of HCMC-STATCOM is obtained. The compensation range of HCMC-STATCOM is wider than that of chain star Statcom with the same output voltage level. The control system of HCMC-STATCOM is studied. The compensation current is controlled by decoupling the positive and negative sequence, and the balance control strategy of the three-phase bridge unit and the shaping circuit is given. Finally, the model of HCMC-STATCOM based on MATLAB / Simulink simulation platform is built, and the simulation results are in good agreement with the theoretical analysis.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM464
【参考文献】
相关期刊论文 前10条
1 徐莹;赵鹏豪;赵成勇;许建中;江伟;别晓玉;;桥臂交替导通换流器的模块最优冗余配置方法[J];电力系统自动化;2017年02期
2 郑剑飞;应建平;胡志明;;基于混合拓扑的中压静止无功发生器的研究[J];电器与能效管理技术;2016年20期
3 汤广福;庞辉;贺之渊;;先进交直流输电技术在中国的发展与应用[J];中国电机工程学报;2016年07期
4 李宋;叶满园;;混合级联多电平逆变器混合频率载波调制技术[J];高电压技术;2015年07期
5 季振东;孙毅超;李东野;赵剑锋;黄允凯;;星形和三角形连接的链式H桥STATCOM不平衡补偿分析[J];高电压技术;2015年07期
6 杜翼;江道灼;林志勇;尹瑞;王玉芬;梁一桥;;混合级联多电平换流器型静止同步补偿器的优化设计[J];电力系统自动化;2015年06期
7 张国荣;沈奇;;单相有源电力滤波器直流侧电容与电压波动关系分析及设计[J];电力系统自动化;2015年04期
8 金渊;梁晖;陈彪;;七电平混合级联型光伏并网逆变器研究[J];电工技术学报;2015年04期
9 耿俊利;梁晖;金渊;;基于SVPWM调制的混合级联七电平逆变器优化控制策略[J];电网技术;2015年02期
10 邱长青;黄声华;;抑制直流母线电压波动的四象限级联型变频器前馈控制策略[J];电网技术;2015年01期
相关博士学位论文 前2条
1 张云;非对称混合多电平逆变器调制策略及功率均衡控制研究[D];哈尔滨工业大学;2010年
2 孙醒涛;混合不对称多电平逆变器拓扑及控制策略的研究[D];哈尔滨工业大学;2009年
相关硕士学位论文 前6条
1 宋振浩;混合级联H桥型STATCOM调制策略研究[D];中国矿业大学;2016年
2 陈伟;三角形链式静止同步补偿器补偿不平衡负载能力分析及控制[D];重庆大学;2015年
3 阎宏;功率单元级联型SVG控制策略的研究[D];兰州交通大学;2014年
4 林志勇;基于混合级联多电平换流器的STATCOM研究[D];浙江大学;2014年
5 张艳芳;用于不平衡负载补偿的D-STATCOM控制方法的研究[D];西安理工大学;2009年
6 黄庆利;一种新型混合级联逆变器的研究[D];中南大学;2008年
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