模块化多电平换流器的环流抑制方案及快速仿真算法
发布时间：2018-09-19 21:17
【摘要】：模块化多电平换流器高压直流输电技术在主体部分、控制和保护系统中均采用了模块化结构,有其他拓扑结构无法企及的技术优势,可以大幅提升电压源换流器直流输电的性能,因此,其应用前景非常广阔。本文在研究MMC拓扑结构、运行机理、数学模型以及调制技术等的基础上,对子模块电容电压波动、相问环流及其抑制方案以及MMC的快速仿真算法展开了研究。 首先,研究了MMC内部环流的机理及其对交流侧输出相电压的影响,在MMC的环流中,二次谐波环流最为显著。其次,为了抑制二次谐波环流,本文提出了三相解耦二次谐波环流抑制算法,根据换流器交、直流侧瞬时功率平衡,分别求得上、下桥臂子模块电容电压的参考值,该参考值在一个工频周期内围绕某一恒定值呈周期性变化,可使得各子模块电容电压的不均衡程度明显降低,二次谐波环流得到有效抑制。最后,在研究MMC内部环流及其抑制方案的过程中,当电平数较高时,仿真速度会变慢,为解决该问题,基于电容器和电抗器的时域等效模型,提出了MMC的快速仿真算法,该算法无需对子模块进行近似处理,在不降低准确性的情况下减小节点导纳矩阵的规模,大大提升了MMC在PSCAD/EMTDC环境中的仿真速度,且与MMC的控制策略有很好的兼容性。 本文所提出的环流抑制方案和快速仿真算法均已在PSCAD/EMTDC电磁暂态仿真软件中搭建了相应的模型,通过仿真验证了其有效性。
[Abstract]:The modularized multilevel converter HVDC transmission technology adopts modularized structure in the main part, control and protection system, which has the technical advantage that other topologies can not match. It can greatly improve the DC transmission performance of voltage source converter, so its application prospect is very broad. Based on the study of MMC topology, operation mechanism, mathematical model and modulation technology, this paper studies the capacitance voltage fluctuation of submodule, the interphase circulation and its suppression scheme, and the fast simulation algorithm of MMC. Firstly, the mechanism of internal circulation of MMC and its influence on the output voltage of AC side are studied. The second harmonic circulation is the most obvious in the circulation of MMC. Secondly, in order to suppress the second harmonic circulation, a three-phase decoupling second-harmonic circulation suppression algorithm is proposed. According to the instantaneous power balance of the converter and the DC side, the reference values of the capacitor voltage of the upper and lower arm modules are obtained, respectively. The reference value changes periodically around a constant value in a power frequency cycle, which can reduce the unbalance of capacitance voltage of each submodule and restrain the second harmonic circulation effectively. Finally, in the process of studying the internal circulation of MMC and its suppression scheme, the simulation speed will slow down when the level number is high. In order to solve this problem, a fast simulation algorithm of MMC is proposed based on the equivalent time-domain model of capacitors and reactors. The algorithm does not need to approximate the sub-modules, and reduces the size of node admittance matrix without reducing the accuracy, which greatly improves the simulation speed of MMC in PSCAD/EMTDC environment, and has good compatibility with MMC control strategy. Both the proposed scheme and the fast simulation algorithm have been built up in the PSCAD/EMTDC electromagnetic transient simulation software, and their effectiveness is verified by simulation.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM46
本文编号：2251362
[Abstract]:The modularized multilevel converter HVDC transmission technology adopts modularized structure in the main part, control and protection system, which has the technical advantage that other topologies can not match. It can greatly improve the DC transmission performance of voltage source converter, so its application prospect is very broad. Based on the study of MMC topology, operation mechanism, mathematical model and modulation technology, this paper studies the capacitance voltage fluctuation of submodule, the interphase circulation and its suppression scheme, and the fast simulation algorithm of MMC. Firstly, the mechanism of internal circulation of MMC and its influence on the output voltage of AC side are studied. The second harmonic circulation is the most obvious in the circulation of MMC. Secondly, in order to suppress the second harmonic circulation, a three-phase decoupling second-harmonic circulation suppression algorithm is proposed. According to the instantaneous power balance of the converter and the DC side, the reference values of the capacitor voltage of the upper and lower arm modules are obtained, respectively. The reference value changes periodically around a constant value in a power frequency cycle, which can reduce the unbalance of capacitance voltage of each submodule and restrain the second harmonic circulation effectively. Finally, in the process of studying the internal circulation of MMC and its suppression scheme, the simulation speed will slow down when the level number is high. In order to solve this problem, a fast simulation algorithm of MMC is proposed based on the equivalent time-domain model of capacitors and reactors. The algorithm does not need to approximate the sub-modules, and reduces the size of node admittance matrix without reducing the accuracy, which greatly improves the simulation speed of MMC in PSCAD/EMTDC environment, and has good compatibility with MMC control strategy. Both the proposed scheme and the fast simulation algorithm have been built up in the PSCAD/EMTDC electromagnetic transient simulation software, and their effectiveness is verified by simulation.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM46
【参考文献】
相关期刊论文 前10条
1 屠卿瑞;徐政;郑翔;张静;;一种优化的模块化多电平换流器电压均衡控制方法[J];电工技术学报;2011年05期
2 杨晓峰;范文宝;王晓鹏;郑琼林;;基于模块组合多电平变换器的STATCOM及其控制[J];电工技术学报;2011年08期
3 刘钟淇;宋强;刘文华;;基于模块化多电平变流器的轻型直流输电系统[J];电力系统自动化;2010年02期
4 屠卿瑞;徐政;管敏渊;郑翔;张静;;模块化多电平换流器环流抑制控制器设计[J];电力系统自动化;2010年18期
5 管敏渊;徐政;;模块化多电平换流器型直流输电的建模与控制[J];电力系统自动化;2010年19期
6 李强;贺之渊;汤广福;司德亮;郑斌毅;殷志良;;新型模块化多电平换流器空间矢量脉宽调制方法[J];电力系统自动化;2010年22期
7 郭捷;江道灼;周月宾;胡鹏飞;梁一桥;;交直流侧电流分别可控的模块化多电平换流器控制方法[J];电力系统自动化;2011年07期
8 王姗姗;周孝信;汤广福;贺之渊;滕乐天;刘隽;;模块化多电平HVDC输电系统子模块电容值的选取和计算[J];电网技术;2011年01期
9 李强;贺之渊;汤广福;包海龙;王熙骏;王韧;;新型模块化多电平换流器空间矢量脉宽调制的通用算法[J];电网技术;2011年05期
10 屠卿瑞;徐政;郑翔;管敏渊;;模块化多电平换流器型直流输电内部环流机理分析[J];高电压技术;2010年02期
，本文编号：2251362
本文链接：https://www.wllwen.com/kejilunwen/dianlilw/2251362.html
