混合型多电平换流器的可靠性分析

发布时间：2019-04-04 12:02

【摘要】：柔性直流输电技术以其有功无功独立控制,没有换相失败等优点,在未来的直流输电场合展示出更加广阔的应用前景。柔性直流输电技术在近几年得到了快速发展,其中,混合型多电平换流器以其具有直流故障自关断能力和良好的经济性,在柔性直流输电领域得到深入研究。换流器可靠性分析是混合型多电平换流器一个重要研究点,也是混合型多电平换流器模块最优冗余配置的重要参考因素之一。针对上述问题,论文将分别从古典概型角度和分布函数角度对混合型多电平换流器的可靠性加以分析。首先对混合型多电平换流器的概念及分类方法加以阐述,即混合型多电平换流器包括混合模块化多电平换流器(Hybrid Modular Multilevel Converter,Hybrid MMC)、桥臂交替导通换流器(Alternate Arm C onverter,AAC)和混合级联多电平换流(Hybrid Cascaded Multilevel Converter,HCMC),并展示上述三种换流器的拓扑,进一步结合拓扑分析其稳态工作原理和暂态闭锁原理,并据此设计模块初始配置数目。然后从古典概型的角度,假设各子模块的可靠性保持不变,且模块间相互独立,建立可靠性分析模型,依次分析混合模块化多电平换流器中不同类型子模块的冗余数目配置对换流器可靠性的影响,桥臂交替导通换流器中的导通开关模块和整形电路子模块不同冗余配置数目对换流器可靠性的影响,混合级联多电平换流器中的导通开关模块和整形电路子模块对换流器可靠性的影响。在可靠性分析的基础上,分析器件的有效利用率以衡量经济性,设计三种换流器的最优冗余配置并加以对比,为实际工程的冗余配置提供参考和借鉴。最后,从分布函数的角度,假设各子模块的可靠性随时间变化,且考虑了子模块间的相关性,并以混合型多电平换流器中的混合MMC为例,基于Copula理论和Copula函数建立可靠性模型,分析子模块间的相关程度和冗余配置对换流器可靠性的影响。
[Abstract]:Flexible HVDC technology has the advantages of independent control of active power and reactive power and no commutation failure, so it has a wider application prospect in the future HVDC transmission field. Flexible DC transmission technology has been developed rapidly in recent years, in which hybrid multi-level converter has been deeply studied in the field of HVDC transmission due to its DC fault self-switching ability and good economy. Reliability analysis of converter is an important research point of hybrid multi-level converter, and it is also one of the important reference factors for optimal redundancy configuration of hybrid multi-level converter module. In order to solve these problems, the reliability of hybrid multi-level converter is analyzed in terms of classical probability and distribution function. Firstly, the concept and classification method of hybrid multilevel converter are described. That is, hybrid multilevel converter includes hybrid modular multilevel converter (Hybrid Modular Multilevel Converter,Hybrid MMC), bridge arm alternating conduction converter (Alternate Arm Converter,. (AAC) and hybrid cascade multilevel converter (Hybrid Cascaded Multilevel Converter,HCMC), and show the topology of the above three converters, and further analyze the steady-state working principle and transient locking principle, and then design the initial configuration number of modules according to the topology. Then from the classical probability point of view, assuming that the reliability of each sub-module remains the same, and the modules are independent of each other, a reliability analysis model is established. The influence of redundant number of different types of sub-modules on the reliability of hybrid modular multilevel converter is analyzed in turn. The effect of the number of redundant configurations of the on-switch module and the shaping circuit sub-module on the reliability of the converter in the bridge-arm alternating conduction converter. The effect of on-switch module and shaping circuit sub-module on the reliability of hybrid cascade multilevel converter. On the basis of reliability analysis, this paper analyzes the effective utilization ratio of the devices to measure the economy, designs and compares the optimal redundancy configuration of the three converters, and provides reference and reference for the practical engineering redundancy configuration. Finally, from the point of view of distribution function, the reliability of each sub-module is assumed to vary with time, and the correlation between sub-modules is considered. Taking the hybrid MMC in hybrid multilevel converter as an example, the reliability model is established based on Copula theory and Copula function. The influence of the correlation degree and redundancy configuration among sub-modules on the reliability of converter is analyzed.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM46

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