基于改进人工鱼群算法的特定谐波消除策略研究

发布时间：2018-07-14 16:08

【摘要】：随着电力电子技术的快速发展,逆变器系统在大功率牵引、交直流调速、不间断电源、太阳能光伏发电等领域的应用日趋广泛,因此逆变器调制策略成为研究热点。由于PWM调制方式的局限性,造成了较大的谐波污染问题,特别是在对于开关损耗、电磁兼容、波形质量要求较高的领域,如何降低逆变器输出谐波含量已经成为学者研究的主要课题。本文在研究多种调制策略的基础上,针对抑制谐波效果较好的特定谐波消除调制策略展开了深入研究。特定谐波消除调制策略实现的难点在于特定消谐方程组的求解,目前主要的求解方法为传统数值方法和智能算法,传统数值方法在求解过程中依赖于初值的适当选取,智能算法如遗传算法、差分进化算法容易陷入局部极值,影响求解精度。针对以上不足,本文提出以人工鱼群算法对特定消谐方程组进行求解,详细阐述了人工鱼群算法对于特定消谐问题的求解过程;针对人工鱼群个体之间缺少超越可视域局限的联系的问题,引入差分变异算子,提出改进人工鱼群算法;针对人工鱼群算法参数多的特点,对于算法中移动步长、可视域范围、拥挤因子、差分变异算子等因素的影响进行了详细研究分析,最后将改进人工鱼群算法的求解结果进行了特定消谐仿真分析和实验研究。本文通过将改进人工鱼群算法与其它智能算法对比,表明了其在求解消谐问题上具有一定的优越性;应用改进人工鱼群算法针对不同开关角数的情况进行求解,将所得开关角用于搭建的特定消谐仿真模型,一方面能够依据调制度有效控制基波幅值,另一方面能够有效消除指定频次的谐波,从而证明了改进人工鱼群算法求解的正确性和有效性;通过对改进人工鱼群算法参数的分析,选取了较优的移动步长、可视域以及差分变异策略作为求解参数;最后在两电平逆变功率系统上验证了不同频率、不同开关角个数下的基于改进人工鱼群算法的特定谐波消除调制策略的效果。
[Abstract]:With the rapid development of power electronic technology, inverter system has been widely used in the fields of high-power traction, AC / DC speed regulation, uninterruptible power supply, solar photovoltaic power generation and so on. Because of the limitation of PWM modulation mode, the problem of harmonic pollution is caused, especially in the field of switching loss, electromagnetic compatibility and waveform quality. How to reduce the harmonic content of inverter output has become the main research topic of scholars. Based on the research of various modulation strategies, this paper makes a deep research on the specific harmonic elimination modulation strategy which has better harmonic suppression effect. The difficulty of realizing the special harmonic elimination and modulation strategy lies in the solution of the specific harmonic elimination equations. At present, the main methods are traditional numerical method and intelligent algorithm. The traditional numerical method depends on the proper selection of initial value in the process of solution. Intelligent algorithm such as genetic algorithm, differential evolution algorithm is easy to fall into the local extremum, which affects the accuracy of the solution. In order to solve the above problems, the artificial fish swarm algorithm is proposed to solve the specific harmonic elimination equations, and the process of solving the specific harmonic elimination problem by artificial fish swarm algorithm is described in detail. In view of the lack of contact between artificial fish groups beyond the limits of horizon, the difference mutation operator is introduced to improve the artificial fish swarm algorithm. In view of the characteristics of the artificial fish swarm algorithm with many parameters, the moving step size and the visual domain range of the artificial fish swarm algorithm are discussed. The effects of crowding factor and differential mutation operator are analyzed in detail. Finally, the results of the improved artificial fish swarm algorithm are simulated and tested. By comparing the improved artificial fish swarm algorithm with other intelligent algorithms, it is shown that the improved artificial fish swarm algorithm has certain advantages in solving harmonic elimination problems, and the improved artificial fish swarm algorithm is applied to solve different switching angles. The switching angle can be used to build a special harmonic elimination simulation model. On the one hand, it can effectively control the amplitude of the fundamental wave according to the modulation system, on the other hand, it can effectively eliminate the harmonics of the specified frequency. Through the analysis of the parameters of the improved artificial fish swarm algorithm, the optimal moving step size, visual domain and differential mutation strategy are selected as the solution parameters. Finally, the effect of the special harmonic elimination modulation strategy based on the improved artificial fish swarm algorithm with different frequency and number of switching angles is verified on a two-level inverter power system.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM714.3;TP18

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