统一电能质量调节器的控制策略研究

发布时间：2019-03-08 12:33

【摘要】：随着经济与科技的飞速发展,精密设备得到了广泛的应用,使得用户对电能质量的要求也越来越高。与此同时,非线性负载向电网中注入了大量的电流谐波,导致电能质量问题日趋严重。因此,研究有效提高电能质量的方法具有极其重要的社会与现实意义。统一电能质量调节器弥补了传统无源电力滤波器和有源电力滤波器的不足,可对电网中的电压谐波和非线性负载产生的电流谐波同时进行补偿。控制策略的优劣,直接关系到UPQC的补偿效果,本文采用基于能量控制思想的无源混合控制策略,对UPQC的补偿效果进行优化,使补偿后电网中的电压和电流波形维持近似正弦波,有效净化电网,提升了电网的电能质量。在电网电压突变和负载突变时,仍可以保持良好的补偿效果。本文首先简要介绍了课题的背景和意义,分析了较为常用的谐波检测方法和系统控制策略。针对基于瞬时无功功率理论的检测方法因使用锁相环导致的检测误差,提出了基于电网工频时钟的谐波检测法。在得到较为准确的检测结果之后,介绍了两电平UPQC分别在EL模型和PCHD模型下的无源混合控制策略。第4章在两电平UPQC的基础上,介绍采用TNPC三电平逆变器作为UPQC主电路的三电平UPQC。第5章针对无源混合控制策略中,参数固定不变的缺点,设计了模糊无源混合控制策略,实现了注入阻尼的自动调整。在各章的结尾都进行了相关的仿真验证。
[Abstract]:With the rapid development of economy and science and technology, precision equipment has been widely used, which makes users more and more demanding for power quality. At the same time, a large number of current harmonics are injected into the power grid by nonlinear load, which leads to serious power quality problems. Therefore, it is of great social and practical significance to study the methods of improving power quality effectively. The unified power quality regulator makes up for the shortcomings of traditional passive power filter and active power filter. It can compensate both voltage harmonic and current harmonic generated by nonlinear load in the power network at the same time. The advantages and disadvantages of the control strategy are directly related to the compensation effect of UPQC. In this paper, the passive hybrid control strategy based on the idea of energy control is adopted to optimize the compensation effect of UPQC, so that the voltage and current waveforms in the power network after compensation are maintained to approximate sine wave. Effectively purify the power grid, improve the power quality of the grid. When the voltage change and load mutation, the compensation effect can still be maintained. In this paper, the background and significance of the project are introduced briefly, and the commonly used harmonic detection methods and system control strategies are analyzed. In view of the detection error caused by the use of phase-locked loop (PLL), a harmonic detection method based on power-frequency clock is proposed for the detection method based on instantaneous reactive power theory. After the accurate detection results are obtained, the passive hybrid control strategies for two-level UPQC under the EL model and the PCHD model are introduced. In chapter 4, based on the two-level UPQC, the three-level UPQC. using TNPC three-level inverter as the main circuit of UPQC is introduced. In chapter 5, the fuzzy passive hybrid control strategy is designed to realize the automatic adjustment of injection damping, aiming at the disadvantage that the parameters are fixed in the passive hybrid control strategy. At the end of each chapter, the related simulation verification is carried out.
【学位授予单位】：北京信息科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM761

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