电力系统谐波检测与补偿方法研究

发布时间：2018-03-13 11:14

本文选题：谐波检测　切入点：互补集合经验模态分解　出处：《上海电机学院》2017年硕士论文　论文类型：学位论文

【摘要】：迅猛发展的电力电子技术,致使电力系统中非线性负载越来越多,谐波污染问题也越来越严重,而越来越多的精密仪器不断涌现,用户对电能质量的要求也越来越高。因此,研究效果更好,精度更高的谐波检测分析方法,为电力系统中谐波治理提供可靠的依据,便具有了非常重要的意义。首先,从整体上对电力系统谐波理论进行了介绍,其中包括谐波的基础知识、国家规定的谐波衡量方式及其衡量标准以及几种传统的谐波检测分析方法,并对这几种方法进行了分析。其次,详细分析了传统的经验模态分解(EMD)理论与互补集合经验模态分解(CEEMD)理论的工作原理,理论与仿真相结合,论证了互补集合经验模态分解理论的优越性;之后介绍了希尔伯特变换,并将该变换与互补集合经验模态分解相结合,提出了一种时域与频域相结合的谐波分析方法——CEEMD-HT算法。通过仿真实验,结果表明,该算法能够得到目标信号的瞬时频率以及瞬时幅值等信息,具备良好的谐波检测与分析能力。接着,理论推导了瞬时功率理论以及瞬时无功功率理论,得出在三相电压畸变的情况下,直接应用瞬时无功功率理论的p-q检测模型存在较大的检测误差。针对该模型所存在的问题,结合互补集合经验模态分解的特点,提出了C-EEMD算法,该算法能够处理畸变电压,得到电压基波;将C-EEMD算法与p-q检测模型相结合形,得到了一种时域内的谐波检测模型——改进的p-q检测模型。将改进的p-q检测模型与i_p-i_q检测模型进行对比仿真分析,结果表明,改进的p-q检测模型能够在时域内对系统的谐波总量进行实时检测,有效的解决了电压畸变对该系统的影响,并且比i_p-i_q检测模型的检测精度更高。最后,本文介绍了谐波补偿的基本原理及其种类,分析了有源电力滤波器的主电路以及控制策略,并对并联型有源电力滤波器进行了模型的搭建,将改进的p-q检测模型加到有源电力滤波器的谐波检测模块当中,仿真结果表明,该有源滤波器能够有效的实现对谐波电流的实时补偿,并且效果良好。
[Abstract]:With the rapid development of power electronics technology, there are more and more nonlinear loads in power system, and the problem of harmonic pollution is becoming more and more serious. The harmonic detection and analysis method with better effect and higher precision is of great significance to provide reliable basis for harmonic treatment in power system. Firstly, the harmonic theory of power system is introduced. It includes the basic knowledge of harmonics, the measurement methods and standards of harmonics prescribed by the state, and several traditional harmonic detection and analysis methods. The working principle of the traditional empirical mode decomposition (EMD) theory and the complementary set empirical mode decomposition (CEEMD) theory are analyzed in detail. The advantages of the complementary set empirical mode decomposition theory are demonstrated by combining the theory with simulation. Then, the Hilbert transform is introduced and combined with the complementary set empirical mode decomposition. A harmonic analysis method, CEEMD-HT algorithm, is proposed, which combines time domain and frequency domain. The simulation results show that, The algorithm can obtain instantaneous frequency and instantaneous amplitude of target signal, and has good ability of harmonic detection and analysis. Then, the instantaneous power theory and instantaneous reactive power theory are derived theoretically. In the case of three-phase voltage distortion, the p-q detection model which directly applies instantaneous reactive power theory has a large detection error. In view of the problems existing in this model and the characteristics of complementary set empirical mode decomposition, a C-EEMD algorithm is proposed. The algorithm can deal with the distorted voltage and obtain the fundamental wave of the voltage. The C-EEMD algorithm is combined with the p-q detection model. An improved p-q detection model in time domain is obtained. The comparison between the improved p-q detection model and the iStack p-iq detection model is carried out. The results show that, The improved p-q detection model can real-time detect the total harmonics of the system in time domain, which effectively solves the influence of voltage distortion on the system, and has higher detection accuracy than the iStup _ iq detection model. Finally, This paper introduces the basic principle and types of harmonic compensation, analyzes the main circuit and control strategy of active power filter, and builds the model of shunt active power filter. The improved p-q detection model is added to the harmonic detection module of the active power filter. The simulation results show that the active power filter can effectively realize the real-time compensation of harmonic current, and the effect is good.
【学位授予单位】：上海电机学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM935;TM714.3

【参考文献】