分布式光伏发电系统谐波检测与抑制方法的研究

发布时间：2018-05-01 01:20

  本文选题：分布式光伏发电系统 + 谐波检测　； 参考：《沈阳农业大学》2017年硕士论文

【摘要】：随着能源问题和环境问题的日益突出,清洁可再生能源开始备受关注,太阳能以其绿色资源丰富等优势成为最有发展前景的新能源之一,随之,光伏发电也开始逐渐占据发电市场,成为缓解能源问题的方法之一,但光伏发电系统中存在的电力电子器件,会在发电并网过程中带来谐波问题,导致传统电网的电能质量下降,所以,如何抑制光伏并网系统中的谐波问题,是光伏并网系统研究的重点内容之一。本课题基于分布式光伏发电系统的构成及工作原理,分析分布式光伏发电系统谐波产生机理,继而全面对分布式光伏发电系统的谐波检测和抑制的方法展开探究。以某一沿海地区实例为研究对象,收集实例运行数据,结合温度和日照分析光伏发电系统发电特征,并检测该系统运行时的各次谐波参量,以公用电网标准衡量其电能质量,并针对其谐波问题,提出搭建具有有源滤波器功能的光伏并网系统。在课题研究过程中,比较基于傅里叶变换和瞬时无功理论的谐波检测方法,对于基于傅里叶变换在检测光伏发电系统谐波中存在频谱混叠、栅栏效应、频谱泄露等问题,通过加Hanning窗和全相位快速傅里叶变换进行改善,对于既能检测谐波又能补偿无功的瞬时无功理论谐波检测方法,比较其P-q和i_p-i_q两种谐波检测方法,选择在有电压畸变情况下检测准确度高的i_p-i_q检测法。根据有源电力滤波器和光伏并网发电的结构及工作原理的异同点,提出将分布式光伏发电系统与有源电力滤波器有机结合,构建具有有源滤波器功能的光伏并网系统,同时实现光伏并网和谐波与无功补偿,针对系统中的直流侧电压、指令电流合成和电流跟踪逆变器等三个主要组成部分的控制方法进行选择和设计,并在MATLAB/Simulink仿真平台上搭建了仿真模型验证其可行性和正确性。
[Abstract]:With the increasingly prominent energy and environmental problems, clean and renewable energy began to receive much attention. Solar energy has become one of the most promising new energy sources because of its rich green resources. Photovoltaic power generation is also gradually occupying the power generation market, as one of the ways to alleviate the energy problem, but the existence of power electronic devices in the photovoltaic power system will bring harmonic problems in the process of grid connection. Therefore, how to suppress the harmonic in photovoltaic grid-connected system is one of the most important issues in the research of grid-connected photovoltaic system. Based on the structure and working principle of distributed photovoltaic system, the harmonic generation mechanism of distributed photovoltaic system is analyzed, and the methods of harmonic detection and suppression in distributed photovoltaic system are studied. Taking an example of a coastal area as the research object, collecting the operation data of the example, analyzing the characteristics of photovoltaic power generation system combined with temperature and sunshine, and detecting the harmonic parameters of the system, the power quality of the photovoltaic system is measured according to the standard of public power network. Aiming at the harmonic problem, a photovoltaic grid-connected system with active filter function is proposed. In the course of the research, the harmonic detection methods based on Fourier transform and instantaneous reactive power theory are compared. There are problems such as spectrum aliasing, fencing effect and spectrum leakage in detecting harmonics of photovoltaic power system based on Fourier transform. By adding Hanning window and all phase fast Fourier transform, the harmonic detection method of instantaneous reactive power theory, which can detect harmonics and compensate reactive power, is compared between P-q and i_p-i_q harmonic detection methods. Select the i_p-i_q detection method with high accuracy under the condition of voltage distortion. According to the similarities and differences of the structure and working principle of active power filter (APF) and photovoltaic grid-connected generation, a photovoltaic grid-connected system with the function of active power filter (APF) is constructed by combining the distributed photovoltaic system (DPV) and active power filter (APF) organically. At the same time, the photovoltaic grid-connected and harmonic and reactive power compensation are realized. The control methods of three main components of DC side voltage, instruction current synthesis and current tracking inverter are selected and designed. A simulation model is built on the MATLAB/Simulink platform to verify its feasibility and correctness.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM615;TM935
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本文编号：1827094