摘要随着世界能源危机的加剧，光伏发电因其发电过程无污染，光伏器件使用寿命长等优点而受到广泛重视。其中，光伏并网发电模式因具有初期投资较低，输出电能稳定等优点，目前已成为光伏发电利用发展最快的形式。65567

孤岛检测是分布式发电并网研究的难点，特别是在逆变器输出与负载功率平衡时难以检测出孤岛。频率或相位偏移等主动检测方法会向电网注入谐波，而且在逆变器输出与负载相位相匹配时会导致孤岛检测失效。

输出功率扰动法其原理为逆变器通过对其输出电流施加扰动，使其输出功率发生变化，进而使其输出电压产生改变。本文研究了一种新的孤岛检测方法——主动电流扰动法。主动电流扰动法本质上是一种输出功率扰动法。该方法不影响电网的频率，不向电网注入谐波，而且在单台运行时不存在不可检测区，仿真和实验结果验证了该方法的正确性。

毕业论文关键词   并网逆变器  光伏系统  孤岛检测  主动电流扰动法

毕业设计说明书（论文）外文摘要

Title  Study on islanding detection of grid-connected photovoltaic inverter based on output power perturbation method

Abstract

With the world energy crisis intensifies, photovoltaic power generation because of its generating process has no pollution, the photovoltaic devices service life is long have attracted wide attention. Among them, PV grid-connected mode because of its low initial capital investment, output power stability and other advantages, has become a form of photovoltaic power generation using the fastest .

It is difficult to detect islanding in distributed generation research, especially when power balance between the output of inverter and the load. Frequency or phase shift methods which inject harmonic into grid is ineffective when phase match between the output of inverter and the load. The principle of the output power perturbation method by applying the perturbation on the output current of the inverter , so that the output power is changed, and then change its output voltage, a new method for islanding detection based on active current disturbing is proposed in this paper. Active current disturbing is essentially a power output perturbation method ,This method doesn’t effect the frequency of grid, inject harmonic to grid and have non detection zone when operating alone. This method has been proved by simulations and experiments.

Keywords  Grid-connected inverter  PV systems  islanding detection  active current disturbing

目   次

1  绪论 5

1.1  课题研究背景 5

1.2  国内外光伏发电现状 5

1.3  光伏发电系统简介 7

1.4  孤岛检测技术的历史与现状 10

1.5  选题依据及本文主要的研究内容 11

2  光伏并网发电系统的孤岛效应及检测方法 11

2.1  孤岛效应 11

2.2  孤岛效应的检测 14

2.3  本章小结 18

3  功率扰动法的孤岛检测及Matlab的仿真 19

3.1  Matlab软件介绍 19

3.2  光伏并网反孤岛原理仿真 21

3.3  功率扰动法孤岛检测仿真