论文总字数:24769字
摘 要
在国家发布光伏扶贫相关文件后,大量光伏扶贫项目开始被规划和建立,因此大规模的分布式电源将接入配电网。由于光伏出力具有很强的不确定性,因此可能给电网带来相当严重的问题。
从功率角度分析,当分布式光伏电源渗透率较高时,接入的配电网的潮流分布将会发生较大变化,甚至发生电压越限,对传输线路及变压器的可靠安全运行造成影响。从谐波角度分析,所有的光伏发电设备均具有大量电力电子器件,因此发电过程产生谐波是不可避免的。同时由于分布式电源的不确定性,产生的谐波也是不确定的。当一个或几个光伏设备接入配电网后,谐波进入了配电网中,谐波含量将影响电网输电的电能质量,严重情况下,谐波可能损害输电设备,造成线路故障。
本文从IEEE33节点网络入手,分别对接入不同数量光伏的基波潮流和谐波潮流进行计算和分析。分别对基波潮流和谐波潮流的计算结果通过不同的方法进行风险评估,以直观的图形方式表示接入分布式电源的配电网的运行风险。本文采用Matlab软件进行程序的编写,实现含光伏发电配电网的概率潮流计算和概率谐波潮流计算,并根据得到的基波电压越限风险和谐波THD数值进行了风险评估和分析。
关键词:分布式电源、概率潮流、概率谐波潮流、风险评估
Abstract
A large number of photovoltaic poverty alleviation projects have been planned and established after the state issued relevant documents on photovoltaic poverty alleviation. Therefore, large-scale distributed power generation will be connected to the distribution network.Due to the strong uncertainty of photovoltaic output, it may bring serious problems to the power grid.
From the perspective of power analysis, when the permeability of distributed photovoltaic power supply is high, the power flow distribution of the connected distribution network will change greatly, and even exceed the voltage limit, which will affect the reliable and safe operation of transmission lines and transformers.From the perspective of harmonic analysis, all photovoltaic power generation equipment has a large number of power electronic devices, so the generation of harmonic is inevitable.At the same time, due to the uncertainty of distributed power supply, the harmonic generated is uncertain.When one or several photovoltaic devices are connected to the distribution network, the harmonic enters the distribution network, and the harmonic content will affect the power quality of the transmission network. In serious cases, the harmonic may damage the transmission equipment and cause line fault.
Starting from the IEEE33 node network, this paper calculates and analyzes the fundamental load flow and harmonic load flow connected with different quantities of pv.The calculation results of fundamental load flow and harmonic load flow are evaluated by different methods.In this paper, Matlab software is used to write the program to realize the probability load flow calculation and probability harmonic load flow calculation of photovoltaic power distribution network, and the risk assessment and analysis are carried out according to the fundamental voltage overlimit risk and harmonic THD value obtained.
Keywords: distributed power supply, probability flow, probability harmonic flow, risk assessment
目 录
摘 要 1
Abstract 2
第一章 绪论 1
1.1研究背景 1
1.2国内外研究现状 1
1.2.1电力系统概率潮流研究现状 1
1.2.2电力系统谐波潮流研究现状 2
1.2.3电力系统风险评估研究现状 4
1.3本文研究内容 5
1.3.1含光伏出力建模的概率潮流计算 5
1.3.2谐波潮流计算 5
1.3.3风险评估 5
第二章 概率潮流计算 7
2.1基波潮流计算 7
2.2光伏出力建模 9
2.3概率潮流计算 10
2.3.1概率密度函数 10
2.3.2分布函数 10
2.3.3原函数 10
2.3.4概率潮流计算 11
2.4算例分析 11
2.4.1光伏建模分析 12
2.4.2基波潮流计算结果 13
2.4.3概率潮流计算结果 16
第三章 谐波潮流计算 17
3.1谐波电流源的建立 17
3.2电气元件等效模型 19
3.2.1同步发电机 19
3.2.2变压器 19
3.2.3交流线 19
3.2.4负载 20
3.3谐波潮流计算 20
3.4算例分析 21
3.4.1谐波电流源建模结果 21
3.4.2单光伏算例 24
3.4.3多光伏算例 25
第四章 风险评估 29
4.1电压越限指标 29
4.2THD越限风险 29
4.3算例分析 30
4.3.1单光伏算例 30
4.3.2四光伏算例 34
第五章 总结与展望 37
5.1总结 37
5.2展望 37
参考文献 38
致 谢 40
第一章 绪论
1.1研究背景
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