智能变电站隔离开关操作引起的瞬态干扰特征及仿真毕业论文

 2022-09-26 14:51:10

论文总字数:26369字

摘 要

进入新世纪以来,随着生活条件的显著提高以及国家经济水平的快速飞跃,我国的人均用电量也在飞速增长。智能电网的全面推进与自动化配套设施的广泛投入使用应运而生。在气体绝缘式变电站(Gas Insulated Substation, GIS)内有许多电磁干扰源,最常见的是开关操作产生的电磁骚扰。开关操作过电压对变电站的电磁骚扰问题也成为了影响变电站稳定运行的主要原因。为了深入了解智能变电站隔离开关操作瞬态干扰的原理,提高智能设备在GIS开关操作过程中的工作可靠性,保证变电站良好稳定运行,本文系统分析了电磁骚扰的来源以及耦合方式,并搭建单变单回路开关操作过电压的模型进行仿真,对回路中多个位置的电流电压波形进行对比、分析与观察,总结了系统各部分特快速暂态过电压(Very Fast Transient Overvoltage, VFTO)的特性。论文主要研究内容包括:

(1)结合现代电力发展情况,阐明了研究电磁暂态干扰问题的现实意义,并介绍了国内外目前的研究成果。详细介绍了开关操作时VFTO的产生原理,并分类总结了变电站内存在的主要电磁干扰源,且对一些常见的电磁耦合机理进行了简单介绍,从而为下文对电磁故障产生原因的分析奠定理论基础。

(2)通过对比分析多种电力系统仿真软件,结合课题特点选用电磁暂态仿真软件EMTP。在介绍了暂态仿真建模的流程后,利用EMTP建立了可重复击穿的隔离开关模型,通过电弧重燃判定环节、电弧熄灭判定环节和开关控制环节等将系统连接起来。

(3)仿真得到变电站系统不同位置的采集信号,并对信号进行特性分析,重点综合评估了合闸时系统一次侧各个部分的过电压和过电流特征水平。观察发现开关第一次击穿发生在0.079s时,之后电弧交替熄灭与重燃,产生VFTO,在空间激荡起电磁波,对线路产生干扰,整个过程持续约0.31s。在此过程中对骚扰电流进行记录并做频谱分析,观察骚扰信号的能量分布。

关键词:GIS开关分合闸,特快速暂态过电压,暂态仿真,电弧

ABSTRCT

Since the beginning of the new century, China's living standards have steadily improved. At the same time, the demand for industrial production has also been greatly improved, China's electricity consumption is also increasing. The comprehensive promotion of smart grid and the extensive use of automation facilities have emerged as the times require. There are many sources of electromagnetic interference in the GIS substation, the most common one is the electromagnetic interference coming with the switch operation. The overvoltage caused by switching operation in the substation has become the main reason for interfering the stable operation of substations. In order to understand the principle of transient disturbance caused by intelligent substation disconnector operation and improve the reliability of intelligent equipment in GIS switch operation, the source and coupling method of electromagnetic disturbance are analyzed, and the disconnector operation simulation model the is constructed. According comparing, analysing and observing the loop at multiple locations of the voltage and current levels, the characteristics of the very fast transient over–voltage (VFTO) in each part of the system are summed up. The main contents of the thesis include:

(1) Combining with the development of modern electric power, this paper expounds the research background and significance of this subject, and analyzes the current research situation in this field. The principle of VFTO generation in switch operation is introduced in detail, and the main sources of electromagnetic interference in substation are summarized and summarized. Some of the common electromagnetic coupling mechanisms are briefly introduced, which will lay a theoretical foundation for the analysis of the cause of electromagnetic failure The

(2) Through the comparative analysis of a variety of power system simulation software, combined with the characteristics of the selection of electromagnetic transient simulation software EMTP. After introducing the process of transient simulation modeling, EMD is used to establish the model of repeatable breakdown switch, and the system is connected by arc reignition judgment link, arc extinguishing judgment link and switch control link.

(3) Simulation of the substation system at different locations of the acquisition signal, and the characteristics of the signal analysis, focusing on the overall evaluation of the system when the first side of the system over-voltage and over-current characteristics of the level. Observe that the first breakdown of the switch occurs at 0.079 s, after the arc alternately extinguished and re-ignited, resulting in VFTO, in the spatial oscillation from the electromagnetic waves, the interference of the line, the whole process lasted about 0.31s. In this process, the disturbance current is recorded and spectrum analysis is performed to observe the energy distribution of the disturbance signal.

KEY WORDS: GIS switch operation, very fast transient overvoltage, transient simulation, arc

目录

摘要 I

Abstract II

第一章 绪论 1

1.1引言 1

1.2国内外研究现状 2

1.2.1开关操作电磁骚扰的测量研究 2

1.2.2开关操作电磁骚扰的仿真建模 3

1.3本文主要研究内容 3

1.4 本文组织结构 3

第二章 开关操作电磁骚扰的产生机理及耦合方式 5

2.1概述 5

2.2产生机理 5

2.3 变电站二次侧暂态过电压的耦合方式 6

2.3.1 变电站二次侧暂态过电压的来源及其特性 6

2.3.2变电站暂态过电压的主要耦合方式 7

2.4本章小结 9

第三章 智能变电站一次侧开关操作过电压仿真 10

3.1 概述 10

3.2 电力系统电磁暂态仿真分析 10

3.3 隔离开关分合空载短线操作电磁瞬态仿真的EMTP实现 12

3.3.1 隔离开关操作空载短线的电气接线图 12

3.3.2 各元件的等效电路和参数选取 12

3.3.3 隔离开关分合闸的EMTP模型建立 13

3.4 本章小结 17

第四章 隔离开关分合空载短线的仿真分析 18

4.1 概述 18

4.2仿真结果分析 18

4.2.1 隔离开关两侧电压分布 18

4.2.2开关侧短线电压分布 20

4.2.3 电流互感器一次侧电流分布 21

4.2.4变压器侧电压分布 23

4.2.5 闸刀状态波形 24

4.3本章小结 24

第五章 总结与展望 25

5.1总结 25

5.2展望 25

致 谢 26

参考文献 27

第一章 绪论

1.1引言

随着生活条件的显著提高以及国家经济的快速飞跃,我国的人均用电量也在飞速增长。为满足民用及多方面需求,结合我国能源资源与使用中心分布不协调的现状,如何大量有效率地输送电能到远距离地方成为一个需要研究的问题,因此有必要全面推进智能电网并追求配套设施智能化。于是,二次设备被逐渐引入变电站与智能控制系统配合工作,同时在变电站高压开关场中使用二次设备逐渐成为一种主流的方式。但二次设备中有许多电子设备由超大规模集成电路组成,由于这种结构特点,这些电子设备很容易受周围电磁干扰的影响,所以这对二次设备的绝缘水平、可靠性以及抗干扰性能提出更严格的要求。

气体绝缘式变电站(Gas Insulated Substation, GIS)以其占地面积小、元件密封受干扰小、运行安全可靠等优点,被广泛应用于电力系统中,图1.1为特高压GIS试验场。但在GIS隔离开关切合空载短线过程中,由于动静触头之间空气击穿产生电弧,会在一次侧产生一种幅值较大、频率极高、波前时间很短的特快速瞬态过电压,使开关触头间隙重复击穿,产生一系列骚扰电磁波[1]。GIS设备由隔离开关、接地刀闸、断路器、导电杆、互感器、连接件和出线终端等组成,特快速暂态过电压(Very Fast Transient Overvoltage, VFTO)严重时可在GIS设备的不同位置通过电磁干扰出现故障。这需要我们采取措施来维持变电站稳定又可靠地运行,同时,还对其他工作在高压环境下的电力系统的绝缘能力的水平提出了更高的标准。

剩余内容已隐藏,请支付后下载全文,论文总字数:26369字

您需要先支付 80元 才能查看全部内容!立即支付

课题毕业论文、开题报告、任务书、外文翻译、程序设计、图纸设计等资料可联系客服协助查找。