《课程设计基于MATLAB的电力系统短路故障仿真于分析.doc》由会员分享，可在线阅读，更多相关《课程设计基于MATLAB的电力系统短路故障仿真于分析.doc（27页珍藏版）》请在三一办公上搜索。
1、电力系统建模及仿真课程设计总结报告 题 目：基于MATLAB的电力系统短路故障仿真于分析姓 名 某某某 学 号 200x0417xxx 院 系 自 机 学 院 班 级 0x级电气x班 指导教师 某某莫 摘 要本次课程设计是结合电力系统分析的理论教学进行的一个实践课程。电力系统短路故障，故障电流中必定有零序分量存在，零序分量可以用来判断故障的类型，故障的地点等，零序分量作为电力系统继电保护的一个重要分析量。运用Matlab电力系统仿真程序SimPowerSystems工具箱构建设计要求所给的电力系统模型，并在此基础上对电力系统多中故障进行仿真，仿真波形与理论分析结果相符，说明用Matlab对电力
2、系统故障分析的有效性。实际中无法对故障进行实验，所以进行仿真实验可达到效果。关键词：电力系统；仿真；短路故障；Matlab；SimPowerSystemsAbstract The course design is a combination of power system analysis of the theoretical teaching, practical courses. Power system short-circuit fault, the fault current must be zero sequence component exists, and zero-seque
3、nce component can be used to determine the fault type, fault location, the zero-sequence component as a critical analysis of power system protection. SimPowerSystems Toolbox building design requirements to the power system model using Matlab power system simulation program, and on this basis, the po
4、wer system fault simulation, the simulation waveforms with the theoretical analysis results match, indicating that the power system fault analysis using Matlab effectiveness. Practice can not fault the experiment, the simulation can achieve the desired effect.Keywords: power system; simulation; fail
5、ure; Matlab; SimPowerSystems目 录一、引言- 3 -1、故障概述- 3 -2、故障类型- 3 -二、电力系统模型- 4 -三、电力系统仿真模型的建立与分析- 4 -3.1 电力系统仿真模型- 5 -3.2 仿真参数设置- 6 -3.3 仿真结果分析- 8 -3.3.1正常运行分析- 8 -3.3.2单相接地短路故障分析- 9 -3.3.3两相短路故障分析- 12 -3.3.4两相接地短路故障分析- 15 -3.3.5三相短路故障分析- 18 -四、结论- 21 -五、参考文献- 21 -六、心得体会- 22 -一、引言1、故障概述短路是电力系统的严重故障。所谓短路，
6、是指一切不正常的相与相之间或相与地（对于中性点接地的系统）发生系统通路的情况。电力系统在运行中，相与相之间或相与地（或中性线）之间发生非正常连接（即短路）时流过的电流。其值可远远大于额定电流，并取决于短路点距电源的电气距离。例如，在发电机端发生短路时，流过发电机的短路电流最大瞬时值可达额定电流的1015倍。大容量电力系统中，短路电流可达数万安。这会对电力系统的正常运行造成严重影响和后果。供电网络中发生短路时,很大的短路电流会使电器设备过热或受电动力作用而遭到损坏,同时使网络内的电压大大降低,因而破坏了网络内用电设备的正常工作.为了消除或减轻短路的后果,就需要计算短路电流,以正确地选择电器设备、
7、设计继电保护和选用限制短路电流的元件。2、故障类型三相系统中发生的短路有 4 种基本类型：三相短路，两相短路，单相对地短路和两相对地短路。其中，除三相短路时，三相回路依旧对称，因而又称对称短路外，其余三类均属不对称短路。在中性点接地的电力网络中，以一相对地的短路故障最多，约占全部故障的90。在中性点非直接接地的电力网络中，短路故障主要是各种相间短路。为了保证电力系统运行的功能和质量，在设计、分析和研究时必须保证系统的静态和动态特性。现代电力系统是一个超高压、大容量和跨区域的巨大的联合系统，电力系统事故具有突发性强、维持时间短、复杂程度高、破坏力大的特点，因而使得事后对故障原因分析、查找变得尤其
8、困难。由于在实际系统上进行试验和研究比较困难，因此借助各种电力系统动态仿真软件电力系统的设计和研究已成为有效途径之一。Matlab在电力系统建模和仿真的应用主要由电力系统仿真模块(Power System Blockset简称PSB)来完成。Power System Block是由TEQSIM公司和魁北克水电站开发的。PSB是在Simulink环境下使用的模块,采用变步长积分法,可以对非线性、刚性和非连续系统进行精确的仿真，并精确地检测出断点和开关发生时刻。PSB程序库涵盖了电路、电力电子、电气传动和电力系统等电工学科中常用的基本元件和系统仿真模型。通过PSB可以迅速建立模型，并立即仿真。PS
9、B程序块程序库中的测量程序和控制源起到电信号与Simulink程序之间连接作用。PSB程序库含有代表电力网络中一般部件和设备的Simulink程序块，通过PSB可以迅速建立模型，并立即仿真。二、电力系统模型电力系统中输送和分配电能的部分称为电力网,它包括升降压变压器和各种电压等级的输电线路 、动力系统、电力系统和电力网简单示意如图三、电力系统仿真模型的建立与分析电力系统仿真主要是对短路类型中的三相短路、两相短路和单相接地短路的电流、机端电压波形进行分析。利用Matlab软件中的电力系统模块库(PSB)，建立了模型，它对电力系统设备的设计和选用有一定的参考价值。同时电压电流波形可以直观的了解，便
10、于建立系统的观念。3.1 电力系统仿真模型题目要求：发电机G：50MW、13.8kV，保持恒定，Y连接；变压器T-1：13.8/220kv；线路L：100km，负荷LD：5MVA 。系统仿真模型如下：3.2 仿真参数设置各元件参数设置如下：(1) 发电机参数设置发电机额定容量为50MVA,额定电压为13.8KV，额定频率为60Hz，Yg连接，其它采用默认值。(2) 三相变压器参数设置额定频率为60Hz，一次侧电压13.8KV，二次侧电压220KV。其他采用默认值。(3) 三相输电线参数设置线路长100Km。(4) 负荷参数设置额定容量为50MVA。(5) 故障模块参数设置短路故障是用三相故障元
11、件来模拟的，故障时间段可通过Transition Times来设置，设置为0.010.05秒。其余的短路故障模型可以通过修改三相故障模块的参数设置来实现，将在以下仿真过程中进行设置。（a）三相交流电源G （b）三相测量元件 （c）三相双绕组变压器 T-1 （d）线路L （e）三相故障模块 （f）负荷LD3.3 仿真结果分析3.3.1正常运行分析正常运行时发电机输出端电压波形正常运行时发电机输出端电流波形分析：电力系统未发生短路故障时，发电机端的电压和电流均成正弦变化，三相交流电源的三相电压和电流之间相位不同，而幅值的大小是相同的。3.3.2单相接地短路故障分析将三相电路短路故障发生器中的“故障
12、相选择”选择A 相故障,并选择故障相接地选项,故障时间为0.010.05秒;在万用表元件中选择A 相、B 相和C 相电流作为测量电气量, 激活仿真按钮。（此处以A相接地短路为例）A相接地短路故障点三相电流：A相接地短路故障点三相电压：分析：当A相发生接地短路时故障点A相电压降为零，、非故障相即BC两相电压上升为线电压，其夹角为60。故障切除后各相电压水平较原来升高，这是中性点电位升高导致的。故障点各相电压：分析: 当输电线路发生A 相接地短路时,B 相、C 相电压没有变化。在正常状态时，三相短路故障发生器处于断开状态,A相电压也不变,不为0. 在0. 01s 时,三相短路故障发生器闭合,此时A
13、 相接地短路,其短路电压波形发生了剧烈的变化,电压降为0.在0. 05s时,三相短路故障发生器打开,故障排除,此时故障点A 相电压迅速恢复。故障点各相电流：分析：当输电线路发生A 相接地短路时,B 相、C 相电流没有变化,始终为0。在正常状态时，三相短路故障发生器处于断开状态,A相电流为0. 在0. 01s 时,三相短路故障发生器闭合,此时A 相接地短路,其短路电流波形发生了剧烈的变化,但大体上仍呈正弦规律变化.在0. 05s时,三相短路故障发生器打开,故障排除,此时故障点A 相电流迅速变为0。发生单相接地短路故障时发电机端电压波形：发生单相接地短路故障时发电机端电流波形：分析:当0.01秒时
14、发生单相接地短路,发电机端故障相电压下降,而两个非故障相电压未发生变化,发电机段故障相电流未发生变化,而两个故障相电流开始变化,振幅增大.0.05秒时,故障解除,发生变化的电压和电流迅速恢复到原来的幅值.3.3.3两相短路故障分析将三相电路短路故障发生器中的“故障相选择”选择A 相和B相故障,并选择故障相接地选项,故障时间为0.010.05秒;在万用表元件中选择A 相、B 相和C 相电流作为测量电气量, 激活仿真按钮。即发生A相和B相两相短路故障。（以AB两相短路为例）AB两相短路故障点三相电流：AB两相短路故障点三相电压：分析：在A、B两相发生短路故障时，非故障相C相电压波形幅值增大。A相和
15、B相电压降为0V。C相未发生故障,其短路电流为零.两相短路时,短路故障点电流中没有零序分量,而正序分量与负序分量大小相等但方向相反.故障点各相电压：分析:(选故障点A相观察)在稳态时，故障点A相电压由于三相电路短路故障发生器处于断开状态，因而电压为正弦变化。在0.01s时，三相电路短路故障发生器闭合，此时电路发生A、B两相短路，故障点A相电压发生变化，突变为0V。在0.05s时，三相电路短路故障发生器断开，相当于排除故障。此时故障点A相电压波动恢复正弦波形。故障点B相与A相近似.(选故障点C相观察)故障点C相: 在稳态时，故障点C相电压由于三相电路短路故障发生器处于断开状态，因而电压为正弦变化
16、幅值约为5000V。在0.01s时，三相电路短路故障发生器闭合，此时电路发生A、B两相短路， C相电压发生变化，突变为6000V。由图形可以得出以下结论：由于C相为非故障相，其电压波形仅在两相短路期间波的幅值变大，但是波形不变。故障点各相电流：分析：（选取故障点A相观察）在稳态时，故障点A相电流由于三相电路短路故障发生器处于断开状态，因而电流幅值为0A。在0.01s时，三相电路短路故障发生器闭合，此时电路发生A、B两相短路，故障点A相电流发生变化，由于闭合时有初始输入量和初始状态量，因而波形下移，呈正弦波形变化。在0.05s时，三相电路短路故障发生器断开，相当于排除了故障。此时故障点A相电流迅
17、速上升为0A。(选取故障点B相观察)：在稳态时，故障点B相电流由于三相电路短路故障发生器处于断开状态，因而电流为0A。在0.01s时，三相电路短路故障发生器闭合，此时电路发生A、B两相短路，故障点B相电流幅值发生变化，由于闭合时有初始输入量和初始状态量，因而波形上移，呈正弦波形变化。在0.05s时，三相电路短路故障发生器断开，相当于排除故障。此时故障点B相电流迅速下降为0A。 (选取故障点C相观察): 在A、B 发生两相短路时，故障点C相电流没有变化，始终为0A。同时也符合理论计算如式2-14可知。发生两相短路故障时发电机端电压：发生两相短路故障时发电机端电流：分析:当0.01秒时发生两相短路
18、,发电机端故障点两相电压幅值下降,而非故障相电压幅值增大一点,但并不多,发电机段故障点两相电流幅值增大,而非故障相电流幅值变化更大.0.05秒时,故障解除,发生变化的电压和电流迅速恢复到原来的幅值.3.3.4两相接地短路故障分析将三相短路故障发生器中“故障相选择”的A相和B 相选中,并选择故障相接地选项;在万用表元件中选择A 相、B 相和C 相电流作为测量电气量, 激活仿真按钮. （以AB两相接地故障为例）：AB两相接地故障点三相电流：AB两相接地故障点三相电压：故障点各相电压：分析：在A 相、B 相发生接地短路时,C 相电压没有变化,但不为0. 对于故障相A 相和故障相B 相电压:在稳态时,
19、故障点A 相、B 相电压由于三相短路故障发生器处于断开状态,因而电压不为0. 在0. 01s 时,三相短路故障发生器闭合,此时电路发生A 相、B 相接地短路,故障点A 相和B相电压变化,变为0. 在0. 05s 时,三相短路故障发生器打开,相当于排除故障,此时故障点A 相、B 相电压有迅速恢复.故障点各相电流：分析：在A 相、B 相发生接地短路时,C 相电流没有变化,始终为0. 对于故障相A 相和故障相B 相电流:在稳态时,故障点A 相、B 相电流由于三相短路故障发生器处于断开状态,因而电流为0. 在0. 01s 时,三相短路故障发生器闭合,此时电路发生A 相、B 相接地短路,故障点A 相电流
20、波形下移,故障点B 相电流波形上升,呈正弦规律变化. 在0. 04s 时,三相短路故障发生器打开,相当于排除故障,此时故障点A 相、B 相电流变化为0.发生两相接地短路故障时发电机端电压：发生两相接地短路故障时发电机端电流：分析:当0.01秒时发生两相接地短路,发电机端故障点两相电压幅值下降,而非故障相电压幅值增大一点,但并不多,发电机段故障点两相电流幅值增大,而非故障相电流幅值变化更大.0.05秒时,故障解除,发生变化的电压和电流迅速恢复到原来的幅值.但是比较两相短路不接地的情况,干扰更强一点3.3.5三相短路故障分析将三相短路故障发生器中“故障相选择”的三相故障3个都选中;在万用表元件中选
21、择A 相、B 相和C 相电流作为测量电气量. 激活仿真按钮。三相短路故障点三相电流：三相短路故障点三相电压：故障点各相电压：分析：在稳态时,故障相各相电压由于三相短路故障发生器处于断开状态,因而电压不为0. 在0. 01s 时,三相短路故障发生器闭合,此时电路发生三相短路,故障点各相电压发生变化,故障点各相电压都降为0. 在0. 05s 时,三相短路故障发生器打开,相当于排除故障,此时故障点各相电压迅速恢复.故障点各相电流：分析：在稳态时,故障相各相电流由于三相短路故障发生器处于断开状态,因而电流为0. 在0. 01s 时,三相短路故障发生器闭合,此时电路发生三相短路,故障点各相电流发生变化,
22、由于闭合时有初始输入量和初始状态量,因而故障点各相电流波形上升或者下降. 在0. 05s 时,三相短路故障发生器打开,相当于排除故障,此时故障点各相电流迅速下降为0.发生三相短路故障时发电机端电压：发生三相短路故障时发电机端电流：分析:当0.01秒时发生三相短路,发电机端故障点三相相电压幅值下降,发电机端故障点三相电流幅值增大.0.05秒时,故障解除,发生变化的电压和电流迅速恢复到原来的幅值.四、结论在所给的电力系统中K处选取了不同的故障类型(三相短路、单相接地短路、两相短路、两相接地短路)进行仿真，比较仿真结果，结果表明运用Matlab对电力系统故障进行分析与仿真，能够准确直观地考察电力系统
23、故障的动态特性，验证了Matlab在电力系统仿真中的强大功能。 五、参考文献待添加的隐藏文字内容11.于永源，杨绮雯.电力系统稳态分析M中国电力出版社，2007. 2.王晶，翁国庆，等. 电力系统分析的MATLAB/SIMULINK仿真与应用. 西安电子科技大学出版社. 2008. 3.刘卫国. MATLAB程序设计与应用M. 北京：高等教育出版社，2008.六、心得体会通过本次课程设计的实训,我对电力系统故障以及Matlab软件有了更深的认识。但由于在校期间学习不扎实，以及实践经验的缺乏，在实训过程中有很多地方还需要好好阅读资料以及课本.但是经过这次实训,让自己的动手能力加强了,并对所学习的
24、课本知识进行了巩固,这对于我来说是很好的一次机会,也让我更好的学习了这种仿真软件的使用以及特点和方法.Employment tribunals sort out disagreements between employers and employees.You may need to make a claim to an employment tribunal if: you dont agree with the disciplinary action your employer has taken against you your employer dismisses you and yo
25、u think that you have been dismissed unfairly.For more information about dismissal and unfair dismissal, seeDismissal.You can make a claim to an employment tribunal, even if you haventappealedagainst the disciplinary action your employer has taken against you. However, if you win your case, the trib
26、unal may reduce any compensation awarded to you as a result of your failure to appeal.Remember that in most cases you must make an application to an employment tribunal within three months of the date when the event you are complaining about happened. If your application is received after this time
27、limit, the tribunal will not usually accept it.If you are worried about how the time limits apply to you, take advice from one of the organisations listed underFurther help.Employment tribunals are less formal than some other courts, but it is still a legal process and you will need to give evidence
28、 under an oath or affirmation.Most people find making a claim to an employment tribunal challenging. If you are thinking about making a claim to an employment tribunal, you should get help straight away from one of the organisations listed underFurther help.If you are being represented by a solicito
29、r at the tribunal, they may ask you to sign an agreement where you pay their fee out of your compensation if you win the case. This is known as adamages-based agreement. In England and Wales, your solicitor cant charge you more than 35% of your compensation if you win the case.If you are thinking ab
30、out signing up for a damages-based agreement, you should make sure youre clear about the terms of the agreement. It might be best to get advice from an experienced adviser, for example, at a Citizens Advice Bureau. To find your nearest CAB, including those that give advice by e-mail, click onnearest
31、 CAB.For more information about making a claim to an employment tribunal, seeEmployment tribunals.The (lack of) air up there Watch mCayman Islands-based Webb, the head of Fifas anti-racism taskforce, is in London for the Football Associations 150th anniversary celebrations and will attend Citys Prem
32、ier League match at Chelsea on Sunday.I am going to be at the match tomorrow and I have asked to meet Yaya Toure, he told BBC Sport.For me its about how he felt and I would like to speak to him first to find out what his experience was.Uefa hasopened disciplinary proceedings against CSKAfor the raci
33、st behaviour of their fans duringCitys 2-1 win.Michel Platini, president of European footballs governing body, has also ordered an immediate investigation into the referees actions.CSKA said they were surprised and disappointed by Toures complaint. In a statement the Russian side added: We found no
34、racist insults from fans of CSKA.Age has reached the end of the beginning of a word. May be guilty in his seems to passing a lot of different life became the appearance of the same day; May be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been very m
35、essy, in my mind constantly. Always feel oneself should go to do something, or write something. Twenty years of life trajectory deeply shallow, suddenly feel something, do it.一字开头的年龄已经到了尾声。或许是愧疚于自己似乎把转瞬即逝的很多个不同的日子过成了同一天的样子；或许是追溯过去，对自己那些近乎偏执的怪异信念的醒悟，这些天以来，思绪一直很凌乱，在脑海中不断纠缠。总觉得自己自己似乎应该去做点什么，或者写点什么。二十年的
36、人生轨迹深深浅浅，突然就感觉到有些事情，非做不可了。The end of our life, and can meet many things really do?而穷尽我们的一生，又能遇到多少事情是真正地非做不可？During my childhood, think lucky money and new clothes are necessary for New Year, but as the advance of the age, will be more and more found that those things are optional; Junior high school
37、, thought to have a crush on just means that the real growth, but over the past three years later, his writing of alumni in peace, suddenly found that isnt really grow up, it seems is not so important; Then in high school, think dont want to give vent to out your inner voice can be in the high schoo
38、l children of the feelings in a period, but was eventually infarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown a basketball hoops, suddenly found himself has already cant remember his appearance.童年时，觉得压岁钱和新衣服是过年必备，但是随着年龄的推进，会越来越
39、发现，那些东西根本就可有可无；初中时，以为要有一场暗恋才意味着真正的成长，但三年过去后，自己心平气和的写同学录的时候，突然就发现是不是真正的成长了，好像并没有那么重要了；然后到了高中，觉得非要吐露出自己的心声才能为高中生涯里的懵懂情愫划上一个句点，但毕业晚会的时候最终还是被梗塞在了咽喉，后来再次站在他曾经挥汗如雨的球场，看着他投过篮球的球框时，突然间发现自己已经想不起他的容颜。Originally, this world, can produce a chemical reaction to an event, in addition to resolutely, have to do, an
40、d time.原来，这个世界上，对某个事件能产生化学反应的，除了非做不可的坚决，还有，时间。A persons time, your ideas are always special to clear. Want, want, line is clear, as if nothing could shake his. Also once seemed to be determined to do something, but more often is he backed out at last. Dislike his cowardice, finally found that there
41、are a lot of love, there are a lot of miss, like shadow really have been doomed. Those who do, just green years oneself give oneself an arm injection, or is a self-righteous spiritual.一个人的时候，自己的想法总是特别地清晰。想要的，不想要的，界限明确，好像没有什么可以撼动自己。也曾经好像已经下定了决心去做某件事，但更多的时候是最后又打起了退堂鼓。嫌恶过自己的怯懦，最终却发现有很多缘分，有很多错过，好像冥冥之中真的
42、已经注定。那些曾经所谓的非做不可，只是青葱年华里自己给自己注射的一支强心剂，或者说，是自以为是的精神寄托罢了。At the moment, the sky is dark, the air is fresh factor after just rained. Suddenly thought of blue plaid shirt; Those were broken into various shapes of stationery; From the corner at the beginning of deep friendship; Have declared the end of t
43、he encounter that havent start planning. Those years, those days of do, finally, like youth, will end in our life.此刻，天空是阴暗的，空气里有着刚下过雨之后的清新因子。突然想到那件蓝格子衬衫；那些被折成各种各样形状的信纸；那段从街角深巷伊始的友谊；还有那场还没有开始就宣告了终结的邂逅计划那些年那些天的非做不可，终于和青春一样，都将在我们的人生中谢幕。Baumgartner the disappointing news: Mission aborted. r plays an imp
44、ortant role in this mission. Starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weat
45、her lives. It will climb higher than the tip of Mount Everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. As he crosses the boundary layer (called the tropopause),e can expect a lot of tur
46、bulence.The supersonic descent could happen as early as Sunda.The weatheThe balloon will slowly drift to the edge of space at 120,000 feet ( Then, I would assume, he will slowly step out onto something resembling an Olympic diving platform.Below, the Earth becomes the concrete bottom of a swimming p
47、ool that he wants to land on, but not too hard. Still, hell be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end. Skydiver preps for the big jumpWhen he jumps, he is expected to reach the speed of sound - 690 mph (1,110 kph) - in less than 40 seconds. Like hitting the top of the water, he will begin to slow
