电力系统概述

1、电力系统分析 课程Instructor: (87603153, ) Instructors Assistant: （87600948， ）12007-4-9 电力系统概述 2 参考教材韩祯祥主编，电力系统分析，浙江大学出版社,2005.12第3版 陈珩编著，电力系统稳态分析，水利电力出版社,1995.11第2版 J. Duncan Glover, Mulukutla S. Sarma，Power system analysis and design，3rd ed ，Thomson Learning, 2002 （电力系统分析与设计，英文版，机械工业出版社，2004，7 ） 22007-4-9

2、电力系统概述 3 本学期课程的主要内容 电力系统概述 电力系统元件参数和等值电路、电力网络数学模型 简单和复杂电网潮流计算 对称分量法、电力系统三相短路实用计算、不对称短路故障分析 32007-4-9 电力系统概述 4 电力系统概述电力系统历史和现状 电力系统的电压等级和额定电压 电力系统中性点接地方式 电力系统发展趋势 电力系统的关键技术 42007-4-9 电力系统概述 5 早期电力系统发展的历程碑1882年，爱迪生创立了Pearl St. Station 1882年，德国建立第一条输电线路, 15002000V dc， 59km，输电效率25% 1884年，Frank J Sprague

3、 produced dc 电动机 1885年，William Stanley发明了商用的变压器 1888年，俄国人多布洛奥斯基发明三相交流制和效率很高的三相异步电动机。 1891年，德国建立了世界第一条三相交流高压输变电系统，12kV,175km输电线路,输电效率达到80%52007-4-9 电力系统概述 6 电力系统构成G M M 电力网电力系统动力系统 发电厂 水轮机 发电机升压变压器输电线路降压变压器用户 用电设备62007-4-9 电力系统概述 7 电力系统构成72007-4-9 电力系统概述 8 电力系统构成电力网：变压器和不同电压等级输电线路组成的网络 电力系统：发电机、电力网及用

4、电设备 动力系统：电力系统+发电厂的动力部分 （火力发电厂的锅炉、汽轮机和水力发电厂的水库、水轮机以及核动力发电厂的反应堆等）82007-4-9 电力系统概述 9 Geographic map of regional power in China NC: North China华北; EC: East China华东; CC: Central China华中; SC: South China南方; NW: Northwest China西北; NE: Northeast China东北 新疆、西藏、山东和海南92007-4-9 电力系统概述 10 发电厂利用自然界蕴藏的各种能源来生产电能。按所

5、使用能源的不同，发电厂可以分为：火力、水力、原子能、地热、潮汐、风力以及太阳能发电厂等。目前在电力系统中起主导作用的是火力、水力和原子能发电厂 102007-4-9 电力系统概述 11 能量转换过程水力发电厂 利用水流的动能和势能来生产电能。水驱动水轮机转动，与水轮机直接相连的发电机将机械能转换成电能。水能机械能电能 火力发电厂 利用煤、石油、天燃气或其它燃料所产生的热能,在锅炉中将水变成高温高压蒸汽,推动汽轮机,带动发电机发电。化学能热能机械能电能 原子能发电厂 利用核燃料在反应堆中产生的热能, 将水变成高温高压蒸汽,推动汽轮机,带动发电机发电。核能机械能电能 112007-4-9 电力系统

6、概述 12 最大的发电机组和发电厂汽轮发电机组:130万千瓦(US)；中国60万千瓦 火电厂: 6台80万千瓦(俄罗斯)；江苏 162.5万千瓦 水轮发电机组:70万千瓦(US)；中国70万千瓦 水电厂: 18台70万千瓦(巴西)；三峡预计26台70万=1820万千瓦，2010年全部建成投产,将是世界最大的水电厂 核电机组: 130万千瓦(前苏联)；秦山30万千瓦 核电厂: 454.6万千瓦(日本)；大亚湾2台90万千瓦122007-4-9 电力系统概述 13 电力传输电压传输相同功率的电力,电压越高输电损耗越小,但是电压越高,输变电设备的绝缘要求要求增高.因此要综合考虑 计算输电电压的Sti

7、ll公式，因此线路越长，传输功率越大，要求的传输电压越高.132007-4-9 电力系统概述 14 交流电力传输输电系统采用3相3线制 产生交流电动机需要的旋转磁场 相同电压时,每条线路传输的功率是单向2线制的1.15倍 可以获得单相交流电 低压配电系统采用3相4线制142007-4-9 电力系统概述 15 直流电力传输直流输电优点 相同电压有效值时，有利于绝缘 线路电感为零，无无功功率，损耗小 无电容电流，不产生介质损耗，有利于电缆输电 传输容量不受稳定极限的限制 一般架空线路500700km以上，电缆3040km以上可以考虑采用直流输电 直流输电电压变换难以实现,切断直流比交流难 常采用单

8、极和双极方式152007-4-9 电力系统概述 16 输电技术的发展输电技术发展的特点是努力减少线路损失，经济合理的减少线损的方法是提高输电电压，输电技术的全部发展史就是持续不断地提高电压等级，同时提高输送功率和输送距离，解决线路走廊问题（美国条765kV线路的输送能力相当于条345kV线路，而所需走廊宽度分别为60m 和225m) 提高输电电压，与线路，变压器和断路器等的绝缘密切相关162007-4-9 电力系统概述 17 高压架空输电线路1898 年美国33kV 120km输电线路,针式绝缘子 1906年美国发明悬式绝缘子(11500kV)，1908和 1923 年分别建成110kV和22

9、0kV输变电工程 1959年前苏联500 kV输变电工程 1965年加拿大760 kV输变电工程 1985年前苏联1150kV输变电工程（降压运行） 19101914美国和前苏联科学家发现电晕临界电压与导线直径成比例,促使了铝线，钢芯铝绞线，扩经或分裂导线的使用172007-4-9 电力系统概述 18 高压电缆线路1879年，爱迪生，铜棒上绕包黄麻穿入铁管，纽约地下输电1908年，英国20kV1911年，德国60kV1965年，美国345kV1970年，500kV直流电缆 聚乙烯绝缘电缆275kV;油侵纸质绝缘电缆275kV;高压油管式电缆182007-4-9 电力系统概述 19 电压等级与输

10、配电网络电压等级(线路及用电设备额定电压): 3kV, 6kV, 10kV, 35kV, 110kV, 220kV, 330kV, 500kV, 735kV,1000kV 输电网:220kV级以上主干电力线路 二级输电网: 110kV 220kV,连接区域性的发电厂和大用户 高压配电网: 6kV 35kV 低压配电网: 1kV及以下电网络 192007-4-9 电力系统概述 20 设备额定电压设定的基本原则用电设备额定电压系统额定电压Ue 发电机的额定电压105%Ue 变压器一次绕组 Ue - 105% Ue 变压器二次绕组 105% -110% Ue202007-4-9 电力系统概述 21

11、3kV及以上系统的额定电压212007-4-9 电力系统概述 22 电力系统中性点(接地)运行方式有效接地系统或大接地电流系统。过电压水平和输变电设备所需的绝缘水平较低，但是系统发生单相接地短路故障时短路电流很大, 用于220kV及以上的电力系统中 非有效接地系统或小接地电流系统发生单相接地短路故障时短路电流很小，故障相对地电压降为零；非故障相对地电压升高为线电压其值主要由电容电流组成, 用于60 kV及以下的配电系统中 222007-4-9 电力系统概述 23 电能质量频率 额定频率：50Hz 频率偏差和延时时间：0.2Hz，延时小于30分钟， 电压 电压偏差：36kV及以上：正负偏差的绝对

12、值之和小于额定电压的10%；220V：额定电压的+7%、-10% 三相平衡度：2% 波形 正弦波电压和电流有谐波畸变率的限制232007-4-9 电力系统概述 24 电力系统基本任务和运行特点 运行特点 电能不能大规模储存 过渡过程很短 发输配电自动化 高可靠性要求 基本任务 保证供电可靠 保证良好的电能质量 提高电力系统运行经济性242007-4-9 电力系统概述 25 我国电力系统发展-发电装机容量 1996年我国发电总装机容量23654.2万千瓦, 占世界第二位，核电比例占0.9% (比较：美国78350， 日本23373.7 ，俄罗斯21085.7，,加拿大11361.2万千瓦， 分别

13、列1、3 、4、,5位，核电均占10%以上) 我国电力工业的超常规发展，年投资500亿以上，20年增长约4.9倍 1981: 6913万千瓦 1991: 15147万千瓦,十年增长8234万千瓦 2001:33861万千瓦,十年增长18714万千瓦252007-4-9 电力系统概述 26 我国输变电网络建设1981年底，我国第一项自行施工设计的500kV平武输变电工程建成投产。截至2000年底，500kV线路总长26837km，变电容量9447kVA。 已构成我国电网的骨干网络 1990，我国第一项+/-500kV直流输电工程线路双极建成投产，将华东,华中两大电网联在一起,标志着我国进入大电网

14、、大机组、交直流高压输电的新阶段 从装机容量密度和线路承载度来评价,我国电网特别是500kV电网结构与发达国家相比,有较大差距.262007-4-9 电力系统概述 27 世界电力工业的发展趋势世界发电量的年增长率趋缓，而一些发展中国家，特别是亚洲国家仍维持较高的电力增长速度 电力技术的发展向效率、环保的更高目标迈进 电业管理体制和经营方式发生变革，由垄断经营逐步转向市场开放 27Chinas Future in Electric Energy Fast-Growing Chinas PowerDevelopments and Challenges By Felix F. Wu and Shut

15、i Fu 282007-4-9 电力系统概述 29 IntroductionIn just a quarter century, chinas economy has transformed itself from a relatively closed agriculture based system to a market-oriented system with World Trade Organization membership and a reputation as the manufacturing capital of the world. Recent expansion i

16、n electric generation and transmission has been phenomenal. China now ranks second in the world in terms of installed generation capacity and electricity production. 292007-4-9 电力系统概述 30 Electricity Supply in China Since the economic reform in 1980, China has experienced unprecedented economic growt

17、h. The energy intensity, measured in terms of energy consumption in kilogram of coal equivalent per economic output in dollar of Chinese yuan, dropped from 1.33 to 0.46. 302007-4-9 电力系统概述 31 GDP in billions of U.S. dollars, 312007-4-9 电力系统概述 32 Percentage share of electricity in total energy consump

18、tion.322007-4-9 电力系统概述 33 The installed generation capacity in China has reached 440.7 GW at the end of 2004, with annual production of 2,187 trillion Wh, making it the second highest in the world. At present, about 75% of generation is from thermal power plants, 25% from hydro power plants, and a v

19、ery small percentage (0.4%) from nuclear. Figure 3 depicts the trend in annual installed generation capacity and production since 1980. 332007-4-9 电力系统概述 34 Total installed generation capacity in GW (read columns) and annual electricity production in 10 trillion Wh (blue columns)342007-4-9 电力系统概述 35

20、 However, it lags far behind in terms of per capita electricity consumption. Indeed, with roughly 1,000 kWh per capita per annum, China is still in the category of a developing country. 352007-4-9 电力系统概述 36 Challenges in Electricity Supply Per capita annual electricity consumption in China today is

21、roughly 1,000 kWh, compared with more than 5,000 kWh in Hong Kong and over 12,000 kWh in the United States. The number will definitely rise as Chinas economy continues to grow and peoples standard of living further improves. Some forecasts put the installed generating capacity at a level of 950 to 1

22、,000 GW by the year 2020, or 250% of today. 362007-4-9 电力系统概述 37 The governments diversification plan calls for a reduction in the dependency on coal generation, which has a significant adverse environmental impact, from 75% today to 65% by 2020, upholding hydro generation at around the present perc

23、entage level and increasing more environmentally benign gas generation to 6%, nuclear to 34%, and renewables to 2%. 372007-4-9 电力系统概述 38 China is endowed with large hydro potential; it is estimated that the exploitable hydro capacity is 378 GW, ranked first in the world. The government has an aggres

24、sive plan to develop hydro generation from the present 108 GW to 260 GW by 2020 (thus upholding hydro at 25% of the total generation capacity). The most famous hydro power project under construction, which will become the largest such plant in the world, is the Three Gorges. Three Gorges, due for co

25、mpletion in 2009, will consist of 26 generators of 700 MW each, or a total of 18.2 GW. 382007-4-9 电力系统概述 39 China is endowed with large hydro potential; it is estimated that the exploitable hydro capacity is 378 GW, ranked first in the world. The government has an aggressive plan to develop hydro ge

26、neration from the present 108 GW to 260 GW by 2020 (thus upholding hydro at 25% of the total generation capacity). The most famous hydro power project under construction, which will become the largest such plant in the world, is the Three Gorges. Three Gorges, due for completion in 2009, will consis

27、t of 26 generators of 700 MW each, or a total of 18.2 GW. 392007-4-9 电力系统概述 40 China is endowed with large hydro potential; it is estimated that the exploitable hydro capacity is 378 GW, ranked first in the world. The government has an aggressive plan to develop hydro generation from the present 108

28、 GW to 260 GW by 2020 (thus upholding hydro at 25% of the total generation capacity). The most famous hydro power project under construction, which will become the largest such plant in the world, is the Three Gorges. Three Gorges, due for completion in 2009, will consist of 26 generators of 700 MW

29、each, or a total of 18.2 GW. 402007-4-9 电力系统概述 41 China is endowed with large hydro potential; it is estimated that the exploitable hydro capacity is 378 GW, ranked first in the world. The government has an aggressive plan to develop hydro generation from the present 108 GW to 260 GW by 2020 (thus u

30、pholding hydro at 25% of the total generation capacity). The most famous hydro power project under construction, which will become the largest such plant in the world, is the Three Gorges. Three Gorges, due for completion in 2009, will consist of 26 generators of 700 MW each, or a total of 18.2 GW.

31、412007-4-9 电力系统概述 42 Beginning in 2002, China intensified legal construction on environment protection and resources conservation and launched a series of rules and regulations for levying pollutant discharge fees, emission standards of air pollution for thermal power plants, standards on water extr

32、action quotas, etc. Power plants are beginning to use clean coal technology to reduce SO2 and NOX. 422007-4-9 电力系统概述 43 According to some statistics, the average cost of products per kWh of energy in China is still three times higher than the world average and ten times higher than in the United Sta

33、tes. There is a lot of room for energy conservation. 432007-4-9 电力系统概述 44 For example, air-conditioning load constitutes about 30% of the summer load in Beijing; considerable energy may be saved by improving air-conditioning efficiency. China has recently conducted several demand-side management (DSM) studies, all with positive conclusions. Experimental peak load pricing is being conducted. The government has succ