文档库 最新最全的文档下载
当前位置:文档库 › 上海交大电力专业英语试卷

上海交大电力专业英语试卷

上海交大电力专业英语试卷
上海交大电力专业英语试卷

I. Translation of Terms (Total 40 points)

A. Find the Chinese Counterparts of English Terms (Subtotal20 points, 20 questions, 1 point per question)

EMC: electromagnetic compatibilty

EMI: electromagnetic interference

EMS: electromagnetic susceptibility /sensibility

EMF: electromagnetic force

EMF: electromotive force

B. Find the English Counterpart of Chinese Terms

(Subtotal10 points, 20 questions, 1 point per question)

II. Fill in Blanks with an appropriate option

( Total 10 points, 10 questions, 1 point per question)

1. SOM-5780 provides the highest available performance on the smallest

embedded module nowadays, while SOM-5780's modular design concept lowers the total cost of ownership (TCO) for customers. (ordinary, state-of-the-art, outdated, backward)

2. The use of biomass can dependence on foreign oil,because biofuels

are the only renewable liquid transportation fuels available. (decrease, reduce, increase, keep)

3. The rotor is made to turn smoothly jets of steam from nozzles around the periphery of the turbine cylinder. (to make use of, in terms of ,by means of, according to)

4. There are other possible sources of energy direct solar, wind power, tidal power, etc., but none of these has yet gone beyond the pilot-plant stage. (such as, for example, unlike, like)

5. Geothermal energy is an enormous, heat and power resource that is clean (emits little or no greenhouse gases.), reliable (average system availability of 95%), and homegrown (making us less dependent on foreign oil). (overutilized, overuse, out of use, underuse)

6. Geothermal resources range from shallow ground to hot water and rock several miles below the earth’s surface, and even down to the extremely hot molten rock called magma. (farther, extra, further, far)

7. Biomass can be used for fuels, power production, and products that would

be made from fossil fuels. (likewise, otherwise, differently, likely)

8. Binary cycle plants, which pass moderately hot geothermal water by a secondary fluid with a much boiling point than water. (higher, lower, medium, large)

9. Ocean covers more than 70% of earth’s surface, making them the world’s largest solar collectors. The sun’s heat the surface water a lot more than the deep ocean water, and this temperature difference creates thermal energy. (warms, burns, cools, boils)

10. Biomass, on the other hand, release carbon dioxide that is balanced by the carbon dioxide captured in its own growth (depending how much energy was used to grow, harvest, and process the fuel) ( mostly, largely, mainly, nearly)

III. Fill in Blanks with appropriate pronunciations for mathematical expressions (Total 10 points, 10 questions, 1 point per question)

1. 42

: ;

5

2. ..

7.069: ;

3. ;

4. 10log x : ;

5. x : ;

6. 222100x y z ++=: ;

7. ()a b c +=: ;

8. ()y f x =: ;

9. 22d y dx : ; 10. ()b

a f x dx ? : ;

IV. Explain the following special terms in a or two sentences

(Total 10 points, 10 questions, 1 point per question)

1. Circuit Power Factor(PF): ;

2. Total harmonic distortion(THD): ;

3. Partial Weighted Harmonic Distortion (PWHD ): ;

4. Displacement Factor(DF): ;

5. Distortion Factor (Dist.F): ;

6. Capacitance: ;

7. Electromagnetic compatibility (EMC) : ;

8. Short-Circuit Power : ;

9. Interphase Equipment:

;

10. Short-Circuit Ratio:

; V. Reading and Comprehension for the following five short passages

(Total 10 points, 5 questions, 2 point per question)

Solar energy

Photovoltaic (solar cell) systems convert sunlight directly into electricity. A solar or PV cell consists of semi-conducting material that absorbs the sunlight. The solar energy knocks electrons loose from their atoms, allowing the electrons to slow through the material to produce electricity. PV cells are typically combined into modules are mounted in PV array. PV arrays can be used to generate electricity for a single building or, in large numbers, for a power plant. A power plant can also use a concentrating solar power system, which uses the sun’s heat to generate electricity. The sunlight is collected and focused with mirrors to create a high-intensity heat source. This heat source produces steam or mechanical power to run a generator that creates electricity.

1. Write down the provided two approaches to use solar energy.

Geothermal

Geothermal resources range from shallow ground to hot water and rock several mils below the Earth’s surface, and even farther down to the extremely hot molten rock called magma. Mile-or-more-deep wells can be drilled into underground reservoirs to tap steam and very hot water that can be brought to the surface for use in a variety of applications.

2. Write down one of the possible titles.

Hydrogen

Fill vehicle fuel tanks with it instead of gasoline. Pipe it to homes for heating and cooling instead of natural gas, and to generate electricity on site instead of sending electricity through transmission lines. And emit only water vapor where it is used. Fuel

cells unit that electrochemically combine hydrogen and oxygen to produce electricity and heat offer the promise of making hydrogen an ideal universal fuel. Make that an ideal energy carrier scaler rather than a fuel, because while hydrogen does grow on trees and fall with the rain, it does not happen occur naturally by itself. It cannot be mined or harvested. But other energy sources can be used to make hydrogen, and then the hydrogen transported or stored for use where and when needed.

3. Write down the reason(s) for clean energy resource for Hydrogen.

Biomass energy

We have used biomass energy or “bioenergy”-the energy from plants and plant-derived materials-since people began burning wood to Cook food and keep warm. Wood is still the largest biomass energy resource today, but other sources of biomass can also be used. These include food crops, grassy and woody plants, residues from agriculture or forestry, and the organic component of municipal and industrial wastes. Even the fumes from landfills (which are methane, a natural gas) can be used as a biomass energy source.Biomass can be used for fuels, power production, and products that would otherwise be made from fossil fuels.

4. Write down the available applications of biomass energy.

Ocean mechanical energy

Ocean mechanical energy is quite different from ocean thermal energy. Even though即使the sun affects all ocean activity, tides are driven primarily by the gravitational pull of the moon, and waves are driven primarily by the winds. As a result, tides and waves are intermittent sources of energy, while ocean thermal energy is fairly constant/variable . Also, unlike thermal energy, the electricity conversion of both tidal and wave energy usually involves mechanical devices/components.

5. Write down the difference between tide energy and wave energy for ocean mechanical energy.

VI. Translate the following paragraphs into English

(Total 10 points, 5 questions, 2 point per question)

6.1地热geothermal就是从地球内热获取的一种能源,可以用于各种各样的用途,包括发电、建筑物的制热和制冷等。

6.2绝大部分可再生能源或直接或间接取自太阳。当然并非所有的可再生能源都来自太阳。

6.3另外,海洋的潮汐能来源于月亮与太阳对地球的万有引力gravitational pull。与其他可再生能源不同,生物质/量可以直接转化为液体燃料,即生物燃料。

6.4 光伏(太阳能电池)系统能够将阳光直接转化为电。太阳能或光伏电池由能够吸收阳光的半导体材料构成。

6.5 海洋能够产生两种类型的能量:来自太阳发热的热能,来自潮汐与波浪的机械能。海洋机械能与海洋热能有很大的不同.

VII. Translate the provided paragraphs into Chinese (select 5 and only 5 of them) (Total 10 points, 10 questions, 2 point per question)

7.1 The use of the voltage/frequency (V/F) converter in digital voltmeters and data loggers has lead to the development of a wide range of units.

7.2 A further advantage is that the technique is easily adaptable to those installations where complete physical and/or electrical isolation is required.

7.3 The simple circuit requires considerable modification to produce a linear output with minimum changes in pulse rate, due to temperature changes.

7.4 By measuring the time between pulses this problem is not so acute, but some of the advantages of the V/F technique are lost, i.e. the high noise rejection.

7.5 The basic circuit of a V/F converter, which produces pulses proportional to voltage input, is shown in Fig.2, where each pulse will have the same width and height.

7.6 Distribution includes all the parts of the electricity systems between the power

sub-stations supplied from high-voltage transmission lines and the consumers’ switch.

7.7 Electric power is received from sub-stations and distributed to the consumers at the voltage levels and with the degree of continuity that are acceptable to the various types of consumer.

7.8 Transmission lines are generally protected by distance relays. These relays provide high-speed primary protection along with slower speed backup protection.

7.9 Backup protection is provided by zone-2 distance relays that are set to reach a fixed percentage of the shortest line emanating from the remote bus. The remaining part of the lines emanating from the remote bus is generally protected by zone-3 relays.

7.10 With the deployment of microprocessor-based relays having communication capabilities, it is now possible to develop and implement adaptive protection systems.

7.11 In these systems, the relay settings can be automatically adjusted for making the protection more attuned 协调to the prevailing system conditions.

6.12 In transmission line, if the distance, the power and the power line loss are fixed, the total weight of the conductor varies inversely as the square of the transmission voltage.

7.13 For the economic transmission of power over considerable distances, the voltage must be high. Naturally with higher voltages the insulation cost also rises.

7.14 Ocean thermal energy is used for many applications, including electricity generation. There are three types of electricity conversion systems: closed-cycle, open-cycle, and hybrid-cycle.

7.15 Biodiesel 生物柴油is made by combining alcohol 酒精with vegetable oil, animal fat, or recycled cooking grease. It can be used as an additive to reduce vehicle emissions or in its pure form as a renewable alternative fuel for diesel engines.

上海交通大学英语水平考试样题及答案

上海交通大学英语水平考试样题 Part II Integrated Reading (30%) Section 1 Banked Cloze (10%) Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. You may not use any of the words in the bank more than once. Give your answers to the questions on your ANSWER SHEET. Attention:You need to change the forms of the words in the word bank where necessary. (注意:请把答案写在答题卷上,否则以零分处理) A name might tell you something about a person's background. Names can be 1) __________ of class and race. Data show African Americans are far more likely than other 2) __________ groups to give their children uncommon names. White people tend to 3) ________ more familiar names that were formerly popular with more affluent white people. The new study purports to show a link between name and outcome of life: The more 4) _________ your name, the more likely you are to land in juvenile hall. That's because we know that boys with uncommon names are more likely to come from a socio-economically 5) _________ background, which means that they also are more likely to get involved with crime. Even the researchers readily admit that it's not a name alone that 6)_______ a child's outcome, but rather the circumstance underlying the name. The researchers first assigned a popularity score to boys' names, based on how often they showed up in birth records in an undisclosed state from 1987 to 1991. Michael, the No. 1 boy's name, had a Popular Name Index score of 100; names such as Malcolm and Preston had index scores of 1. The researchers then assessed names of young men born during that time who landed in the juvenile justice system. They found that only half had a rating higher than 11. By 7) __________, in the general population, half of the names scored higher than 20. "A 10% increase in the popularity of a name is associated with a 3.7% 8) _________ in the number of juvenile delinquents who have that name." Still, the study theorizes that teenagers named Malcolm might also 9) ___________ because their peers treat them differently or they just don't like their names. And since the study's release last week, the name-crime 10) ___________ has been written or talked about in major media outlets. Section 2 True or False Judgement & Sentence Completion (10%) Directions:In this part, you will find 7 statements and 3 incomplete sentences followed by the reading passage. For questions 1-7, mark Y (for YES) if the statement agrees with the information given in the passage; N (for NO) if the statement contradicts the information given in the passage; For questions 8-10, complete the sentences with the information given in the passage. Attention: For questions 1-7, one more point will be deducted if you do n’t answer

《数值计算方法》试题集及答案

《数值计算方法》复习试题 一、填空题: 1、????? ?????----=410141014A ,则A 的LU 分解为 A ??? ?????????=? ?????????? ?。 答案: ?? ????????--??????????--=1556141501 4115401411A 2、已知3.1)3(,2.1)2(,0.1)1(===f f f ,则用辛普生(辛卜生)公式计算求得 ?≈3 1 _________ )(dx x f ,用三点式求得≈')1(f 。 答案:, 3、1)3(,2)2(,1)1(==-=f f f ,则过这三点的二次插值多项式中2 x 的系数为 , 拉格朗日插值多项式为 。 答案:-1, )2)(1(21 )3)(1(2)3)(2(21)(2--------= x x x x x x x L 4、近似值*0.231x =关于真值229.0=x 有( 2 )位有效数字; 5、设)(x f 可微,求方程)(x f x =的牛顿迭代格式是( ); ( 答案 )(1)(1n n n n n x f x f x x x '--- =+ 6、对1)(3 ++=x x x f ,差商=]3,2,1,0[f ( 1 ),=]4,3,2,1,0[f ( 0 ); 7、计算方法主要研究( 截断 )误差和( 舍入 )误差; 8、用二分法求非线性方程 f (x )=0在区间(a ,b )内的根时,二分n 次后的误差限为 ( 1 2+-n a b ); 9、求解一阶常微分方程初值问题y '= f (x ,y ),y (x 0)=y 0的改进的欧拉公式为

( )] ,(),([2111+++++=n n n n n n y x f y x f h y y ); 10、已知f (1)=2,f (2)=3,f (4)=,则二次Newton 插值多项式中x 2系数为( ); 11、 两点式高斯型求积公式?1 d )(x x f ≈( ?++-≈1 )] 321 3()3213([21d )(f f x x f ),代数精 度为( 5 ); 12、 解线性方程组A x =b 的高斯顺序消元法满足的充要条件为(A 的各阶顺序主子式均 不为零)。 13、 为了使计算 32)1(6 )1(41310-- -+-+ =x x x y 的乘除法次数尽量地少,应将该表 达式改写为 11 ,))64(3(10-= -++=x t t t t y ,为了减少舍入误差,应将表达式 19992001-改写为 199920012 + 。 14、 用二分法求方程01)(3 =-+=x x x f 在区间[0,1]内的根,进行一步后根的所在区间 为 ,1 ,进行两步后根的所在区间为 , 。 15、 、 16、 计算积分?1 5 .0d x x ,取4位有效数字。用梯形公式计算求得的近似值为 ,用辛卜 生公式计算求得的近似值为 ,梯形公式的代数精度为 1 ,辛卜生公式的代数精度为 3 。 17、 求解方程组?? ?=+=+042.01532121x x x x 的高斯—塞德尔迭代格式为 ?????-=-=+++20/3/)51()1(1)1(2)(2)1(1 k k k k x x x x ,该迭 代格式的迭代矩阵的谱半径)(M ρ= 121 。 18、 设46)2(,16)1(,0)0(===f f f ,则=)(1x l )2()(1--=x x x l ,)(x f 的二次牛顿 插值多项式为 )1(716)(2-+=x x x x N 。 19、 求积公式 ?∑=≈b a k n k k x f A x x f )(d )(0 的代数精度以( 高斯型 )求积公式为最高,具 有( 12+n )次代数精度。

西安交通大学计算方法B上机报告

计算方法上机报告

姓名: 学号: 班级:能动上课班级:

题目及求解: 一、对以下和式计算: ∑ ∞ ? ?? ??+-+-+-+=0681581482184161n n n n S n ,要求: ① 若只需保留11个有效数字,该如何进行计算; ② 若要保留30个有效数字,则又将如何进行计算; 1 算法思想 (1)根据精度要求估计所加的项数,可以使用后验误差估计,通项为: 1421114 16818485861681 n n n a n n n n n ε??= ---<< ?+++++??; (2)为了保证计算结果的准确性,写程序时,从后向前计算; (3)使用Matlab 时,可以使用以下函数控制位数: digits(位数)或vpa(变量,精度为数) 2 算法结构 ;0=s ?? ? ??+-+-+-+= 681581482184161n n n n t n ; for 0,1,2,,n i =??? if 10m t -≤ end; for ,1,2,,0n i i i =--??? ;s s t =+ 3 Matlab 源程序 clear; %清除工作空间变量 clc; %清除命令窗口命令 m=input('请输入有效数字的位数m='); %输入有效数字的位数 s=0;

for n=0:50 t=(1/16^n)*(4/(8*n+1)-2/(8*n+4)-1/(8*n+5)-1/(8*n+6)); if t<=10^(-m) %判断通项与精度的关系break; end end; fprintf('需要将n值加到n=%d\n',n-1); %需要将n值加到的数值 for i=n-1:-1:0 t=(1/16^i)*(4/(8*i+1)-2/(8*i+4)-1/(8*i+5)-1/(8*i+6)); s=s+t; %求和运算 end s=vpa(s,m) %控制s的精度 4 结果与分析 若保留11位有效数字,则n=7,此时求解得: s =3.1415926536; 若保留30位有效数字时,则n=22, 此时求解得: s =3.8。 通过上面的实验结果可以看出,通过从后往前计算,这种算法很好的保证了计算结果要求保留的准确数字位数的要求。 二、某通信公司在一次施工中,需要在水面宽度为20米的河沟底部沿直线走向铺设一条沟底光缆。在铺设光缆之前需要对沟底的地形进行初步探测,从而估计所需光缆的长度,为工程预算提供依据。已探测到一组等分点位置的深度数据(单位:米)如下表所示:

机械工程及自动化专业本科专业人才培养目标体系-上海交通大学

上海交通大学电气工程与自动化本科工程型—— 卓越工程师教育计划培养方案 一、学科专业及项目简介 电气工程与自动化专业是上海交通大学历史最悠久的专业,已逾百年,为国家培养了大批社会精英。 本专业目前为教育部“第一类特色专业”,也是教育部“卓越工程师”培养专业,体现强弱电、软硬件相结合的特色,将学生培养成为具有国际视野,具有综合运用所学的科学理论与技术方法从事与电气工程相关的系统运行和控制、电工技术应用、信息处理、试验分析、研制开发、工程管理以及计算机技术应用等领域的人才。本专业本科生在“全国大学生节能设计大赛”和“全国大学生电子设计大赛”等比赛中屡创佳绩。毕业生大量进入电力公司等国企、世界五百强企业,约1/3的学生进入国内外大学继续深造。 在《教育部关于实施卓越工程师教育培养计划的若干意见》文件引导下,我校电气工程与自动化专业被列入教育部第一批“卓越工程师教育培养计划”,为此,从2009级开始,电气工程与自动化专业每年有35名本科生按卓越工程师教育培养计划进行培养,其三个特点为:1)行业企业深度参与培养过程(共同制定培养计划,企业设立“工程实践教育中心”);2)学校按通用标准和行业标准培养工程人才;3)强化培养学生的工程能力和创新能力。我校“电气工程与自动化”专业卓越工程师培养依托于上海交大电气工程一级学科及上海电气、上海电力、施耐德电气等企业和其他研究所。其特色为:1)学科基础好,电气工程一级学科拥有博士学位授予权,涵盖了电力系统及其自动化、高电压与绝缘技术、电机与电器、电力电子与电力传动、电工理论与新技术五个二级学科,其中电力系统及其自动化为国家重点培育学科。2)师资力量雄厚,电气工程系现有教职工98人,其中院士2人,以及一批在国内外有一定影响、承担国家及地方重大工程项目的中青年专家,并有一大批企业导师参与指导。该专业学位硕士点还依托教育部重点“电力传输与功率转换”实验室、高电压试验设备研究开发中心、风力发电研究中心、国家能源智能电网(上海)研发中心、上海市高压电器产品质量监督检验站,给学生们提供大量的实习、实践及参与各类科研项目的机会。

上海交通大学出国留学专用本科成绩单英文模板

SHANGHAI JIAOTONG UNIVERSITY TRANSCRIPT OF RECORDS FOR UNDERGRADUATE STUDENT Department: School of Naval Architechture&Ocean Engineering Major: Naval Architechture&Ocean Engineering Name: abcd Course Credits Score Credits Score 1990-1991 Academic Year 1st Semester 2nd Semester Military Theory Physical Education Englisn Advanced Mathematics General Physics Algorithmic Language Engineering Drawing Linear Algorithm Naval Architechture and Ocean Engineering Situation and Policy History of the C.P.C General Physics Lab Introduction Of World Ship Building Taste Of Art and Life 4 2 10 16.5 6 4 6 4 2 1 / / / / B A C C A B B C A A / / / / / 2 10 15 10 / / / / 1 6 6.5 2 3 / A C B A / / / / B B B B B 1991-1992 Academic Year 1st Semester 2nd Semester Theoretical Mechanics Ship Structure Physical Education English Maxism Principle Engineering Mathemics Material Mechanics Situation and Policy Electronic Technique Electromic Circuit &Technology Lab Ship Drafting Fluid Mechanics CET-4 Machine Training Naval Practice 9 5 2 10 6 9.5 4 1 / / / / / 7 / A B A C B B C A / / / / / A / 5 / 2 10 6 / 10 1 9 4 5 11.5 / / 5 B / A C A / A B A B A B C / PASS 1992-1993Academic Year 1st Semester 2nd Semester Situation and Policy Fundamentals of Law Ship Statics Fundamentals of Machine Design Machine Design Principles of Microcomputer Ship structural Mechanics Foundament of Management Science Ship Ressitence Ship Reliability Professional English Ocean Energy Utility Socialist Construction of China Ship structural Mechanics Ship and Ocean Engineering Materials Shipbuilding Technique Shipbuilding Econmy Ship Propulsion Ship Dynamic Equipment Vehicle Electromechanical Equipment and Principle Submarine Strength Ship Equipment The Autocontrol Therory of Means of Delivery Structure Optimum Design Specialized Practice 1 3 5 10 2 6 6 6 4.5 4 4 3 / / / / / / / / / / / / / A C B C C B C A B A C B / / / / / / / / / / / / / 1 / / / / / / / / / / / 6 4 3 7 5 6 4 2 4 3 3 3 10 B / / / / / / / / / / / B C A B B B B A A C C A PASS 1993-1994 Academic Year 1st Semester 2nd Semester Ship Strength and Structure Design Regulation Design of Ship Structure Ship Maneuver and Oscilation Principle of Ship Design Ship Vibration Exercise of Principle of Ship Design Ship Group Techniques Computer-aided Ship Construction Prediction of Ship Manoeuvablility Ship Propeller Computing Ship Seakindliness Ship Characteristic Trial Research Situation and Policy Undergraduate Thesis 5 2 4.5 4 4 2 3 3 3 3 4 4 1 / A C C C C B C B B C C PASS A / / / / / / / / / / / / / / 27 / / / / / / / / / / / / / B Note: 1.The transformation rules are illustrated in the attached chart on the back of this paper. 2.There is two grades system in some test marks: Pass(above 60 or 通过) or Fail (below 60 or 未通过). 3.The score of University English is improved one level if he or she study English from band 2 or higher. Registrar:Archives , Shanghai Jiaotong University 11/08/2002

数值计算方法三套试题及答案

数值计算方法试题一 一、 填空题(每空1分,共17分) 1、如果用二分法求方程043=-+x x 在区间]2,1[内的根精确到三位小数,需对分( )次。 2、迭代格式)2(2 1-+=+k k k x x x α局部收敛的充分条件是α取值在( )。 3、已知?????≤≤+-+-+-≤≤=31)1()1()1(211 0)(2 33x c x b x a x x x x S 是三次样条函数,则 a =( ), b =( ), c =( )。 4、)(,),(),(10x l x l x l n 是以整数点n x x x ,,,10 为节点的Lagrange 插值基函数,则 ∑== n k k x l )(( ),∑== n k k j k x l x 0 )(( ),当2≥n 时= ++∑=)()3(20 4x l x x k k n k k ( )。 5、设1326)(2 47+++=x x x x f 和节点,,2,1,0,2/ ==k k x k 则=],,,[10n x x x f 和=?07 f 。 6、5个节点的牛顿-柯特斯求积公式的代数精度为 ,5个节点的求积公式最高代数精度为 。 7、{}∞ =0)(k k x ?是区间]1,0[上权函数x x =)(ρ的最高项系数为1的正交多项式族, 其中1)(0=x ?,则?=1 04)(dx x x ? 。 8、给定方程组?? ?=+-=-2211 21b x ax b ax x ,a 为实数,当a 满足 ,且20<<ω时, SOR 迭代法收敛。 9、解初值问题00(,)()y f x y y x y '=??=?的改进欧拉法?????++=+=++++)],(),([2),(] 0[111] 0[1n n n n n n n n n n y x f y x f h y y y x hf y y 是 阶方法。 10、设 ?? ????????=11001a a a a A ,当∈a ( )时,必有分解式T LL A =,其中L 为下三角阵,当其对角线元素)3,2,1(=i l ii 满足( )条件时,这种分解是唯 一的。 二、 二、选择题(每题2分) 1、解方程组b Ax =的简单迭代格式g Bx x k k +=+) () 1(收敛的充要条件是( )。 (1)1)(A ρ, (4) 1)(>B ρ 2、在牛顿-柯特斯求积公式: ? ∑=-≈b a n i i n i x f C a b dx x f 0 )() ()()(中,当系数) (n i C 是负值时,

市场环境下电力系统的安全可靠性问题

市场环境下电力系统的安全可靠性问题 谭伦农!张保会!刘海涛 "西安交通大学电气工程学院!陕西省西安市#$%%&’( 摘要)在竞争的电力市场中!由于各电力公司*电力采办公司*电网公司分属不同的经济实体!从而 导致在系统运行和规划设计中对系统安全可靠性因素的考虑与传统电力系统存在巨大的区别+文中针对市场环境下电力系统的安全可靠性问题!从电网运行*电网规划*电力系统维修*反事故自动装置等几方面进行了探讨+指出)安全性将融入经济性中!传统电力系统中的安全性指标将不再单独存在!而只是作为可能给相应公司带来经济利益的一种措施,传统电力系统中的某一安全性指标在市场环境下是否会得到执行*执行到何种程度将取决于这一指标的执行是否会给相应的公司带来经济上的好处+ 关键词)电力市场,电力系统,安全性,可靠性中图分类号)-.# /0,1$0/2’收稿日期)0%%$3%43%4+ 5引言 在开放的电力市场中!买卖双方通过互联的电 力网络来协商其价格!进行电能的交易+在一定的需求水平下!买方希望以较低的价格获取电能!而卖方希望以较高的价格卖出电能+显然对买卖双方而言!参与市场的目的是为了追求自身的最大经济利益!而绝非为了系统的安全可靠性+作为电力市场中的另一方!电网公司只有在一个安全运行的电网上才能使得买卖双方的交易成为可能+类似于证券交易所!电网公司对买卖双方收取交易佣金!其收益的大小与交易量的大小成正比!但该收益并非其净收益!因为电网公司不仅要为建设*维护电网付出费用!还要为维持电网的运行支付费用"例如辅助服务的购买(+ 可见!虽然电网公司负责电网的运行!但其维护电网运行的目的仍然是为了追求自身的最大经济利益!在电网建设*运行上的投入应视可能的收益而定!而非仅仅为了系统的安全可靠性+当然!系统安全可靠性的破坏有可能使得各方的经济利益受到损害!但此时市场参与者保证系统安全可靠运行的目的仅仅是为了更好地维护自己的经济利益+换言之!在传统的电力系统运行中!可靠性高于经济性,而在电力市场中!可靠性服务于经济性+在市场环境下!维持电网安全可靠运行的动力来自市场各参与方对经济利益的追求!而非来自各种安全*可靠类的规程+ 本文针对电力系统运行和规划设计中的一些安全可靠性因素做了初步的探讨+ 6电网运行安全可靠性的考虑 67689:安全经济运行的考虑 在传统的电力系统中!;9$标准是输电系统静态安全评估的标准之一!即系统中$个发电机组 或$个电网设备"线路*电缆*变压器(退出运行时! 系统仍应能维持运行<$= +显然!;9$标准的执行将导致系统在正常情况时运行于非最优状态下+而在市场环境下!电网公司的目标是获得最大的经济效益+所以;9$标准是否执行!执行到什么程度!均取决于经济效益+亦即)通过比较;9$安全经济运行与不计;9$安全经济运行"正常网络的经济运行(的经济指标!确定为确保;9$安全经济运行而付出的代价,若不计及;9$安全经济运行!则系统运行可靠性将降低+为此!电网公司可能付出如下代价)>因为负荷预测的不准确性可能导致较计及 ;9$ 标准时更大的停电损失,?因为单一线路或设备故障而导致的可能的停电损失+ 在市场环境下!更可能的情况是系统能够在部 分运行方式下不切机*切负荷的应付部分的设备故障!而在另外一些设备故障或另外一些运行方式下!系统将会以切机或切负荷的方法进行处理!因为此时为保障供电的付出将大于切机*切负荷的赔款+67@备用容量对经济指标可能导致的损害系统运行涉及的备用主要有负荷备用和事故备用+在传统的电力系统中!负荷备用容量的大小应根据系统负荷的大小*运行经验并考虑系统中各类用 电的比重确定<0= !一般为最大负荷的0AB C A!大系统采用较小数值!小系统采用较大数值+事故备用的容量大小应根据系统容量*发电机台数*单位机组 $ $第04卷第4期 0%%0年/月0C 日 D E F 204G E 24 H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H .I J 20C !0%%0 万方数据

上海交通大学研究生英文面试

A soldier,a communist Party of China,a JavaDevelopment Engineer,anda student,it’sme,my name is Zhang Kaiming.fromhunanprovince.When I retired fromthe army,I faced two difficult choices,going towork directly or continuing further education.I love academic learning and researching.And I have ever got Shanghai scholarship.But without learning for more than two years made melose the confidence tostart from the beginning.Ientered a technology company engaged in development until the appearance of the Enrollment Project for Master Degree Candidates of College Veterans.I decided to bet with my own life and give it a try.This is the reason why I am here.My Alma mater is University ofShanghai for Science and Technology where campus environment is very beautiful.It’salso the place where my dream starts.My major in undergraduate period is the Electronic Information Science and Technology---It’s a subject covering hardware and software knowledge. .Shanghai Jiao Tong University is a place where many students dreamof.therehas long history,profoundculture,strong learning atmosphere and the talents professors.Oncesome onetold me a joke.She said she had ever taken the postgraduate examination.When she thought about whether she should go to Shanghai Jiao Tong university or FudanUniversity,the result is that she thought too much,Becauseshe failed the exam.But now I want to tell her,it not a joke.We should have dreams,What if it will be true?

数值计算方法试题及答案

数值计算方法试题一 一、填空题(每空1分,共17分) 1、如果用二分法求方程在区间内的根精确到三位小数,需对分()次。 2、迭代格式局部收敛的充分条件是取值在()。 3、已知是三次样条函数,则 =( ),=(),=()。 4、是以整数点为节点的Lagrange插值基函数,则 ( ),( ),当时( )。 5、设和节点则 和。 6、5个节点的牛顿-柯特斯求积公式的代数精度为,5个节点的求积公式最高代数精度为。 7、是区间上权函数的最高项系数为1的正交多项式族,其中,则。 8、给定方程组,为实数,当满足,且时,SOR迭代法收敛。 9、解初值问题的改进欧拉法是 阶方法。 10、设,当()时,必有分解式,其中为下三角阵,当其对角线元素满足()条件时,这种分解是唯一的。 二、二、选择题(每题2分) 1、解方程组的简单迭代格式收敛的充要条件是()。(1), (2) , (3) , (4) 2、在牛顿-柯特斯求积公式:中,当系数是负值时,公式的稳定性不能保证,所以实际应用中,当()时的牛顿-柯特斯求积公式不使用。 (1),(2),(3),(4), (1)二次;(2)三次;(3)四次;(4)五次 4、若用二阶中点公式求解初值问题,试问为保证该公式绝对稳定,步长的取值范围为()。 (1), (2), (3), (4)

三、1、 2、(15 (1)(1) 试用余项估计其误差。 (2)用的复化梯形公式(或复化 Simpson公式)计算出该积分的近似值。 四、1、(15分)方程在附近有根,把方程写成三种不同的等价形式(1)对应迭代格式;(2)对应迭代格式;(3)对应迭代格式。判断迭代格式在的收敛性,选一种收敛格式计算附近的根,精确到小数点后第三位。选一种迭代格式建立Steffensen迭代法,并进行计算与前一种结果比较,说明是否有加速效果。 2、(8分)已知方程组,其中 , (1)(1)列出Jacobi迭代法和Gauss-Seidel迭代法的分量形式。 (2)(2)求出Jacobi迭代矩阵的谱半径,写出SOR 迭代法。 五、1、(15分)取步长,求解初值问题用改进的欧拉法求的值;用经典的四阶龙格—库塔法求的值。 2、(8分)求一次数不高于4次的多项式使它满足 ,,,, 六、(下列2题任选一题,4分) 1、1、数值积分公式形如 (1)(1)试确定参数使公式代数精度尽量高;(2)设,推导余项公式,并估计误差。 2、2、用二步法 求解常微分方程的初值问题时,如何选择参数使方法阶数尽可能高,并求局部截断误差主项,此时该方法是几阶的。 数值计算方法试题二 一、判断题:(共16分,每小题2分) 1、若是阶非奇异阵,则必存在单位下三角阵和上三角阵,使唯一成立。()

计算方法教学大纲-致远学院-上海交通大学

上海交通大学致远学院2014年秋季学期 《随机过程》课程教学说明 一.课程基本信息 1.开课学院(系):致远学院 2.课程名称:《随机过程》(Stochastic Processes) 3.学时/学分:64学时/4学分 4.先修课程:概率论 5.上课时间:周二、四,3-4节课 6.上课地点:中院207 7.任课教师:韩东(donghan@https://www.wendangku.net/doc/6017633673.html,) 8.办公室及电话:数学楼1206,54743148-1206 9.助教:张登(zhangdeng@https://www.wendangku.net/doc/6017633673.html,) 10.Office hour:周四下午3-5点,数学楼1206 二.课程主要内容(中英文) 随机过程是定量研究随机现象(事件)统计规律的一门数学分支学科。学习《随机过程》的主要目的是:了解、认识随机现象的统计性质;知道如何构造随机模型并且能计算和分析随机事件随时间发生变化的的概率及其相关性质。《随机过程》主要包括:Poisson过程、Markov过程、鞅过程、Bronian 运动、随机分析基础(Ito积分与随机微分方程)、平稳过程等。 Stochastic Processes are ways of quantifying the dynamic relations of sequences of random events. It is a branch of mathematics. The main content of this course includes: General theory of stochastic processes; Poisson process and renewal theorems; Martingales; Discrete-time Markov Chains; Continuous-time Markov Chains; Brownian motion; Introduction to stochastic analysis; Stationary processes and ARMA models. 第一章概率论精要 主要内容:概率公理化,全概率公式和Bayes 公式,随机变量及其数字特征、条件期望、极限定理。重点与难点:条件期望和极限定理。 第二章随机过程的基本概念 主要内容:随机过程的定义、随机过程的存在性、随机过程的数字特征。 重点与难点:随机过程的存在性。 第三章Poisson 过程 主要内容:Poisson过程的定义及性质,首达时间与其间隔的分布,Poisson过程的极限定理。 重点与难点:首达时间间隔与Poisson过程的关系。 第四章Markov过程

电网可靠性分析

电网可靠性分析 随着社会经济的发展, 科学技术的进步及人民生活水平的不断提高, 人们对电力的需求和依赖性越来越大, 对安全稳定供电的要求越来越强。然而, 受到电力系统自身原因和外部干扰的影响, 电网事故时有发生, 这不但使电力经营企业的经济效益受到损失,而且对电力用户和整个社会都将造成严重的影响。 一、影响电力安全的因素 ⑴内部因素 内部因素主要可归纳为: ①电力系统主要元件故障:发电机、变压器、电线故障; ②控制和保护系统故障:保护继电器的隐性故障、断路器误动作、控制故障或误操作等; ③计算机软、硬件系统故障; ④信息、通信系统故障:与EMS系统失去通信、不能进行自动控制和保护、信息系统故障或拥塞、外部侵入信息通信系统; ⑤电力市场竞争环境的因素:电力市场中各参与者间的竞争与不协调、在更换旧的控制和保护系统或发电装置上缺少主动性; ⑥电力系统不稳定:静态、暂态、电压、振荡、频率不稳定等。 ⑵人为因素 不少大事故都与继电保护有关, 而这些保护的选型、整定和检查都与设计人员和运行人员的知识水平、敬业精神息息相关。常见的人为因素可概括为操作人员误操作, 控制和保护系统设置错误、蓄意破坏(包括战争或恐怖活动)等。 ⑶自然灾害 影响供电运行的自然灾害主要包括雨淞和雾淞、冻雨造成电线积冰, 或大雪积压在电线上, 厚度过大时会压断电线;大于7 ~ 8级的风会吹倒电杆, 龙卷风和风暴会刮倒线路杆塔;雷击危害高压线路和变压器,击破磁瓶, 造成跳闸,一有大风,有可能产生震动、跳跃和碰线引起速断保护跳闸;雾、毛毛雨、空气污染等造成“污闪”现象, 导致绝缘子绝缘水平降低, 出现短路事故;暴雨造成铁塔、电杆倾倒或浸泡电器, 引起停电事故;直径大于等于10毫米的冰雹能砸坏电器电线。 二、相应的技术措施 ⑴精心规划电网设计, 做好技术创新工作

上海交通大学留学生本科入学考试中国概况

上海交通大学外国留学生本科入学考试(样题)科目:中国概况及世界近现代史(文科) 建议用时:_60_分钟 一填空题(每个空格1分,共计25分) 1. 中国古代与阿拉伯和欧洲进行丝绸贸易的一条陆上通道被称为。 2. 1984年,为了解决台湾问题,邓小平提出了“”的方针。 3. 北宋时期,发明了活字版印刷,极大地提高了印刷效率,促进了文化的传播与发展。 4.西安最著名的名胜是,它被人们称为“世界第八大奇迹”。 5.中国外交政策的根本原则用一句话来说就是。 6.在中国刑事案件的侦查、拘留、预审都由司法机关中的负责。 7. 原始社会末期,黄河流域以黄帝为首的部落和以炎帝为首的部落结盟,形成中华民族的祖先,所以中华民族又称为。 8. 1989年国家宣布开发,通过开发这一地区,带动上海和长江三角洲以至全国的经济发展。 9. 亚洲地区国家自古以来受中国历史文化影响很大,从而逐渐形成了地球上的。 10.明朝李时珍写的《》记载了近2000余种药物,是中医经验总结性著作,在世界医学史上具有重要意义。 11.1905年,伟大的资产阶级革命家孙中山在日本建立了中国第一个资产阶级政党同盟会,并成功地发动了,推翻了中国两千多年的封建统治。 12. 提出“仁政说”,认为“民为贵,社稷次之,君为轻”,这在当时具有十分进步的思想意义。 13. 中国对外贸易的基本政策是。 14. 1937年7月7日,在北京附近发生了“”,中国军队奋勇抗战,标志中国的抗日战争开始。 15. 由于季风周期性变化和地势等因素影响,中国的气候具有、雨热同季的特征。

16. 中国两个最大的淡水湖鄱阳湖和洞庭湖都地处平原。 17. 根据中国国的行政区划,全国共有各省级行政区,其中面积最大的是。 18 .两千多年以前的春秋战国时代,社会变革剧烈,思想活跃,形成了著名的“”局面,产生了众多的思想学派。 19. 对美国废除黑奴制度起到决定性作用的是的发表。 20.1941年12月7日,日本偷袭珍珠港,标志的爆发。 21. 的广泛使用是世界第三次科技革命的核心。 22.俄国总理普京曾指出“苏联解体是全民族的重大悲剧”。这一悲剧发生的时间是 年。 23. 1955年在印度尼西亚举行的万隆会议通过了,显示了新兴民族独立国家的巨大团结力量。 24. 近代科学的奠基人、发现自由落体理论、证明新天文学正确性的是文艺复兴时代意大利科学家。 二选择题(每题只有一个正确答案,每题1分,共40分) 1.中国古代经济中心逐渐从北向南转移的主要原因是。 A.统治阶级的政策调整 B.自然环境的不断变化 C.北方多次的动乱 D.对外贸易的发展 2. 鉴真和尚东渡日本和玄奘西游学习、传播佛教文化都体现了唐朝文化的特点。 A.影响巨大 B.世界领先 C.高度繁荣 D.兼容并蓄 3. 我国著名的“五岳”中,位于河南省的是。 A.恒山 B.衡山 C.嵩山 D.泰山 4. 中国古代青铜器制造技术令人称赞和感叹,从以下几张图片可以看出,当时的青铜器 主要是。

上海交通大学--大学英语(一)

上海交通大学大学英语(一) 题目1 My father is leaving ______Shanghai tomorrow. 选择一项: a. to b. In c. Into d. For 题目2 Excuse me for breaking in, _______I have some news for you. 选择一项: a. yet b. so c. but d. and 题目3 ____ girl dressed _____ black is her sister Rose. 选择一项: a. The; in b. The; on c. A; on d. A; in 题目4 There’s lots of fruit_________ the tree. Our little cat is also in the tree.选择一项: a. on b. at c. in

d. under 题目5 The people in this city have planted ________ trees along both sides of the streets. 选择一项: a. a lot of b. a large amount of c. much d. a great deal of 题目6 They all go outing on such a warm spring day ______ Mark. He is busy with his lessons now. 选择一项: a. except b. beside c. besides d. except for 题目7 I'll have a cup of coffee and _____. 选择一项: a. two breads b. two pieces of breads c. two piece of breads d. two pieces of bread 题目8 The baby is hungry,but there's ____ milk in the bottle. 选择一项: a. few b. a few c. a little

相关文档
相关文档 最新文档