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王江彬的英文翻译定稿——标注版

王江彬的英文翻译定稿——标注版
王江彬的英文翻译定稿——标注版

毕业设计英文翻译(中文)

专业电气工程及其自动化

姓名王江彬

学号 201009034

指导教师田铭兴

Steinmetz电路电容器失效对电力系统谐波响应的影响

Luis Sainz, Joaquín Pedra, Member, IEEE, and Manuel Caro

摘要

牵引系统一般是单相负载,会导致电压不平衡,继而影响电力系统的运行。通常是将三角形连接的电抗与单相负载相连的方法来减少电压不平衡的。这些电抗和单相负载的集合就是Steinmetz电路。Steinmetz电路中的电容性电抗会与系统感性电抗之间产生并联谐振,这会破坏电能质量。这篇文章分析性地指出并联谐振的频率并且研究电容器损耗对其设计值的影响。为了证实所得的分析结果,也给出了实验测量数据。

关键词:扫描频率、谐波分析、电能质量

1 引言

虽然电力系统一般运行在平衡条件下,但它可以连接诸如牵引系统的单相负荷。这些负荷会引起不平衡负荷母线电压,因为它们消耗非对称的线电流[1]。这些不平衡条件会影响正常的电力系统运行[2-3]。出于这个原因,通常采用带有单相负载的三角形连接电抗来降低电力系统的不平衡。三角形连接的电抗和单相负载组成的集合(通常被称为Steinmetz电路)可以让网络负载承受对称的电流。

Steinmetz电路设计的目的就是确定平衡单相负载消耗不平衡电流所需的电抗值。由于电力系统中的非线性设备越来越多,设计必须考虑在非正弦条件下电路的性能和行为。因此,在上述条件下,Steinmetz电路的电容器和供电系统电感之间产生的并联谐振必须定位以防止当Steinmetz电路连接时的谐波问题。显然,谐振位置受Steinmetz电路本身损坏或其熔断器损坏时电容器损耗的影响。

这种谐振问题在文献[7]中提出。后来,该问题又在文献[8]中得到研究,并且得到了并联谐振的数值分析。在文献[8]中,通过对来自于电力系统谐波阻抗的几组曲线进行数值拟合来预测系统只在五次谐波、七次谐波以及十一次谐波共存情况下的谐振问题。最近,经文献[9]分析,可以通过电力系统谐波阻抗的理论研究来定位谐振。一个预测Steinmetz电路单相负荷任何值和任何谐波的谐振表达式也在文献[9]中得到阐述。

本文继续以上关于在Steinmetz电路存在下的电力系统谐波响应研究。特别是,文献[9]中推出的用于预测并联谐振频率的解析表达式扩展到开始考虑设计值下Steinmetz电路电容器损耗对谐振频率的影响。实验测量已在实验室中对理论研究中所得的解析表达式得到了验证。

2Steinmetz电路设计

图2.1给出了带有供电系统和非线性负载的Steinmetz电路:

图2.1 被研究系统

在该电路中,单相阻抗负载用1L L L L =k k Z Y R jkX -=+来建模,这里k 是被研究

谐波,L R 是负载电阻,L X 是供电电压基频条件下的负载电抗。该单相负载以三

角形连接方式被接到电容器(1222=/k k Z Y jX k -=-)以及一个纯电感(1111=k k Z Y

jkX -=)上来平衡负荷电流(A1I ,2B1A1I I α=,C1A1I I α=,j2/3=e πα)。Steinmetz 电路设计的过程(例如电容器和单相负载阻抗电感的确定)已在文献[8]中提出并得到了简化。Steinmetz 电路所消耗的三相谐波电流由三相谐波电压确定(如图2.1所示),其关系式表示为式(2.1):

A 1A

B B L B

C 2CA C 101001100001100k k k k k

k k k k I Y V I Y V Y V I -????????????????=-????????????????-???????? (2.1)

Steinmetz 电路三相基波电流的对称分量(A1I ,B1I ,C1I )就可以用Fortescue

变换得到,具体变换公式如式(2.2)所示: 01A121B12C111111131p n I I I I I I αααα????????????=??????????????????

(2.2) 其中,23=j e π

α。

不平衡因数由序电流1p I 和1n I 分析确定,计算式如下式(2.3)所示: 222

1A1B1C1AB111BC1L1CA1211221A1B1C1AB111BC1L1CA1211==1n i p I I I I V Y V Y V Y m I I I I V Y V Y V Y αααααααααα++++-=?++++- (2.3)

因此,此因子的最终表达式取决于公共耦合点平衡或不平衡电压的考虑。在本文中,为了简化非正弦条件下电路的设计,对平衡电压作了考虑(2BC1AB1V V α=,CA1AB1V V α=)。得到的不平衡因数体现在公式(2.4)中:

1

11n i p I m I ==其中,L L1=/R Z λ是单相负载基波功率因数;L1Z 是基波频率下负载阻抗的模值;

21/2=/m λλ((1)-1)

。 最后,对称无功元件(电容2X 和电感1X )的设计是通过迫使基波电流不平衡因素为0(例如可以使负序电流为0)而实现的。这表明具有式(2.5)所示关系:

1X =

;2X =(2.5)

在(2.5)式中,所讨论的电路(带有电容和电感)只有在负载基波功率因数满

足条件/21λ<≤时才是可行的(02>X )。在本文中,功率因数的研究值

)(9.01???=λ是电力系统的常用值。

3 电力系统谐波响应

根据图2.1,必须研究非线性负荷角度的系统谐波响应,继而研究确定电力系统的谐波响应。这意味着要分析由供电系统和如图3.1所示的Steinmetz 电路构成的被动组。

图3.1 供电系统和Steinmetz 电路的谐波特性

在研究中引入c d 来表示Steinmetz 电路电容器真实值和在(2.5)式中得出的

21/()X C ω=这一设计值的偏离程度。因此,谐波研究时所考虑的电容值是:c d C

?(例如22/(/)/1/()k c c c Z d jX k d j d C k ω=-=-?)。这一参数表示由电容器本身或其熔断器损坏而造成的电容器损耗。如果1c d =,则电容器就具有(2.5)式中的设计值。而如果1c d <,则电容器电容值就比其设计值低。在本文中,这一参数的研究值为(0.251)c d =???。这一参数已被列入图3.1,用来分析系统谐波特性研究中Steinmetz 电路电容器值偏离其设计值的后果。

图3.1中的谐波特性可以用它的等效谐波阻抗矩阵B k Z 来描述,这种矩阵表

述的非线性节点中k 次谐波的三相电压和电流关系如下公式(3.1)所示: 1

A AA A

B A

C A S 1212A B BA BB BC B S 1L L B CA CB CC C 2L S 2L C C c c c c k k V Z Z Z I Y Y d Y Y d Y I V Z Z Z I Y Y Y Y Y I Z Z Z I d Y Y Y d Y Y I V -++--????????????????????==-++-??????????????

???????--++??????????(3.1) 这里11S S S S =()k k Y Z R jkX --=+对应电源系统的导纳,而L k Y ,1k Y ,2k Y 对应Steinmetz 电路元件的导纳(见第二部分)。为了得到式(3.1),用到了电压节点法,这一方法将图3.1中的N 点作为参考点。

可以观察到谐波阻抗矩阵k Z (k Z 阻抗也就是AA k Z 到C C k Z )的对角阻抗和非对角阻抗直接描述了系统谐波特性。两组的阻抗计算是有必要的,因为任何这些

阻抗的共振都会导致相应电压失真水平的升高。

举个例子,图3.1中网络(例如k Z 阻抗)的谐波响应在实验室中由以下数据

来衡量:

(1) 供电系统标幺值S 0.02190.0493Z j =+;

(2) Steinmetz 电路标幺值L 1.368, 1.0R λ==以及由(2.5)式得出的1X 和2X 的标幺值12 2.372X X ==。

这些数据是在基值B 230V U =以及B S 2.7VA k =下得出的。

在1c d =和0.5c d =这两种情况下的系统谐波响应都是在考虑了Steinmetz 电路电容器的上述值(标幺值2 2.372X =)得情况下测得的。k Z (例如AA k Z 到C C k Z )阻抗值的测量都在图3.2中对两种情况进行了绘制(1c d =的情况用实线,0.5c d =的情况用虚线)。

(a) (b)

(c) (d)

(f) (g)

(h) (i)

(j)

图3.2 Steinmetz 电路存在时的测量阻抗和频率矩阵

可以看到:

(1) Steinmetz 电路的连接(实线绘制的1c d =的情况)造成了k Z 阻抗的并联谐振。在这个例子中,共振接近五次谐波(251/50 5.02p k ≈=,这里251HZ 是所测并联谐振的频率而50HZ 是基频)。

(2) 如果Steinmetz 电路遭受电容器损耗,k Z 阻抗的并联谐振就会转移到更高的频率。在这个例子中,50﹪的电容器损耗(虚线绘制的0.5c d =的情况)将并联谐振转成七次谐波(360/507.2p k ≈=,这里360HZ 是被测并联谐振的频率

而50HZ 是基频)。

(3) 电路的非对称谐振特性导致对谐波电压的非对称性影响。最关键的谐振发生在A 相和C 相之间,这两相之间有电容器连接。两相都具有最高的谐波阻抗,所以会出现最高谐波电压。

在下面的章节中,对该系统的谐波特性进行了分析研究,也对上述并联谐振的频率进行了分析定位。

4 电力系统谐波响应的分析研究

4.1电力系统谐波阻抗

在本项研究中,k Z 阻抗(阻抗AA k Z 到C C k Z )的模值是从(3.1)式中得到的,k Z 阻抗(阻抗AA k Z 到C C k Z )的模值计算公式如式(4.1)所示: 2S S 12L 12L 2L AA S 2S S 12L 12L 2L BB S 2S S 12L 12L 2L CC S 1S 2L 2AB BA S AC CA (2)()(2)()(2)()()c c c k k k k c c c k k

k k c c c k k

k k k c k c k Lk k k k k c k k Y Y Y d Y Y Y d Y Y d Y Y Z Y D Y Y Y d Y Y Y d Y Y d Y Y Z Y D Y Y Y d Y Y Y d Y Y d Y Y Z Y D Y Y d Y Y d Y Y Z Z Y D d Y Z Z ++++++=++++++=++++++=+++====2S 1L 1S L S 1212BC CB S ()()k k k Lk k k k c k k c k k k k k Y Y Y Y Y Y D Y Y Y d Y Y d Y Z Z Y D ????

????

??????

?+++???+++?==

?? (4.1) 其中,

2S S 12L 1122L 2()3(())k c c c k D Y Y Y d Y Y Y Y d Y d Y Y =++++++ (4.2)

在上面(4.1)式的分析中,电源系统的导纳和Steinmetz 电路的元件参数为: S 1S 22L L 11(1)k k k k m Y j Y kX Y j Y R jk λ?≈-=-????==?+?, (4.3)

其中电源系统的电阻S R 已被忽略,并且认为(2.5)式可以得到Steinmetz 电路元件的导纳。

我们还可以看到阻抗模值(系统谐波响应)取决于五个变量:谐波次数k 、

电源系统基波电抗S X 、单相负载电阻L R 、单相负载基波功率因数λ以及偏差参

数c d 。

4.2 电力系统谐波阻抗归一化

利用单相负载电阻L R 作为参考可以将(4.1)式的k Z 阻抗归一化。这样,归一化阻抗(阻抗AA L k Z R 到C L C k Z R )的大小就只取决于四个变量:谐波次数k 、供电系统基波电抗与单相负载电阻之比S L X R 、单相负载基波功率因数λ和偏差

参数c d 。 例如,归一化阻抗的模值AA L k Z R 可以表示为下面的(4.4)式: 22L S S 12L 12L 2L AA 2L L S L (2)()=c k c c k k k k R Y Y Y d Y Y Y d Y Y d Y Y Z R R Y R D ++++++ (4.4)

该式中只有L S k R Y 、L 1k R Y 、L 1c k R d Y ?、L L k R Y 这几项,这些项分别为:

L S L 1S L L 2L L 1/11k k c k k m R Y j R Y kX R R d Y R Y jk λ?=-=-????==?+?

, (4.5)

这对其它k Z 阻抗的模值计算也一样。 我们可以看到S L X R 这个比率等于该比率的逆S L (1/)/S S λ?(例如

S L S L S L

///S S X Z X R λλ?=?=),这里S S 是PCC 总线的短路功率,而L S 是单相负载的视在功率。因此,在考虑S L /S S 比值[1]以及基波功率因数)(9.01???=λ的

正常范围时,那么研究中使用的S L /X R 值就为S L /(00.2)X R =???。

4.3并联谐振的位置解析

考虑到变量λ、S L /X R 以及c d 时,接下来的对(4.1)式中归一化阻抗的三级研究就允许对并联谐振的谐波p k 进行分析定位。在第一和第二阶段,对归一化

阻抗的并联谐振进行数值分析并且提出了一种谐振定位的近似方法。在第三阶段中,并联谐振的分析定位是建立在前一阶段的基础上的。

4.3.1 并联谐振的数值定位 并联谐振(例如,阻抗模值AA k Z 到CC k Z 相对于谐波k 的最大值)和阻抗值分母相对于谐波k 的最小值一致,其值如下(4.6)式所示: AA CC S {}{}k k k k Den Z Den Z Y D =???== (4.6)

在(4.6)式中,可以看到阻抗值分母的最小值与(4.2)式中k D 的最小值一致。 为了只应用四个变量k 、λ、S L /X R 以及c d ,上述结论可以推广到归一化阻

抗模值(阻抗AA L k Z R 到CCk L Z R )以及式k D 的归一化值(例如2L k R D ?)。

因此,对于给定的功率因数λ、以及给定比值S L /X R 和偏差参数c d ,并联

谐振对于所有阻抗具有相同的谐波因子p k ,而且与k D 或2L k R D ?的最小值一致。

为了说明这一点,研究了图3.1中S L /=0.018X R 以及=1.0λ的系统,在该过程中考虑了Steinmetz 电路电容器的两个值,一个是设计值( 1.0c d =),一个是相对于设计值50﹪的电容器损耗值(0.5c d =)。得到的阻抗结果AA L k Z R 示于图4.1

中的(a)和(b)。阻抗的模值AA L k Z R 绘制在图4.1(a)中,它的分子项AA L {}k Num Z R 和分母项的k D 项绘制在图4.1(b)中。

(a)

(b)

图4.1 归一化阻抗模值最大值的位置 可以观察到归一化阻抗的最大值与k D 项的最小值一致。对于另一个阻抗值k Z 也是一样的。

根据以上研究,图4.2表示出了功率因数λ、比值/S L X R 以及参数c d 的不同

值下的并联谐振谐波p k 。并联谐振已被数值定位为k D 项的最小值(图中实线)。

(a)

(b)

(c)

图4.2 并联谐振的位置解析

可以注意到:

(1) 并联谐振的谐波p k 会随功率因数 、比值S L /X R 以及参数c d 的增加而增加;

(2) 如果单相负载的功率因数接近于统一值,则低次谐波(p k =5或7)情况

下发生并联谐振的可能性就会增加;

(3) 图2.3中测得的并联谐振(S L /=0.036X R ,=1.0λ以及 1.0c d =和0.5)用点P 和Q 表示,数值研究和系统的被测谐波特征一致;

(4) 图4.1的模拟并联谐振(S L /=0.018X R ,=1.0λ以及 1.0c d =和0.5)用点R 和S 表示。 在这一部分中已经证明通过k D 项或2L k R D ?项的最小值来定位并联谐振这一方法提供的结果与归一化阻抗k Z 的模值最大值是一致的。然而,从(4.3)式中

分析确定的并联谐振过于复杂,不可能得到定位这种谐振的公式。所以,下面就用到了一种近似方法。

4.3.2 对并联谐振的近似分析定位

对式(4.2)中k D 的七项进行数值研究分析看七项中有没有某些项可以被忽略。

为了这样做,根据(4.4)式,k D 的后面六项(S 12k k Y Y ,S 22k c k Y d Y ?,S L 2k k Y Y ,

123k c k Y d Y ?,1L 3k k Y Y ,2L 3c k k d Y Y )可作为第一项(例如2S k Y )

。并且对以下的比率得到了数值研究,得到了式(4.7):

2S 1S 12S L 22S 2S 22S L S L S 3222S L 422212S 42S L 221L S 5222S L 2==()2==()212==()13==(31)()31)==)((1)k k k m k k c k k m c k k k k m k m k c k k m c k k k m k m k m Y Y X C Y R Y d Y X C k Y R Y Y X C k j Y k k R Y d Y X C d k Y R Y Y X C k Y k R λλλλλλλλλ-+---++-+-+

+222L S 6222S L )31)==)()(1)c k k m k c m k m j d Y Y X C d k k j Y k R λλλ?????????????????--+?+?

(4.7)

为了分析不同项对于k D 的贡献,复数比率的实部和虚部Re{}hik hk C C =以及Im{}hik hk C C =(这里h 取1到6的值)已被计算出来并且对应S L /X R 的不同值被绘制在图4.3中。功率因数等于1,偏差参数(实部表示的1c d =和虚部表示的0.25c d =)的2个极值在图4.3中得到了考虑。已经对曲线并联谐振的对应谐波

p k 进行了计算(例如,对于S L /=0.036X R ,=1λ,1c d =)

,在这里用到了=5p k 的

情况。

图4.3 对k D 各项贡献率的研究

从图4.3中可以得到:

(1) 1k C 、2k C 以及4k C 的虚部为0,在图中没有画出;

(2) 因为=1λ,21/2=/0m λλ=((1)-1),所以3k C 、5k C 以及6k C 的实部为0,

而没有画出来;

(3) 比率1k C 、4k C 以及5k C 对k D 的贡献在并联谐振谐波方面比其它比率要小,因此可以忽略。

同样的结论也适应于和统一值不同的功率因数值以及参数c d 的其它值。在

这种情况下,3k C 、5k C 以及6k C 的实部就不是0而要进行分析。 因此,k D 项就可以近似为公式(4.8): 2S S 2L 2L 2()3k k k c k k c k k aprox D Y Y d Y Y d Y Y ≈+++ (4.8)

4.3.3 对并联谐振的分析定位 为了分析定位并联谐振的谐波,k aprox D 的关于k 次谐波的最小值可以分析得

到。为可行起见,功率因数的值必须固定。因此,当且仅当=1λ、0.95以及0.9时才可得到k

aprox D 的最小值。先定义S L /x X R τ=,则结果就是如下式(4.9):

p k λ=,(4.9)

其中:

21,143221************c c G x d G x d d x G x λττλτττλτ===?=-??=++??=??

2,3,

(4.10) 20.954320.95220.9527.96(2.0910.72)1195.51(14.62149.94)(4.37 12.8142.83)(2.10 5.39)0.25

14 6.180.67

c c c c c G x

d x G x d x d d x d x G x x λττλττττλττ===?=--+?=+-++??++++??=++?1,2,3, (4.11) 以及: 20.94320.9220.927.86(0.6915.74) 2.17194.08(4.87219.32)(0.48 6.2992.31)(1.5217.14) 1.18

4.72 3.050.49c c c c c G x d x G x d x d d x d x G x x λττλττττλττ===?=--+?=++++??++++??=++?1,2,3, (4.12)

这些表达式用虚线画在了图4.2中。可以观察到解析表达式允许并联谐振处于一个可以接受的误差范围。

举个例子,解析表达式(4.9)与(4.10)可以预测实验室中测量得到的表示于图

3.2的谐振。结果是:当1c d =时,,1

4.95p k λ==,当0.5c d =时,,17.06p k λ==。 必须指出,k aprox D 最小值的分析研究允许表达式1,G λ、2,G λ以及3,G λ中的功率因数λ取任意值。在本文中,由于缺乏空间,只得到了3个功率因数条件(=1λ、0.95以及0.9)下的表达式。

可以观察到(4.9)式结合(4.10)、(4.11)以及(4.12)式允许预测比值/S L x X R τ=、偏差度c d 以及三功率因数的任何值下的并联谐振谐波p k 。

在文献[8]的以前研究中,比值x τ的表达式表示只在五次、七次以及十一次谐波条件下才激起并联谐振,该表达式对任意功率因数可以进行数值分析得到。因此,只有谐振接近于上述谐波次数时,并联谐振才能被近似预测。在文献[9]中,给出了可以对比值S L /x X R τ=与功率因数λ的任何值下的并联谐振谐波p k 进行定位的表达式,但该表达式只考虑了Steinmetz 电路电容器的设计值1c d =的情况。

5 电阻对电力系统谐波响应的影响

供电系统的电阻和Steinmetz 电路的电感在以前的研究中没有被考虑。一般来说,这些电阻可以抑制系统谐波响应,可以改变系统的共振频率。

在这一部分中,是通过考虑上述电阻(例如1S S S S 1/()k k Y Z R jkX -==+以及

111111/()k k Y Z R jkX -==+)从(4.1)式中对这种影响进行数值分析的。

数值分析已经证明供电系统电阻S R 可以抑制k Z 阻抗但不改变谐振频率。

举个例子,现在来分析图2.1中的网络,它是由给Steinmetz 电路(标幺值

L 4=1.0R λ=,以及12==6.928X X )

供电的供电系统(S S S 0.144/0X R X ==,、0.1、0.5)组成的。阻抗AA k Z 的模值可以从(4.1)式中求得,已将它绘制在了图5.1中。

图5.1 供电系统电阻对驱动阻抗的影响

可以观察到供电系统电阻会影响驱动阻抗的值但不会影响谐振频率。谐振频率由(4.9)和(4.10)式得到,考虑到S L /=0.144/4=0.036x X R τ=以及1c d =(例如

=1=4.95p k λ,)

,该频率也可由图4.2(点P )决定。 数值论证得到Steinmetz 电路的电感电阻不会改变已有系统的谐波响应(这已经由值为110X 的电阻得到论证)。事实上,可以观察到为了定位并联谐振,S 12k k Y Y 、123k c k Y d Y ?、1L 3k k Y Y 这些项就可以忽略,继而以k aprox D 代替k D 。如果在Steinmetz 电路的电感中添加一个电阻(1111/()k Y R jkX =+),谐波导纳项S 12k k Y Y 、123k c k Y d Y ?、1L 3k k Y Y 对系统谐波响应的影响将会更小。

因此,虽然并不考虑系统电阻,但是在第四节中论述的系统谐振频率的数值特征还是有效的。

6 电力系统谐波响应的实验测量

举个例子,图3.1中网络的谐波响应在实验室中得到测量,该网络参数为:标幺值S 0.02190.0493Z j =+,L 1.368R =(基值B 230V U =,B 2.7VA S k =)。并联谐振频率的测量是在三功率因数 1.0λ=、0.95、0.9以及Steinmetz 电路电容器5个不同偏差度1c d =、0.75、0.5、0.35和0.25的情况下进行的。根据以上电阻L R 以及单相负载的功率因数λ,Steinmetz 电路电抗的相应值可以从(2.5)式中计算得到。

频率响应测量用一个4.5kV A 的交流埃尔加开关放大器的电源来实现的,该电源可以可以产生任意频率(40HZ~5000HZ)的正弦波形。还用到了型号为YOKOGAWA DL 708E 的数字显示器作为测量装置。

并联谐振频率的测量在图6.1中用虚线进行了绘制。在该图中,(4.10)式中所得的结果用实线绘制。必须应用比值S L /0.0493/1.3680.036x X R τ===来获得实线所示的解析曲线。所得解析结果的充分性在图6.1中得到了证实。

图6.1 并联谐振的位置分析图

可以看到,虽然在分析研究中忽略了电阻,但是谐振频率的计算结果与实验测量数据完全一致。

7 结论

本文研究了Steinmetz 电路的容抗与供电系统感抗之间产生的并联谐振。就其设计值而言Steinmetz 电路的电容器损耗在研究中得到了考虑。定位并联谐振频率的表达式从电力系统谐波阻抗中分析得到。该解析表达式用来对谐振频率进行预测,进而判断是否已对系统嵌入用来平衡单相负载的Steinmetz 电路。该表达式还包括了Steinmetz 电路电容器损坏对谐振的影响。可以观察到如果Steinmetz 电路电容器出现损耗,那么并联谐振就会转移到更高频率。分析研究被实验测量所验证。

参考文献

[1] T.-H. Chen, ―Criteria to estimate the voltage unbalances due to high -speed railway demands,‖

IEEE Trans. Power Syst., vol. 9, no. 3, pp.1672–1678, Aug. 1994.

[2] S. Y . Lee and C. J. Wu, ―On -line reactive power compensation schemes for unbalanced

three-phase four wire distribution feeders,‖ IEEE Trans.Power Del., vol. 8, no. 4, pp. 1958–1965, Oct. 1993.

[3] S. T. Sobral, ―Interference between faulted power circuits and communication circuits or

pipelines-simplification using the decoupled method,‖ IEEE Trans. Power Del., vol. 6, no. 4,

pp. 1599–1606, Oct.1991.

[4] L. S. Czarnecki, ―Reactive and unbalanced currents compensation in three-phase

asymmetrical circuits under non-sinusoidal conditions,‖IEEE Trans. Instrum. Meas., vol. 38, no. 3, pp. 754–759, Jun. 1989.

[5] ——, ―Minimization of unbalanced and reactive currents in three-phase asymmetrical circuits

with non-sinusoidal voltage,‖Proc. Inst. Elect. Eng. B, vol. 139, no. 4, pp. 347–354, Jul.

1992.

[6] L. Sainz, O. Jordi, and M. Chindris, ―Steinmetz system study under nonsinusoidal

conditions,‖ in Proc. IASTED Int. Conf., Rhodes,Greece, Sep. 19–22, 2001, pp. 106–111. [7] L. Sainz, J. Pedra, and M. Caro, ―Study of electric system harmonic response,‖ IEEE Trans.

Power Del., vol. 19, no. 2, pp. 868–874, Apr.2004.

[8] ——, ―Steinmetz circuit influence on the electric system harmonic re sponse,‖ IEEE Trans.

Power Del., vol. 20, no. 2, pp. 1143–1156, Apr.2005.

[9] M. Caro, L. Sainz, and J. Pedra, ―Study of the power system harmonic response in the

presence of the Steinmetz circuit,‖ Elect. Power Syst.Res., vol. 76/12, pp. 1055–1063, Aug.

2006.

户口本英文翻译模板

Household Register Under Supervision of The Ministry of Public Security of P.R.C. Points for Attention 1. The Household Register has a legal force to identify the status of a citizen and the relationship of family members. It is a main basis for the household registration office to make residence investigation and check. When the household registration office makes residence investigation and check, the householder or anyone of the family members shall bring forth on his/her own initiative the Household Register. 2. The Household Register shall be under proper keep of the householder. No alter, transfer and lease is allowed. The loss of the Household Register must be reported to the household registration office promptly. 3. Only the household registration office has the power to make registration on the Household Register. No any other units and individuals are allowed to make any records on it. 4. Any increase or decrease of family members in the household or any alteration of the registration items shall be registered on the Household Register by reporting to the household registration office. 5. If the whole family has moved out of the jurisdictional area of the residence, the Household Register shall be submitted to the household registration office for cancellation.

中国户口本英文翻译模板

Under Supervision of the Ministry of Public Security of that need attention I. Household Register has the legal force to prove the citizenship status and the relationship between family members and it is the main basis for the household registration institution to investigate and check the household registration. The head of household or the member of the household shall initiatively submit the household register for checking at the time that the staff in the household registration authority conducts investigation and check of the Household Register. II. The head of the household shall keep the Household Register properly and is prohibited to alter, assign and lend the Household Register privately. If the Household Register is lost, the head of the household shall immediately report to the household registration authority. III. The registration rights of the Household Register shall belong to the registration authority. Any other unit and individual shall not make any records on the Household Register. IV. If the household has personnel increase or decrease or change of registered items, they shall apply to the registration authority for declaration with the Household Register. V. Upon migrating of the whole household from the precinct, the household shall submit the Household Register to the household registration authority for revocation. Issuing Date: xx/xx/20xx Page 1

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冀教版小学英语四年级下册英语课文翻译精编 W O R D版 IBM system office room 【A0816H-A0912AAAHH-GX8Q8-GNTHHJ8】

L e ss o n 1 你好吗? ①你,你们②你的,你们的 ③新的④小学生 ⑤朋友 Part 1 一位新老师 1. 你好!我是你们的新老师!欢迎大家返校! 2. 你好!我叫詹妮。 3. 你好,詹妮!你可以叫我伍德先生。 很高兴认识您,伍德先生! 我也是。 4. 你好,伍德先生!我叫 丹尼。很高兴认识您, 伍德先生! 我也是。 Part 2 一位新朋友 1. 詹妮,这是史蒂文。他 是一位新同学。 2. 你好,史蒂文!感觉怎 么样? 我很好,谢谢!你呢? 非常棒,谢谢! 3. 史蒂文,这些都是我的 朋友。他叫丹尼。她叫 基姆。 4. 你好,丹尼!你好,基 姆!你好! Lesson 2 这是你的铅 笔吗? ①铅笔盒②尺子 ③蜡笔(粉笔) ④直尺⑤谁的 ⑥哪,哪里(特殊疑 问词) Part 1 我的铅笔盒 1.这是我的铅笔盒。里面 有什么? 有一支铅笔、一支钢 笔、一把尺子和几只蜡 笔。 Part 2 这是谁的铅笔? 1. 这是你的铅笔吗,詹 妮? 不,不是我的。 2. 这是斯蒂文的铅笔吗? 不,不是他的。 3. 这是基姆的铅笔吗? 不,不是她的。

4.这是谁的铅笔? 是丹尼的铅笔! 我的铅笔在哪儿呢?Lesson 3 他们在哪儿? ①教室②什么(特殊 疑问词)③黑板 ④书桌⑤书包 ⑥在…前面 ⑦在…中间⑧在…旁 边⑨在…下面 Part 1 我的教室 1. 这是我的教室,你能看 到些什么? 教室前面有一块黑板。 有许多桌子和椅子。 课桌上有一些铅笔、尺 子、彩笔和书本。 桌子里面有书包。 Part 2 他们在哪儿? 1. 丹尼在桌子和椅子之 间。 2. 詹妮在基姆的旁边。基 姆在詹妮的旁边。 3.那个书包在课桌上。书 在书包里面。课桌下面 有一些蜡笔。 Part 3 说一说 课桌上有一个书包、一个 铅笔盒和三只钢笔。 课桌旁边有一把椅子。 课桌里面有三本书。 课桌下面有五支蜡笔。课 桌上方有一盏吊灯。 课桌和椅子之间有一个黑 板擦和一块橡皮。 Lesson 4 那有多少书? ①多少(词组)② 把…放到…上面 Part 1 丹尼的游戏 1. 我的桌子上有多少本 书,詹妮? 2. 一、二、三、四、五、 六、七、八。有八本 书。 3.让我们在这八本书上面 再放八本书。现在我的 桌子上有多少本书? 4. 十六本! 5. 让我们在这十六本书上 面再放二十九本书。现 在我的桌子上有多少本 书? 6. 一本!

英语强化翻译 汉化版

Due to …no cure no pay? basis, salvors traditionally looked for incidents with high chance of success in saving ships and cargoes on board, ignoring environmental protection. 基于“无效果,无报酬”的惯例,传统上救助方着重于事故中如何以高成功率救援船舶和货物而忽视了对环境的保护。 The International Convention on Salvage 1989 changes the scene with an introduction of Article 14: 在1989版国际救助公约中,以第14条条款的规定改变了这种现象: 1. If the salvor has carried out salvage operations in respect of a vessel which by itself or its cargo threatened damage to the environment and has failed to earn a reward under Article 13 at least equivalent to a special compensation assessable in accordance with this article, he shall be entitled to special compensation from the owner of that vessel equivalent to his expenses as herein defined. 1,如果救助方考虑到所救船舶或货物对环境已有污染的危险而开始了打捞救助作业,同时依据本公约不能获得基于第13条款的最低特别补偿款,救助方可以从船东处获得他所花费相当的特别补偿款。 2. If, in the circumstances set out in paragraph 1, the salvor by his salvage operations has prevented or mimimized damages to the environment, the special compensation payable by the owner to the salvor under paragraph 1 may be increased up to a maximum of 30 per cent of the expenses incurred by the salvor. 2,在这种情况下,如按照第1项设定的情形,救助方因其救助行为已达到预防或使环境污染最小化的成果,船东依第1项所给付给救助方的特别补偿款可以在救助方最大花费的基础上增加30%。 3. Salvor?s expenses for th e purpose of paragraphs 1 and 2 means the out-of-pocket expenses reasonably incurred by the salvor in the salvage operation and a fair rate for equipment and personnel actually and reasonably used in the salvage operation, taking into consideration the cri teria set out in Article 13, paragraph 1(h), (i), and (j).? 3,第1,2项中所说的救助方花费是指救助方用于救助行为中关于救助设备,救助人员的额外,合理,公平费率的预算之外的支出,结合考虑第13条款中第1(h),(i),(j)项的规定。 4. The total special compensation under this article shall be paid only if and to the extent that such compensation is greater than any reward recoverable by the salvor under article 13. 4,只有在基于第13款情况下,补偿款远多于救助方能获得的救助报酬,全部的特别补偿款才应该支付。 5. If the salvor has been negligent and has thereby failed to prevent or minimize damage to the environment, he may be deprived of the whole or part of any special compensation due under this article. 5,如果是由于救助方疏忽而至其没能防止污染或使污染最小化,救助方可以被剥夺获取全部或部分基于公约的特别补偿款。

中国户口本英文翻译#精选.

Registration of Residence Basic Information of Household Issuing Date: xx/xx/20xx Page 1

Register of Residence Change住址变动登记 Page 2 Registration card for permanent residence(常住人口登记卡1) Non-agricultural family非农家庭户口 Registration date : 20xx-xx-xx

Registration Change and Records 登记事项变更和更正记载 Page 4 Registration card for permanent residence(常住人口登记卡2) Non-agricultural family非农家庭户口Registration date : 20xx-xx-xx Page 5 Registration Change and Records 登记事项变更和更正记载

Page 6 Registration card for permanent residence(常住人口登记卡3) Registration date : 20xx-xx-xx Non-agricultural family非农家庭户口 ---------------------------------------------- End of Records -------------------------------------------------- 最新文件仅供参考已改成word文本。方便更改

Unit高职英语课文及翻译定稿版

U n i t高职英语课文及 翻译 HUA system office room 【HUA16H-TTMS2A-HUAS8Q8-HUAH1688】

Unit 1 Text A College—A Transition Point in My Life 1 When I first entered college as a freshman, I was afraid that I was not able to do well in my studies. I was afraid of being off by myself, away from my family for the first time. Here I was surrounded by people I did not know and who did not know me. I would have to make friends with them and perhaps also compete with them for grades in courses I would take. Were they smarter than I was? Could I keep up with them? Would they accept me? 2 I soon learned that my life was now up to me. I had to set a study program if I wanted to succeed in my courses. I had to regulate the time I spent studying and the time I spent socializing. I had to decide when to go to bed, when and what to eat, when and what to drink, and with whom to be friendly. These questions I had to answer for myself. 3 At first, life was a bit difficult. I made mistakes in how I used my time. I spent too much time making friends. I also made some mistakes in how I chose my first friends in college. 4 Shortly, however, I had my life under control. I managed to go to class on time, do my first assignments and hand them in, and pass my first exams with fairly good grades. In addition, I made a few friends with whom I felt comfortable and with whom I could share my fears. I set up a routine that was really my own — a routine that met my needs.

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ANNOUNCEMENTS 1.Household register has the legal validity that certifies the attorneyship of a citizen and the relationship of family members, and it is the main reference for the censor and checkup of domiciliary register which is undertaking by the household registration authority. When the functionary of household registration authority censor and verify the household register, the familia and members of this family shall take the initiative in presenting the household register. 2.The familia shall take the household register in safekeeping, the household register is prohibited to be alterred, transferred and leased. In case of that the household register is lost, the household registration authority should be informed. 3.The right for registering the household register shall be performed by the household registration authority, any other unit and individual shall not make any records on the booklet. 4.The member of this family shall go to the household registration authority for transacting the declaration and registration, applying bring with the booklet, in case of the increase and decrease of the members and the alteration of registration items. 5.In case of that the whole family moves out of the residency, the Household register shall be turned in and cancelled.

户口本英文翻译

ATTENTION 1.Residents Booklet have the force of law with proof of citizenship and relationship between family members. It is the main basis for the Household Registration Office to investigating and verifying the situation of the residence. House owner and family members should hand in the Residents Booklet when the household registration officer investigate and check the household registration 2.House owner should keep the Residents Booklet safely. It should not be altered, transfer, lend. Please report Household Registration Office. when being lost. 3.The rights of registration of Residents Booklet belong to Household Registration Office. Any other unit or individuals shall not make any records in the booklet 4.House owner should register the changes of family members or the other contents. 5.All family members moving out of residence jurisdiction should hand in Residents Booklet to Household Registration Office. No.

英文翻译定稿2009-6-18

宣传画册文稿翻译: 封面:济人药业 JIREN PHARMACEUTICAL 扉页:诚善济人药信为民 Honest Jiren, Yaoxin Benefits People. P1 华佗故里,药材之乡 Huatuo?s Home, Herbs? Hometown P2 序:董事长致辞、领导关怀 President?s Address, Leaders? Solicitude 魅力济人:效能组织、精锐团队、诚信经营、硕果累累 Charming Jiren: Efficient Organization, Elite Team, Honest Management, Rich Fruits. 实力济人:产研一体、科技创新、核心产业、精良药品、中药材种植基地、中药饮片、中成药。 Strength Jiren: Production with Research, Scientific Technological Innovation, Core Industry, Refined Medicines, TCM Herb Planting Base, TCM Prepared Pieces, TCM Formulas. 严密检测,质量保障 Strict Inspection, Quality Guarantee 活力济人 Vigorous Jiren P3 概述

Introduction P4 :安徽济人药业有限公司成立于2001年,现有员工700多人,占地面积300多亩,建筑面积5万多平方米,银行信用AAA级。 Anhui Jiren Pharmaceutical Co., Ltd. (Jiren or Jiren Pharmaceutical) was set up in 2001 with more than 700 staff, covering an area of over 200,000 square meters and a building area of over 50,000 square meters, with bank credit of AAA. 公司坚持走高新技术产业化的发展道路,不断打造核心竞争力,形成了由中药材规范化种植、中药饮片、中药配方颗粒、中成药研发、生产、销售为一体的现代中药产业链。 Our Company insists on the developing ways of high and new technology industrializations, continues to create the core competitive power, and has formed the modern TCM industrial chains in the systematic TCM herb standardization planting, TCM prepared pieces, single TCM concentrated granule, TCM formula research, production and sale. 公司坚持“先做人、后做药”的经营理念和“诚善济人、药信为民”的企业宗旨,按照以人文本的科学发展观,建立了现代企业制度,实现了现代化、科学化管理。建立了安徽省中药提取工程研究中心和省级企业技术中心。 Our Company insists on the managing philosophy of …Being a Honest Person First and Doing Things Second?and on the company?s

英国出国签证办理——全家户口本英文翻译模版绝对权威官方

Points for Attention 1. Household register has legal effectiveness to certify a resident’s identity and relations between family members. It is the main basis for household registration authority to make survey and check the census register. The head of the household and the family members should hand out the household register on their own initiative when Staff members of the authority make survey and check. 2. The head of the household should keep the register properly. It is forbidden to alter privately, to transfer and to borrow or lend. If the register is lost, please let household registration authority know immediately. 3. The right of the household registration belongs to household registration authority. Any other unit or individual mustn’t make record on the register. 4. In case of the increase or decrease of the family members, the register should be handed to household registration authority for registration. 5. If the whole family moves from the jurisdictional area, the register should be handed to household registration authority for cancellation.

英语翻译定稿!!!!

1.An abstract serves an important function in a research report. It communicates the scope of your paper and the topics discussed to your reader. In doing so, it facilitates research. Abstracts help scientists to locate materials that are relevant to their research from among published papers, and many times scientists will only read a paper’s abstract in order to determine whether the paper will be relevant to them. Considering your audience and their needs will help you to determine what should be included in your abstract.——摘要在研究报告中发挥着重要作用。它把你论文的视野和讨论的主题传达给读者。这样做有利于研究。摘要帮助科学家从发表的论文中找到与他们研究相关的文献资料,科学家常常只阅读一篇论文的摘要从而决定此论文是否与他们的研究有关。考虑到你的读者和他们的需求会将帮助你决定摘要该包含什么。 2.An informative abstract acts as a report in miniature, encapsulating the whole paper. It summarizes the key information from every major section in the body of the report, and provides the key facts and conclusions from the body of the report. A good way to develop an informative abstract is to devote a sentence or two to each of the major parts of the report. If space permits, you can provide contextual information such as background of the problem and the significance of the research, but you can also omit contextual information because the abstract is not supposed to serve as an introduction to the subject matter of the report----your introduction will serve that role. You should, however, include key numerical facts to make the informative abstract brief and readers will not be surprised to see key data in an informative abstract.——信息性摘要作为微型报告,概括了整篇论文。它总结了报告主体各个主要部分的关键信息,并且提供了报告主体的关键事实和结论。写信息摘要的一个很好的方法就是从报告的每一主要部分提炼一两句话。如果篇幅允许,你可以提供给一些与上下文有关的信息,如问题背景和研究的意义,但是你也可以省略这些信息,因为摘要不应作为文章主要内容的介绍,因为你的引言担当这一角色。然而你应该要包含关键数据从而使得信息摘要简洁明了,并且读者将不会因在信息摘要中看到关键数据而惊讶。 3.An indicative abstract (sometimes called descriptive abstract) merely includes information about the purpose, scope and methods used to arrive at the findings contained in the original document.The function of indicative abstract is to help readers understand the general nature and scope of the research article. An indicative abstract indicates the subject and main findings of the paper but it does not go into a detailed step-by-step account of the process involved. It is brief and concise, from which readers can decide if they should continue to read the entire paper. This type of abstract is often used in writing theoretical papers, commentary articles, and in some circumstances, conference proceedings.

户口簿英文翻译

(Translations) ____________________________________________________________________________________________ Registered Permanent Residence (Translations) Household Register Notice 1. Permanent residential book has the force and effect that can certify the citizen’s identity and relations between family members. It’s also the main gist for the census of permanent residence registration authority. The householder and family member have the liability to present the permanent residential book to the officer when the census is being taken. 2. The householder should keep the permanent residential book properly and it’s prohibited to have any modification, transfer and lend out which is not authorized. Also the householder shall report to the permanent residence registration authority immediately for the losing of the book. 3. The permanent residence registration authority is the only one who has the authority for the registration, any other unit of person is not allowed to write anything on the book. 4. The householder shall come to the permanent residence registration authority with for re-registering if there are any changes about the family members and other recorded items. 5. The householder shall go to the permanent residence registration authority to revoke the book if the family moves out the dominated district. ____________________________________________________________________________________________ Registered Permanent Residence (Translations)

户口本英文翻译

户口本内容: 第一页注意事项(五条内容) ATTENTION Residents Booklet have the force of law with proof of citizenship and relationship between family members. It is the main basis for the Household Registration Office to investigating and verifying the situation of the residence. House owner and family members should hand in the Residents Booklet when the household registration officer inv estigate and check the household registration . 2. House owner should keep the Residents Booklet safely. It should not be altered, transfer, lend. Please report Household Registration Office. when being lost. 3.The rights of registration of Residents Booklet belong to Household Registration Office. Any oth er unit or individuals shall not make any records in the bookle.t 4.House owner should register the changes of family members or the other contents. 5.All family members moving out of residence jurisdiction should hand in Residents Booklet to Ho usehold Registration Office. 户别:Type of Household 非农业家庭户口:Non-agricultural family 户主姓名:Name of Householder 沙岭派出所:Shaling Police Station 户号:Household number 住址:Current residential address 沈阳市于洪区沙岭镇沙岭小区24号1-1-1: Room 1-1,Unit 1,No.24 Building.Shaling Block,Shaling Town,Yuhong District,Shenyang 印章内容: 辽宁省公安厅:Public Security Department of Liaoning 省级公安机关户口专用章:Authorized supervisor 沈阳市公安局:Public Security Bureau of Shenyang 沙岭派出所:Shaling Police Station 户口登记机关:Authorized Administrator 承办人签章:Registrar 于洪:Yuhong District 董德银:Dong Deyin 沙岭:Shaling 2006年9月12日签发:Date of Issue:12th September 2006 李刚页 住址变动登记:Register of Residence Change 变动后的住址:New Address 变动日期:Date of registration update 承办人签章:Registrar

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