电气化铁道动力供电系统模拟_英文_

电气化铁道动力供电系统模拟_英文_
电气化铁道动力供电系统模拟_英文_

第5卷第3期2005年6月

交通运输系统工程与信息

Journal of T ranspo rtati on System s Engineering and Info r m ati on T echno logy V o l 15N o 13June 2005

文章编号:100926744(2005)0320093215

交通科学与工程

Traction Power System Si m ula tion

i n Electr if ied Ra ilways

T .K .Ho 1,Y .L .Ch i 1,L .K .Siu 2,L .Ferreira

3

(1.D epartm ent of E lectrical Engineering ,Hong Kong Po lytechnic U niversity ,Hong Kong ,Ch ina ;2.Kow loon 2Canton R ail w ay Co rpo rati on ,Hong Kong ,Ch ina ;3.Schoo l of C ivil Engineering ,Q ueensland U niversity of T echno logy ,

A ustralia )

Abstract : E lectricity has been the m aj o r source of pow er in mo st rail w ay system s .R eliable ,efficient and safe pow er distributi on to the trains is vitally i m po rtant to the overall quality of rail w ay service .L ike any large -scale engineering system ,design ,operati on and p lanning of tracti on pow er system s rely heavily on computer si m ulati on .T h is paper review s the m aj o r features on modelling and the general p ractices fo r tracti on pow er system si m ulati on ;and introduces the developm ent of the latest si m ulati on app roach w ith discussi ons on si m ulati on results and p ractical app licati ons .R em ark s w ill also be given on the future challenges on tracti on pow er system si m ulati on .Key words : electrified rail w ays ;computer si m ulati on ;tracti on pow er system CLC nu m ber : U 223.6

电气化铁道动力供电系统模拟

何天健1,池云莉1,邵乐基2,L .Ferreira 3

(1.香港理工大学电气工程系,中国香港;2.九龙区铁路公司,中国香港;3.昆士兰技术大学民用工程系,澳大利亚)

摘要: 电力是现今大部份铁道系统的动力来源Λ可靠、有效率及安全的电力输送对整

体铁道服务质素尤为重要,跟其它大型工程系统一样,铁道供电系统的设计,运作及筹划相当倚重计算机仿真Λ本文将回顾铁道供电系统仿真的模型及一般常规,并通过模拟结果例子及实际应用,介绍最新的模拟方式发展Λ本文亦对铁道供电系统仿真的未来挑战作出评论Λ

关键词: 电气化铁道;计算机模拟;动力供电系统中图分类号: U 223.6

收稿日期:2005204218

何天健(1966-),男,中国香港人,香港理工大学电机工程系副教授,主要研究方向为铁路系统传真,铁路牵引与供变电技术,交通控制模型等Λ

0 I n troduction

E lectricity has becom e the p ri m ary sou rce of tracti on pow er in m odern rail w ays .A ll m etro system s are now operated by electricity in one

fo r m o r ano ther .W h ile the diesel o r coal driven train s are still heavily u sed in som e coun tries ,they

are

often

li m ited to

long 2distance

comm u tati on

and o r

freigh t

tran spo rtati on .

E lectricity u tilisati on is the trend of rail tran spo rtati on,ju st the sam e as fo r social advancem en t.N o t on ly does it p rovide a reliab le pow er sou rce and enab le robu st train p erfo r m ance,it is also an environm en tally friendly m ean s to con sum e energy.Sm oke and po llu tan ts from com bu sti on engines are si m p ly no t accep tab le fo r op erati on s in enclo sed environm en t,p articu larly in m etro system s.

E li m inating the need to carry fuel on board m ay be seen as ano ther advan tage of u sing electricity fo r rail w ay tracti on.How ever,the pow er distribu ti on along the rail w ay lines and the equ i pm en t to facilitate pow er tran s m issi on ju st po se ano ther m ajo r engineering p rob lem in stead.

Indeed,the advan tages of electric tracti on pow er do no t com e w ithou t a h itch.

E lectrom agnetic incom p atib ility w ith the signalling system s w as the early p rob lem and is still raising m ajo r concern s.In som e cases, p hysically sep arated system s fo r tracti on pow er and signalling have to be adop ted,such as the4-rail arrangem en t in the L ondon U nderground [1].W ith advanced pow er electron ics tracti on drive system,har m on ics m ay be generated, w h ich is sign ifican t enough to con tam inate the electricity supp lied to o ther u sers.O ther concern s include safety(touch vo ltage on rails),operati on (overloading,system fau lt and po ssib le equ i pm en t failu res),p ro tecti on(ligh tn ing and vandalis m),m ain tenance(rail co rro si on due to stray cu rren t,pan tograph and overhead line in teracti on)and p lann ing(line ex ten si on s, sho rter headw ay o r h igher speed).

W ith the inevitab ly h igh cap ital co st in a rail w ay system,the study on tracti on pow er system starts from the design stage.Sizes and locati on s of the feeding sub stati on and ratings of the pow er equ i pm en t to cater fo r the expected traffic vo lum e are am ong the first questi on s from electrical engineers.Energy co st is also i m po rtan t fo r the op erato rs in the nego tiati on of electricity tariff.T he range of variati on s of pow er and vo ltage at certain po in ts of the pow er netw o rk,robu stness to ab so rb fau lts and capab ility to handle regenerated energy(from regenerative b rak ing)are the key issues in op erati on s. Fu rther,the p ro jected u sage,as w ell as the po ssib ility and ex ten t of overloading,of the pow er system equ i pm en t,p rovides the u sefu l info r m ati on on m ain tenance w o rk.

A com p rehen sive study on the tracti on pow er system has to be carried ou t even befo re the system is bu https://www.360docs.net/doc/5811517897.html, pu ter si m u lati on is conceived as the on ly viab le m ean s to enab le such study. Si m u lati on s of differen t app roaches and scales are u sed ex ten sively to investigate vari ou s k inds of system studies.Si m u lati on m odels and techn iques on rail w ay tracti on system s w ere first develop ed th ree decades ago.Since then,they have m atu red th rough a num ber of evo lu ti on s on m odel accu racy and com pu tati onal efficiency and served the pu rpo ses of vari ou s app licati on s fo r rail w ay engineers,operato rs and researchers.How ever, the developm en t of tracti on pow er system si m u lati on seem ed to com e to a gradual halt ten years ago becau se of the satu rati on of app licati on requ irem en ts.In recen t year,driven by the increasingly dem anding requ irem en ts on system reliab ility and availab ility,service quality and traffic dem and from p lann ing view po in t and coup led w ith the po ssib le need of real2ti m e app licati on s from operati on view po in t,new developm en t in si m u lati on app roach and u tilisati on of advanced com p u ting techn iques have su rfaced.

T h is paper ai m s to review the m odels, difficu lties and app licati on s of tracti on pow er system si m u lati https://www.360docs.net/doc/5811517897.html, parison s are then m ade on the si m u lato rs w ith the traditi onal and the latest app roaches of pow er flow calcu lati on, fo llow ed by the discu ssi on s of inco rpo rating the advan tages of m odern com pu ting hardw are and softw are to enhance the app licab ility of the si m u lato rs.

1 Traction Power Supply System s

T he tracti on pow er system is,in its si m p lest

49交通运输系统工程与信息2005年6月

fo r m ,a huge electrical circu it .T he pow er supp ly m ay be in single o r m u lti p le sou rces and the

feeding arrangem en ts vary in differen t system s .T he com p licati on s ,as illu strated later ,m o stly com e from A C tracti on pow er supp lies .T he loads in the electrical circu its are the train s w h ich are m oving and dem anding differen t levels of pow er

acco rding to their op erati onal m odes and sp eeds .A train m ay becom e a sou rce if regenerative

b rak ing is allow ed .

In o rder to attain steady 2state so lu ti on of the electrical circu it ,the sou rces ,feeding netw o rk s and loads m u st be p roperly m odelled ,w h ich is no si m p le task ,given the varieties of supp ly system s and operati on conditi on s .T h is secti on exam ines the featu res of tracti on pow er system s and discu sses the con siderati on s and difficu lties in m odelling .

1.1 Power Suppl ies 1.1.1 DC supp lies

DC rail w ays are operated at relatively low er vo ltages .600V ,750V and 1.5kV are the typ ical figu res [2].T he DC tracti on pow er com es from track side rectifier sub stati on s linked to the A C distribu ti on netw o rk .Each feeding sub stati on covers a secti on of track bu t there is no r m ally no iso lati on betw een adjacen t secti on s ,w h ich i m p lies a m u lti p le 2sou rce system .T he secti on length is sub stan tially

sho rter

becau se of the low er distribu ti on vo ltage level

.It shou ld be no ted that the tracti on cu rren t can be as h igh as a few

thou sand am peres .O verhead catenary o r a th ird rail (o r even track side sliding con tact ),w ith runn ing rail retu rn ,is em p loyed to distribu te pow er to train s .F ig .1show s a typ ical DC supp ly netw o rk fo r a b ranched tw o 2road service .Sw itchgear and iso lato rs on A C side and circu it b reakers on DC side are in stalled fo r p ro tecti on and fau lt m anagem en t

.F ig .1 B ranched tw o 2road netw o rk w ith DC supp ly

DC rail w ays are u sually less su scep tib le to electrom agnetic in terference even though har m on ics from the rectifier sub stati on s o r tracti on equ i pm en t requ ire p rop er filtering .L eakage cu rren t th rough the runn ing rails how ever cau ses co rro si on on the rails .T he rail 2to 2earth conductivity ,w h ich deter m ines the am oun t of leakage cu rren t ,dep ends on so il p roperties and the earth ing structu re in the su rroundings .T he h igh retu rn cu rren t th rough the rails also develop s vo ltage on rails ,w h ich

m ay be hazardou s to personnel w o rk ing clo se to the rails .

D esp ite being a m u lti p le 2sou rce system ,DC tracti on pow er system does no t cau se too m any difficu lties to the so lu ti on calcu lati on p rocess in si m u lati on (train s m ay becom e sou rces w ith regenerative b rak ing to tu rn the circu it in to a m u lti 2sou rce system anyw ay )becau se of the si m p le feeding arrangem en t .W hen the locati on s of train s and resistance of rails and overhead cab les are know n ,it is on ly tedi ou s to estab lish

5

9第3期T racti on Pow er System Si m ulati on in E lectrified R ail w ays

the electrical circu it in o rder to so lve fo r the vo ltages and cu rren ts in the circu it.B ranches and m u lti2track lines are comm on in rail w ays and they ju st m ake the electrical circu it m o re com p licated.

A pp rop riate netw o rk partiti on ing w ill certain ly reduce the com p u tati onal dem and of the so lu ti on p rocess.

A s som e sub stati on s are equ i pp ed to receive pow er from the DC system and release it back to the A C side so as to ab so rb the excessive fed2back energy from regenerative b rak ing,the b i2 directi onal flow of pow er shou ld be inco rpo rated in the m odels.How ever,the i m po rtan t featu re is that recep tive sub stati on s allow pow er flow in one directi on(from A C to DC)m o st of the ti m e and they on ly p er m it reversal of pow er flow w hen it is necessary.

1.1.2 A C supp lies

Pow er fo r A C rail w ay tracti on is ob tained from u tility supp ly system,at tran s m issi on o r sub2tran s m issi on vo ltage level,th rough tracti on feeding sub stati on s.25kV tracti on netw o rk at50 o r60H z is the m o st comm on ly adop ted system. T he rail line is u sually divided in to a num ber of iso lated feeding secti on s and each secti on is fed by a single2phase supp ly from a tran sfo r m er w ith in the secti on.Pow er is carried to the train s th rough overhead catenary and cu rren t takes the rails as retu rn path s.H igh catenary vo ltage allow s low er tracti on cu rren t and s m aller pow er lo ss w h ile the secti on length(o r distance betw een adjacen t feeding tran sfo r m ers)can be kep t relatively long, typ ically over10km.A djacen t secti on s are supp lied by differen t p hases of a32phase netw o rk and they are sep arated by track neu tral. P rovisi on s of iso lato rs and s w itchgear are necessary fo r track neu tral and parallel secti on s to enab le con tinual feeding in cases of failu res and ou tages by iso lating certain fau lty equ i pm en t o r secti on o r even reconfigu ring to a differen t feeding netw o rk.

A num ber of feeding arrangem en ts are availab le,including direct supp ly w ith o r w ithou t retu rn conducto rs,boo ster tran sfo r m er(

B T)and au to tran sfo r m er(A T)system s.Several con siderati on s,such as pow er tran s m issi on efficiency,vo ltage regu lati on and in terference supp ressi on,have to be taken on the adop ti on of the su itab le feeding arrangem en t fo r a p articu lar tracti on pow er system.

D irect connecti on of the tran sfo r m er secondary to the catenary and rails is the m o st straigh tfo r w ard m ean s of pow er feeding. Sign ifican t rail2to2earth leakage cu rren t is the m ajo r draw back of th is feeding arrangem en t becau se of the inevitab le rail2to2earth i m p edance. Co rro si on on rails is no longer an issue becau se of A C cu rren t.How ever,the i m balance betw een the supp ly cu rren t on the overhead cab le and the retu rn cu rren t on the rails(the difference betw een the tw o being the rail2to2earth leakage cu rren t), coup led w ith the physical separati on betw een overhead cab le and rails,is often one of the m ain cau ses of electrom agnetic in terference to the lineside telecomm un icati on equ i pm en t.A s show n in F ig.2,the additi on of a retu rn conducti on,in parallel w ith the catenary and connected to the rails at regu lar in tervals,help s reduce the leakage cu rren t,bu t on ly to a certain ex ten t

.

F ig.2 D irect feeding w ith return conducto r

B T feeding p rovides ano ther m ean s of in terference reducti on by fo rcing the cu rren t to flow in the retu rn conducto r rather than in the rail. How ever,it is at the exp en se of poo rer vo ltage regu lati on becau se of additi onal i m pedance of B T s.H aving allow ed pow er to be tran s m itted at the vo ltage tw ice as h igh as the op erating vo ltage,A T feeding i m p roves system efficiency. In terference supp ressi on is ano ther advan tage of A T feeding.In additi on,A T feeding p rovides

69交通运输系统工程与信息2005年6月

better vo ltage regu lati on and allow s longer in terval betw een tran sfo r m ers[3],w h ich is essen tial fo r service reliab ility of long2distance rail lines,if no t ju st the cap ital co st.Bo th B T s and A T s are p laced at regu lar in tervals w ith in a feeding secti on.Illu strated in F igs.3and4,B T feeding op erates by balancing cu rren ts on the tw o w indings of the tran sfo r m ers w h ilst A T relies on vo ltage balancing.B y in troducing B T s o r A T s w ith in the feeding secti on,the cu rren t is fo rced to retu rn via the retu rn conducto rs.Such m an i p u lati on of cu rren t retu rn path is how ever at the expen se of m o re conducto rs(m o stly overhead)along the lines and m o re com p licated cu rren t distribu ti on s.

T he additi onal equ i pm en t w ith B T and A T feeding p resen ts ex tra m odelling w o rk s in the si m u lati on.T he electrical param eters of the equ i pm en t are often availab le from m anufactu rers o r op erato rs bu t they have to appear as com p lex num bers(e.g.i m p edance in stead of resistance) becau se of the A C natu re.T he scale and com p lex ity of com pu tati on requ ired is then inflated sign ifican tly.It is also necessary to exam ine the cu rren t distribu ti on in the conducto rs along the line as the m u tual i m p edances am ong the conducto rs,as w ell as the adm ittances to the ground,p lay i m po rtan t parts in the steady2state so lu ti on.T rain po siti on relative to the locati on s of B T s o r A T s ho lds keys to cu rren t distribu ti on and differen t train po siti on s m ay lead to differen t circu it configu rati on s.O ne con so lati on from m odelling view po in t is that the feeding sub stati on s here are no t in terfaces betw een A C and DC system s,as in DC rail w ays.T he com p licati on of pow er flow directi on does no t ex ist in A C supp lies even w ith excessive pow er recovered from regenerative b rak ing.

1.2 L oads

In a typ ical in ter2stati on run,a train accelerates from a stati on to the m ax i m um p er m issib le sp eed,m ain tain s the speed and b rakes to a com p lete stop at the nex t stati on.It therefo re goes th rough a w ide range of speeds,differen t op erati on m odes and hence the pow er dem and m ay vary sign ifican tly w ith in a sho rt peri od of ti m e.T rain speed and operati on m ode are the decisive facto rs of the i m m ediate am oun t of pow er requ ired by the train as a load.T hey are how ever deter m ined by the tracti on equ i pm en t characteristics,train w eigh t,aerodynam ics, track geom etry and drive con tro l.T he electrical rep resen tati on of the train s in the circu it as a variab le load(and som eti m es sou rce)requ ires carefu l m odelling in the si m u lati on.

W ith the m oving train s,the configu rati on of the electrical circu it keep s changing and the so lu ti on relevan t to one in stan t m ay no t be valid to the nex t.If it is necessary to attain the details of the tracti on pow er system behavi ou r and train in teracti on,the electrical circu it has to be updated and the new circu it so lu ti on is to be re2 calcu lated at every regu lar ti m e in terval over a long sp an of ti m e.T rain m ovem en t si m u lati on is the basic accom pan ied functi on to p rovide train po siti on,speed and operati on m ode fo r the pu rpo ses of estab lish ing the electrical circu it.T he pow er netw o rk so lu ti on p rocess,u sually w ith m an i p u lati on of large2scale m atrix equati on s,at each ti m e in terval thu s i m po ses trem endou s com p u tati onal dem and to the si m u lati on.In fact, the pow er netw o rk so lu ti on is al w ays the m o st ti m e2con sum ing step of a w ho le system si m u lati on in rail w ays[4].

2 M odell i ng

T h is secti on discu sses the featu res in the tracti on pow er si m u lati on m odels w h ich requ ire carefu l con siderati on s.

2.1 Power suppl ies and feed i ng networks

2.1.1 DC supp lies

T he pow er sou rce at the sub stati on is assum ed to be a con stan t(u sually vo ltage)sou rce w ith equ ivalen t sou rce resistance.W hen the pow er system calcu lati on does no t com e up w ith a so lu ti on becau se of excessive over2vo ltage at the sub stati on o r cu rren t flow ing in oppo site directi on (u sually resu lted from regeneravivetive b rak ing),

79

第3期T racti on Pow er System Si m ulati on in E lectrified R ail w ays

the sub stati on m ay be re2m odelled as a passive load to allow pow er to go back to the supp ly system,p rovided that the sub stati on is suppo sed to be capab le of do ing so.

O nce the train po siti on s are know n,the resistances betw een train s are tho se of the overhead lines(o r con tact w ires)and the rails sep arating the train s if the resistance p er un it length of these conducto rs is assum ed to be con stan t.In p ractice,the resistances of the conducto rs are cu rren t2dep enden t[5]even though the variati on is no t disp ropo rti onate.Such dep endency can be inco rpo rated in the si m u lati on m odel fo r better accu racy bu t the so lu ti on p rocess m ay take m o re ti m e w ith m o re iterati on s.

R ail2to2earth leakage cu rren t is ano ther issue leading to com p licati on.T he leakage is a distribu tive p henom enon along the rail and it can be m odelled w ith a fin ite2elem en t app roach,in w h ich the rail is divided in to a num ber of elem en ts of equal length and a certain po rti on of the cu rren t flow ing th rough each elem en t leak s th rough the rail2to2earth resistance w h ile the rem ain ing carries on to the nex t elem en t.A s a resu lt,the rails have to be rep resen ted by a num ber of resistances in series,in stead of one resisto r on ly,in tersected w ith the rail2to2earth resistances in betw een.A s rail2to2earth leakage cu rren t does no t directly affect train in teracti on s th rough the pow er system,the ju stificati on of its inclu si on in the si m u lati on m odel is thu s deter m ined by the app licati on s of the si m u lato r.

2.1.2 A C supp lies

Feeding sub stati on s are still m odelled as con stan t vo ltage sou rces.A dditi onal conducto rs (m o stly overhead)and lineside equ i pm en t(B T s o r A T s)can be rep resen ted by app rop riate i m p edances and m u tual inductances in the electrical circu it.How ever,the m odelling of the m u tual inducti on am ong the p arallel conducto rs requ ires the fin ite2elem en t app roach again.T he p hysical sizes,relative resistivity,per m eab ility and geom etry of the conducto rs,relative p er m ittivity of the m edium,cu rren t distribu ti on and earth ing conditi on s are essen tial in th is m u lti2 conducto r m odel[3].Fu rther,as the rail is of un ique shap e,calcu lati on of i m pedance,w h ich is cu rren t and frequency dependen t,is far from easy.It can be treated as a single cylindrical steel conducto r,upon sub stan tial p re2p rocessing com p u tati on,w ith differen t cro ss2secti on areas fo r a w ide range of frequencies[5].R ail2to2earth leakage cu rren t can be conven ien tly included in th is fin ite2elem en t app roach,w h ich is a bonu s. W ith the distribu ted elem en ts,the num ber of com ponen ts in the electrical circu it becom es very h igh and the circu it is qu ite com p licated even befo re the train s are in serted.

In o rder to reduce the scale of com pu tati on requ ired,conducto rs w ith the sam e longitudinal vo ltages can be com b ined(e.g.the tw o rails)as one.T here are still at least th ree along2the2line conducto rs w ith B T and A T feeding,as show n in F ig.3and F ig.4

.

F ig.3 BT

feeding

F ig.4 A T feeding

2.2 L oads

T rain s,as loads,can be si m p ly m odelled as passive and pow er2con sum ing elem en ts in the electrical circu it to rep resen t its functi on as a pow er sink.In the case of A C rail w ays,the load shou ld con sist of the resistive and reactive com ponen ts to illu strate its pow er facto r. How ever,such si m p licity does no t reflect the dependence of pow er dem and on train sp eed and

89交通运输系统工程与信息2005年6月

operati on m ode,as w ell as vo ltage2sen sitive natu re of the load.

O ne app roach is to derive the train cu rren t and tracti on effo rt requ ired,given the train speed and operati on m ode,from the tracti on equ i pm en t characteristics(availab le from the op erato rs o r m anufactu rers),fo llow ed by estab lish ing a vo ltage2i m p edance(T heven in equ ivalen t circu it) o r cu rren t2adm ittance(N o rton equ ivalen t circu it) m odel[6],w h ich is p iecew ise linear.T he equ ivalen t circu it m ay con tain a hypo thetically negative i m pedance to indicate the pow er2sink ing p roperty of the load.D etailed tracti on equ i pm en t characteristics con tain ing tracti on p erfo r m ance w ith in a range of vo ltage variati on can be adop ted to m odel the vo ltage2dep enden t perfo r m ance of the load.T he data are u sually m ade ready p ri o r to the si m u lati on and sto red in the si m u lato r as look2up tab les fo r easy and ti m e2efficien t referencing.

A no ther app roach is to w o rk back from the ou tp u t m echan ical pow er.F rom the requ ired tracti on effo rt to su stain a certain sp eed o r to p roduce accelerati on,the ou tpu t pow er can be calcu lated from the train w eigh t,track geom etry, o ther train m ovem en t param eters and pow er lo sses.Given the efficiency of the tracti on system,the inp u t electrical pow er is attained and an equ ivalen t circu it w ith respect to the pow er dem and can again be u sed to rep resen t the load. It is a si m p ler app roach bu t it relies on com p rehen sive m odelling of all po ssib le pow er lo sses du ring train m ovem en t.

2.3 Power network solution

W ith the m odels of pow er supp ly and tracti on equ i pm en t availab le,the circu it of the electrified rail w ay line is estab lished fo r the calcu lati on of vo ltages and cu rren ts at vari ou s po in ts of in terest.T he m o st direct app roach is to fo r m u late a m atrix equati on from the electrical circu it u sing either m esh o r nodal analysis[6].T he so lu ti on is attained from so lving th is m atrix equati on w ho se coefficien t m atrix size depends on the num ber of train s and com p lex ity of the netw o rk.T h is app roach is m o re su itab le fo r com p lex electrical netw o rk s becau se it is often easier to iden tify nodes than loop s in non2p laner netw o rk s.F rom a p rogramm ing persp ective, au tom atic netw o rk set2up p rocedu res and advanced netw o rk graph techn iques are desirab le in the i m p lem en tati on,w ith the u se of the nodal app roach.

T he coefficien t m atrix in the pow er netw o rk so lu ti on is sparse,banded and symm etric fo r a si m p le tw o2track netw o rk.W hen the netw o rk con sists of b ranches and loop s,the bandw idth of the coefficien t m atrix increases and the sp arsity deteri o rates.F ig.5show s the circu it rep resen tati on of a typ ical DC tracti on pow er netw o rk w ith b ranches.It is no t difficu lt to see that the rail w ay tracti on pow er netw o rk is characterised by secti on s of ladder type netw o rk s infrequen tly cro ss2connected.Fo r th is characteristic topo logy,the sparse m atrix techn ique coup led w ith efficien t m atrix eli m inati on m ethods leads to an exp editi ou s netw o rk so lu ti on,since it does no t suffer from the fill2in s that the direct inversi on of the coefficien t m atrix requ ires.It has to be stressed again that if the fin ite2elem en t app roach is adop ted to m odel the conducto rs,the electrical circu it netw o rk w ill be fu rther com p licated and the size of the m atrices w ill be driven up con siderab ly.

W ith the coefficien t m atrix being po sitive defin ite (PD),symm etric and sparse,m any sparse m atrix eli m inati on techn iques tailo red fo r PD m atrices, such as L L T decom po siti on and Cho lesky decom po siti on,are app licab le.Fo r sparse m atrix so lu ti on techn iques,the essence is equati on2 o rdering.T here are generally tw o types of o rdering m ethods nam ely,static and dynam ic o rdering.T yp ical exam p les of static o rdering fo r long and th in ladder typ e netw o rk s include the Cu th ill and M cKee algo rithm[7]and reverse Cu th ill and M cKee algo rithm[8],w h ich m ake u se of the p rop erty that the zero elem en ts situated befo re the first non2zero elem en t on any row al w ays

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第3期T racti on Pow er System Si m ulati on in E lectrified R ail w ays

rem ain zero .Fo r dynam ic o rdering ,the m in i m um degree algo rithm p rovides an efficien t alternative fo r so lving the netw o rk m atrix .T h is is actually a heu ristic algo rithm to find an o rdering fo r the coefficien

t m atrix w h ich suffers

from low fill 2in s w hen it is facto red .T he m in i m um degree algo rithm

is p articu larly su itab le fo r so lving

m edium to large netw o rk s ,in w h ich there are 200nodes and m o re .Fo r s m aller netw o rk s ,the m in i m um

degree

algo rithm

becom es

a

less

efficien t op ti on since a sign ifican t po rti on of the overall p rocessing ti m e is u sed in the sym bo lic facto risati on p rocess

.

F ig .5 T he equivalent circuit of a typ ical pow er netw o rk w ith branches

Partiti on ing the electrical netw o rk in to several s m aller ,m o re m anageab le sub 2circu its by

node sp litting [9]

is one of the comm on m ethods to enhance si m u lati on efficiency .T h is techn ique ,

also know n as diakop tics [10]

,invo lves tearing a given netw o rk in to a num ber of indep enden t p arts and pu tting the so lu ti on s of the divided p arts together to fo r m the so lu ti on of the o riginal p rob lem .T he natu ral tearing po in ts in tracti on pow er netw o rk are the b ranches becau se the coefficien t m atrix of an iso lated b ranch is h igh ly sparse .How ever ,the num ber and size of the to rn p arts depend on netw o rk topo logy and num ber of

train s on the b ranches respectively [11]

.2.4 I n tegra tion with tra i n m ove m en t

T racti on pow er system si m u lato r on ly p rovides a steady so lu ti on fo r a given train conditi on .In o rder to estab lish vo ltage and cu rren t p rofiles over ti m e at certain po in ts of the pow er netw o rk w h ile train s are m oving in the rail w ay system ,it is essen tial to in tegrate the m ovem en t si m u lato r .

T ak ing in to accoun t the track geom etry ,signalling con strain ts ,ti m etab le o r headw ay conditi on s ,tracti on equ i pm en t behavi ou r and civil engineering speed restricti on s ,a train m ovem en t si m u lato r derives the sp eed ,po siti on and op erati on m ode of each train at each and every specific ti m e in tervals .O ne of the key facto rs in train m ovem en t is inevitab ly the tractive effo rt p roduced by the tracti on m o to rs .Perfo r m ance of the tracti on m o to rs is a functi on of train vo ltage and cu rren t w h ich are in tu rn calcu lated by the tracti on pow er system si m u lato r acco rding to train sp eed ,po siti on and operati on m ode .A s a resu lt ,in teracti on s betw een pow er system and train m ovem en t si m u lato r are necessary fo r the con siderati on of dynam ic train behavi ou r .

3 Si m ula tion and Appl ica tion s

Tw o si m u lati on app roaches on the m odels described are discu ssed here ,one w ith the 001交通运输系统工程与信息2005年6月

the o ther w ith a new m ethod of p robab ilistic calcu lati on w h ich p rovides an alternative p ro spective.Som e exam p les of si m u lati on resu lts are show n here to illu strate the differences in their functi onalities.A num ber of app licati on s of tracti on pow er system si m u lati on are then given to dem on strate its value in p ractice.

3.1 D eter m i n istic si m ula tion

In m o st app licati on s on op erati on and design, the fu ll details of in teracti on s am ong train s th rough the tracti on pow er system and betw een feeding system and train s are called fo r. Si m u lati on s under differen t operati onal conditi on s and traffic dem ands(o r‘w hat2if’scenari o studies),including no r m al and ex trem e,are requ https://www.360docs.net/doc/5811517897.html, p rehen sive m odels w ith the con siderati on s stated in the p revi ou s secti on s are requ ired in the si m u lati on and the netw o rk so lu ti on,how ever tedi ou s,is attained deter m in istically w ith respectab le accu racy.

T racti on pow er system si m u lati on is ti m e2 based and accom p an ied by a train m ovem en t si m u lato r.F rom all last know n train sp eeds and po siti on s,the pow er system si m u lato r estab lishes the pow er netw o rk w ith resp ect to the train po siti on s,track layou t and feeding arrangem en t; and so lves fo r the vo ltages and cu rren ts fo r one ti m e step.W ith the train vo ltages and cu rren ts p assed back to the train m ovem en t si m u lato r,it calcu lates the nex t train speeds and po siti on s. T he p rocess then repeats at every ti m e in terval. T h is rep etitive in teracti on betw een the pow er system and train m ovem en t si m u lato rs is illu strated in F ig.6.Softw are i m p lem en tati on is qu ite straigh tfo r w ard bu t still tedi ou s. N onetheless,system atic data m anagem en t and sub stan tial am oun t of data sto rage are strongly requ ired.

F igs.7and8show the sam p le resu lts of vo ltage and cu rren t variati on s at a feeding sub stati on in a typ ical DC m etro line w ith nom inal vo ltage of1.5kV.T hey indicate the loading at the sub stati on at a p articu lar traffic conditi on, and peak s and ranges of variati on s can

be

F ig.6 Interacti on betw een pow er system

and train movem ent si m ulato rs

iden tified easily.F igs9and10illu strate the vo ltage and cu rren t of a train as it m oves along the line and they allow m on ito ring of the train pow er dem and.T he resu lts from the pow er system si m u lati on al w ays co rrespond to the train m ovem en t.Fo r exam p le,cu rren t peak and vo ltage di p indicate accelerating train w h ilst a train in regenerative b rak ing is reflected by negative cu rren t flow and vo ltage rise

.

F ig.7 T rain vo ltage against

distance

F ig.8 T rain current against distance

T he ou tcom es from the pow er netw o rk si m u lato r are the exact vo ltages,cu rren ts and pow er flow p rofiles at all crucial po in ts in the netw o rk at every ti m e step over a peri od of ti m e.T hey are p roven to be very u sefu l fo r pow er engineers, rail w ay operato rs and m ain tenance personnel alike.How ever,as the resu lts com e from ti m e2

101

第3期T racti on Pow er System Si m ulati on in E lectrified R ail w ays

F ig .9 Substati on vo ltage against ti m

e

F ig .10 Substati on current against ti m e

con sum ing calcu lati on s and the ou tp u t data is

often vo lum inou s (w ith the size of the pow er netw o rk and num ber of train s )fo r analysis ,no t to m en ti on the po ssib ility of fu rther p rocessing and sto rage ,detail redundancy ,though an advan tage at ti m es ,is a draw back of th is deter m in istic app roach fo r certain app licati on s .Even though the resu lts give detailed accoun t of the electrical behavi ou r of the pow er system s and train s ,it has to be said that no t every detail is requ ired in m o st app licati on s .

M o st of the ex isting tracti on pow er system si m u lato rs

[6,12-15]

,as w ell as o ther comm ercially availab le p ackages [16]

,em p loy th is deter m in istic app roach .T hey are also equ i pped w ith reasonab le u ser in terfaces to enab le the inpu t (and ou tp u t )of the vast am oun t of data requ ired fo r (and p roduced by )the si m u lati on .N early all of them have been tailo r 2m ade to su it the p u rpo ses of p articu lar system s o r specific studies and hence som e of them m ay no t be p roperly docum en ted in p ub lic dom ain .

3.2 Probab il istic si m ula tion

A

new ly

developed

alternative

is

a

p robab ilistic app roach in w h ich the ou tcom es are

p robab ility den sity functi on s (pdf )of vo ltage o r pow er flow at certain po in ts of the pow er system ,indicating the ranges of variati on s of

such

param eters and hence the loading conditi on s ,on p robab ilistic basis w ith a si m p le and ho listic rep resen tati on ,w h ile sk i pp ing the tedi ou s p rocess of ex tracting the requ ired data from huge am oun t of si m u lati on resu lts .How ever ,the traditi onal

tracti on pow er si m u lato rs by deter m in istic

app roach are no t to be rep laced by tho se from th is

p robab ilistic app roach .T he p robab ilistic app roach indeed p rovides a differen t view po in t of in sigh t in to the tracti on pow er system behavi ou r and hence su its differen t pu rpo ses of app licati on s .

To bu ild the necessary pdfs ,train po siti on is the starting po in t and its ow n pdf is estab lished from

typ ical

speed p rofiles of in ter 2stati on

run s [17]

,w h ich can be generated by an off 2line

train m ovem en t si m u lato r .T he random sam p le draw n

from

the

train

po siti on

cum u lative

p robab ility functi on is u sed to deduce train speed and operati on m ode ,and hence the train pow er dem and is derived from the tracti on equ i pm en t characteristics .W ith the loading conditi on s (train s )know n ,the pow er netw o rk is so lved to p roduce the vo ltage ,cu rren t and pow er flow at certain po in ts .T he p rocess is repeated w ith sufficien t num ber of random sam p les of train po siti on and the resu lting p dfs are fo r m ed in M on te Carlo si m u lati on techn ique .T he p rocess is summ arised in F ig .11.M u lti p le train s of specific ti m etab les (o r headw ays )are pu t in to the calcu lati on

acco rding

to

their

suppo sed

sep arati on s so that the effects they i m po se on

each o ther can be inco rpo rated [18]

.

A s there is no direct in teracti on betw een train m ovem en t and pow er system si m u lato rs in th is app roach ,the exact detail of the relati on sh i p betw een train vo ltage and speed m ay no t be fu lly reflected .A gain ,the p u rpo ses of the app licati on decide the level of details in the ou tp u t ,and thu s the si m u lati on app roach to be adop ted .

201交通运输系统工程与信息2005年6月

F ig .11 P rocessing from a train po siti on samp le to pow er system so luti on

T he resu lts from th is app roach basically give

the sam e info r m ati on on the tracti on pow er system behavi ou r over a p eri od of ti m e as in the deter m in istic app roach and they rely on the sam e m odelling con siderati on s in the calcu lati on .T he m ain difference is in the fo r m ats of ou tpu t p resen tati on .A s show n in the sam p le resu lts p resen ted here ,the sizab le data on the variati on s of a circu it p aram eter (vo ltage ,cu rren t o r pow er flow )is cap su lated in a single grap h of p robab ility den sity functi on w hereas the details of exact value at a specific po in t of ti m e are h idden .D esp ite the differen t in terp retati on s of ou tpu t ,com pu tati on dem and on tracti on pow er system si m u lati on is how ever very m uch si m ilar in bo th deter m in istic and p robab ilistic app roaches .T he general exp erience in th is app roach is that the M on te Carlo si m u lati on requ ires at least 10,000sam p les to estab lish reliab le p dfs .

P robab ilistic

app roach

is

no t

yet

as

comm on ly adop ted as the deter m in istic one bu t it serves its pu rpo ses as a supp lem en t to the fo r m er .

F ig .

12and F ig .

13are exam p les of

vo ltage and pow er dem and pdfs of a train in an A C rail w ay w ith A T feeding .W ith a nom inal supp ly vo ltage of 27.5kV ,the vo ltage sp reads over bo th sides of the nom inal value (and pow er p df sp illing on

bo th sides of 0MW ),w h ich indicates

that regenerative b rak ing is allow ed .F ig .14-F ig .

16com pare the pow er dem and pdfs at a feeding sub stati on under the sam e traffic conditi on s w ith the th ree differen t feeding arrangem en ts .A T feeding ,as exp ected ,p rovides better vo ltage regu lati on w ith a narrow er sp read in the p df .3.3 Appl ica tion s

T here

have

been

num erou s

p ractical

F ig .12 T rain vo ltage pdf

F ig .13 Pdf of active pow er dem and of a train

F ig .14 T rain vo ltage pdf of train w ith direct feeding

app licati on s of tracti on pow er system si m u lati on .Even though the ob jectives of the app licati on s m ay on ly focu s on a particu lar aspect of the pow er system ,the si m u lati on of the w ho le system is u sually needed to facilitate the fu ll functi on s of the aspect in questi on .System sizing on equ i pm en t and com ponen ts is an indispen sab le

3

01第3期T racti on Pow er System Si m ulati on in E lectrified R ail w ays

F ig .15 T

rain vo ltage pdf w ith BT feeding

F ig .16 T rain vo ltage pdf w ith A T feeding

step in the design stage .A s each rail w ay is

un ique in its traffic dem and ,track geom etry and operati on ,tests on pow er rating li m its o r capacities

[19]

and clai m ed p erfo r m ance

[20]

w ith

resp ect to the characteristics of the rail w ay system are com p u lso ry even befo re p rocu rem en t of the m ajo r equ i pm en t of the system .U n su rp risingly ,w ho le

system p erfo r m ance analysis w ith com p lete inco rpo rati on of train

m ovem en t

si m u lato r

[21]

to

exam ine

the

com p atib ility am ong differen t sub 2system s ,as w ell as their ow n functi onalities ,is al w ays one of the m ain p u rpo ses of si m u lati on .W h ile a fu ll system

analysis

w arran ts si m u lati on of

deter m in istic app roach ,the uncertain ty on som e system p aram eters at early stage of p lann ing m ay find the p robab ilistic app roach m o re su itab le . D ynam ic behavi ou r of the pow er system in the cou rse of operati on is ano ther m ajo r top ic of in terest .A s vo ltage stab ility is vital to con sisten t train p erfo r m ance ,a num ber of studies have investigated vo ltage fluctuati on s in differen t

system s [22-24]

under vari ou s op erati on conditi on s .

A pp licati on s ,such as studies on stray cu rren t [25]

,

touch vo ltage [26]and earth cu rren t [27]

,are also

found w ith good ex ten t of success ;w h ile analysis

on har m on ics [28],fau lt detecti on [29]

and electrom agnetic com p atib ility needs the tracti on pow er system si m u lati on as an aux iliary too l to supp ly background data .Fo r pow er engineers ,resu lts

from

p robab ilistic

si m u lati on

give

sufficien t indicati on s to peak dem and and vo ltage variati on s .O n the o ther hand ,rail w ay op erato rs

m ay need detailed si m u lati on resu lts w hen they need to investigate con tinuou s changes on vo ltage and cu rren t over a specific ti m e 2sp an .

In additi on to studies related to the pow er system ,tracti on pow er system si m u lati on has also com e to the aid of train operati on and

con tro l

.W hen train op erati on is m an i pu lated to fit particu lar ti m etab les o r schedu les ,the resu lting pow er dem and and o r energy con sum p ti on have to be checked fo r po ssib le saving and o r infringem en t of system con strain ts .Pow er system si m u lati on has been em p loyed to evaluate the i m pacts and m erits of re 2starting

regi m es of train queues [30]

and differen t coasting con tro l strategies to m eet run 2ti m e

requ irem en ts [31]

by si m p ly p roviding the data on the supp lied pow er and energy under specific train op erati on arrangem en ts .

4 FurtherR Cha llenges

Si m u lati on

al w ays

relies

on

accu rate

m odelling of the functi on s and behavi ou r of the system to p roduce reliab le resu lts .In tracti on pow er system si m u lati on ,the m odels on vari ou s com ponen ts of the system are qu ite m atu re .D esp ite con tinu ing effo rt to pu rsue m o re accu rate and elabo rated m odels ,such as rail track ,rail

i m p edance ,m o to rs [32-34]

and even driver behavi ou r ,

the

ou tpu ts

from

the

ex isting

si m u lato rs are of accep tab le accu racy upon verificati on .T here are al w ays new system s o r set 2up s w h ich requ ire differen t m odelling and

M eglev is one exam p le [35-37]

.Fu rther developm en t on m odelling often enhances the level of details in the ou tp u t o r targets selected

investigati on ob jectives .

401交通运输系统工程与信息2005年6月

O n the o ther hand,com pu tati onal dem and is certain ly go ing up w ith m o re com p licated m odels. If it is desirab le to m ain tain the app licab ility of the si m u lato rs o r even to inco rpo rate them in to on2line con tro l softw are in an adviso ry ro le in the fu tu re,parallel p rocessing techn iques[38]to reduce com p u tati on ti m e and a carefu lly structu red app roach to softw are validati on are requ ired. Parallel p rocessing can be app lied to bo th hardw are and softw are.W ith hardw are,a num ber of p rocesso rs can be connected in a specific configu rati on and the difficu lty is to sp read the com pu tati on even ly to the p rocesso rs to ach ieve the m ax i m um th roughpu t.O n the configu rati on of p rocesso rs,there are m any po ssib le system s,based on differen t p aram eters such as con tro l m echan is m,m em o ry configu rati on and num ber of p rocesso rs.Since the m atrix is a22D data structu re,it can be easily m apped in to a linear o r a m esh array.

Even w ith a single p rocesso r,p arallel p rocessing is still po ssib le w ith the aid from softw are.PC s are still the comm on adop ted p latfo r m s fo r si m u lati on and their pop u lar In ter Pen tium III o r above p rocesso rs allow p arallel data p rocessing w ith in their structu re.T hey include S I M D(Single In structi on M u lti p le D ata) registers w here data p arallel op erati on s can be p erfo r m ed si m u ltaneou sly.Stream ing S I M D ex ten si on has p rovided a pow erfu l com pu tati on too l fo r p erfo r m ance i m p rovem en t.T he SSE registers are1282b it w ide and they can sto re floating2po in t values,as w ell as in tegers and characters.T here are eigh t SSE registers in a single p rocesso r,each of w h ich can be directly addressed u sing the designated nam es.U tilising the SSE registers in the tracti on pow er system si m u lati on softw are becom es a straigh tfo r w ard p rocess w hen su itab le too ls[39]are availab le.In the case of in tegers,eigh t162b it in tegers can be sto red and p rocessed in p arallel.Si m ilarly, p arallel m an i pu lati on of fou r322b it floating2po in t values also fit the1282b it registers.

W ith322b it float2po in t num bers rep resen tati on in the tracti on pow er si m u lato r,a m ax i m um com pu tati onal speed2up rati o of4is expected w ithou t any additi onal hardw are.In a p revi ou s study[40],a speed2up rati o of around3is ach ieved w ith LU decom po siti on of m atrix, depending upon the size of the m atrix.T he m ain reason fo r no t attain ing the m ax i m um speed2up of SSE m echan is m is the p rocessing overhead on pack ing data in to,as w ell as unpack ing data from,the1282b it fo r m at.T he num ber of p ack ing and unpack ing operati on s is p ropo rti onal to N2, w here N is the size of the m atrix.Softw are techn iques,such as loop ro lling and p re2fetch ing, have been app lied in a sub sequen t study[41]to i m p rove the sp eed2up rati o sligh tly.Fu rther w o rk s on em p loying assem b ly codes to accelerate the execu ti on of th is secti on of softw are p rogram are now undertaken.

5 Conclustion

T h is paper review s the key m odelling featu res in tracti on pow er system si m u lati on and h igh ligh ts the difficu lties w ith the supp ly system s and loads.R esu lts attained from tw o app roaches of si m u lati on,deter m in istic and p robab ilistic,are p resen ted to illu strate the diversity of ou tpu t fo r m ats.A w ide range of successfu l app licati on s, electrical2related o r o ther w ise,has also been in troduced b riefly here to dem on strate the versatility of the si m u lati on s.Ex ten sive w o rk on parallel p rocessing is iden tified as one of the p ri m ary directi on fo r fu rther developm en t on tracti on pow er system si m u lati on,particu larly w hen it is to be included in real2ti m e app licati on s. T racti on pow er system si m u lati on has been a w idely adop ted bu t un sung com p u ter2aided engineering too l fo r rail w ay pow er engineers fo r the last tw o decades.T h is paper co llectively summ arises the research effo rt and exp erience on the ex isting si m u lato rs and their underlying p rinci p les.W ith the advances in hardw are and softw are,new ly developed tracti on pow er system si m u lato rs m ay evo lve w ith fresh functi onalities

501

第3期T racti on Pow er System Si m ulati on in E lectrified R ail w ays

and featu res bu t the fundam en tals on m odelling and system con strain ts rem ain.A ccu rate,reliab le and efficien t si m u lati on is still critically essen tial fo r studies and analysis of all natu res at the design,op erati on and p lann ing stages of electrified rail w ay system s,w h ich is an in tegrated p art of rail w ay tran spo rtati on system engineering.

ACKNOWL ED GE M ENTS

T he au tho rs gratefu lly acknow ledge the generou s financial suppo rt p rovided by the R esearch Gran t Council of Hong Kong(Po lyU 5104 51E).T he au tho rs w ish to thank the referees fo r their valuab le comm en ts w h ich certain ly helped i m p rove the pap er sub stan tially.

References

[1] J in,J.,A llan,J.,Goodm an,C.J.and Payne,K.

Single Po le2to2Earth Fault D etecti on and L ocati on

on a Fourth2rail DC R ail w ay System.IEE P roc.

E lectr.Pow er A pp l.,vo l.151,no.4,pp.498-

504,2004.

[2] H ill,R.J.E lectric R ail w ay T racti on-Part3

T racti on Pow er Supp lies’,Pow er Engineering

Journal,1994,275-286.

[3] Shao,Z.Y.A uto2T ransfo r m er Pow er Supp ly

System fo r E lectric R ail w ays’,PhD T hesis,

U niversity of B ir m ingham,1988.

[4] Goodm an,C.J.,Siu,L.K.and Ho,T.K.A

R eview of Si m ulati on M odels fo r R ail w ay System s.

Internati onal Conf.O n D evelopm ent in M ass

T ransit System s,pp.80-85,1998.

[5] B row n,J.C.,A llan,J.and M ellitt,B.Calculati on

and M easurem ent of R ail I mpedances A pp licable to

R emo te Sho rt C ircuit Fault Currents.IEE P roc-B,

vo l.139,no.4,pp.295-302,1992.

[6] M ellitt,B.,Goodm an,C.J.and A uthurton,R.I.

M.Si m ulato r fo r Studying Operati onal and Pow er2

supp ly Conditi ons in R ap id2transit R ail w ays.P roc.

IEE,vo l.125,no.4,pp.298-303,1978.

[7] Cuth ill,E.and M cKee,J.R educing the Bandw idth

of Sparse Symm etric M atrices.P roc.24th N at.

Conf.A https://www.360docs.net/doc/5811517897.html,put.M ach,A C M Publ.},pp.

157-172,1969.

[8] Geo rge,A.and L iu,https://www.360docs.net/doc/5811517897.html,puter So luti on of

L arge Sparse Po sitive D efinite System s.Englew ood

C liffs:P rentice2H all,1981.

[9] Roh rer,R.A.C ircuit Partiti oning Si m p lified.IEEE T rans.on CA S,vo l.35,no.1,pp.2-5,1988. [10] K ron,G.,D iakop tic-T he P iecew ise So luti on of

L arge2scale System s},L ondon:M acdonald,1963. [11] Goodm an,C.J.and Siu,L.K.DC R ail w ay Pow er

N etw o rk So luti on by D iakop tic.P roc.of A S M E

IEEE Jo int R ailroad Conference,pp.103-110,

1994.

[12] Goodm an,C.J.,M ellitt,B.and R am bukw ella,

N.B..CA E fo r the E lectrical D esign of U rban R ail

T ransit System https://www.360docs.net/doc/5811517897.html, PRA I L87,pp.173-193,

1987.

[13] Chan,W.S..W ho le System Si m ulato r fo r A C

T racti on,PhD T hesis,U niversity of B ir m ingham,

1988.

[14] Yu,J.G.,Khan,A.M.M.and L o ring,K..

Computer Si m ulati on of T ransit Pow er System s.

IEE Internati onal Conf.on Si m ulati on,pp.93-

98,1998.

[15] M artin,P..T rain Perfo r m ance and Si m ulati on.

IEEE W inter Si m ulati on Conf.,pp.1287-1294,

1999.

[16] Ho,T.K.,M ao,B.H.,Yuan,Z.Z.,L iu,H.D.

and Fung,https://www.360docs.net/doc/5811517897.html,puter Si m ulati on and

M odelling in R ail w ay A pp licati https://www.360docs.net/doc/5811517897.html,puter

Physics Comm unicati ons,vo l.143,no.1,pp.1-

10,2002.

[17] Ho,T.K.,W ang,J.L eung,K.K.,T se,C.T.

and Siu,L.K..P robabilistic L oad F low

Calculati on fo r A C T racti on Supp lies w ith A T

Feeding.$6^{th$IEE Internati onal Conf.on

A dvances in Pow er System Contro l,Operati on and

M anagem ent,pp.530-534,2003.

[18] Ho,T.K.,Ch i,Y.L.,W ang,J.and L eung,K.

K..L oad F low in E lectrified R ail w ays.$2^{nd

$IEE Internati onal Conf.on Pow er E lectronics,

M ach ines and D rives,pp.498-503,2004.

[19] Chen,C.S.,Chuang,H.J.and Fan,L.J..

D esign of M ain T ransfo r m er Capacity fo r

E lectrified R ail w ay Pow er System s.IEEE

Internati onal Conf.on Pow er System T echno logy,

pp.311-316,2000.

[20] M ellitt,B.,Goodm an,C.J.and A rthurton,R.I.

M..Si m ulati on Studies of Energy Saving w ith

Chopper Contro l on the Jubilee L ine.P roc.IEE,

125,4,pp.304-310,1978.

[21] W illiam s,J.and A llan,J..System s Engineering

fo r M ass T ransit R ail w ays.Internati onal Conf.on

E lectric R ail w ays in a U nited Europe,pp.15-19,

1995.

[22] Glover,J.D.,Kusko,A.and Peeran,S.M..

601交通运输系统工程与信息2005年6月

T rain V o ltage A nalysis fo r A C R ailroad

E lectrificati on.IEEE T rans.on Industry

A pp licati ons,vo l.20,no.4,pp.925-934,

1984.

[23] H ill,R.J.and Cevik,I.H..O n2line Si m ulati on of

V o ltage R egulati on in A uto transfo r m er2fed A C

E lectric R ailroad T racti on N etw o rk s.IEEE T rans.

on V eh icular T echno logy,vo l.42,no.3,pp.365

-372,1993.

[24] H si,P.H.,Chen,S.L.and L i,R.J..Si m ulati on

O n2line D ynam ic V o ltages of M ulti p le T rains under

R eal Operating Conditi ons fo r A C R ail w ays.IEEE

T rans.on Pow er System,vo l.14,no.2,1999. [25] Yu,J.G..T he Effects of Earth ing Strategies on

R ail Po tential and Stray Currents in DC T ransit

System s.IEE Conf.on D evelopm ent in M ass

T ransit System,pp.,1998.

[26] Yu,J.G.,Goodm an,https://www.360docs.net/doc/5811517897.html,puter A nalysis of

Touch and Step V o ltages fo r DC R ail w ays.

COM PRA I L92,1992.

[27] H ill,R.J.and Cai,Y.:‘Si m ulati on of R ail

V o ltage and Earth Currents in a PC2based DC

T racti on Pow er Si m ulato r.P roc.of

EL ECTO SO FT93:Softw are fo r E lectrical

Engineering A nalysis and D esign,pp.319-326,

1993.

[28] Gale,D.and Skarpetow sk i,G..H ar monic

Interacti ons of a GTO T hyristo r T h ree Phase

Converter System on a25kV R ail w ay T racti on

Supp ly System.Conf.on R ail w ay Engineering,

1998.

[29] B row n,J.C.,A n Investigati on into Sho rt C ircuit

Faults on the Pow er Supp ly of DC T racti on

System,PhD T hesis,U niversity of B ir m ingham,

1989.

[30] Ho,T.K.and W ong,K.K..Peak Pow er D em and

R educti on U nder M oving B lock Signalling U sing

Expert System.IEE P roc.2E lectr.Pow er A pp l.,

vo l.150,no.4,pp.471-482,2003.

[31] W ong,K.K.and Ho,T.K..Coast Contro l fo r

M ass R ap id T ransit R ail w ays w ith Search ing

M ethods.IEE P roc.2E lectr.Pow er A pp l.,vo l.

151,no.3,pp.365-376,2004.

[32] H ill,R.J.,Carpenter,D.C.and T asar,T..

R ail w ay T rack A dm ittance,Earth2leakage Effects

and T rack C ircuit Operati ons.P roc.of A S M E

IEEE Jo int R ailroad Conference,pp.52-62,

1989.

[33] H ill,R.J.and Carpenter,D.C..R ail T rack

M odelling fo r Signalling and E lectrificati on System

Si m ulati on.R ail Eng.Int.,vo l.19,no.4,pp.16

-20,1990.

[34] Yu,J.G.,Struand,R.W.and D enning,L.R..A

General M o to r M odelling M ethod fo r T ransit

System Si m ulati on https://www.360docs.net/doc/5811517897.html, PRA I L94,1994. [35] Scho lle,E.A.,Schw artz,J..Pow er D issi pati on

due to V ibrati on2Induced D isturbances in M aglev

Superconducting M agnets.IEEE T rans.on

A pp lied Superconductivity,vo l.4,no.4,pp.205

-210,1994.

[36] Am etani,A.,Kato,R.,N ish inaga,H.and O kai,

M..A Study of T ransient Induced V o ltages on a

M aglev T rain Co il System.IEEE T rans.on Pow er

D elivery,vo l.10,no.3,pp.1657-1662,1995.

[37] Zahn,M..Pow er D issi pati on and M agnetic Fo rces

on M eglev R ebars.IEEE T rans.on M agnetics,

vo l.33,no.2,pp.1021-1036,1997.

[38] H ill,R.J.and Cevik,I.H.:‘Parallel Computer

Si m ulati on of A uto transfo r m er2fed A C T racti on

N etw o rk s.Jo int A S M E IEEE R ailroad Conf.,pp.

157-164,1990.

[39] Intel C C++Comp iler C lass L ibraries fo r S I M D

Operati ons U ser’s Guide,Intel,2000.

[40] Fung,Y.F.,E rcan,M.F.,Ho,T.K.and

Cheung,W.L..‘SSE Based Parallel So luti on fo r

Pow er System s N etw o rk Equati ons’.L ecture

N o tes in Computer Science2073,pp.862-872,

2001.

[41] Fung,Y.F.,E rcan,M.F.,Ho,T.K.and

Cheung,W.L..‘A Parallel So luti on To L inear

System s’.M icrop rocesso rs andM icro system s,vo l.

26,no.1,pp.39-44,2002.

701

第3期T racti on Pow er System Si m ulati on in E lectrified R ail w ays

常见职务、职位英文翻译

常见职位、职务英文译名 Accounting Assistant 会计助理 Accounting Clerk 记帐员 Accounting Manager 会计部经理 Accounting Stall 会计部职员 Accounting Supervisor 会计主管 Administration Manager 行政经理 Administration Staff 行政人员 Administrative Assistant 行政助理 Administrative Clerk 行政办事员 Advertising Staff 广告工作人员 Airlines Sales Representative 航空公司定座员 Airlines Staff 航空公司职员 Application Engineer 应用工程师 Assistant Manager 副经理 Bond Analyst 证券分析员 Bond Trader 证券交易员 Business Controller 业务主任 Business Manager 业务经理 Buyer 采购员 Cashier 出纳员 Chemical Engineer 化学工程师 Civil Engineer 土木工程师 Clerk/Receptionist 职员/接待员 Clerk Typist & Secretary 文书打字兼秘书 Computer Data Input Operator 计算机资料输入员 Computer Engineer 计算机工程师 Computer Processing Operator 计算机处理操作员 Computer System Manager 计算机系统部经理 Copywriter 广告文字撰稿人 Deputy General Manager 副总经理 Economic Research Assistant 经济研究助理 Electrical Engineer 电气工程师 Engineering Technician 工程技术员 English Instructor/Teacher 英语教师

常见职务职位英文翻译

常见职务职位英文翻译 希望对你有帮助哦!总公司Head Office分公司Branch Office营业部Business Office人事部Personnel Department(人力资源部)Human Resources Department总务部General Affairs Department财务部General Accounting Department销售部Sales Department促销部Sales Promotion Department国际部International Department出口部Export Department进口部Import Department公共关系Public Relations Department广告部Advertising Department企划部Planning Department产品开发部Product Development Department研发部Research and Development Department(R&D)秘书室Secretarial PoolAccounting Assistant 会计助理Accounting Clerk 记帐员Accounting Manager 会计部经理Accounting Stall 会计部职员Accounting Supervisor 会计主管Administration Manager 行政经理Administration Staff 行政人员Administrative Assistant 行政助理Administrative Clerk 行政办事员Advertising Staff 广告工作人员Airlines Sales Representative 航空公司定座员Airlines Staff 航空公司职员Application Engineer 应用工程师Assistant Manager 副经理Bond Analyst 证券分析员Bond Trader 证券交易员Business Controller 业务主任Business Manager 业务经理Buyer 采购员Cashier 出纳员Chemical Engineer 化学工程师

电气化铁道主要供电方式

接触网的供电方式 我国电气化铁路均采用单边供电方式,即牵引变电所向接触网供电时,每一个供电臂的接触网只从一端的牵引变电所获得电能(从两边获得电能则为双边供电,可提高接触网末端网压,但由于其故障范围大、继电保护装置复杂等原因尚未有采用)。复线区段可通过分区亭将上下行接触网联接,实现“并联供电”,可适当提高末端网压。当牵引变电所发生故障时,相邻变电所通过分区亭实现“越区供电”,此时供电范围扩大,网压降低,通常应减少列车对数或牵引定数,以维持运行。 1、直接供电方式 如前所述,电气化铁路采用工频单相交流电力牵引制,单相交流负荷在接触网周围空间产生交变电磁场,从而对附近通信设施和无线电装置产生一定的电磁干扰。我国早期电气化铁路(如宝成线、阳安线)建设时,处于山区,地方通信技术不发达,铁路通信采用高屏蔽性能的同轴电缆,接触网产生的电磁干扰影响极小,不用采取特殊防护措施,因此上述单边供电方式亦称为直接供电方式(简称TR供电方式)。随着电气化铁路向平原和大城市发展,电磁干扰矛盾日显突出,于是在接触网供电方式上采取不同的防护措施,便产生不同的供电方式。目前有所谓的BT、AT和DN供电方式。从以下的介绍中可以看出这些供电方式有一个共同特点,即在接触网支柱田野侧,与接触悬挂同等高度处都挂有一条附加导线。电力牵引时,附加导线中通过

的电流与接触网中通过的牵引电流,理论上讲(或理想中)大小相等、方向相反,从而两者产生的电磁干扰相互抵消。但实际上是做不到的,所以不同的供电方式有不同的防护效果。

2、吸流变压器(BT)供电方式 这种供电方式,在接触网上每隔一段距离装一台吸流变压器(变比为1:1),其原边串入接触网,次边串入回流线(简称NF线,架在接触网支柱田野侧,与接触悬挂等高),每两台吸流变压器之间有一根吸上线,将回流线与钢轨连接,其作用是将钢轨中的回流“吸上”去,经回流线返回牵引变电所,起到防干扰效果。 由于大地回流及所谓的“半段效应”,BT供电方式的防护效果并不理想,加之“吸——回”装置造成接触网结构复杂,机车受流条件恶化,近年来已很少采用。 BT供电方式原理结线图 H—回流线;T—接触网;R—钢轨; SS—牵引变电所;BT—吸流 变压器。 牵引网阻抗与机车至牵引变电所的长度不是简单的线性关系。随着机车取流位置的不同,牵引网内的电流分布可有很大不同,例如图中当机车位于供电臂内第一台BT前方时,牵引负荷未通过吸流变压

常见职位职务英文翻译

常见职位职务英文翻译 Accounting Assistant会计助理 Accounting Clerk记帐员 Accounting Manager会计部经理 Accounting Stall会计部职员 Accounting Supervisor会计主管 Administration Manager行政经理 Administration Staff行政人员 Administrative Assistant行政助理 Administrative Clerk行政办事员 Advertising Staff广告工作人员 Airlines Sales Representative航空公司定座员 Airlines Staff航空公司职员 Application Engineer应用工程师 Assistant Manager副经理 Bond Analyst证券分析员 Bond Trader证券交易员 Business Controller业务主任 Business Manager业务经理 Buyer采购员 Cashier出纳员 Chemical Engineer化学工程师 Civil Engineer土木工程师 Clerk/Receptionist职员/接待员 Clerk Typist&Secretary文书打字兼秘书 Computer Data Input Operator计算机资料输入员Computer Engineer计算机工程师 Computer Processing Operator计算机处理操作员Computer System Manager计算机系统部经理 Copywriter广告文字撰稿人 Deputy General Manager副总经理 Economic Research Assistant经济研究助理 Electrical Engineer电气工程师 Engineering Technician工程技术员 English Instructor/Teacher英语教师 Export Sales Manager外销部经理 Export Sales Staff外销部职员 Financial Controller财务主任 Financial Reporter财务报告人 F.X.(Foreign Exchange)Clerk外汇部职员 F.X.Settlement Clerk外汇部核算员 Fund Manager财务经理 General Auditor审计长 General Manager/President总经理

各种职位的英文翻译

各种职位的英文翻译 qa 是英文 quality assurance 的简称,中文含义是质量保证; qc 是英文 quality control 的简称,中文含义是质量控 制。 IPQC 是过程检验工程师 JQE 是品质工程师 DQA 是设计品保工程师 SQE 共货商管理工程师 Administration( 行政部分) 行政主管 File Clerk 档案管理员 行政助理 Office Manager 办公室经理 行政秘书 Receptionist 接待员 办公室文员 Secretary 秘书 Inventory Control Analyst 存货控制分析 Staff Assistant 助理 Mail Room Supervisor 信件中心管理员 Stenographer 速记员 Order Entry Clerk 订单输入文员 Telephone Operator 电话操作 员 Shipping/Receiving Expediter 收发督导员 Ticket Agent 票务代理 Vice-President of Administration 行政副总裁 Typist 打字员 Executive and Managerial( 管理部分 ) Retail Store Manager 零售店经理 Food Service Manager 食品服务经理 Executive Marketing Director 市场行政总监 HMO Administrator 医疗保险管理 Assistant Store Manager 商店经理助理 Operations Manager 操作经理 Assistant Vice-President 副总裁助理 Production Manager 生产经理 Chief Executive Officer(CEO) 首席执行官 Property Manager 房地产经理 Chief Operations Officer(COO) 首席运营官 Branch Manager 部门经理 Controller(International) 国际监管 Claims Examiner 主考官 Director of Operations 运营总监 Controller(General) 管理员 Field Assurance Coordinator 土地担保协调员 General Manager 总经理 Management Consultant 管理顾问 District Manager 市区经理 Hospital Administrator 医院管理 President 总统 Import/Export Manager 进出口经理 Product Manager 产品经理 Insurance Claims Controller 保险认领管理员 Program Manager 程序管理经理 Insurance Coordinator 保险协调员 Project Manager 项目经理 Inventory Control Manager 库存管理经理 Regional Manager 区域经理 Manager(Non-Profit and Charities) 非盈利性慈善机构管理 Service Manager 服务经理 Manufacturing Manager 制造业经理 Vending Manager 售买经理 Telecommunications Manager 电信业经理 Vice-President 副总裁 Transportation Manager 运输经理 Warehouse Manager 仓库经理 Education and Library Science( 教育部分 ) Daycare Worker 保育员 ESL Teacher 第二外语教师 Developmental Educator 发展教育家 Head Teacher 高级教师 Foreign Language Teacher 外语教师 Librarian 图书管理员 Guidance Counselor 指导顾问 Music Teacher 音乐教师 Library Technician 图书管理员 Nanny 保姆 Physical Education Teacher 物理教师 Principal 校长 School Psychologist 心理咨询教师 Teacher 教师 Special Needs Educator 特种教育家 Teacher Aide 助理教师 Art Instructor 艺术教师 Computer Teacher 计算机教师 College Professor 大学教授 Coach 教练员 Assistant Dean of Students 助理训导长 Archivist 案卷保管员 Vocational Counselor 职业顾问 Tutor 家教、辅导教师 Auditor 审计师 Accountant 会计员,会计师 Administration Assistant 行政助理 Administrator 行政主管 Assistant Manager 副经理 Assistant Production Manager 副厂长 Business Manager 业务经理 Cashier 出纳员 Chief Accountant 总会计主任 Chief Engineer 总工程师 Civil Engineer 土木工程师 Clerk 文员(文书) Director 董事 Electrical Engineer 电气工程师 Executive Director 行政董事 Executive Secretary 行政秘书 Financial Controller 财务总监 Foreman 领班,组长 General manager 总经理 Junior clerk 低级文员(低级职员) Manager 经理 Marketing Executive 市场部主任 Marketing Manager 市场部经理 Marketing Officer 市场部办公室主任 Mechanical Engineer 机械工程师 Merchandiser 买手(商人) Messenger 信差(邮递员) Office Assistant 写字楼助理(办事员) Administrative Director Executive Assistant Executive Secretary General Office Clerk

电气化铁道与城轨交通(地铁、轻轨)供电方式比较分析

山东职业学院 毕业论文 题目:电气化铁道与城轨交通(地铁、 轻轨)供电方式比较分析原所在系:电气工程系 原专业班级:电气自动化技术 转入后班级:电气化铁道技术 姓名:xx 指导老师:xxxx 完成日期:2012 3 29

山东职业学院毕业论文评审表 指导教师:论文成绩: 指导教师评语: 指导教师签名: 年月日复审人:论文复审成绩: 复审人评语: 复审人签名: 年月日

山东职业学院毕业论文答辩情况记录 答 辩 题 目 对学生回答问题的评语 正确 基本 正确 经提示 回答 不 正确 未 回答 答辩委员会(或小组)评语: 答辩成绩: 答辩负责人签名: 年 月 日 系毕业论文领导小组审核意见: 组长签名: 年 月 日 注:毕业论文总成绩中,指导成绩占40%,复审成绩占20%,答辩成绩占40%

目录 第1章概述 (1) 第2章牵引供电系统 (2) 2.1 铁路牵引供电系统的供电方式 (2) 2.1.1 直接供电方式 (2) 2.1.2 吸流变压器(BT)供电方式 (2) 2.1.3 自耦变压器(AT)供电方式 (3) 2.1.4 直供+回流(DN)供电方式 (3) 2.2 城市电网对地铁的供电方式 (4) 2.2.1 集中供电方式 (4) 2.2.2 分散供电方式 (5) 2.2.3 混合供电方式 (5) 第3章牵引网的供电 (6) 3.1 铁路牵引网的供电方式 (6) 3.1.1 单边供电 (6) 3.1.2 上下行并联供电 (6) 3.1.3 双边供电 (7) 3.2 城轨牵引网的供电方式 (7) 3.2.1 第三轨 (7) 3.2.2 第四轨 (7) 3.2.3 架空电缆 (8) 总结 (9) 致谢 (10) 参考文献 (11)

电气化铁道供电系统

电气化铁道供电系统与设计课程设计报告 班级: 学号: 姓名 指导教师: 评语:

1. 题目 某牵引变电所丙采用直接供电方式向复线区段供电,牵引变压器类型为110/27.5kV,三相V-v接线,两供电臂电流归算到27.5kV侧电流如表1所示。 表1 已知参数 供电臂供电臂 长度km 端子平均电流 A 有效电流A 短路电流A 穿越电流A 左臂21.9 β238 318 917 206 右臂24.7 α184 266 1052 217 2. 题目分析及解决方案框架确定 在设计过程中,先按给定的计算条件求出牵引变压器供应牵引负荷所必须的最小容量,然后按列车紧密运行时供电臂的有效电流与充分利用牵引变压器过负荷能力,求出所需要的容量,称为校核容量。这是为确保牵引变压器安全运行所必须的容量。最后计算容量和校核容量,再考虑其他因素(如备用方式等),然后按实际系列产品的规格选定牵引的台数和容量,称为安装容量或设计容量。然后再变压器型号的基础之上,选取室外110kV侧母线,室外27.5kV侧母线以及室外10kV侧母线的型号。三相V,v结线牵引变压器是近年新研制的产品,它是将两台容量相等或不相等的单相变压器器身安装于同一油箱内组成的。三相V-v结线牵引变电所中装设两台V,v 结线牵引变压器,一台运行,一台固定备用。三相V-v结线牵引变电所不但保持了单相V-v结线牵引变电所的牵引变压器容量得到充分利用,可供应牵引变电所自用电和地区三相负载,主接线较简单,设备较少,投资较省,对电力系统的负须影响比单线小,对接触网的供电可实现双边供电等优点,最可取的是,解决了单相V-v结线牵引变电所不便于采用固定备用及其自动投入的问题。考虑到V-v接线中装有两台变压器的特点,在确定110kV侧主接线时我们采用桥形接线。按照向复线区段供电的要求,其牵引侧母线的馈线数目较多,为了保障操作的灵活性和供电的可靠性,我们选用馈线断路器100%备用接线,这种接线也便于故障断路器的检修。按照选取的变压器的容量以及110kV侧的和牵引侧的主接线,可以做出设计牵引变电所的电气主接线。

各种职位的英文翻译

各种职位的英文翻译 qa是英文quality assurance 的简称,中文含义是质量保证;qc是英文quality control的简称,中文含义是质量控制。IP QC是过程检验工程师 JQE是品质工程师 DQA是设计品保工程师 SQE供货商管理工程师 Administration(行政部分) Administrative Director 行政主管File Clerk 档案管理员 E xecutive Assistant 行政助理O ffice Manager 办公室经理 E xecutive Secretary 行政秘书Receptionist 接待员 General Office Clerk 办公室文员Secretary 秘书 Inventory Control Analyst 存货控制分析Staff Assi s tant 助理 Mail Room Supervisor 信件中心管理员Stenographer 速记员 Order E ntry Clerk 订单输入文员Telephone Operator 电话操作员 Shipping/Receiving E xpediter 收发督导员Ticket Agent 票务代理 Vice-P resident of Administration 行政副总裁Typi s t 打字员 E xecutive and Managerial(管理部分) Retail Store Manager 零售店经理Food Service Manager 食品服务经理 E xecutive Marketing Director 市场行政总监HMO Administrator 医疗保险管理 Assi s tant Store Manager 商店经理助理Operations Manager 操作经理 Assi s tant Vice-P resident 副总裁助理P roduction Manager 生产经理 Chief E xecutive O fficer(CE O) 首席执行官P roperty Manager 房地产经理 Chief Operations O fficer(COO) 首席运营官Branch Manager 部门经理 Controller(International) 国际监管Claims E xaminer 主考官 Director of Operations 运营总监Controller(General) 管理员 Field Assurance Coordinator 土地担保协调员General Manager 总经理 Management Consultant 管理顾问District Manager 市区经理 Hospital Administrator 医院管理P resident 总统 Import/E xport Manager 进出口经理P roduct Manager 产品经理 Insurance Claims Controller 保险认领管理员P rogram Manager 程序管理经理 Insurance Coordinator 保险协调员P roject Manager 项目经理 Inventory Control Manager 库存管理经理Regional Manager 区域经理 Manager(Non-P rofit and Charities) 非盈利性慈善机构管理Service Manager 服务经理 Manufacturing Manager 制造业经理Vending Manager 售买经理 Telecommunications Manager 电信业经理 Vice-P resident 副总裁 Transportation Manager 运输经理Warehouse Manager 仓库经理 E ducation and Library S cience(教育部分) Daycare Worker 保育员E SL Teacher 第二外语教师 Developmental E ducator 发展教育家Head Teacher 高级教师 Foreign Language Teacher 外语教师Librarian 图书管理员 Guidance Counselor 指导顾问Music Teacher 音乐教师 Library Technician 图书管理员Nanny 保姆 P hysical E ducation Teacher 物理教师P rincipal 校长 School P sychologist 心理咨询教师Teacher 教师 Special Needs E ducator 特种教育家Teacher Aide 助理教师 Art Instructor 艺术教师Computer Teacher 计算机教师 College P rofessor 大学教授Coach 教练员 Assi s tant Dean of Students 助理训导长Archi v ist 案卷保管员 Vocational Counselor 职业顾问Tutor 家教、辅导教师 Auditor 审计师 Accountant 会计员,会计师 Administration Assistant 行政助理 Administrator 行政主管 Assi s tant Manager 副经理 Assi s tant P roduction Manager 副厂长 Business Manager 业务经理 Cashier 出纳员 Chief Accountant 总会计主任 Chief E ngineer 总工程师 Civil E ngineer 土木工程师 Clerk 文员(文书) Director 董事 E lectrical E ngineer 电气工程师

电气化铁道供电比赛试题及答案

电力牵引供变电技术比赛试卷 一、判断题(每小题2分,共30分) 1.我国电气化铁道牵引变电所由国家区域电网供电。(√)2.超高压电网电压为220kv—500kv。(×)3.采用电力牵引的铁路称为电气化铁路。(√)4.我国电气化铁道牵引变电所供电电压的等级为110kv—220kv。(√)5.电力系的电压波动值:就是电压偏离额定值或平均值的电压差。(√)6.电力牵引的交流制就是牵引网供电电流为直流的电力牵引电流制(×)7.由于铁路电力牵引属于二级负荷,所以牵引变电所须由两路高压输电线供电。(×)8.单相结线牵引变电所的优点之一是:牵引变压器的容量利用率(额定输出容量与额定容量之比值)可达100%。(√)9.单相结线牵引变电所的优点之一是:对电力系统的负序影响最小。(×)10.我国电气化铁路采用工频单相25 kV交流制。(√)11.对于三相YN,dll结线牵引变压器当两供电臂负荷电流大小相等时,重负荷绕组的电流大约是轻负荷绕组的电流的3倍。(√)12.三相YN,d11结线牵引变电所的缺点之一是:不能供应牵引变电所自用电和地区三相电力。 (×) 13.斯科特结线牵引变电所的优点之一是:当M座和T座两供电臂负荷电流大小相等、功率因数也相等时,斯科特结线变压器原边三相电流对称,不存在负序电流。(√)14.单边供电:接触网供电分区由两个牵引变电所从两边供应电能。(×)15.最简单的牵引网是由馈电线、接触网、轨道和大地、回流线构成的供电网的总称。(√) 二.填空题(每小题2分) 1.通常把发电、输电、变电、配电、用电装置的完整工作系统称为电力系统。 2.牵引变电系统由牵引变电所、接触网、馈电线、回流线、轨道、分区所、开闭所、 自耦变压器站、分段绝缘器和分相绝缘器等组成。 供电方式一般在重载铁路、高速铁路等负荷大的电气化铁路上采用。 4.分相绝缘器的作用是:串在接触网上,把两相不同的供电区分开,并使机车平滑过渡; 主要用在牵引变电所出口处和分区所处。

电气化铁路牵引供电系统试卷1

电气化铁路供电系统 试卷1 一、单项选择题(在每小题的四个备选答案中,选出一个正确的答案,并将其代码填入题干后的括号内。每小题1分,共20分) 1.我国电气化铁道牵引变电所由国家( )电网供电。 ( ) A 超高压电网 B 区域电网 C 地方电网 D 高压电网 2.牵引网包括 ( ) A 馈电线、轨道和大地、回流线 B 馈电线、接触网、轨道和大地、回流线 C 馈电线、接触网、回流线 D 馈电线、接触网、电力机车、大地 3.通常把( )装置的完整工作系统称为电力系统。 ( ) A 发电、输电、变电、配电、用电 B 发电、输电、配电、用电 C 发电、输电、配电、 用电 D 发电、输电、用电 4.低频交流制牵引网供电电流频率有:( ) ( ) A 50Hz 或25Hz B 30Hz 或50Hz C 2163 Hz 或25Hz D 20Hz 或25Hz 5.单相结线牵引变电所牵引变压器的容量利用率(额定输出容量与额定容量之比值)可达( )。 ( ) A 100% B 75.6% C 50% D 25% 6.牵引变压器采用阻抗匹配平衡变压器时,阻抗匹配系数等于1时, 且副边两负荷臂电流I I αβ = ,原边三相电流( ) ( ) A 平衡 B 无负序电流 C 对称 D 有零序电流 7.交流牵引网对沿线通信线的静电影响由( )所引起。 ( ) A 牵引网电流的交变磁场的电磁感应 B 牵引网电场的静电感应 C 牵引网电场的高频感应 D 牵引电流的高次谐波 8.牵引网导线的有效电阻0r r ξ=(0r 是直流电阻;ξ是有效系数)。对于 工频和牵引网中应用的截面不太大的铝、铜等非磁性导线,有效系数ξ( )。 ( ) A ξ≈1 B ξ≈2 C ξ≈3 D ξ≈4 9.以下不属于减少电分相的方法有( )。 ( ) A 采用单相变压器

名片常用职位英文翻译

名片常用职位英文翻译Board chairman 董事长 General Manager/President 总经理 Deputy General Manager 副总经理Executive Director执行总监CEO 首席执行官 Deupty general Manager常务副总General Manager Assistant 总经理助理 CTO 技术总监 CFO 财务总监 Operation Director 运营总监Branding Dirctor 品牌总监Marketing Director营销总监General Manager‘s Secretary 总经理秘书 Vice Minister of Sales Department 销售部副部长 Vice-general manager of Sales 销售副总 Sales director 销售总监General Educating Supervisor教学总监 Vice Manager 副经理 Marketing Manager 市场部经理 Market Supervisor 市场专员Business Manager 业务经理Account Manager 客户经理 Market Analyst 市场分析员Market Development Manager 市场开发部经理 Marketing Manager 市场销售部经理 Marketing Staff 市场销售员Marketing Assistant 销售助理Marketing Executive 销售主管Marketing Representative 销售代表 Marketing Representative Manager 市场调研部经理 Business Controller 业务主任Sales and Planning Staff 销售计

电气化铁道主要供电方式

电气化铁道主要供电方 式 Company number:【0089WT-8898YT-W8CCB-BUUT-202108】

接触网的供电方式 我国电气化铁路均采用单边供电方式,即牵引变电所向接触网供电时,每一个供电臂的接触网只从一端的牵引变电所获得电能(从两边获得电能则为双边供电,可提高接触网末端网压,但由于其故障范围大、继电保护装置复杂等原因尚未有采用)。复线区段可通过分区亭将上下行接触网联接,实现“并联供电”,可适当提高末端网压。当牵引变电所发生故障时,相邻变电所通过分区亭实现“越区供电”,此时供电范围扩大,网压降低,通常应减少列车对数或牵引定数,以维持运行。 1、直接供电方式 如前所述,电气化铁路采用工频单相交流电力牵引制,单相交流负荷在接触网周围空间产生交变电磁场,从而对附近通信设施和无线电装置产生一定的电磁干扰。我国早期电气化铁路(如宝成线、阳安线)建设时,处于山区,地方通信技术不发达,铁路通信采用高屏蔽性能的同轴电缆,接触网产生的电磁干扰影响极小,不用采取特殊防护措施,因此上述单边供电方式亦称为直接供电方式(简称TR供电方式)。随着电气化铁路向平原和大城市发展,电磁干扰

矛盾日显突出,于是在接触网供电方式上采取不同的防护措施,便产生不同的供电方式。目前有所谓的BT、AT和DN供电方式。从以下的介绍中可以看出这些供电方式有一个共同特点,即在接触网支柱田野侧,与接触悬挂同等高度处都挂有一条附加导线。电力牵引时,附加导线中通过的电流与接触网中通过的牵引电流,理论上讲(或理想中)大小相等、方向相反,从而两者产生的电磁干扰相互抵消。但实际上是做不到的,所以不同的供电方式有不同的防护效果。 2、吸流变压器(BT)供电方式 这种供电方式,在接触网上每隔一段距离装一台吸流变压器(变比为1:1),其原边串入接触网,次边串入回流线(简称NF 线,架在接触网支柱田野侧,与接触悬挂等高),每两台吸流变压器之间有一根吸上线,将回流线与钢轨连接,其作用是将钢轨中的回流“吸上”去,经回流线返回牵引变电所,起到防干扰效果。 由于大地回流及所谓的“半段效应”,BT供电方式的防护效果并不理想,加之“吸——回”装置造成接触网结构复杂,机车受流条件恶化,近年来已很少采用。

名片常用职位英文翻译

名片常用职位英文翻译 Board chairman 董事长 General Manager/President 总经理 Deputy General Manager 副总经理 Executive Director执行总监 CEO 首席执行官 Deupty general Manager常务副总 General Manager Assistant 总经理助理 CTO 技术总监 CFO 财务总监 Operation Director 运营总监 Branding Dirctor 品牌总监 Marketing Director营销总监 General Manager‘s Secretary 总经理秘书 Vice Minister of Sales Department 销售部副部长Vice-general manager of Sales销售副总 Sales director 销售总监 General Educating Supervisor教学总监 Vice Manager 副经理 Marketing Manager 市场部经理 Market Supervisor 市场专员 Business Manager 业务经理 Account Manager 客户经理 Market Analyst 市场分析员 Market Development Manager 市场开发部经理Marketing Manager 市场销售部经理 Marketing Staff 市场销售员 Marketing Assistant 销售助理 Marketing Executive 销售主管 Marketing Representative 销售代表 Marketing Representative Manager 市场调研部经理Business Controller 业务主任 Sales and Planning Staff 销售计划员 Sales Assistant 销售助理 Sales Clerk 店员、售货员 Sales Coordinator 销售协调人 Sales Engineer 销售工程师 Sales Executive 销售主管 Sales Manager 销售部经理 Salesperson 销售员 Project Manager 项目经理 Project Director 项目总监 Technical manager技术主管 President 行长

地铁和电气化铁路的牵引供电系统对比分析

地铁和电气化铁路的牵引供电系统有很大区别下面就通过对电气化铁道与城轨交通供电方式比较分析来进一步说明两者供电方式的异同。以帮助人们进一步了解。 1铁路牵引供电系统的供电方式 1.1 直接供电方式 电气化铁路采用工频单相交流电力牵引制,单相交流负荷在接触网周围空间产生交变电磁场,从而对附近通信设施和无线电装置产生一定的电磁干扰。我国早期电气化铁路(如宝成线、阳安线)建设时,处于山区,地方通信技术不发达,铁路通信采用高屏蔽性能的同轴电缆,接触网产生的电磁干扰影响极小,不用采取特殊防护措施,因此上述单边供电方式亦称为直接供电方式(简称TR供电方式)。随着电气化铁路向平原和大城市发展,电磁干扰矛盾日显突出,于是在接触网供电方式上采取不同的防护措施,便产生不同的供电方式。目前有所谓的BT、AT和DN供电方式。从以下的介绍中可以看出这些供电方式有一个共同特点,即在接触网支柱田野侧,与接触悬挂同等高度处都挂有一条附加导线。电力牵引时,附加导线中通过的电流与接触网中通过的牵引电流,理论上讲(或理想中)大小相等、方向相反,从而两者产生的电磁干扰相互抵消。但实际上是做不到的,所以不同的供电方式有不同的防护效果。如图所示; 直接供电方式 1.2 吸流变压器(BT)供电方式 这种供电方式,在接触网上每隔一段距离装一台吸流变压器(变比为1:1),其原边串入接触网,次边串入回流线(简称NF线,架在接触网支柱田野侧,与接触悬挂等高),每两台吸流变压器之间有一根吸上线,将回流线与钢轨连接,其作用是将钢轨中的回流“吸上”去,经回流线返回牵引变电所,起到防干扰效果。由于大地回流及所谓的“半段效应”,BT供电方式的防护效果并不理想,加之“吸——回”装置造成接触网结构复杂,机车受流条件恶化,近年来已很少采用。如图所示 吸流变压器(BT)供电方式

AT供电方式在电气化铁路中的应用

AT供电方式在电气化铁路中的应用 【摘要】电气化铁道在国民经济飞速增长中发挥着越来越重要的作用,其AT供电方式已经成为高速、准高速及重载线路建设的主要方向。AT供电方式供电电压比直供方式高一倍,电压损失降为1/4,防干扰效果好,扩大了牵引变电所间隔,自耦变压器并联于接触网上,不需增设分段点。 【关键词】自耦变压器;供电方式;特点;原理 我国电气化铁道采用单相工频25Kv交流制,由于单相大电流在线路周围空间产生较强电磁场,是临近通信广播设备等产生杂音干扰和感应电压。为减少电气化铁道对沿线通信设备的干扰,保障其设备、人身安全及正常工作,在牵引供电系统中采取了许多干扰措施,形成了不同的供电方式。目前我国的牵引供电方式主要有四种:直接供电方式、BT供电方式、直供加回流线供电方式、AT供电方式。AT供电方式又称自耦变压器供电方式。日本铁路为防止通讯干扰,在实行交流电气化的前期,在牵引网中普遍应用了吸流变压器一回流线电路。为了克服高速、大功率机车在这种电路中通过吸流变压器分段时,在受电弓上产生强烈电弧的缺点,后来发展了一种新的牵引网供电方式—AT供电方式。随着对外开放和引进国外先进技术,电气化铁道在国民经济飞速增长中发挥着越来越重要的作用,我国逐渐在新建电气化铁道上采用了AT供电方式。 在AT牵引变电所中,牵引变压器将110Kv三相电降压至55Kv,然后经自耦变压器两端分别接到接触网和正馈线上,自耦变压器中心抽头与钢轨相连。则钢轨与接触网间的电压正好是自耦变压器两端电压的一半25Kv,与正常接触网电压相同。 在AT供电方式区段,与接触网同杆架设在田野侧的还有一条保护线,它相当于架空地线,在自耦变压器处保护线接接触悬挂接地部分或双重绝缘子中部同钢轨连接。保护线电位一般在500V以下,正常情况下无电流通过。当绝缘子发生闪络时,短路电流可通过保护线作为回路,减少了对铁路信号轨道电路的干扰。同时对接触网其屏蔽作用,也减少了对架空通信线路的干扰,另外起避雷线的作用,雷电可以通过接在保护线上的放电器入地。 横向连接线将钢轨与保护线并联,其目的是在钢轨对地泄漏电阻和机车取流较大时,降低钢轨电位。 1 AT供电方式(自耦变压器)特点 1)2×27.5Kv系统,供电电压比直供方式高一倍,电压损失降为1/4,牵引网单位阻抗约为直供方式的1/4(实际略高),电能损失小,显示了良好的供电特性; 2)牵引变电所的间距大,易选址,减少了外部电源的工程数量和投资;

常用中英文职务翻译大全

※董事长 Board Chairman ※总经理 General Manager ※副总经理 Vice General Manager ※总经理秘书 Secretary ※总经理助理 General Manager's Assistant ※市场营销部经理 Manager of Marketing Department ※销售部经理 Sales Manager ※餐饮部经理 Food and Bererage Manager ※客房部经理 Housekeeper ※康乐部经理 Recreation Dept Manager ※财务部经理 Financial Controller ※信息部经理 Info Manager ※人事部经理 Personnel Manager ※工程部经理 Chief Engineer ※保安部经理 Chief Security Officer ※办公室主任 Director of Executive Office ※大堂副理 Asst Manager ※物资经理 Logistic & Purchasing Dept.Manager ※会计 Accountant ※销售工程师 Sales Engineer ※生产经理 Production Dept.Manager ※销售工程师 Sales Engineer ※工会主席 Labour Union chairman ※操作工 Operator ※库管员 Warehouse Keeper ※技术工程师 Technicial Engineer ※销售一部经理 Sales Dept.Manager ※接待员 Receiptionalist ※配料员 Operator ※保洁员 Purifier ※人事经理助理 HR Assistant ※炊事员 Canteen Worker ※质保经理 QC Dept.Manager ※Sr Engineer--Supplier Quality Engineering 高级工程师-供应商质量工程师, ※Sr Engineer Team Lead 高级工程师主管※Oracle Database Administrator Oracle数据库管理员※HR Sr. Staffing Administrator人力资源高级招聘主管※Logistic Supervisor物流主管※ITA Sr Administrator ITA高级行政人员※车间班长 Group Leader ※叉车司机 Driver ※机修工 Operator ※采购主管 Purchase Manage ※综合管理部 Colligation and Management Dep ※财务部部长 Finance Dep.Minister ※市场部部长助理 Market Dep.Minister's assistant ※生产部部长助理 Produce Dep. Ministarls assistant ※研发工程师 Develop Engineer ※业务主办 Operation Direct ※计划员 Programmer ※更夫 Bellman ※技术服务部经理 Technical Service Dept.Manager ※物资内勤 Secretary ※技术服务工程师 Technician Service Engineer ※销售二部经理 Sales Dept.Manager ※车间主管 Production Supervisor ※内勤 Secretary ※出纳 Cashier ※检验员 hecker ※市场部经理 Marketing Dept.Manager ※区域销售经理 Regional Sales Manager ※IT工程师 IT Engineer ※研磨工 Operator ※司机 Driver ※清扫工 Purifier ※人力资源部经理 Human Resources Manager ※文员 Clerk ※财务经理 Finance Dept.Manager ※技术发展部经理 Technical Development Dept.Manager ※电工 Electrician ※送货员 Deliveryman ※挤压工 Operator ※行政经理 Administrative Dep.Manager ※运输协调员 Traffic Coordinator ※副总工程师 Vice - Chief Engineer ※接待员 Receiptionalist ※配料员 Operator ※保洁员 Purifier ※人事经理助理 HR Assistant ※炊事员 Canteen Worker ※会计 Accountant ※质保经理 QC Dept.Manager ※机械师 Machinist ※工程主管 Facilities Supervisor ※采购员 Buyer ※车间班长 Group Leader ※叉车司机 Driver ※机修工 Operator ※行政经理 Administrative Dep.Manager ※运输协调员 Traffic Coordinator ※副总工程师 Vice - Chief Engineer ※综合管理部部长 Colligation and Management Dep.Minister ※网络主管 Network Manage ※综合管理部总务 Colligation and Management Dep.General Affair ※市场部部长 Market Dep.Minister ※市场部项目总理 Market Dep.Item Manager ※质保部 Quantity Engineer ※工艺员 Engineer ※调度员 Dispatcher ※采购主管 Purchase Manage ※综合管理部 Colligation and Management Dep ※财务部部

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