CA2147258A1 - Contactless power delivery system - Google Patents

Abstract

A contactless power transfer system (30, 30", 150, 300, 400), especially for powering underwater electric loads (34, 34', 34", 306, 314, 315, 316, 434), including movable loads, such as underwater vehicles (308, 310), elevators (173), or worksite equipement (34", 306). A converter (38, 174, 177, 338, 432) supplies high frequency power to a conductor loop (40, 165, 175, 340, 440). A
coupling sheath or link (50, 50", 150, 350, 450) has a core-mounted conductor (60, 160, 460) at least partially surrounded by a magnetic core (52, 452) which slidably receives a portion of the conductor loop within the link. An optional secondary converter (44, 175, 177, 344) converts power from the core-mounted conductor to meet the load requirements. A contactless power distribu-tion system is also submersible to deliver power to underwater loads through clamped-on or captive links attached at any location along the conductor loop. Methods are also provided of powering loads, including those submersed in water, including seawater, or other non-magnetic liquid mediums.

Description

2 1 ~ 7 2 5 8 PCI/US93/10068 CONTACTLESS POWER DELIVERY SYSTEM
ra ~ ,u..doftheIn~
This ~' - is a t t of co-pending lj~' ~tn No. 07/767,024, fil.,d S~r ~ ~ 27,1991, having the same ill~ , and which i,, hereby i S by ref,.~ ~ ~
The present invention relates generally to systemD for delivering power from an el~;h ' source to an electric load, ' ' . delivery when there is relative motion between the source and the load, and more ~ uloAly to an i~.uv~ ' 1 A ce t~ t'~ power delivery andlor diDl,:L ~ system, and to methods for --e . ~ g this ' ;~ power transfer without contact of 10 primary and s3co~ . ' such as may be used in ullde... electric vehicles, elevators, t~,~u~uy work sites, oceanographic study and the lilce.
There are several i~n applications where the ability to transfer power under water can A~ r~A.~ly affect ~.r~,. -e - ~ es For e~cample, Dub~.Ditle vehicles cannot generate energy under water through internsl c- ' ~)n which e~cpends precious o~ygen. The most common 15 method of supplying power to wbmersible vehicles involves using on-board batteries for energy storage.
Battery capacity then beeomes the msjor 1 ~ for r .' DulJ~DilJ1- vehicles, both in terms of mission length and ~.rul -e of energy intensive taslcs.
The problem of D.~ Jlyillg energy to land-based electric vehicles while they are moving on a roadway has been considered difficult to solve. In the past, systems i ~ ., Iarge amounts of 20 el~l. 1 power, wch as up to one A~ tt~ to a moving load have I ' ~.n~lly used means that are , ~ t, and F ~ ' -lly unsafe, such as sliding or rolling metal contacts, sliding carbon bruDhes, and trailing cables. For e~am~le, r ' O ~* sliding contacts have been used e~tensively for trolleys and urbsn transit systems trsveling on rails. However, these railway traction sy6tems are not a viable c r ~ 1' for I ' ~,~t use because water, and espe~ially salinated seawater, conducts 25 ele~ whereas air, to a point, acts as an insulator. ~ p..~1- include we~r, corrosion, reliability and -e of sliding ~ ' --' contact systems.
Re~Aently, some of these ~ ' 1 have been ~ig ~ in land-based systems using inductively coupled flat coils in ~ with power d~ll~ to transfer power from a fi~ed source to a moving vehicle. For e~cample, the following three articles propose various systems having a fi~ed 30 primary winding buried in a roadway along which electric vehicles travel: K. T ' ' , S.E. ~hl ~
and E.H. Lechner, ~L.lu~ Power Transfer to an Electric Vebicle,- 8th 1 . -' Electric Vebicle S.~ . - W. ' _,to.l, DC, October, 1986; E.H. Lechner and S.E. S~ The I'~- l~ Powered Electric Vehicle - An All-electric Hybrid System,~ 8th ~ - ' Electric Vebicle S~.-~l.cb~;.....
W- ' g~ . DC, October, 1986; and S.E. S,AI~1- 1 "re" "Systems F.~g;. ~ ;.-g of the Roadway Powered 35 Electric Vehicle Technology~ 9th 1 nnol Electric Vebicle Sy . - . Toronto, Ont. Cana~a, November, 1988. However, these systems suffer a variehy of dl....~ P ' , ~' ' g the need for PnA,he~
coils along the path of travel, ' ,.y fast and accurate air gap control, and the ~u~ c;~nt of two large flu~ CC'llP~tif or cn~ rti~ surf_ces. Each of these dla~ c seriously impacts on the ~xn~n... s practicality of thece systems, as well as their prar~tirality for underwater ~ r 1 nnc As a specific e~ample, the State of Cslifnmia is cn~ Pring an electric vehicle highway proposal for cnnta^thp-cc fliCtrih ~i. of power to moving v hicles. In the California , r ~ - ~ cables are 5 buried in the roadway and energized. The vehicle carriec . n inAurtif n coil which receives induced current for use in plU~ Dh)n and battery .~ .g. The California system uses a pociti. g control on the vehicle to maintain the distance between the two flu~ collArtinn surfaces of the buried cable and the coil to within five ~~ D to provide ~ffirjPnt power piclcup.
The l'al ' - sydGm h~c aeverd dl..~..t- ' For e~unple, the normal ttractive forces 10 between the vehicle and the buried cable can reach high levels during the required power transfer. The attractive forces also increase the frictional forces required to move the vehicle along the roadway. The controller must counter these -a-ttractive forces by ps)citinning the vehicle-mounted collector above the roadway surface. ~AAi~ ly, the magnetic coupling between the cable and coil in the California system is poor due to the large air gap, yielding poor Grl. i A~, low pv.._./~._;ght density (i.e., kilowatts per ~ilngram), and poor util n - of core material. To ~s~-- 'A for the large air gap space between the v~' -'f~ collector nd the buried primary cnn~' l ,r a very large primary converter jD required to power the buried c4nA~lrtnr. To improve the magnetic coupling, the roadway cable must be buried with Ci~if amounts of ,7 r core material, which greatly ill~lc~s the initial and O~A g costs of the Califsmia system.
While the problem of power delivery to moving electric loads in land-based a~, ' - nng is ~ - g, the problem of power delivery under water is tlC ' ly more rL ~ g~
Thus, a need e~ists for an improved manner of del.~_.~g power ~ from a source to AAn dectric load, especially where there is relative motion between the source and the load, such as may be used in ullde.~. c u mining, and electrical vehicle al)p' , which is directed toward U._.~UIIIillg, and not tP ~~ to, the above 1 and d 1~ ge6.
S . of the I~
In ~l~' ~ with an ill ~ .--..'~1;.. - ~ of the present invention, a cn~a~tl~c power delivery system is providGd for d~ ....g power between first and second ' ,tc D to provide a fle~ible power delivery system for arcless coupling in h~luuD and other e.,~ such as in 1 ~ r~ - - This c~a~tl power delivery system aiso deliverc power when there ic relative motion, i.e. Iinear and/or l~ -l, between first and second CA ' ' 1~ The firct cn-~ at least partially DUII~ ' a portion of the second c-- l`-- '(-r, and a magnetic core at least partially DU IU ~ a portion of the first c ' so as to transfer power between the first and second c~ by magnetic in~ tirr This power transfer occurs ', ' of the position and tion of 35 the second cn~ ,2. relative to the first co~ lor. Either the first or second cnn~lmrt~2r may serve as the primary winding and the other as the ~ ~ winding. Metuods are al o provided of powering a movable electric load or a st. tionary load from a movable source, and of distributing power to a plurality of portable electric loads.

WO 94/09558 2 1 ~ 7 2 ~ 8 PCI/US93/10068 An overall object of the present invention is to provide an improved cnn~ort~ manner of delivering power ~de.. _ from a source to an electric load.
A further object of the pre6ent i~ "nn i6 to provide an improved cnntoA-'~ powerdelivery sy6tem and method for delivering power underwater to movable ' - g_d electric loads.
Another ohject of the present invention is to provide an improved fle~ible power di6tributi~n sy6tem.
An a' ~ nnol object of the present invention is to provide a safer, more reiiable, efficient and e - ~ Dy6tem for I r .mg power ~ between a 60urce and an electrical load.
Still another object of the present invention i6 to improve underwater study, mining and 10 ~ 'nn capabilities.
The present i~ "nn provides the ability to deliver great ~, of electrical power ~d~ across large water-filled gaps, CVIli. nnolly referred to in land-based systems as ~air gaps, "
during relative motion between the source and the load. Underwater cnn~oA~ power delivery is ~liDh~ by O ~ in~ ctjnn across a DUb~IO~ radial interwinding space (described below).
F~ , cigrliF e,an - advantages rnay be obtained by using high opel ~ L~ ;P-C with this ' power transfer scheme. The cn^~oAtlpcc power delivery system is not sensitive to ~ n ' g ~ - between the primary and I ' ~ c~ , Ieaving the system e 11y rr ~ by the position of the cn~ ,. within the core window. F~ , this underwater cnn~oA~lp-~c power delivery is I ' , ~d by linear and ,o~ . ' motion of the coupling link when 20 traveling along the 1ength of the fLl~ed ~ ' I .
The present ill~ relates to the above features and objects individually as well as collectively. These and other objects, features and a 1~ ~ - of the present ,..~. 'nn will become apparent to those skilled in the art from the following d~r~ pti~ and dl~.lllOD~ Brief D~ ;r '- _ ~ of the D~wi~
Fig. I is a ' - bloclc diagram cf one form of a cnn~ l~c power delivery system of the present ill~r~tiu;
Fig. 2 is a front e1~ ; ' view of one form of a dual coupling sheath or link of the present ,..~ couple~ with a ~
Fig. 3 is a side ~ i -' view taken along lines 3--3 of Fig. 2;
Fig. 4 is a c ' - ' ' - and pel-D~h~ _ view of one form of a dual link of the present il~ n having a vable D~nd~ ~ IOUI
Fig. 5 is a radial sectional view of one form of coupling link of the present invention having a core with a gap in the flu~c path;
Fig. 6 is a radial sectional view of one form of a split hinged coupling link of the present 35 invention having a core with a minimal air gap in the flu~ path dcring F
Fig. 7 is a radial sectional view of one form of a coupling link of the present invention having a split hinged core with a gap in the flu~ path and an; ' -ed core;

WO 94/09558 2 ~ ~ 7 2 5 8 4 PCI/US93/10068 Fig. 8 is a radial sectional view of an alternat~ form of 8 coupling linl~ of the present inverltion having a split core with a gap in the flu~ path and aw . ' ~ d core;
Fig. 9 is a L ' ~ diaglam of an e~ circuit of a coupling linlc of the present w~ ~ a cn~
Fig. 10 is a partial radial sectional view illu~h_" g the radial A;.-~ --c of one form of a coupling lin~ ~WIUUl~g a cn~ ctor, each of the present invention;
Fig. 11 is a graph of leal~age ~ as 8 function of interwincling space for an Fig. 12 is a - ' ~ bloclc diagrun of one form of a s~ Jctor portion of a power delivery system of the present i.~
Fig. 13 is a ' r block diagram of one form of a primary side converter of the present illvwtioll;
Fig. 14 is a s~' - block diagram of one form of a s~ondu~ side converter of tke present inv. ~ ~n;
Fig. 15 is a side d~,~.. tiû.. dl view taken along line 15--15 of Fig. 8;
Fig. 16 is a p~ e view of a portion of one form of a fle~ible power distribution system of the present i~
Fig.17isunscaled ' r side~ -' viewofoneformofanu.ld~,.... or submersible c '- power delivery system of the present i,l~tioll;
Fig. 18 is a c~-- .1.;. r~A ' " ~ and ~.~ e view of one form of another alternate c~-- t-- Ik ~ power delivery system of the present inv. ~;- ;
Fig. 19 is a ,: ' -d ' - and pe.~ e viewof the cnn~P~tl~cc power delivery system of Fig. 18;
Fig. 20 is a graph of power transfer through a land-based p,ulul~ unit co~u~ led in ~.~' - with the present ;~ ;
Fig. 21 is a ~~' ~ partial cutaway ~.~ e view of one form of a p.ulul~
submersible ~ '- power delivery system of the present i ~. -Fig. 22 is a graph of power loss versus ~ for the p..,lot~ system of Fig. 21;
Fig. 23 is a radid sectiond view of one form of an alternate split hinged coupling link of the prese~t i~
Fig. 24 is a r~dial sectional view of one fonn of an altem~te l;plit hinged coupling linl~ of the present invention; and Fig. 25 is a radial sectional view of one form of another alternate split coupling link of the present i..~ tion.
Det~liledD~_;"l - of PrefelTedF b~ ~
Figs. 1-4 illustrate a generd e_ ~ ' of a cnnt~tl~C power delivery system 30 co~l.~ ' in accol ' -e with the present invention for deliverirg power from an electric source 32 to an electric loaA inA;~ generally as 34, with a specific embodirnent of a movable electric load indicated 21472~8 as 34'. The system 30 is rliQC ^Q~i in general terms, first for a hnd-based system, and then in c, lP~i terms, for an underwater cnn~p^~lp-c-c power delivery system 300 (see Fig. 17). Most of the e~ nc for the air-based system 30 apply equally to the ' ~ ~,~ system 300.
The source 32 may be Pl e current (AC) power or direct current (DC) power, or5 a c r n of AC and DC power. For a I ' ~ -- i system, typically the source 32 is a utility system providing AC power at a line L., ~, for e~ample, 60 Hz in the United States. The electrical load 34 may ta~e on a variety of confi~ u~ electric vehicles .~ui...,g a power boost or .~h~u~, haulage and Cu~ ~g F~ '. t, such as may be used in mining; batteries requiring ~Dch~ ~i"g, ;.~rl~ when in motion; linearly moving loads in a captive path, such as in eh,~ D~
10 conveyors and the like; robotic arms having c ..~ rotating joints or ~uiiing linear motion in D~U LI with a co.,~or line; portable electric loads where fle~ibilityis a priority, such as p~u~5~Di./e loads in mine face and co~l.u;lion site ~r~ nC te.~l~r wo~ sites where quiclc setup is a priority, such as in military or naval l~r~ nc and undersea loads or loads located in other ;r liquids. Several specific P~ are ~ e~~ d further below with reference to Fig. 1~.
This list of e~ , ' for the electric load 34 is provided merely by way of illUD~ n, and it is apparent that many other . rl b~n~ may find the c~ntPrtl power delivery system 30 described herein to be of use. For e~cample, while for c~ . .e the ill ~d en kYlin~P-nt- initially discuQss power transfer from a fi~ed primary to a moving ~ , it is apparent that the primary and e ~ may be reversed. Thus, power flow from a moving source 32' to a tl ~ 1 load 34 is also 20 within the ~cope of the present i;. as well as .~eiv g power from I ~ 'nn, rather than just power delivery from a surface source to a ' ~i load. It is also apparent that the relative motion of the primary and ' .~ ill d herein may be due to linear and/or rotary motion of either C4--y~ f -~t with respect to the other. The actual values for the F D ~' d herein will of course vary by 1. r~'~ ' , and the values shown here are given only by way of e~ample.
R~tng Q~ifirJ~Ily to Fig. 1, primary c~ 36 couple a primary-side c<JI,~.,.h,l 38 to the e1~ct~ir~1 source 32 which may be a three phase AC source, a single phase or other polyphase source or a DC source. The system ~rih~d herein may operate totally at the line L. . ~ of the AC
source 32. IR, _~_" it is p.ef~ d to gain r~ ~ " cr~ s ~ ~k p~.ru -~
a b~. and ~ ~ useful C0~1~5~ ' by using the primary co..~-t.. 38 to increase the L. l ~ of ~ . . for instan^e on the order of 400 to 5,000~ eF-- ~ e upon the most cost effective type of . ~_.t~.., and the ' of the circuit as seen by the primary c<;..;e.~. Ac 8 practical e~ , to c~ e - devices, there are tradeoffs between the device cost, ~i~l~g L~ -s and loss cnn~;~ nrc due to heating and the lilce. The L~, ~ of ~,~ generally d~-~s as the power rating ~s, based upon the~se e. - cnnrP nC A specific Pm~imP~t of 35 a primary c~...,~..tcr 38 is ~' d in greater detail below (see Fig. 13). The high L~ AC output of the primary converter 38 is supplied to a primary . ' : or primary loop 40.
In the illustrated e_' - ' . c~ . . 42 deliver power from an optional s~on~ ~-side C4 ~ ,- h,- 44 to the load 34. The secondary converter 44 receives power through a WO 94/09558 2 1 4 7 2 5 8 -6- PCI`/US93/10068 sv~ond u.~ c~ or or S~O~ loop 46 in a manner d~"b~ in further detail below. Various types of 3~ converter designs may be used, ranging from simple to comple~c as required by the par.icular ~ t~ In ~sorne ~J~' t ' 5~ the ~o~d~.~ cOu~ncr 44 may be used to cnnt~ifit~n the power to the load 34 in terrns of voltage or current regulation, phase change, voltage boo(st or Lv~u~ y S control, ~uch as to provide power to load 34 at a desired AC frequency, or as direct current (DC) power.
The - ' ~ c~ ~_.lv. 44 may also provide inner loop control, such as by p.uc~g feedback from the load, as opposed to outer loop control involvingfeedback to the prirnary ~ ,. 38. An i~
e ' - ' for the optional ~ ,.tv. 44 is .1;~- - ~3 further below (see Fig. 14).
Power is delivered from the prirnary cn-~ ~, 40 to the ~ ~r co~lu,lu, 46 by a 10 slidable coupling device, such as a link or coupling sheath 50. The core 52 may be of a f~ v c matf~rial, such as a co..~ olldl silicon steel or an ~v,~Lvus steel. The core 52 may be ~ and hinged or have flu~ path air gaps as llt~C~rih~A further below. The prirnary loop 40 is slidably received within linlt 50.
Figs. 14 illustrate the link 50 as a dual link having two identical link members 56 and 15 58. The primary loop 40 has power flow sending and returrl portions 40' and 40", respectively. The first link member 56 is slidably received on the sending cm.-l~ , 40',and the second link member 58 is slidably rec~ived on the return portion 40~. Other ~ c described further below illustrate a single link rnember, such as 58, coupled with a single primary c ~1~ ~,. The selection of a single member or dual ~. . for the link 50 depends upon the ~ ' ~, r~'~ " in which the .
20 system 30 is u~sed, as well as various ~r~ -- C; ~ lo~l to provide the most efficient and 8~ ' unit for a given ~ r The ~u..~ ~ cn~ 46 includes a core-mounted ~ .~ winding 60 which may be a tubular copper member 60, ' -lly ~lu~d~ by core 52. Alternatively, it is apparent that the 6~ winding 60 may also be c~---.~--;-~ of a plurality of discrete elements evenly Jl~h-l,~ lt;d 25 about the inner surface of the core to provide a uniform ~ -- of current. The 6~Cû~ winding 60 may be split or c, ~ intv at least two hubular members r ~~ from one another and COI~~ d to join one another iD a lr~r~ih~ direction. Alternatively, the ~ winding 60 may be C-shaped or U shaped in rsdial cross section.
The se ' .~ winding 60 and core 52 are defined as being: ' -'ly ~ -30 about a l-~v ' ' a~is Y. For P~ , referring to Fig. 2, the iink member 56 has a ~ v;lY~ nl a~cis Yl, and link member 58 has a lf~ a~is Y2. In the ill ' ideal ~ the ~- ' ,. 40 is located u~l~r~ Ally within the ~.~ winding 60 and the core 52, and Ihv.efv,e has a l~ngihl~lin~l a~is colinear with the ll ~ ' -l a~es of the linl~ members 56, 58. The term ~cn~Pctle-cc~ as used herein rneans without any el~ l contact between the primary and s3condu~ .hAli.l~,other than magnetic 35 coupling between the v. ' g Tn Fig. 3, the current flow of the primary and s~ond~ ~ current is jllllctrD-ff~- lly. The current through c~r~ c~or segment 40' moves out of the paper as int~ir~ by the dot (&IU..' 1) therein, and the current through c-~ . 40~passes into the paper as j~ ir5~f.d by the 2~472S8 WO 94/09558 ~ PCI/US93/10068 X (arrow tail) therein. Similar conventions are use~ at four locations about the ~.;~)hc,.y of the ~xo ~ cnn~llstnr 60to ~' ' Ily indicate the direction of current flowtho~lLu~gL.In .~ r~g the one possible theory of '-r- '-1 for the illustrated emky~ ont~ the- . . is that the power flows from the fi%ed primary c~n~' I ,r 40 to the movable 6~u~ ~
S c~ r 60 of link 50. It is also equally possible to have power ~ ' by the movable load and h r .od from the outer winding 60 to the inner winding 40 (see Fig. 18), or to have the s~..d&..
c~ ur moving and the linlc fi~e~. As used herein, the term ~fi%ed~refers to being secured in a relatively singular location, although it is apparent that the fi%ed member may fle~ or move su~..' as required or directed during o~ n To illustrate the concepts of the present invention, the c4ntortl~c power delivery system 30 is d~ hed herein for two basic e~l.c ' ' ;, one for a bile electric load 34' (see Figs. 17-19), and the other for a clamp-on lin~ 34 used for power distribution (see Fig. 16). For e~ample, the link 50 moves with the moving load 34' and requires a radial cle~ -e, referred to herein as an ~ dillg space~ S shown in Fig. 3.
The interwinding space S is distinct from an ~air~ gap G in the flu~ path of core 52, as shown in Fig. 5. The term "air gap~ as used herein refers not only to air, but to any non ~n~.lic gaseous or liquid medium, such as seawater, flowing through the gap G, and C(J~>.;~Illg the envhu~nl in which link 50 travels or is located.
Thl s, the link 50 with primary Cf~ to. 40 inserted therein provides a generally coa%ial 20 ~u ~ This coa~ial nature yiddc low lealcage ' -e which enables the use of high r.~ . c in the .~ system 30, and results in high power ~ The dis~ current of the s~o~u ~ winding 60 ~.u~J~ the current of the inner primary c~ ur 40, and has been given the narne ~coa%ialwinding I r l~_r~ or ~CWT~by the i...~ ~ of the present invention. Fu.lL~.~.e, coa~ial winding transformer theory may be used to analyze link 50 with loop 40 passing lh~ uugh, and for . .~ -e this ~- is ! refer-ed to herein as a CWT. The various ll~rul~.
concepts p.~ ~ herein rnay be similar in some aspects to cuu~ - -1 current I ~u.~, theory for i~ll~ t, relaying, ~nd radio fi~ power supply ll rl ~ nnc~ e~cept that the core used herein is not .~;.,t~d to ~,ll in the linear region. Further, for power b~ansfer at high f.~l. -;~.c, it is desirable to have a low b ~u.~r leakage i~d - -e The power density of core 52 is directly proportional to the L~u~.~ of the powerp~csing thr~>ugh the ~ 40, 6C). Therefore, the use of high L~~ power paæsing through link 50 - t~ e&~ the o~ g power density of the e ' system 30. Also, the use of high L.~ y currents in system 30 ad~ allows the use of small-size c~ o.. l~ to provide the required power transfer. These concepts are feasible to , ' in a pr~tical sense, and may be 35 cor~l,u. t~ at a ps~qlti~lly low cost.
A. AlternateLinkC~ u. 3t Several of the cores and link members shown herein for the purposes of illustration are .ylill~;~l ~l~.~ having basically circular or square cross sections. However, it is apparent that other WO 94/09558 PCI`/US93/10068 2 ~ ~ 7 2 ~ 8 -8-cro~ section~l shy~ y be used to at least partially surround c~ vr 40, in toroidal or .~lh-~,~l confi~. 'nnC, such as .. ~ ~ lo~ elliptical or emi~ircular cross ~ections. Several basic CWT core confi~5 "nnC are shown, with one being a toroidal, gapless core, as shown in Figs. 1-4 and 6. Another basic CWT core configuration has Y Cffhaped core with an air gap G in the ,i.-,u-llf~,.~li~l magnetic flu~
5 path of the core (see Figs. 5, 7 snd 8). Several .~ g~u_ nnC having r ~ le cores are shown in Figs. 23-25.
Referring to Fig. 5, an alternate linlc member 58b has a C-shaped core member 52b with an ~air~ g&p G. In contrast, the gapless core 52a of Fig. 3 is captive, not easily detached from the primary c~ble 40, and more . r ~ ' for a load moving in a ~ ~'y fi~ed p~th. The C-shaped 10 core 52b may be easily removed by pas6ing the primary cable 40 through the air gap, and is more suitable for 1Oads res~uiring ~ - - to the source. The flu~ path ~ of Fig. S includes the air g&p G with the flu~ traveling across gap G between surfaces 61 &nd 61' of core 52b. It is apparent that the air g&p may travel any radial path or a path skewed to the radius, i.e.,a chordal path or a spiral path linlcing the core inner and outer surfaces.
The portable cl&m~on link (see Fig. 16) typically does not move co.~ - o~ly along the primary cable, although some lateral motion may be Pc~n ~ Rather, the i t~"..h di.,g space S of the clampon link is only required for jnC~ n &nd p~V~ on during rugged use &nd is preferred to be less than for a moving linlc. A cross sectional view of a suitable cl&mp on link member 58c is shown in Fig. 6 as having two r ~ 1~. mating core portions or ~ 52c &nd 52c' joined together, for 20 in6tance by a hinge 62. The r ~^ core ~ may be joined by a I ' -IIIP! used in clamp on ~U~D, which may use a Hall effect or the ~ t;~ material Du.luu..li..g a cc~ lo, to monitor the current flowing thl,.etLo~-gL. A variety of other means may be used to secure the two core s~
together, ;-~ l;.,g ' ' fasteners, and the ~ - forces of P l on between the core ~5~
when flw~ is flowing in the sune direction through each core segment. The s~;ond~ ~ c~n~' ' of link 25 member 5& is also r 1^ and split into two ~ , 60c and 60c' DUllu '-~ by the core halves 52c and 52c~ y. This c~ design ~h~c~.l ~ the feature of being .,~._ l^ in a b ' "-lly radial direction with the feature of a gapless core, that is ~gapless~ to the e~tent there is a minimal air gap between the core s~ogr~ntc when ;he link is closed.
Fig. 7 illustrates an altemate ~_L- ' of a ~ C-shaped linlc member 58d 30 ill ~ as having two core member 52d &nd 52d' joined together, wch &S by a hinge 64, which may be the s&me &S hinge 62. The ~ ~ ~ winding of link member 58d is also split into two c. ~ 60d and 60d'. The C-shaped core of Fig. 7 h~ an ~air~g&p G which receives a prirnary ~ ' t( wpport 80 which may be a plurality of discrete members (not shown). Howe~!er, the ill ~' wpport 80 is a c~ y~:~-, member having two inwlative members 81 &nd 82 joined together by a flu~
35 c4n~ n . ~ lg member, such &S &n I-beam shaped member 83 of a ~agn.o~ic material. The ,, r rnernber 83 is wpported within the air gap by in~ulative member 81 which e~tends outwardly from a fi~ed surface 84 adjacent to the electric load 34'.

WO 94/09S58 2 1 ~ 7 2 5 8 PCI~/US93/10068 The flu~ path ~ of Fig. 7 has an ~ air gap ~ d to that shown in Fig. 5.
The , c ~ e of the air gap is d~.G d by providing the magnetic member 83 across the air gap. The air gap , ~ ~Gl~ ' -- ih al80 reduced by providing a pair of . ' -~d surface arGa .. 86 and 86' at the core adjscent the ~ir gap, defining a flu~ path 88 i' ~, as shown in S Fig. 7. The flu~c path 88 of corG 52d,52d' is ~, d by tho ~ - member 83 of the ~ . -support &0 into two c~ , and thus would include the magnetic p~, :b.lity of the member 83.
If the support 80 is one of a series of discrete supports (not shown), typically between such discrete supports the flu~ path 88 is . . i~ only of air, f g that air is the medium in which the system is ,Lr~ g. The total air gap G remains the sarne, but srnaller when support 80 is in gap G, regardless of buu~ln& r - of the link member 58d in ILI_liO~ ' 1l ' ~ by arrow 89, which is ~ -lly perp~lir~lo~ to the r~ial a~is X. In the . ~ of Fig. 7, the air gap G rnay be kept to a ..-:-.:..-- -.. which ~ 1~ g~l~ reducG~ the total weight of the cor~ ~, 52d and 52d',and which ad~ ;,- :,--, material costs to c~llu~;l the link member 58d.
Referring to Fig. 8, a link member 58e has a C-shaped core 52e which rnay be used with an au~iliary fi~ed core member 90. The fi~ed core member 90 may be a long planar member of a t;~ material _.t. -- l;,.g along the selected path of travel of the electric load 34'. The fi~ed rnagnetic member 90 may be r~ d from an ~ ' g wpport member 92 ~ : g outwardly from a fi~ed surface 94 to support primary ~ ' : 40. The core 52e includes an . ' ~ ~ ~ air gap core face having ~ O 94 and 94' which provide flu~ paths 96,96' between the core 52e and fi~ed ~ - core member 90. The link member 58e of Fig. 8 allows for a larger gap between faces 98 and 98' of core 52e, to allow for greater freedom of vement in the direction i l~l ' by arrow 99, which is ~ ;olly to the a~ial a~cis X. Thus, greater amounts of bounce may be ~ d in the direction h d by arrow 99, ~ L~ul~l~ if the flu~ paths 94,94' remain relatively constant between the ving core 52e and the fi~ed core member 90.
B. Cou~ Linlc TheorY of O~
For ~li.;il~, the analysis of the action of link 50 with respect to primary c~ r 40 will be d~.il~d for the gapless core of Figs. 1-4. The design ~ ~ for the ill ' gapless core and the movable electric load 34' are shown in Table 1.
Table 1: DesiQn C~ for E~ample f = 2000 Hz fr = 2500 HZ
Bm = 1.4T
Nl = 1 N2= 1 Pwg~ core = 7.32gm/cm3 (~I~L~uD metallic glass) Pwgt CU = 8.92gm/cm3 cu = 0.205 x 1~5 ~cm PCore 108~ = 0.226watts/cm 3 WO 94/09558 2 1 ~ ~ 2 5 8 PCI`/US93/10068 t,,,~ul = lmm ~ = 105 (~Ip~ metallic glass) stacking fsctor = 0.75 Loads:
Rating: lOOkW each, 10 units Duty cycle: 100 %
F,~, ~. 0 (dc) Voltage: 600 Path Length: 1 l~m, in 5 s~o.g~.nt~:
High I~ Source:
Rating: 1 MW total F,~. 2000 Hz Cable Current Density: 200amp/cm 2 Socou~ Current Density: 400amp/cm2 (1) E~ Circuit and l~e Ir ~ ~t e As shown in Fig. 9, the CWT equivalent circuit diagram for link 50 and primary c~ ?r 40 is ~ic. The equivalent circuit is oriented with the primary cn~ .. 40 to the left, and the ' ~ winding 60 to the right. The leakage j...l~ e is ' d as LLEAK.~GE, and the c, ~' ' g ' ~ I -E is ' - d as Lm. This ~1~tl~ is known from current-l~ ' theory 20 and is due to the ~cPn~islly 100% linl~age of the primary current by the ~ e flu~ of the winding 60. Any ~gful: ~ e on the ~ond u ~ side is due to the e~temal circuit, that is, any inA ~ -e in the s~condu~ Ioop 46,the s~ond~ cuu~,,t~,r 44,or cn. -l ~ 42 th~,,~.~.
In Fig. 10, the linle member 58 is ill ' ' d in greater detail. The center-most conductor 40 may be an insulated e ' ~u.. '-d by an ' layer 70. The se ' ~ winding 60 has inner and outer l . Iayers 72 and 74, respectively. The primary - l Iayer 70 and the se e ' ~ winding inner j..c..l ~ layer 72 define th~,.cl~ween an .. ' g region di d generally at 76. The s . ~ winding outer ' e layer 74 -, ~ the s~onLu~ c~~ C~Q~ 60 from the ~ ~ core 52. The core 52 may be ~ u.~)~d by an insulative layer 78 which is preferably of a durable plastic, or resilient rubber or other material which could be surrounded by an ~ n~l 30 durable housing (not shown) if required to provide a rugged linlc 50 capable of w ' ' g physical abuses ~n ~,d during normal use. ~1~ r ~Iy~ the ' ~ Iayers 70 and 72 are also of a durable material, sinoe they may be ~;F~Jf d to ,s-~ -' frictional foroes from rubbing against one another during use. Also, the oenter-st c.~ 40 may be ~e t I to env,,~ I abuses.Fig. 10 also ill ' - several ra_ii e ' g from the l~ ~h~1in~l a~cis Y. The various 35 raldii nave the ' p~ with the numeral 1 ' _ the primary ' 40, the numeral 2 . the s~on~u ~ winding 60, the letter ~ g inner, and the letter o~ ' ~ g outer, the letter ~c~inAi~ g the core 52,and the letters ~ins~inAi~ g the jnc~ n layers.

2~-~725~

The CWT has an unusually low lealcage inAu~ -e which allows for 8 high current capacity and the use of high frequency switching converters 38 and 44 in the cnnto~t1p-cc power delivery system 30. The lePlcage ' e per a~ial meter of core length (p~allel with ~ .A;,,-I a~cis Y) rnay be ~t4. -~ in a fasihion similar to that for a coa~ial t~ ~ Iine. For instance, when the outer 5 cnnAnclor can be appro~ ^~ by an infinitely thin current sheet:

GE = [(Nl2 llo) (8~)] [I + 4 In (K)] H/m (I) K = (r2i . rl) 2 1 (2) where:
Nl = primary tums r2j = Ai~ d s~onJ~u~ current sheet radius rl = the prirnary cable outer radius ~o = 1;~ ''lity of free space (4~ 7 H/m) The leakage ir~Allct~ re per a~cial meter for a range of values for the secondary to prirnary ~~- ' r ratio K is shown in the graph of Fig. I l. In a more generalized ~ , K is the ratio of the effective radius of the C4.Y, ~UI~t~i current sheet to the outer radius of the inner-st cn~ r. The ratio K differs from the .. ' g space S as shown in Fig. 10. The ratio K relates to ~n~ r d - , whercas S accounts for ' r in ,A~t~ g available space within the .. ~ing region 76. The Fig. 11 grsiph shows that the leakage ' -e LLEA~.AGE inCreases slowly with the value of K, and is less t,han one Or' .1 per meter for K S 25. Thus, the interwinding ;pace S and interwinding region 76 for relative motion between ' ~ ~l 40 and the interior of link 50 is readily provided.
Fu~ olc, the leakage ' l e L~,UC~GE is insensitive to the position of primary 25 ~ ' - 40 with respoct to the l~g ~- ' ' a~cis Y of link member 58. This c! ic ad~, g~ ~y results in less stringent I~UilC~lts for a position controller between, for instance, a ving vehicle o~ ing the linl~ 50 and the primary c~ r 40 (see Fig. 17). Thus, any relative ~.e~t, linear or ror~ti. --l, between the primary and i~ wi~d~o 40, 60 has a r~Pgligi~'- effect on the leal~age ' -e L~CAGE and the flu~ stays h -lly constant.

WO 94/09558 2 1 ~ 7 2 5 8 PCI`/US93/10068 (2) 1~
The Lm ~ 7ing inAn ' -e for a given core length lc, ~ g there sre no sir gsps G in the Cll~ ~r~.~L&I flu~ path of the core 52a, is:
Lm = [~ N;2 (rCO - rc; ) lc ] [~ (rco + rci )]
where:
~ = core pe. L lity rcO = core outer radius rc; = core inner radius Ic = a~ial core length As with all power delivery h~r~J.~,~, it is desirsble to have the ~ v~ ;ng: h ' Lm be as large ss possible to minimi7P the ms,gnP.ti ~nn current required. Thus, it is sppsrent thst bssed upon the v "7ing ~L ' . e only, it would be desirsble to have the core length Ic be Isrge, resulting in a long, thin core.
15 (3) Power Densit~
The power density per unit weight Pwg~ rnay be d~ A by c.~l,.. & both power snd weight in telms of the given i ~ then d~,~g the rstio th~ .,. For sin~ 91 root - . c vslues, unity power factor, snd r~Pgligi~lr 7ing current Lm snd nPglipil~le losses, it can be shown that the power density is:

PW8t = [2 ~ f Bm Nl il (rCO - rci )] .
[~ (rCO2 - rCj2 ) PW~ cole + (N2 i2 Pwgt-cu )/J 2]
where:
f = L. I .~ (Hz) Bm = pesk flw~ de-nsity (7 ) Pwgt cO~e = core density (kg/m 3) Pw~-cu = COpper density (kg/m3) J2 = s~ circuit current density The power density Pwg~ is ;~ of the core a~isl length Ic~ since the t. c Yoltsge, and hence the t~ r 11~1 power, snd volume both incr~ase linearly with the core length.
However, for a specified power rsting, it is sppsrent thst the core length Ic msy be ophmi7Pd to provide a power density. This snalysis results in Bn CAIIC Iy long, thin core 52 when the primary to se ~ ~ current rstio (il:i2) is near unity. Up to this optim ~m the longest ~ce pl ''~ core, with a 35 .. :..;... -... core radius rc; may be used to achieve ms~im~Tn power density, since the power density is primarily d- ~ by core weight. An 9~1Ai~jnn91 O~.d~g festure that may be provided is the use of two link ~...be.~ 56 snd 58 ss shown in Fig. 2, esch having a co,e length co~t..bul,ng to the total core W O 94/09558 2 1 ~ 7 2 S 8 PC~r/US93/10068 length lc~ here ill ~ ~ as one half of the total core length f Ic or Ic/2. Thus, for the design e~cample given above, the length of the link members 56 and 58 rnay be on the order of 30 cm.
(4) Couelin5! She~th D : _ and Ch~ ~ lic Values The radial ~' - shown in Fig. 10 rnay be ro'---' d by br~j;.. ;..g with the 5 ilm_.LUODI d -- ~n, that i6 radius rl of the prirnary c~ v~o. 40, and then p.Y"sl~ ,, in an outward direction. The equation for power density given above shows that th_ power density is inver~ely proportional to the average core radius when the core weight term is much larger than the copper weight term of the ~- ~ r. The average core radius is related to the prirnary and ~u.,d u~ ampere-turns, as well as the ~.,u~g space S, sinoe the core 52 DUIIU~ iD both ~ u.~g~ 40, 60, and necessarily also 10 enclose~ the ...t.,.~,~dmg region 76. The u~,i on tradeoff fûr having a large .. uling space value S is that the volume of core material, and hence weight, increaDes with the square of the average radius of the core rC(~vgp and the power density Pwg~ d~.~D
Thus, the desired ~.,u~ug space S varies with the particular ~ r~ for the cnntP^t1e-c~ power delivery system 30. For ~ ~y moving loads 34~ ffiriPnt ~. ' g space S
15 rnay be provided so the link 50 rnay be po~itionP~ along the prirnary ~ ' ~r 40 without contact.
However, in pr~qcticslity, ~Dome contact rnay oc~ ..qlly occw between the primary ~ 40 and link 50. Therefore, it may be ~ ' 'e to have the prirnary cu,du.,lu, ' ' '- 70 and the s~ul~d~
winding inner ' 72 be of a low friction ' g rnaterial, Duch as of TEFLON~. For aly - ~ clamp-on linlc (see Fig. 16), the ~.,,.di.l space S must only ~-x -' ~ the I Iayers 70 and 72,without the ~uh~i for a large ~.,~l~ug region 76 as illustrated in Fig. 10. In pr^-ticolity, it may be ~'~~ ''^ to provide for a certain - ~.- ' lg region 76 in the clamp-on . 'x ' t, to L"~ -' ' multiple gauges of primary c ~ -lu~t ..,. 40. For the mobile Wlit 34',an ~.~ud ug space value K = S is realistic, whereas for a clamp-on unit, a realistic ~v uding space value is K = l.æ,using realistic material _s shown in Table 1 above and for a link 50 25 rated at 100 ~W shown in Table 2 below.
Table 2: Coa~ial Windine T. ~I u~r Data l~W: 100 each (10 units) phase: 1 ~" ,~, ~000 Prirnary and Socu~ Voltage: 200 Primary _nd S~con~ ent: 500 C. Pr~n~rY CD ~
The primary c~--l- ~ lor 40 passing through e_ch linlc member 56, 58 i6 ~Nm~ to oe a single turn loo~, with three such serie, c~ e~1 loops 40a, 40b _nd 40c oeing show1~A in Fig. 12 for a system 30 having mobile loads 34'. Each of the series primary loops 40a, 40b and 40c receive power from c~ ~r 100, which may be a low d -e coa~ial power cable, coupled with the primary side c~,,.r~,,t~, 38. Using the split cores, such as of Figs. 5, 7 or 8, or periodiclly opening the hinged unit of W O 94/09S58 PC~r/US93/10068 2 ~ Li7 2 ~ 8 -14-Fig. 6, a movable electric load 34' rnay move along a p-~.u...-ed path from left to right in Fig. 12, and first receive power from prirnary loop 40a, then from loop 40b and finally from loop 40c and so on.
The effect of the primary cable 40 passing through the ~ .~g space 76 of link 50, as viewed from the high r.~ source input of primary c~,,~_.t~" 38, is that there is virtually no affect S e~"lccd due to:
1. Primary cable position relative to the ln~ Gl a~eis Y of the link;
2. The position of linlc 50 along the prirnary cn~ Inr 40; and

3. The ~ ug space S c' -e between the prirnary cond~lor 40 and the interior of the linlc rnember.
10 M nn of stray v tie fields may require close spacing between the sending and receiving portions 40' and 40~ of for e~ample loop 40a. This feature of locating the sending and return paths 40 and 40' in relative close IJ,o~ rnakes the dual link 50 having link rnembers 56 and 58 (see Figs. 1-4) an attractive e-"h~~ for reducing overall core lengths. A dual link rnay also be a more rugged and durable linlc 50.
The i~ u -e of each primary cable loop 40a, 40b and 40c, is considered to be in series with the leakage ~ ~ LLE~GE of link 50, and is given as:

L ~OOp = [(l10 --2 ~r )l [ In (D . rl )] per meter (S) 20 where D is the center-to~enter lateral spacing of the sending and return path cables 40' and 40~.
This equation shows the insensitivity to the i..~ re of the link 50 to the size or gauge of cu du~ lor 40 and to the spacing D between the sending and return loop portions 40' and 40~. This equation also shows the linear ~ ~ of the 3 e of each loop L~oop on length. The loop spacing D may be fi~ed by the ~' - ~ of the cores of linlc members 56 and 58~ with 2 rcO being the possible for a centered prim~ry cable a~is (not shown) ~.~. .. l.. ~g between the link members 56 and 58.
The loop segment input:--r l e Zin for each loop 40a, 40b and 40c is given by:

Zin = ( R pn + R ~d (v;l-"iv) ) + j 2 ~f ( L,oop + Ll ) (6) where each load unit R~ ~ .) is the equivs~lent . at rated output referred to the prim~ry side of the CWT.
When the reactive term on the right of the input:--r ~ ~ ~ equation is much larger than the resistive term to the left, the loop input i.-r ~' -e Zin varies linearly with the loop length and 35 f, ~ " but only lo~ ' lly with the spacing. This cl~t~ lic of the loop input h-y~l ~e suggests c~ g the primary conductor 40 into several small loops, such as 40a, 40b and 40c of Fig. 12, to reduce the loop length and required input voltage. In the design e~ample of Tables 1 and 2, 2~472~

the loop input voltage for one large _egment is over 7 kV, whereas the loop input voltage for S S~
i_ only 4.1 kV.
In the ill ' '~ i ~_' s ' t, the .. -- of the prirnary cable 40 d the power lo& of the entire c ' power delivery system 30, as is the ca_e in other power distribution S and power I ~ ystem_. For a given current den_ity J 1~ prirnary current il and total length per _egment Ih~t~ the , - and power los are given a_:

R pn = ( [ PCU Jl ] ' [ il ] ) ( L bo~ ) (7) Pl0~8 = Pcu J I il I loop (8) The design e~ample colc~ nC ~ d herein are based on five 200 meter loop sev.. ~ three of which are _hown as 40a, 40b, and 40c, with a total of 400 rneter of primary cable length in each loop. The ample ~ lrl~ ~)nC also sssume a dual link 50 having two link member 56 and 58 as shown in Figs. 1-4- The F ~ for the primary loop are given in Table 3 below, L-~""';"V 5 each of the five loop E'V has two 100 kW loads traveling thereon, which appear in ser ie .
Table 3: Primary Loop Segment Data ~ Mobile Clam~on D (cm) 12.998 6.512 Lloop (mH) 0.22 0.16 R ,p; (ohm) 0.033 0.033 P b~. (kW) 8.2 8.2 R b~d (equiv.) (ohm) 0.4/load unit 0.4/load unit Z in (ohm) 0.833 + j2.76 0.833 + j2.07 V in (rms volts) 1441 1117 I hop (rms, amperes) 500 500 P in nux (~W) 200 200 D. Primar~ Side Power El~l~ ~
The ~r I ~ ~ d~ ~ herein uses power electronics to optimize system p~.rl -e and to meet .~.~ realized practicsl design c~n~;' - - In the ill ' ~
30 e_~~ ' t, starting from sn AC or DC source, here illus;trated as a ~~ nnol IL~ ~l~se 60 Hz AC source 32, a high L~ ~ current on the order of 2 kHz is needed for the primary loop 40. At power levels of co~,. ;&l interest, such as grester than one ...c~;.... (I MW), one cost effective . r ~ ~ ~L involves using an input stage, sl}ch as a thyristor rectifier 102 as shown in Fig. 13. The rectifier 102 provides a DC output received by a choke coil 104 to provide a DC curr_nt source for a high L ~ .~ current source inverter (CSI) 106. The current source inverter 106 has a plurality of switches which are controlled to provide a desired high L~, ~ output to an optional , -' -e -' u~. 108. If utility side power factor and h~~ .ic interactions are a concern, harmonic filters (not shown) may be used for reactive and tL '- cr~ t;nn, as is an industry wide standard ~ 4~2S~ -16-practice. Alternatively, re advanced GTO-based (gate twnc,ff thyristor) force co ~d input rectifiers, also known in the industry, may be used.
In the ill ~ ..l, two considerations are used to govern the cboice of co"~e.t~,~ topology for the high L~ current source inverter 106 to provide the desired high L~ p~ -nn First, at the high U~A g L~.,.~, the ~e' e of the primary cnn~ ct~-r 40is Iy inductive. As seen in Table 3 above, the inductive ~ for a 200 rneter segment of primary cable is 2-3 ohms, as opposed to a resistive co . of 0.033 ohms, which clearly indicates that the primary cnn~lvctnr is highly reactive. Cn~ , o~. g the cnnts~tlecc. power delivery system30at500arnperes, which~,.e~.~n~ls to200kW,suggeststheinductiveco........... y)ol~f-~ required to energize Le cable is 700 kVAR. For the entire illustrated system, with a one ~.. .~U rating (1 MW), this co"~ to an inverter rating of 3.5 MVA.
O~ g of the inverter rnay be avoided usmg a resonant inverter topology as is known in the art, for e~ample, as dGsc.ilJGd in an article by F.C. Schwarz and J.B. Kl- - entitled ~Controllable 45 kW Current Sowce for DC MP~hin~c~ IEEE T. I ~ IA, Vol. IA--15, No. 4, July/August, 1979,pp. 437-444. The ir~ -E of the primary cn~ -l - Ic.r 40 may be cornps~ ~e~ using a p~llel resonant capacitor 110 having a , - -c C, cnnn~c~e<l across the output of inverter 106.
The volt ampere reactive (VAR) ~ui-~ t~ of the primary cable 40 may then be supplied by the resonant; . - )r 110, and the inverter 106 then need only supply the real power (watts) needed by the 20 system. A l,.~f~ d topology for the invener 106is a cwrent fed series output parallel resonant (SOPR) inverter, such as that e~tensively used in in~ ti.~n heating r~ rl ~jr~nC at similar L~ s The second concern governing the choice of converter topology is that inveners b ;l~l~& at high L~ s are normally limited by the ...khing losses occurred within the devices.
The use of resonant toprlrg allows device s.. .1~ I~g near zero voltage or zero cwrent crossing points, 25 which results in cjf ~ ~y lower L..it~,Lug losses and the ability to obtain higher L ~
The primary side convener output .~ ~ for the ill 'J e~ample are listed in Table 4 below.
Table 4: Primarv Side Converter Data P-u~t~,, Mobile Clan~on MW 1.0 1.0 voltage (v) 1441 1117 current (a) 694 895 L~,~"~ (Hz) 2000 2000 phase K 5 1.22 The required ~ x Cr for the resonant .1~ r 110 to provide operation at a resonant L~ y f, is:

~1~725~
WO 94/09558 PCI`/US93/10068 Cr =(4 ~2fr2nlLbOp)-l (9?

where nl is the number of IOOP G ~ e.g.,fivein the ill ~ P--.l~1;..- - ~ when the ir~
of link 50 are relatively small and r~gligi~'^ when ~ d to the: ' - of primary loop 40. Thus, 5 in the ill ~ ~ design e~ , values for the resonant _ . - 110 are given in Table 5 below.
Table 5: Resonsnt C`: r Data P~r Mobile Clamp on Cr(~F) 3.7 25.3 Voltage (Vac) 1441 1117 Current 500 500 E. S~Drd ~ Side PowerEle~
The se. ~ .~ side converter 44 may be either one c~ v~,.t~,. for each link member 56, 58 or two discrete converters, but for simplicity is shown in Fig. 14 for the mobile emk~imP-n~ as a single ~ ._.ter 44. The . ~,.ter 44 converts the high f. ~ ~ power received by link 50 into a desired AC L~ or DC power as dictated by the needs of the load 34. The linlc 50 is shown lly in Fig. 14 as a core 52 and ~ winding 60. As shown in Fig. 14, the ~o d~ ~
C~.J~_,t~,t 44 has an optional power factor ~ . r, such as A power factor cc--r-- nn circuit 111, and a rectifier, such as a full wave bridge rectifier 112 which may include an optional ~ ~ g filter(not shown), which are each well known in the art.
The optional power factor correction circuit 111 may include a . r circuit, suchasavariable ~ r,coupledwiththese~ winding60. Thepowerfactorc . ~i lllmay be a simple . r or a power el~llu~c circuit arranged to provide the desired power factor c ~ nn In some ~' s~ it may be p.ef~ ~ to have the ~..d~.~ side of the system 30 appear as merely a resistive load when viewed from the primary sida, particularly from the AC source 32.
This may be a~c4.-~ ~1 by a ~; g the power factor c ~ . 111 to provide unity power factor, such as may be provided by a static VAR c- ~ (SVC).
The ~Ot~h ~ c~ ~/_ t~,. 44 may also include an optional DC-to-DC co ~_.t~ ., such as a DC to DC chopper 113,coupled across the DC output of rectifier 112. The chopper 113 may be a simple 1. switch having collector and emitter coupled across the output of rectifier 112. The chopper 113 matches the DC volhge from rectifier 112 to that required by the load 34.
In this ~ ~ ' t, using a full wave bridge rectifier 112 provides a DC output which is fed through an output filter 114 and deli~ ,d to the load 34. The output filter 114 may make the ~e, ' ~ c~..i~,.t.r 44 appear to the load 34 as a current source. In some . r~ - s, the output filter 114 may be omitted and replaced by a; . ~ (not shown) in parallel with the rectifier output, so the 6~0nd~ ~ c.,.. ~,.l.,. 44 would appear to load 34 as a voltage source.
The e~ ' ~ side co..~, t~ 44 may also provide other outputs and f~-nr~innc, such as receiving inputs from other sensors and operator input c ~ ~c 116 located on-board the load, such as for an electric vehicle. These sensor signals and c e ' are received by a signal c~ ioning WO 94/09558 2 1 ~ 7 2 5 8 PCI/US93/10068 unitll8. Acontroller 120receivescnn~irinnpd signalsl22fromthesignalcn~iit~ 118andoperates to provide a control signal 124 to an au~iliary converter 126. The au~iliary cou~re.t~,, 126 taps a portion of the DC power ~ ~_.t~ by rectifier 112 via cn~ lu~ 128a and 128b and converts this power ~ Lug to the control signal 124 to provide power to a variety of au~iliary system loads 130 via S c(,...l~l~ 132.
1iri~ -lly, it is within the level of skill in the art to provide the secondary side converter 44 with various means to provide voltage boosts, f,~u~ ~ changes, phase changes, and inner loop control. As a further alternative e~li~t, the secondary converter 44 may be similar to the primary cuu~_.h,r of Fig. 13 to pmvide an AC output to load 34. Furthermore, the sxon~u~ side 10 c~ "t~,. may also be modified (not shown) to provide two or more of these various outputs to load 34.
If the power delivered or h f~.,Gd by link 50 is at suitable voltage, current, phase and fi~uen~ y levels, the s~o,~d u ~ side eonverter 44 may be ~ ' For a movable electric load 34' (see Fig. 17), the output of link 50 may be optim by .~ .;..g the position of c~ lor 40 to be ' lly colinear with the lnngi~ inal a~is Y of 15 linlc 50. For e~cample, the e ' ~ C-shaped cores of Figs. 7 and 8 rnay have flu~ sensors mounted in the air gap faces 86, 86' and 94, 94'. Fig. 15 shows one manner of flush nu ..n~ing four flu~ sensors 134a, 134b, 134c and 134d on surface 94 adjacent each corner. The flu~ sensors 134a-134d, such as simple 1/2 diarneter loops of wire or Hall effect sensors, are inlaid s~ Qr? ~inlly flush into the core material and bonded, such as by epo~y, in place. The Hall effect sensors are p,~,f~"~l for norrnal sF 7 20 h.~x ~, and the wire loop sensors are p,ef.,.,~,d for high te~. G applications due to the ~;L~ of the Hall effect sensors at high t.,~ e.
The output from the flu~sensors 134a-134disan input to the sensor bloclc 1160f Fig.14. Theflu~sensorsignaliscnn~liti -' bysignalcn~ nnpr 118andreceivedc~ntroller 120. The controller p..~~ the flu~ sensor signals from each of the core faces 94 and 94' or 86 and 86',and ~' ~Le.ef,ul.l a rQi~inning control signal 136. pnCi~in~ing power 138 from au~iliary converter 126 and the poQi~inning control signal 136 are provided to a rQi-inning actuator (not shown).
F. Sec ~a ~ C~
The ~n~ ~ U~ 46 includes the generally tubular ~ winding 60 in the p.~.f~ d P nlYY' loc~ted to the interior of core 52, and the balance of the s~ond u~ loop .~ ' labeled generally ~Is 46, required to delivery power from the ~o~Lu ~ winding 60 to load 34.
The effective ' -e which u~ q linearly with the length of the s~co..~ c.n IJ,~Q~ 46 ~' - the relative i~arl of the pn~ly of the load 34 to link 50. Co~ Iy, the load 34 could be coupled directly with the s~ouda.~ winding 60 and mounted adjacent to the core outer jn~l ' 9 layer 78, resulting in m nimal s3~0nda.~ circuit ~a -e In the illustrated PmkY~inlpn~ with 35 the primary loop 40 operated in .~ce based on the i ' -~ of loop 40, -' ' m,, the load ' . the s~o~ c - ~l r~ i ' -e is desirably kept at a constsnt value, so as not to affect the resorant f~ fr f the power delivery system 30. Fo~t~t~ , this scheme is readily i~' ' and easily ~compli~h-P-~ the design goals of minimi7~ng trailing c~bles and m obile h~.l.. ~.

WO 94/09558 2 ~ ~ 7 2 ~ 8 PCI/US93/10068 G. S.~ Dil e d Decign The nature of the ~ ~ ' design ~4crrih~- herein is provided from a of the various tradeoffs in the conte~ct of the overall ~.r~ e of the . '- powerdelivery system 30. This section ~' - - thoce ch~t~ r.slics which are umque to the use of the linlc 50 5 with primary . :nr 40, ~nd which tend to impact the design of the overall system 30.
(1) r~ ta- Pb;~ md ~ h ' t~
The - ~ power delivery sy~ctem 30 de&..l,Gd herein adv g~u~ly has a forgiving nature with re;spect to the position of primary cnn~' t 40. This feature greatly reduces the design dem~ndc on the system 30 in several ways, ;~ -g, a . ' ~;o~ in physical strecs of the primary 10 cable, more la~ pe.ru -e ~ui-~i~b of the core position guide actuator and ..,~,-G~d insensitivity to ~' - I cnnAitinnc~ d~ further below. Since the system pe.rJ -e is relatively incensitive to the position of primary cn~ or 40 within the ~ dillg region 76".-, ;..t~ ;"g an e~act position and tension of the primary cnnAl~rtnr 40 is not required. Fu.~ , e~posed live conduct~ , as proposed in earlier systems, may be cc . ' ~ e' ~ herein through the use of irlc~ cables.15 (2) F,~ Issue, The -2 costs of the cnntortl~cc power delivery system 30 may be much lower than the conventional metal-to-metal contact systems. The hardware of system 30 and the capital costs for jnCtDIlirlg the land-based system are much lower than the costs ~ ' with the previous " - Cn~A~( tjn~l systernc such as the flat coil inductively coupled systemc having a portion of the ~ core buried in the roadway (~ d in the background portion above). For the illustrated mobile . ' system 30, all of the core and ~ circuit portion is mobile, and only the primary c ' 40 remains - ~.
For e~ . 'a, the mobile core 52 u~ces the entire core during ope. "nn, whereas in contrast, the stationary buried core of the prior systemc uses only a tiny fraction of the total core at any 25 given time. The greatly reduced amount of core material used in system 30 renders it a far more e~ - system, F- t;~ul~ for electrical vehicle use. The losses in the primary loop increase with current density and cn---),-~ I~r current, so higher efficiency units require either more cn~ lor material or more core material, as seen in F~ nc 7-8.
Since the overall system 10sses increase with the current density and c~
30 current, a higher efr,,~ 50 may require more c~ A ~ r material or more core material. For ~ . 'e, in the cores having an air gap, l~rger ~ . ' ,, are required than for a gaples.. core Ullit.
As a further r 1~ ' G- of system 30, the controlled thyristor input of the primaJy c~ .t~,. 38 provides the capability for full ~.G~a ve enerGPy recovery. For e~ample, since the CWT
35 may transfer power in ather direction, ~iG_ ~ energy recovçry may be useful in elevator~c or tracked vehicles, such as trains, when traveling downhill or d~l~,. g, where there is a surplus of energy which may be cu ~_.t~d and delivered back to the source (see Figs. 18 and 19).

WO 94/09558 2 1 l ~ 2 5 8 PCI`/US93/10068 (3) ~ J Co~ù~u~
The ' power delivery system 30 may be designed to wi ' electrical faults and physical damage,; l l;..g the ability to ride through minor system L~lu.; - , and safely detect and protect the system from major p..'' For e~cample, in the event of a severe electrical fault 5 in the high L~u~.;~ system, a one-half cycle fault cle~ -e time is much faster than at conventiona!
L~~ iP-C, e.g.,l/2 cycle is 250 ~ ds for an r- " ~ L~, ~ of 2,000Hz, which is c . - ~ to 8 I~;lli~nnAc for 60 Hz.
An open circuit situation in the see ' ~ cn..~ toI 46 forces the core 52 into e~ctreme ~ n^ and ov~ ' ", similar to conventional current t~ ~u..,~ ,. Open circuit det~inn 10 and p~ot ,1 ~ may be provided by g for over-voltage c~ '' 'onc, and upon ~etecti--n thereof, ~nri~hing in a fail-safe shunt circuit (not shown) to limit the ~ ~- ~ voltage to ~rr~?tahle levels. An optional l. ~.~. (not shown) may be located between the AC source 32 and the primary converter 38 to provide electrical isolation of the primary loop 40 from the utility grid. Also, such an optional t.~r~.~r may be used for voltage change to allow operation of the primary side converter 38 at 15 optimal levels. Also optional l. ~u~ may be used on only the s~o"~ or on both sides to operate each converter at desired values.
Abnorrnal c ' ~ &_L ' ~d by the system 30 also include various e"~ and physical p..~' to which link 50 and cn~ ur 40 may be ~uL~;e ~d The design of the link50and pr,mary ~ ' 40d-- ,hfd herein has the followingc~;t~ ,l.cs whichenable the system to ~ such physical abuse:
(1) Insensitivity to location within the ,. ~ing space 76 allows for as much physical protection material (not shown) as required;
(2) The relative motion and the large ~ in~ space ~6 promote efficient heat removal from the linl~ 50; and (3) The optional ~ ~ c~ ,t~,r 44 may be mounted in a suitable enclosure on a mobile load 34',and can be designed to be immune to heat, shoclc, and moisture as required for the r t; '~~ ~, ' 'i H. P.t~ ~ Apl~lirR~ o ls Referring now to Figs. 16-19, several .. ~' .- 'nn~ are shown which may be useful in .,.,d~ material handling, elevators, power ~ nh~jn~ &nd recharge l~r~ nn~ for electric ' vehicles and other 2.~ d ~ r t, such as for l~ e~ploration and mining ~ p' - - Other ., ' ~ clude charging on-board batteries, for instance, when a vehicle is parked at rest during brealcs or loading time for moving ~ ', ' Referring to Fig. 16, the . ' power delivery system 30 is configured as a 35 power distribution system having a ' clamp-on link 150, sho~n with c~n~l~ similar to that ~ ~ ihed for link 50 and further; -~b '; e the following features. The link 150 is 6~} ' ~~ for e~ample by l. ' ~--' or pivotal motion, or other opening action. For e~ample, link 150 in Fig. 16 has a hinge 142 with a spring closure member 144 used to urge or bias the clam~on embodiment into a closed WO 94/09558 2 1 4 7 ~ 5 8 PCI`/US93/10068 position. A release latch ~ 146 and hlmdle 148 may be included for easy cwpling and d~ourli~ of the clamp-on link with primary c~r-~ 40.
In a typical I ' ~ ~ design, for a 100 kW load, the linlc 50 weighs appro~ Iy 14 l~ilogr~-nc To ~plug-in~a power tool with a rating of one l~ilowatt (I kW) into the 500 Arnp primary S loop of the above e~carnple, requires a clamp on linl~ 150 having a weight of less than 0.2 ~ ogry~c Fu~ e, the clamp on linlc 150 may be engaged with c~ r 40 without e~l.5r e a user to live cf-~ and without any spar~ which may ignite I J~ material. The clamp-on linl~ 150 may ad~ B - Iy be used in lieu of conventional power centecr couplers. F~ c, with an overhead ~c,r~n~ for ~he primary c,~ 40, trailing cable_ to the portable loads such as 34~, are 10 mir;mi7Pd to reduce hazards to ~_ g ~.~
A further advantage of u_ing current source ~ ics as d~scribed herein for feeding the primary cable 40 allows the use of series-cnnr~ loads 34, which may be coupled or ~cv~pl~ from the primary cn~--lv l~r 40 as required. This diverges gignir '~y from conventional power distribution system where multiple load_ are typically c d in parallel. Using system 30, the 15 load 34 may be clamped on at any location along the primary c~ v~l~.r 40, which ad~ g_ ~ly provides a fle~ible power dictrih~tion system for use ul.d~ . tf . F~ c, since no live contacts are e~posed, electrical arcing during coupling is; ' ' Referring to Fig. 17, one &_t ' of an ~d~".. 1 c~ -11- power delivery system 300 e- u~;t~d in ~. ~, ' -e with the present, ;. is ill ~ for marine ~ io~
20 Several of the - ~ ~ for the ' ~. 1 system 300may be ~ ' -lly the sarne as ~
above for the land-based system 30, and these ,. , have been assigned item numbers h.~,-~d by 300 over their land-based ~ . The system 300 may include a surface power source, such as a g~e.l~ 332 on board an oil drilling rig (not shown), or a boat 302 floating on a surface 304 of a sea or ocean 305. The ~. ' 332 may be coupled to a fossil-fuel burning prime mover, such as an 25 internal ~ ~ nn engine s)r a gas turbine (not shown); however, it is apparent that other sources of energy, such as solar or wind, may also be used.
Via c~ t~-(s) 336, the B ~ 332 may supply power to an optional on-board primary .- i~,.~. 338. A prirnary ~ ' r or cable 340e~tends from the output of c~ .t~,r 338 do ..~..udly into the ocean 305. The primary . ~ ' t ~ 340 is ill ' ' as a loop config~ ~ having 30 sending and retum .~ r portions 340'and 340~"., t;~,ly.
One or more lights 306 may be coupled to and powered by the ~ r 340, for instance, C~ A- ~0~ portion 340'. For l ud~ vehicles, such as a ~ 308 or a tracked vehicle 310 traveling on the ocean floor 311, the lights 30O aid these vehicles in locating the primary conductor 340 for ~ ,ug.
The ' il.c 308 may be eq~ i~d with a ,~ I ''~ arm 312which t.,._~ in a CWT pod cn--y-- ;~ g a coupling sheath or linlc 350. The linlc 350 may be ~ ' -lly as described above for linlcs 50 or 150, and rnay be dual linle as ill ~ in Figs. 1~, or a single linlc as shown in Fig.
17. However, the submersible link 350preferably has core-unted ~ ~ y cn-~-l v;t~ encased or WO 94/09558 2 1 l 7 2 5 8 -22- PCI/US93/10068 -, ' d in a shell, ~uch as ~hell 416 in Fig. 21, of a c.J. f~ ' 'e, wate proof, electrically insulative material, such as a plastic, resin, teflon, rubber or other el- 'f.~ -iC material, or their structural equivalents as known to those sl~illed in the art. The ' - 308 may have an optional secondary-side c~L i_. h. 344 which receives power via a c~ . 346 from the linlc 350.
S The s~v.. d~ c~--e.t,. 344 may supply power to a battery storage system 314,ballast pumps 315, or other loads 316, such as power and control system6 for running the life-support and navigational systems of ~ ' LLte 308. A variety of structurally e~u.~ ' configu. n tc known to those skilled in the art e~ist for ~.._. g wch systems. For e.~nple, power may be supplied directly from the battery 314 to the pumps 315 and other loads 316 as shown, or by using the battery 314 as an input (not 10 shown) to the ~ ~ ~ converter 344 which then supplies power to the pumps and other loads.
The tracked vehicle 310 may be equipped in a similar fashion with an on-board s ' ~ converter, battery storage system, pumps and other loads (not shown) as dPcc~t~ for the ~,ul, ~e 308. The vehicle 310 may return periodically to the primary CUL~dU~ Jr 340 for charging, and after ~ ;iug, continue with _ . t;nn or other duties on the ocean floor 311.
Thus, the converter system 300 may be used to distribute power to a variety of different types of :,ul,L.~.~,_d loads. Other d~ onC for uud~ . sys;tem 300 include eS~pnAing the '~ ope. , range of c4LI~t~tio~l ~ ~ -s, delivering power to uude.~. mining .-- l.;-.--s &nd pU..--.iltg e~ ~J~ i around deep sea oil plalr~.u~.
Using a dual primary ~ ' ~ 340, is believed to be particularly advaul~_aus, for 20 several reasonc. For e~ , the return cn-" i 340~ may be used for pu _.iug a ~ flow of vehicles upward or duwu...ud along cable 340". While vehicles are _~..l;.,g or fln~ .g along cable 340", a;tn.ll Iy vehicles which are already subuh~.~,~ may recharge by coupling their links 350 to the other cable 340'.
Another aigrtifi- advantage of the uL~de.~ t~,r sy6tem 300 is its reliability. If the 25 primary C4' AU~ ~r 340 were to brealc, power delivery to the ' ~ d vehicles 308,310 could cnn~ P-, albeit &t reduced levels. A return current path for power delivered from the primary converter 338 through c ' ~ 340 is provided by using the sea water of ocean 305, since water is a cn~ --- ~r.
Under e~.~ c~ A;~ , on board batteries can be .~ ' ~,_d, and both ~ . and pc.
can be safely retrieved using the l ' ... ?r system 300.
30 An ~ i~if feature of the u~.-._ cn~ortlPcc power delivery system 300, is the ability to transfer control and ~ h r.. through the primary rnnA~rtn- 340 between the ~de... '1 vehicles 308,310 and the boat 302. Other advantages of the submersible cnnt~tlP~c power delivery system 300 include: cnnt~rtlPcc power transfer which . ' - the ne d for e~posed electrical contacts; the e~se with which the linlc 350 is conn~tP~ and d;~n~ d from the 35 primary ~ t 340, allowing rnanual or - ' 7Pd coupling; the capability for high power operation (from a few l~ilowatts to well into the u~.... ~ range); high power density from the use of high f.~u~ AC power and convective cooling provided by the liquid surrounding the coupling link 350;
single or dual primary cn~ 340; cnntir~ o~.~ even after breakage of the primary conductor WO 94/09558 2 1 4 7 2 ~ 8 PCI/US93/10068 340; force neutrsl vp~ n; and the ability to , ~ control and cn.. ~ on signals over the AC power ~ fullu flowing through cnnA~ or 340.
Figs. 18 and 19 illustrate an alternate e~ of a cnn~q~rl~c power delivery system 30~ having the capability for full .cg~ e energy recovery, since the CWT may transfer power 5 in either direction. The system 30~ is ill ~ using an elevator 173 which may be either land-based, or o~d~ such as for use with oil drilling pl~tr In Fig. 18, the elev~tor 173 is ~e.vlug power, as ~ d by arrow P, from a fully .~ig~ ~., four quadrant cvui_.t~,. (labeled as ~F.R.F.Q.C.~)174 through c4~ tc-r 175 which functions as a primary winding. The linl~ 50" is slidably coupled to the c l~ l 175 to transfer power 10 via a c .~ ----tv. 176 between the prirnary co~l~tv. 175 and a second c~_~.,.t~,. 177. The c~ ,.t~,, delivers the required power to a linear motor 178 which then raises the elevstor 173 ~.d~g to the elevator input ,. ~c (not shown). Thus, the linear motor 178 serves as the load 34' as elevator 173 travels upwardly.
In Fig. 19, when the elevator 173 travels downwardly assisted by the force of gravity, 15 the linear motor 178 gen~ surplus power. This surplus power is delivered to converter 177, which then fi~nrtionc as a priy cv"~.,.tu.. Power is delivered from converter 177 to link 50~ via cnnAl~ctors 176. The link 50~ transfers energy as indicated by arrow P' to cnl An~ r 175, which now rl onC as a secondary c~ .r, for delivery to the ~F.R.F.Q.C.~ 174, filnrtinning now as a s~o~i,L.~ cv ~_.t~
Thus, the linear motor 178 of Fig. 19 serves as a mobile g- ; power source 32~ her land-based 20 e~l , ' of l~o ~' ~e energy recovery systems include traclced vehicle systems, such as trains, when traveling downhill or docel~ g, where there is a surplus of energy which may be converted snd deli~ d back to the engine.
Rsther than an elevstor running on a trsck, the p.m~:, ' of system 30~ may be e~ctended to sscent snd descent of the - ' - 308 snd trscked vehicle 310 of the ' rg~d 25 system 300. On bosrd the boat 302, the .eO~ ~re cv ~_tu~ 174 may be b r ~ ' for the primary converter 338, snd the i,~.o~ ' ~ 340 msy serve ss the cn~ t,~.r 175. The cv ~,.t~" 344 on board the ' - 308 or the traclced vehicle 310 rnay serve as cv"~,.t~" 177 to power ballast pumps 315, rsther than motor 178 for sscent. During descent, if the pumps 315 were allowed to function as turbines to serve ss a prime mover for an elecbric ' ~, power rnay be O~, ~' The power 30 g~ ' on board during descent may be used to charge the battery 314, or be deli~re,~d via link 350 and cnn~ cr~r 340 to the converter 338 on boat 302.
I. ~otot~uc O~tlio--T ~ p,vtvl~s were co~.~_t~d snd tested for both the land-based or space-based system 30 and the ~Je.-._ system 300.
35 (1) Land l~d Svstern P~lot~
A l&bv~atv~y p.vlot~ was co~sl~uutad of the cnn~qrrlecc power delivery system 30.
A 2,000Hz ~in~ ql primary current provided 138 arnpere-turns which were circul.ted in a prirnary loop 40 through a linlc 50 having din~cionc as shown in Table 6.

WO 94/09558 2 1 47 2$ 8 -24- PCI/US93/10068 Table 6: Test Coa~ial Windin~ T- ~VIIII~. Data K 20.2 length (cm) 2.54 height (cm) 8.89 width (cm) 8.89 Wgt (I~g) ` 0.557 Vol (cm3) - 92.5 The link 50 iucludcd a single toroidal core 52a c~~ led from 1 mil (0.001 inches) thiclc ~ -L ' ~ metallic glass tape e~ LIg a copper tubular s~o~ winding 60 having a primary 10 cable 40 inserted Ih~..etL. ~' The graph of Fig. 20 shows the data collectcd while .n. .c~...g the primary loop current il when the load ~c Ice is at a fi~ed value. As ~ ~. the power output initially i~ lC~S yua,d,_ ' lly with the current, then less than ~L t lly as the core material The output power test was limited by the labv.~.tu-~ power supply, with the core 52 at r~n voltage, but with much less than the .~ --- current capacity flowing lll~..etluv~.~;L. The 15 data shows Du~rul delivery of ci~ifir~- - power to the s~ond~ ~ winding 60 using the link 50 as described.
Table 7 . 1, ~ the theoretical e~pected values to the ~d results for the power diensities for the linlc c' - and primary ampere turns actually used in the test.
Table 7: T '~._t~ Data 20 P~ t~,. Theoretical Me- ~d Pwgt de~l~ (IcW/~g) 0.80 0.75 Pvo~ (W/cm 3) 5.9 5.6 Both of these F ~ D and the ~d values correlate well with the theoretical values. Higher power levels may be achieved by i".,l~ g the core cross section to handle more voltage 25 or by n~.c~mg the primary loop current. with a p~u~v~liv.,&l decrease in the load , ' -e The values are cigllif- 1~ Iower than the design e~ample, since high values of current were not achieved at 2,000Hz with the available 1 ' .~ ~ Since coa~ial winding 1, CU.~.D generally have been tested at 50 kW in a 50 ~;Hz system by two of the c~:-;. of the present i~ tivn, upRc~Ijng of the p,utvt.~ unit tested is believed feasible (see the article by M. H. Kheraluwala, D. W. Novotny, 30 D. M. Divan, ~Design C~ ' - for High F~ u~ T ~VII~D,~ IEEE-PESC-90 Record, pp. 734-742.
(2) U~ t~ SYstem F~
Fig. 21 ill ~ ~ a I ' .~ ~.olul~ submersible cnn~P~tl~Aqc power delivery system 400. The pn~lul~ system 400 included a tank 402 which was initially filled with distilled water 35 and salt was gradually added to form a saline solution 404 having a c--- I of 30 grams of salt per liter of water. This final c~ n level was chosen because it is ' ~lly equivalent to the salinity of most sea water. Several of the c~ for the p,u ol~c system 400 ~~ d to the WO 94/09558 2 1 4 7 2 ~ 8 PCr/US93/10068 D.L~..i~l- system 300 and the land-b~lsed system 30, and these ~- -T have been assigned item numbers ...~,.~`d by 400 over their l~nd-based cou.,h., b.
For the primary power source, 8 variable high L~current source 432 was used, having 8 range of 5 - 40 I~Hz. A coupling link 450 having a core-unted - ' y conductor 460 and a S core 4j2 was ' ~d in the tanl~ 402. The core 452 was co~l.~t~,d of si~ staclced annular ferrite core sections 405, 406, 407, 408, 409 and 410, each of a standard PC-30 type ferrite core material. The cur~rent source 432 of system 400 was coupled to a prirnary c~ . 440, which was D~ l,~.~d in the tank 402. The primary cn~--l h1-., 440 was looped twice through the ~ cnnA~c~r 460 of link 450.
A pair of load c~ 412 and 414 coupled the ~ ' ~r 460 to a load 434.
The p.~.t< l~ system 400 was tested under I ~. - ,.. ~ c~ ti.---c with a current of 2.8 Amps-rms (root-mean-square) supplied by the current source 432 to flow through the prirnary c~-n~' : r 440. At this current level, with the c~nrl~r~or 440 looped twice through the link 450, the system 4QOwas tested at 5.6ampa~turns. The p~ty~ system 400had . -.. ~. power capability of ~p.~ 'y one kilowatt at a f.~u~y of 20kHz.
The p,vl ~ system 400 was first operated at a L., y of 20 I~Hz and losses were p~"od;~lly ~d as the salinity of solution 404 was ... e~c~ from zero to 30 g~ms/liter.
The losses - ~d were the open-circuit power losses c~",.. g the core loss and losses through the salinated waters ~u..~,u,.~.,.g the coupling link 450. Initially, the core--o~nt~al cnn~ ctQr 406 was not electrically insulated from the DUIlO~g salt water, and the losses were high. For e~ample, referring to 20 the open-circuit power losses graph of Fig. 22, at full sea water . r- ~ and without in~l ' Of c~ r 406 at 20 I~Hz, the losses were grester than 140 watts, as ' ~ d by the data point rnarked with an ~X~ in Fig. 22.
To reduce these lo~, ~,.ef ~l~ the ~ c~ r 460 is encased or e . ' ~ in a sh~ll 416 of a c~nfu ' 'e, electrically insulative, waterproof material. When such a 25 ~. ~.,~f and Pl~tri~`9lly ~ ~ shell ~'-d the ~ ~ c ~ 460,the losse in sea water 404 at 20 IcHz dropped to 33 watts, as shown in Fig. 22. For a 1000 watt output, these losses in sea water at 20 kHz, yield an ,fr ~ of 96.89~. The losses in air at 20 kHz were ~d at 27 watts, which for a 1000 watt output yield an Pffi-i ~ of 97.4 % . Thus, there is only about one half of one pe~ent loss in elr~ using the ' ' 1~ system 400 over the I ~ ~ system 30.
Using the ' d shell 416 to encase the lin~ c ' 460, and at full sea water c - ~ . the p,.~ :~ system 400 was operated at L~ A selected from a r~nge of S kHz through 40 ~Hz. With the tank 402 empty, the p,ulul~ system 400 was also opelated in air at f.~, selected from a range of S kHz through 40 IcHz The open-circuit power losses are plotted for the sea water and air tests over these L~~ 6 in Fig. 22.
From these tests, the use of a high f.. ~ ~ power source with a highly reactiveprimary cable loop 40, 340 make a load resonant c~ ~e.t~,r topology a p,ef~ d e -.l~l;.-~ for the primary side converter 38, 338. The overall cn .P~tlA~c power delivery system 30, as well as the 21~72~8 -26-O~ c~o~tlPc~ system 300, appear to be viable, as well as ~ lly and "~.~ lly ~ for use in a vsriety of systems.
I. Alt#nate ! ;-lk F,rbD ~i .~
Referring to Fig. 23,an alternate linlc member 58f ~-- u~,led in ac~.d -e v.~ith the S present invention has a generally rectangular cross-section. The link member 58f hss a split-hinged core with two hinged core ~,~ 52f and 52f' joined together by hinge 152. In the illu,ctrgted f.ll~ho~ ~.n~, thelinlcincludesaprimaryc~ lo- 160,shownsplitintotwocn~ f~t~ loOfand 160f'.
Fig. 24 illustrates an alternate e~ ' of a link element 58g co~l~ d in P ~cc d - r with the present i~lv~hon which includes three (3) core elements 52g,52g', and 52g~ . In the illustrsted c-.. l~l;. -1, core elements 52g and 52g' are mirror images of one snother which are joined together by a hinge 168. The primary cnn~ lu. is split snd includes CO1IdU~1~JI ~v~ 160g and 160g'. The hinge 168 is optional since the core Cf'gl~.ntC 52g and 52g' may be supplied as a single member united st the split adjacent hinge 168. Similarly, if hinge 168 is omitted, the prirnary winding ~O 160g snd 160g' could also be a single unitary piece.
Fig. 25 illustrstes a link member 58h co slru~l~d in &cco~J~ with the present which has 8 5~O ~~ core ~ ne core C. O~ 52h and 52h'. A winding member 160h is secured to core segment 52h, and a another r ~ l~ to. 165 is .u~,~.t~ from core segment 52h' by a Suppon 172 of an insulstive material. The insulative support 172 rnay be cn..~ or a plurslity of discrete rnembers ~u~,~nih& the cn~ l l .. 165 from the core member 52h'. Together, the cnnA!ct~-r 165, the support 172, and the core segment 52h' may form a movable portion of the link 50, with a fi~ed portion formed by core segme~t 52h snd prirnary cn~ nr 160h, or visa versa.
J. OL~
Use of the present invention also offers several methods of I r liJlg power froman cl~~ source to an electric load with relstive motion i' ~.~m A method is slso provided of delivering power between a first cn~ r and 8 second ~ ' : , such as ' l 40 and 60 of Figs. 1-4, without having direct electrical contact Ih_.~. The method includes the step of providing a first core-unted cn~ t.~r u~ t;olly surrounded by a core of a ~ material. The first c ' r hss a ~ v- .. ~, such ss thst defined by the .. ding region 76, which is configured to receive the second c ' ~r. The method includes the step of coupling the first cn~ lur snd core 30 sround a portion of the second cr- ' I r, snd the step of . v~g one of the first snd second cnn~' I to provide a current to the other of the first snd second c ' 1~ to the~by ~nsfer power between the first and second c~ ..t~
In ~ p.~f~ d . '~ ' t, the power is I ' ~ st a high r.~u~,u~y, with the specific f.~u_.~ chosen d~Jh.V upon the desired ~ rl - ~ and desirable use of the selected power 35 el~it-~ In another ill ' ~ ~mky~il~.n-. the first . ' : and core member sre split so they may be hinged snd opened to receive the seconci c~ lor snd ciosed Ih~ rt.,. to ~Jb ~lly surround the second conductor. In snother p.~,f~,"~l e~nhoAim~nt there may be relative motion between the core snd the second c~nAl~t~r enclosed within the core and primary conductor. This WO 94/09558 2 1 ~ 7 2 5 8 PCr/US93/10068 relative ..~,~l ay be linear and/or .~ r--' with respect to the second cnnA~rtnr, and the power transfer may be from the first cn~ J~ ~.. to the second c~ l v-~r or in the opposite direction. In a further p.ef~ d Pmk!~i,m~nt, multiple cores with first cn~ tors are coupled to a single second cn..-l .,.r.
S In opl,. 'nn the ~,~. rnnto~ delivery system 300 preferably uses a high-L,, ~ c~.t~,. for the prirnary converter 338. The prirnary c~ or 340 is preferably an incf.1 d c~ble or c~ble pair 340' and 340~, as ill ~ in Fig. 17. The CWT pod link 350 preferably is designed with adequate -'- e to prevent wearing of the l f~n around - ~ tnr 340. Multiple - ''^ vehicles, such as the ' - 308 and the traclced vehicle 310, may each draw power from the primary cc~ -lQr 340 by pe~iod;~lly _1 ~ ' g their CWT pod coupling link 350 around primary cn~ .r 340. In Fig. 17, the tracked vehicle 310 is shown with its coupling link open while l~",.~ch g cn-= l~ o, 340 for l~cha Is~g Power received by the ' ^ 308 or vehicle 310 may be used to power the on-board ballast pump 315 for controlling the ascent or descent of the vehicle through the ocean 305. If designed with adequate cl-~ e~, the link 350 may remain coupled to COIfdll~ l 340 to freely slide along its length during travel between the ocean surface 304and the ocean floor 311. E2f ' ' g coupled during ascent and descent conserves energy stored in battery 314 for use in ~ l.;"g mission objectives.
After descent, and upon reaching the ocean floor 311, for e~ample, the tracked vehicle 310, ~'f~ link 450 from the primary cn~ 340 to carry-out its mission. The vehicle 310 may be lowered from the boat by a crane or winch, rather than be ~ ~d with ballast pumps.
Sincethe ' g_d vehicle310and ' illf 308maype.sl 'lyreturn tothecable340for _h~5-..g, theoretically, their missions may be e~tended almost ;...1. l;. ~t~ Ir.
Having ill ~ ~d and d~-ib~ the p. . ' of our ...i~li.~n with respect fo 25 several p.ef.,..~l c - ~ , it should be apparent to those skilled in the art that our invention may be ~ ifi~ in ~ 1 and detail without ~ li. g from such p . For e~ample, other 3~ rl ~ ~ ~ rnay be envisioned for employing the system described herein, as well as suitable material ?-~ nc for the c~ -,. and core, and d - ' v.u - for the . ~. , thereof, and the S~ of other devices and c*nfig. - known to be .' ,,~ "~ by those sl~illed in the art.
30 For instance, the flu~ cnll~ .t or c~ lio~ surfaces adjacent a core gap, such as surfaces 84 and 84' of Fig. 5, need not be flat and need not be centered about a radius, but p..~f bl~ only follow the sarne general contour with 8l r I ' ' Iy the same norrnal distance the ~h._ .. Fu.i' 1;, the prirnary and D~n~u ~ converters may be as d~ . or other devices known to be int~,..' g. ' '^ by those sl~illed in the art rnay be used. We claim all such ~if - falling withir the scope and spirit of the 35 following claims.

Claims (65)

1. A contactless power transfer system for transferring power from a power source to an electric load, comprising:
a first conductor coupled to one of the power source or the electric load;
a core-mounted conductor coupled to the other of the power source or the electric load, with the core-mounted conductor having an outer peripheral surface;
a magnetic core supporting the core-mounted conductor and substantially surrounding the outer peripheral surface, with both the core-mounted conductor and the magnetic core surrounding a portion of the first conductor so as to transfer power from the power source to the electric load; and wherein a portion of the first conductor is slidably received within the core-mounted conductor and magnetic core for relative motion therebetween, with power transfer continuing during the relative motion.

2. A contactless power transfer system according to claim 1 wherein:
the first conductor has an axial length; and the relative motion occurs along the axial length of the first conductor.

3. A contactless power transfer system according to claim 1 wherein:
the first conductor has a longitudinal axis; and the relative motion is rotational substantially about the longitudinal axis of the first conductor.

4. A contactless power transfer system according to claim 1 wherein:
the first conductor is coupled to the power source; and the core-mounted conductor is coupled to the electric load.

5. A contactless power transfer system according to claim 1 further including a first converter coupling the first conductor to the power source.

6. A contactless power transfer system according to claim 5 wherein the first converter includes a resonant converter.

7. A contactless power transfer system according to claim 5 further including a second converter coupling the core-mounted conductor to the electric load.

8. A contactless power transfer system according to claim 1 wherein the magneticcore is separable into at least two core segments for selectively opening to receive and remove the first conductor, with the core segments being joinable to secure the first conductor therein.

9. A contactless power transfer system according to claim 1 wherein the magneticcore comprises a gapless core.

10. A contactless power transfer system according to claim 1 further includING:
a position sensor for sensing the position of the core-mounted conductor relative to the position of the first conductor; and a positioning actuator responsive to the position sensor for positioning the core-mounted conductor in a selected position relative to the position of the first conductor.

11. A contactless power transfer system according to claim 10 wherein the position sensor comprises a flux sensor for sensing the core flux.

12. A contactless power transfer system according to claim 1 wherein:
the core has two flux transferring faces separated by a gap;
the first conductor is mounted from a fixed insulative support member extending through the core gap; and the contactless power transfer system further includes a fixed magnetic core member attached to the fixed insulative support to magnetically link the two flux transferring faces together.

13. A contactless power transfer system according to claim 12 wherein:
the fixed insulative support has a first axis;
the fixed core member has a flux transferring surface substantially perpendicular to the insulative support first axis; and the two flux transferring faces of the core are substantially perpendicular to the insulative support first axis.

14. A contactless power transfer system according to claim 12 wherein:
the fixed insulative support has a first axis;
the fixed core member has two flux transferring surfaces substantially parallel to the insulative support first axis; and the two flux transferring faces of the core are substantially parallel to the insulative support first axis.

15. A contactless power transfer system according to claim 14 wherein the core-mounted conductor and the core are each split into first and second portions which are openable for disengaging the first conductor and closable for engaging the first conductor for power transfer therebetween.

16. A contactless power transfer system according to claim 12 further including:a position sensor for sensing the position of the core-mounted conductor relative to the position of the first conductor; and a positioning actuator responsive to the position sensor for positioning the core-mounted conductor in a selected position relative to the position of the first conductor.

17. A contactless power transfer system according to claim 16 wherein the position sensor comprises a flux sensor for sensing the core flux, the flux sensor being mounted in one of the two flux transferring faces of the core and the fixed core member.

18. A contactless power transfer system according to claim 1 further including:
a fixed magnetic core member cooperating with the core to form a flux path through the core and the fixed core member; and an insulative support extending from the fixed core member and supporting the first conductor.

19. A contactless power transfer system according to claim 18 wherein the core has a gap which receives at least a portion of the fixed core member.

20. A contactless power transfer system according to claim 18 wherein the relative motion occurs along a selected length of the first conductor, the contactless power transfer system further includes plural insulative supports along the first conductor selected length.

21. A contactless power transfer system according to claim 20 wherein the magnetic core comprises a substantially C-shaped core having an air gap to partially surround the first conductor, the air gap slidably receiving the first conductor plural supports therein as the electric load moves along the path.

22. A contactless power transfer system according to claim 20 wherein the magnetic core includes two longitudinally separated portions openably joined together for momentarily opening to allow the plural supports to pass through a longitudinal gap defined between the two longitudinally separated core portions when open.

23. A contactless power transfer system according to claim 1 wherein the core-mounted conductor and the core are each split into first and second portions which are openable for disengaging the first conductor and closable for engaging the first conductor for power transfer therebetween.

24. A contactless power transfer system according to claim 23 wherein the core-mounted conductor and the core first and second portions are pivoted together by a hinge member.

25. A contactless power transfer system according to claim 1 wherein the magnetic core has an air gap.

26. A contactless power transfer system according to claim 25 wherein the magnetic core air gap is sized for passage of the first conductor therethrough.

27. A contactless power transfer system according to claim 1 wherein:
the first conductor is fixed and coupled to the power source; and the core-mounted conductor is coupled to the electric load.

28. A contactless power transfer system according to claim 1 wherein:
the first conductor is fixed and coupled to the power source, the first conductor has power flow sending and return members lying side-by-side along a travel path; and the core-mounted conductor is coupled to the electric load and comprises a pair of core-mounted conductor segments, and the core comprises a pair of core segments one of each surrounding one of the core-mounted conductor segments, with one of the conductor segments surrounding, a portion of one of the sending and return members and the other of the conductor segments surrounding a portion of the other of the sending and return members, with the pair of conductor segments moving side-by-side along the travel path during the power transfer.

29. A contactless power delivery system according to claim 1 further including a secondary converter with a power conditioner for conditioning the power received from the secondary conductor.

30. A contactless power delivery system according to claim 29 wherein:
the power conditioner includes a sensor monitoring the power received from the primary conductor; and the power conditioner is responsive to the monitoring of the sensor.

31. A contactless power delivery system for according to claim 1 wherein:
the power source comprises an AC source; and the primary conductor is substantially fixed to power plural portable electric loads each having a secondary coupling sheath comprising a magnetic core and a core-mounted conductor coupled at selected locations along the length of the primary conductor for distributing power from the AC source to each portable electric load.

32. A contactless power delivery system according to claim 31 wherein the magnetic core has two longitudinally separated portions openably joined together to couple and decouple the sheath with the primary conductor.

33. A contactless power delivery system for according to claim 1 wherein:
the power source comprises an AC source; and the primary conductor powers plural portable electric loads each having a secondary coupling sheath comprising a magnetic core and a core-mounted conductor coupled at selected locations along the length of the primary conductor for distributing power from the AC source to each portable electric load, and the primary conductor is moveable between locations to provide temporary power for the portable electric load while moving between said locations.

34. A contactless power delivery system for according to claim 1 wherein:
the primary conductor comprises a feeder conductor coupled to the power source, and plural fixed primary loops each coupled to the feeder conductor, each primary loop aligned with at least one other primary loop to extend along adjacent portions of a path of travel of the load; and the magnetic core surrounds a portion of the one of the primary loops to receivepower therefrom when moving along the path of travel adjacent said one of the primary loops.

35. A contactless power transfer system according to claim 34 wherein the core and core-mounted conductor are openable to couple and decouple the sheath to each successive aligned primary loop as the load moves along the path of travel.

36. A contactless power transfer system according to claim 1 wherein the core-mounted conductor and the core are each separated into first and second segments which are translationally openable for disengaging the first conductor and translationally closable for engaging the first conductor for power transfer therebetween.

37. A contactless power transfer system according to claim 1 wherein the core-mounted conductor and the core are each separated into first and second segments which are radially openable for disengaging the first conductor and radially closable for engaging the first conductor in radial directions respectively away from and toward a longitudinal axis of the surrounded portion of the first conductor.

38. A coupling sheath, comprising:
a sheath conductor for surrounding a portion of an elongate power conductor, thesheath conductor for coupling to an electric load; and a magnetic core surrounding the sheath conductor to provide a flux path for a magnetic flux induced therein when the sheath conductor and core surround the power conductor, said magnetic flux inducing a current flow within the sheath conductor to deliver power from the power conductor to a load when coupled therewith.

39. A coupling sheath according to claim 38 wherein the power conductor has an insulative cover layer, and the sheath conductor is sized to grip the power conductor insulative cover layer and substantially prevent motion of the coupling sheath along the length of the power conductor.

40. A coupling sheath according to claim 38 wherein the power conductor has an insulative cover layer, and the sheath conductor is sized to slidably move along the length or around the periphery of the power conductor.

41. A coupling sheath according to claim 38 wherein the sheath conductor has an inner surface facing the power conductor when coupled therewith, and the coupling sheath further includes an inner insulative cover layer of a low friction material along the inner surface of the sheath conductor.

42. A method of coupling an electric load to an AC power source, comprising the steps of:
powering one of an elongate conductor or a coupling sheath with the AC power source;
providing the electric load with the other of the elongate conductor or the coupling sheath;
with the coupling sheath having a sheath conductor surrounded by a magnetic core, the sheath conductor electrically coupled to one of the AC power source or the load, and with the coupling sheath being separable into at least two sheath segments; and separating the at least two sheath segments;
receiving a portion of the elongate conductor between at least two segments;
and joining together the at least two sheath segments to surround the portion of theelongate conductor with the coupling sheath to transfer power by magnetic induction from the AC power source to the load.

43. A method according to claim 41 wherein:
at least two of the sheath segments are separable and joinable by a relatively translational motion therebetween;

the separating step comprises sliding the at least two sheath segments apart from one another; and the joining step comprises sliding the at least two sheath segments together.

44. A method according to claim 41 wherein:
at least two of the sheath segments are pivoted together to be pivotally separable and joinable;
the separating step comprises pivotally separating the at least two sheath segments apart from one another; and the joining step comprises pivotally joining the at least two sheath segments together.

45. A method according to claim 42 wherein:
at least two of the sheath segments are radially separable and joinable by a relatively translational motion therebetween in radial directions respectively away from and toward a longitudinal axis of the received portion of the elongate conductor;
the separating step comprises moving the at least two sheath segments substantially radially apart from one another; and the joining step comprises moving the at least two sheath segments together substantially radially toward the elongate conductor.

46. A method according to claim 42 further including, between the separating andreceiving steps, the step of inserting the portion of the elongate conductor between the separated at least two sheath segments.

47. A method according to claim 42, further comprising the steps of:
providing relative motion between the elongate conductor and the coupling sheath;
and transferring power during the relative motion.

48. A method according to claim 47, further comprising the steps of:
providing relative motion comprising motion along the length of the elongate conductor:
supporting the first conductor using plural insulative supports along the length of the first conductor; and wherein the separating step comprises separating the at least two sheath segments to avoid intersecting the plural insulative supports.

49. A method according to claim 47, further comprising the step of providing relative motion comprising radial motion around a periphery of the elongate conductor.

50. A submersible contactless power transfer system for transferring power from a power source to an electric load, comprising:
a first conductor coupled to one of the power source or the electric load;
a core-mounted submersible conductor coupled to the other of the power source orthe electric load; and a submersible magnetic core supporting and surrounding a portion of the core-mounted conductor, with the core-mounted conductor and magnetic core surrounding a portion of the first conductor and submersed in a liquid for transferring power from the source to the load.

51. A submersible contactless power transfer system according to claim 50 wherein a portion of the first conductor is slidably received within the core-mounted conductor and magnetic core for relative motion therebetween, with power transfer continuing during the relative motion while submersed in the liquid.

52. A submersible contactless power transfer system according to claim 51 wherein:
the first conductor has an axial length, a submerged portion submersed in the liquid, and a surface portion extending from the liquid; and the surface portion of the first conductor is coupled to the power source.

53. A submersible contactless power transfer system according to claim 52 wherein:
the relative motion occurs along the axial length of the first conductor; and the core-mounted conductor is coupled to the electric load for travel along the axial length of the first conductor.

54. A submersible contactless power transfer system according to claim 50 wherein the core-mounted conductor is encapsulated in a shell of a waterproof of electrically insulative material.

55. A submersible contactless power transfer system according to claim 50, further including a first converter coupling the first conductor to the power source.

56. A submersible contactless power transfer system according to claim 55 wherein the first converter comprises a high frequency resonant converter.

57. A submersible contactless power transfer system according to claim 50 further including a second converter coupling the core-mounted conductor to the electric load.

58. A submersible contactless power transfer system according to claim 50 wherein:
the first conductor has a axial length, a submerged portion submersed in the liquid, and a surface portion extending from the liquid, with the surface portion of the first conductor coupled to the power source;
a portion of the first conductor is slidably received within the core-mounted conductor and magnetic core for relative motion along the axial length of the first conductor;
the core-mounted conductor is coupled to the electric load for travel along the axial length of the first conductor, with power transfer continuing during said travel while submersed in the liquid;
the core-mounted conductor is encapsulated in a shell of a waterproof electrically insulative material; and the system further includes a high frequency resonant converter coupling the first conductor to the power source, and a second converter coupling the core-mounted conductor to the electric load.

59. A submersible contactless power transfer system according to claim 50 wherein the core-mounted conductor and core are radially movable around a periphery of the first conductor.

60. A submersible coupling link, comprising:
a submersible sheath conductor for surrounding a portion of an elongate power conductor, the sheath conductor for coupling to an electric load submersed in a liquid; and a submersible magnetic core surrounding the sheath conductor to provide a flux path for a magnetic flux induced therein when the sheath conductor and core surround the power conductor, said magnetic flux inducing a current flow within the sheath conductor to deliver power from the power conductor to a load when coupled therewith.

61. A submersible coupling link according to claim 60 wherein the power conductor has an insulative cover layer, and the sheath conductor is sized to slidably move along the length of the power conductor.

62. A submersible coupling link according to claim 60 further including a shell of liquid impervious electrically insulative material encapsulating the sheath conductor.

63. A submersible coupling link according to claim 62 wherein the shell material is selected from one of the group consisting of a plastic, resin, teflon, rubber and synthetic elastomer.

64. A submersible coupling link according to claim 60 further including a core covering of an insulative durable material surrounding the core.

65. A submersible coupling link according to claim 60 wherein the sheath conductor and the core are each split into first and second segments which are openable for disengaging the power conductor and closable for engaging the power conductor for power transfer therebetween.