Electricity transmission system features Hydro-Québec's electricity transmission system

1 electricity transmission system features

1.1 ac 735 / 765 kv power lines

1.1.1 routes


1.2 electricity pylons
1.3 interconnections
1.4 high voltage direct current (hvdc) 450 kv

1.4.1 route


1.5 other features

electricity transmission system features

the system contains more 34,187 kilometres (21,243 mi) of lines , 530 electrical substations. managed hydro-québec transÉnergie, division of crown corporation hydro-québec , part of northeast power coordinating council. has 15 interconnections systems in ontario, new brunswick , northeastern united states , 6,025 mw of interconnection import capacity , 7,974 mw of interconnection export capacity. system has transmission lines reaching power generation facilities located more 1,000 kilometres (600 mi) away population centers. reason, transÉnergie uses voltage of ac 735 kv transmit , distribute electrical power produced hydro-québec s dams, although 315 kv used well. total value of transÉnergie s entire electricity transmission system c$15.9 billion. these reasons, hydro-québec transÉnergie considered world leader in power transmission.

ac 735 / 765 kv power lines

a mae west pylon hydro-québec transÉnergie 735 kv power line, recognizable x-shaped spacers separating 3 4-conductor sets.

from 1965 onwards, 735 kv power line became integral part of québec s power transmission backbone. more one-third of hydro-québec transÉnergie s system consists of high voltage ac 735 / 765 kv power lines, totaling 11,422 kilometres (7,097 mi) strung between 38 substations equipment of voltage. first transmission system 1965 ieee milestone.

the physical size of hydro-québec s 735 kv transmission lines unmatched in north america. 2 other utility companies in same region, new york power authority (nypa) , american electric power (aep) contain @ least 1 765 kv line in power system. however, aep has significant mileage of 765 kv power lines, on 3,400 kilometres (2,100 mi) of 765 kv line traversing broad transmission system; system contains mileage in united states under 1 electrical company. nypa has 219 kilometres (136 mi) of 765 kv line, of contained in single direct interconnection hydro-québec.

the 735 kv power line said lessen environmental impact of power lines, 1 single power line operating @ voltage carries same amount of electric power 4 315 kv power lines, require right-of-way wider 80.0–91.5 metres (262.5–300.2 ft) width required single 735 kv line. each 735 kv line capable of transmitting 2,000 mw of electric power @ distance of on 1,000 kilometres (620 miles) , entire 735 kv grid can carry 25,000 mw of power. power transmission losses on 735 kv grid range 4.5 8%, varying due temperature , operating situations. ordre des ingénieurs du québec named 735 kv power line system technological innovation of 20th century quebec.

in wake of 1998 ice storm levis de-icer installed , began testing in 2007 , 2008.

the lévis substation.


routes

cross rope chainette ( little necklace ) suspension pylons used on parts of 735 kv lines between james bay hydroelectric complex , montreal.

hydro-québec transÉnergie s 735 kv system consists of set of 6 lines running james bay montreal , set of 4 lines churchill falls , manic-outardes power stations quebec city. south shore region of montreal , saint lawrence river between montreal , quebec city contain 735 kv power line loops or rings.

james bay

the james bay hydroelectric dam complex contains several relatively short 735 kv power lines send electricity 3 principal substations, ordered west east: radisson, chissibi, , lemoyne. these substations, 6 735 kv power lines traverse vast expanses of taiga , boreal forest in clear-cut stretches of land; shows in aerial photos. terrain power lines cross part not mountainous, smooth , replete lakes. generally, 4 of lines runs in 2 pairs , other 2 run solo, although 2 single lines run in pair. 2 intermediate 735 kv power lines, 1 in north , 1 in south, connect 6 power lines along path southern quebec.

as lines continue south, diverge 2 sets of 3 735 kv transmission lines. eastern set heads quebec city, connects power lines churchill falls , 735 kv power line loops in saint lawrence river region. western set heads montreal, forms ring of 735 kv power lines around city, linking other power loops in region. section of hydro-québec transÉnergie s power grid contains 7,400 km (4,600 mi) of 735 kv ac , 450 kv dc power line.

manic-outardes power stations / churchill falls


the micoua substation, on quebec s north shore. substation 1 of transÉnergie s transmission hubs.

electrical power generated churchill falls power station sent montreal , population centers of northeastern united states, more 1,200 kilometres (700 mi) away. starting generation station in labrador, power lines span distance of 1,800 metres (6,000 ft) on churchill river gorge , run south-southwest 203 kilometres (126 mi) 3 side-by-side power lines in cleared right-of-way width of 216 metres (709 feet). head southwest through boreal forest, lines traverse flat, smooth rolling hills.

after lines cross quebec-labrador border, known hydro-québec point of delivery, direction of lines becomes due south, , head montagnais substation, substation accessible airport adjacent it. lone 735 kv line stems off substation, heading open pit mine 142 kilometres (88 mi) northwest. terrain crossed power lines becomes hilly , mountainous south of border. lines reach on 800 metres (2,600 ft) in elevation before descending. 3 lines continue heading south until reach substation on north shore of gulf of saint lawrence. there on, 3 lines parallel north shore gulf narrows southwest toward saint lawrence river discharge mouth. northernmost power line diverges other 2 connect manic-outardes power stations located on , around rivière aux outardes , manicouagan river.

triple 735kv mae west towers @ boischatel / l ange-gardien limits, on route 138 east of quebec city, lines crosses st. lawrence river south towards Île d orléans.

as lines near quebec city, northern power line rejoins other 2 735 kv power lines. 3 lines, paralleled 735 kv power line distance north, span on saint lawrence river south shore region, lines form loops encompassing part of saint lawrence river , south shore. loops connected ring of 735 kv power lines around montreal , power lines running south james bay.

electricity pylons

quebec s transmission system contains variety of electrical pylons depending on era , voltage level. older pylon designs tend consume more material newer pylons , higher voltage level, larger tower.

735 kv pylons


two types of single-circuit 735 kv delta pylons near saint-jean-sur-richelieu paralleled dual-circuit 315 kv line. center 735 kv line uses larger version delta pylon while 1 right uses smaller one.

hydro-québec transÉnergie uses several different types of electricity pylons support 735 kv power lines. of them single-circuit, meaning each pylon carries 1 power line 3 bundles of 4 electrical subconductors separated spacers, each bundle transmitting 1 phase of current.

a series of v-guyed towers, near chapais, quebec.

the earliest type of tower used massive self-supporting delta pylon, or waist pylon, consumed 21 tonnes of steel per kilometre of line. type of pylon used first 735 kv power line manic-outardes power stations load centre of montreal. there 2 significant variations of delta pylon; 1 has longer side crossbars such 3 bundles of conductors suspended on v-shaped insulators. other has shorter side crossbars, such 2 outside bundles hung on vertical insulator string , middle bundle hung v-shaped insulator.

over years, hydro-québec researchers engineered new type of pylon, v-guyed tower, reduced materials consumption 11.8 tonnes of steel per kilometre of power line. type of tower includes variation longer side crossbars, conductors hung v-shaped insulator , 1 shorter side crossbar, middle bundle hangs insulator , side bundles strung on vertical insulator strings.

during construction of james bay transmission system, cross-rope suspension tower invented. type of tower features 2 guyed-tower legs similar v-guyed tower, 2 legs don t converge @ tower base. in case of cross-rope suspension tower, tower legs spread apart on 2 different foundations. in addition, crossbar replaced series of suspension cables 3 vertical insulator strings support 3 bundles, allows design consume 6.3 tonnes of steel per kilometre of line. design known chainette (little necklace).

transÉnergie uses two-level pylons angle towers or structures on 735 kv power lines change direction of line or switch position of conductor bundles. delta pylons , three-leg guyed towers used angle towers; referred penguins hydro-québec linemen.

pylons other voltage levels

hydro-québec transÉnergie uses combination of double-circuit three-level pylons , single-circuit delta pylons suspend electrical conductors of other voltages, such 315 kv. ±450 kv high-voltage direct current line in hydro-québec s power grid uses t-shaped tower, lattice or pole, support 2 bundles of 3 conductors on each side. direct current power line uses 2 poles or wider, pyramidal, self-supporting lattice structure angle towers.

174.6 metre pylon adjacent hydro-québec s now-decommissioned tracy power plant.



other pylons

hydro-québec uses tall, large pylons cross large bodies of water, lakes , rivers. these towers said prominent , tallest pylon in hydro-québec s power grid of function. tallest of these located near tracy power station on shore of saint lawrence river, carrying 735kv circuit between lanoraie , tracy. pylon, largest of kind in canada, 174.6 metres (572.8 ft) tall, same height montreal olympic stadium, , larger washington monument in united states (555 feet (169.2 m)).

pylon strength

the pylons , conductors designed handle 45 millimetres (1.8 inches) of ice accumulation without failure, since hydro-québec raised standards in response ice storms in ottawa in december 1986 , montreal in february 1961, left 30 40 millimetres (1.2 1.6 inches) of ice. has led belief hydro-québec transÉnergie s electrical pylons indestructible . despite being more 3 times higher canadian standard of 13 millimetres (0.51 inches) of ice tolerance, ice storm in late-1990s deposited 70 millimetres (2.8 inches) of ice.

interconnections

the outaouais substation, newest of 19 interconnections between hydro-québec s network , neighboring power grids.

across north america, electricity transmission systems interconnected wide area synchronous grids, or interconnections. suppliers legally required follow reliability standards. in 2006, québec s transmission system recognized north american electric reliability corporation (nerc) full interconnection because asynchronous neighboring systems. québec consequently able develop own reliability standards, needed, , these apply in addition relevant north american standards. besides quebec interconnection, there 3 other interconnections in north america: eastern interconnection, western interconnection, , electric reliability council of texas.

hydro-québec transÉnergie has following interconnections systems in neighboring provinces , states:

new york: 2 connections. capacity 1,100 mw import, 1,999 mw export.
ontario: 8 connections. 1,970 mw import, 2,705 mw export.
new england: 3 connections. 2,170 mw import, 2,275 mw export.
new brunswick: 3 connections. 785 mw import, 1,029 mw export.

the maximum simultaneous delivery (export) interconnection common new york , ontario 325 mw.

high voltage direct current (hvdc) 450 kv

in addition 6 735 kv power lines stem james bay project, seventh power line constructed 1,100 kilometres (680 mi) northward extension of existing high-voltage direct current (hvdc) line connecting quebec , new england. power line expansion completed in 1990. result, direct current power line unique because there multiple static converter , inverter stations along 1,480 kilometres (920 mi) long power line. first multiterminal hvdc line in world. ±450 kv power line can transmit 2,000 mw of hydroelectric power montreal , northeastern united states.

route

beginning in converter station next radisson substation, hvdc line heads south , parallels 6 735 kv power lines distance west. traverses same type of terrain other 6 lines; land replete lakes, wetlands, , forested rolling hills. gradually, power line turns southeast, crosses under several 735 kv power lines.

450kv high-voltage direct current (hvdc) line (at right), on south side of autoroute 20 east of nicolet station.

after 6 735 kv wires split 2 groups of 3 power lines each, hvdc line follows eastern group, , western set diverges away. line remains overhead until reaches north shore of saint lawrence river near grondines, 450 kv hvdc line descends underwater tunnel traversing river. power line surfaces on south shore near lotbinière substation. after river crossing, line enters nicolet terminal near sainte-eulalie, northeast of drummondville. south of terminal, line heads south , after relatively short distance, enters des cantons close sherbrooke.

leaving des cantons station, power line crosses canada–us border , passes through hilly appalachian mountains in u.s. state of vermont, reaching elevation of 650 metres (2,130 ft). line continues heading south-southeast , enters state of new hampshire, reaches comerford terminal near monroe. continuing southward massachusetts, line reaches sandy pond terminal outside of boston in ayer. terminal southernmost extent of hvdc line.

in december 2008, hydro-québec, along american utilities northeast utilities , nstar, created joint venture build new hvdc line windsor, quebec deerfield, new hampshire. hydro-québec own segment within quebec, while segment within owned northern pass transmission llc, partnership between northeast utilities (75%) , nstar (25%). estimated cost us$1.1 billion build, projected line either run in existing right-of-way adjacent hvdc line runs through new hampshire, or connect right-of-way in northern new hampshire run through white mountains. 180-to-190-mile (290 310 km) line, projected carry 1,200 megawatts, bring electricity approximately 1 million homes.

other features

transÉnergie uses series compensation alter way electricity behaves in power transmission lines, improves electricity transmission efficiency. reduces need construct new power lines , increases amount of electric power sent population centres. series compensation based on capacitor technology. maintain transmission system performance, transÉnergie sets aside funds research , application of new technologies. in addition power transmission technology, hydro-québec plans offer high-speed internet on transmission lines within few years; utility started testing internet on lines in january 2004.