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City Road Northenergisation

Offshore windfarm totransmission grid

It’s not the power INthat counts …

The big turn on

New products

Offshore windfarmconnections

FAST FORWARD WITH ABB POWER TECHNOLOGIESWinter 2003/4

02 FFWD >> Winter 2003/4

Published by:ABB LimitedPower Technologies DivisionOulton Road, Stone, Staffordshire ST15 0RS

Editor: Karen Strong

Telephone:01785 825050

3 City Road North The new 400kV architect-designed indoorsubstation houses ABB compact gas insulatedswitchgear.

4 NewsA round-up of our latest news.

6 WindpowerAn overview of ABB’s services and productportfolio for offshore windpower projects.

8 Getting connectedABB’s new connections activities extend fromservice alterations for RECs to turnkeymanagement of new connections forcommerce and industry.

9 It’s not the power IN thatcounts …A look at how Static Var Compensators canhelp extend power transfer limits and improvepower flow.

10 The big turn onThe 330MW Cross Sound underwater cablelinking Long Island and Connecticut will help operators share generating capacity.

11 Product roundupWhat’s new in medium voltage switchgear?

12 Take control of yoursubstationsIntegrating substation equipment within a real-time monitoring and control system

contents Be aware of theFACTS

Plans to minimise the risk of winter blackouts and ensureadditional capacity can rapidly be brought on stream arebeing drawn up by the government, Ofgem and the NationalGrid in the wake of recent US and European power failures.

Faults will always occur in power systems. But, if handledcorrectly, they should just result in localised power cuts ofrelatively short duration. Most blackouts are caused byerrors and equipment failures, rather than lack of generationcapacity. So the main focus of attention must surely be onfinding fast and effective ways of increasing the stability ofelectrical grids.

In a blackout the complete system collapses affecting allelectricity consumers in the area. The overload of thetransmission system is often triggered by a single andsometimes minor initial event. The trick is to avoid the‘domino effect’ by rapidly disconnecting the faulty part andhaving the muscles, speed and intelligence within thesystem to stabilise the remaining healthy part.

FACTS (Flexible AC Transmission Systems) are technologiesthat can do just that. They enhance the reliability andflexibility of power transmission systems. And, equallyimportant, they enable better utilisation of existinginfrastructure.

FACTS technologies can be divided into two maincategories – dynamic shunt compensation to maintainvoltage stability and series compensation to increasetransmission capacity and improve the reliability of thepower system.

ABB has helped a number of electrical utilities around theworld utilise FACTS technologies to improve stability andincrease transmission capacity without the need to buildnew overhead lines.

A recent major order is for the Pacific Gas & Electric (PG&E)electrical transmission network in San Francisco, California.The FACTS installation will stabilise the power system duringpeak loading and network contingencies, substantiallylowering the risk of voltage collapses. This contract is thesecond static var compensation (SVC) order from PG&E.

To learn more about how ABB FACTS technologies andpolicies can help prevent blackouts visit the new poweroutages portal site on our web site (www.abb.com).

Issue 6 Winter 2003/4

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Trevor GregoryABB UK Managing Director

Winter 2003/4 >> FFWD 03

substations

Demand for electricity inLondon is growing so it

was hard hats and smiles allround from the ABB andNational Grid team at the newCity Road North substationwhen full energisation tookplace in early August.

CLOSE COOPERATION

The three-year design and buildproject highlights how industry canwork in harmony with the localcommunity and clearlydemonstrates to the regulator andfuture clients that National Gridcan meet the tightest schedules anddeliver a first class service withminimum disruption.

Tom Smith, ABB projectmanager explains. “For NationalGrid and ABB this was one of themost onerous projects undertakenfrom an environmental andcommunity impact point of view.

“City Road North is located ina busy inner-city site in Islington,surrounded by both domestichousing and commercial andindustrial premises. The site alsobacks on to the City Road Basinon the Regent’s Canal. This isbeing regenerated to create avibrant location for business,residential and leisure use.

“In addition to dealing withcontaminated ground and ensuringno land or water pollution whenworking on the site, a great deal oflogistical planning was needed tomove heavy plant and materials inand out and keep the canal accessopen while carrying out majorworks.

“At peak workload we had 50 people on site as well as havingto co-ordinate other contractors,”continues Smith. “Arranging forthe 200-tonne transformer to beshipped to Tilbury Docks and thentransported by road to Islington,for example, involved liasing withno fewer than 24 differentagencies.”

ABB worked in closepartnership with National Grid to meet its strict environmentalcriteria, creating minimal noise anddust nuisance, and complying withthe company’s community relationscontractual requirements tominimise disruption to localresidents and businesses.

National Grid ensured that thelocal community was kept fullyinformed at all stages of the projectvia newsletters and letter drops.One-to-one meetings were held forthose directly affected, particularly

on the tow path route. And a 24-hour free phone help line wasset up to deal with enquiries andconcerns. National Grid alsosupported the annual Angel CanalFestival.

ARCHITECT-DESIGNED

The new City Road Northsubstation has been constructedadjacent to the existing City Roadsubstation. Specifying ABB’scompact gas-insulated switchgear(GIS) technology enabled the400kV substation to be housedinside a new brick buildingdesigned by Markwick Architectsto complement the style of existingbuildings in the area. This is in line with Islington Council’sredevelopment of the City RoadBasin, which aims to improveaccess and recreationalopportunities and enhance thelocal urban environment.

TURNKEY PROJECTAs turnkey project manager,

ABB was responsible for allengineering design and civil worksat City Road North as well as thecomplete installation andcommissioning of the substationswitchgear and ancillaryequipment.

ABB supplied four GISswitchbays and associatedequipment, together with a240MVA 400/132kV transformerand substation protection andcontrol systems. The project alsoincluded the demolition of a four-storey office block. And, diversionof an existing 400kV cable linkingthe City Road substation to theWest Ham substation six milesaway in East London into the newsubstation to make the WestHam/City Road North and CityRoad North/City Road circuits.

City Road North energisationreinforces London power grid

Energisation of National Grid’s new City Road North 400kV indoor substationis helping EDF Energy to reinforce the electricity distribution system serving theLondon area. Located in an urban regeneration area at the City Road canalbasin in Islington, North London, the architect-designed building houses ABB’scompact gas-insulated switchgear.

Work at Rugeley Power Stationincludes responsibilities for

protecting wildlife and providing accessto the onsite nature reserve.

An £8 million contract to upgrade anexisting substation at Rugeley Power Station inStaffordshire has been won by ABB. The work is part of Network Rail’s West Coast Main Linepower supply reinforcement programme. Thecontract places particular emphasis onsafeguarding flora and fauna and protectingbadgers that live on the site.

The contract includes providing two new400/25kV connections and will enable NetworkRail to upgrade its local trackside power suppliesto the 50kV system required for high-speed railservices.

The work involves installing two new ABB400/26.25-0-26.25kV 40+40MVA SGTs(supergrid transformers) at the 400kV NationalGrid substation, constructing a 25kVcompound, supplying switchgear and providing25kV XLPE cables and associated fibre opticpilots between the two sites.

ADVANTAGES OF 50kV SYSTEM

The 50kV system is widely used in mainlandEurope for high-speed services. Power isdistributed down the trackside as a centre-tapped to earth 50kV system with trackside autotransformers feeding conventional 25kV supplyto the locomotives via catenary and pantograph.Compared with the conventional 25kV systeminvolving booster transformers, this arrangementprovides economies in the number of feeder

stations required to supply traction loads andreduced interference on communicationscircuits.

ABB has won all the 400kV power upgradeorders placed to date for the northbound sectionof this line.

NATURE CENTRE

Rugeley Power Station takes its commitmentto safeguarding its physical environment,wildlife and on-site nature reserve very seriously.

It works closely with the local community,especially schools, welcoming visits andproviding a specially-created EnvironmentCentre. Here, people can learn about pollutioncontrol, environmental management and thenatural life that thrives on the site. It also playshost to an angling club that fishes the lake onthe site.

ABB carried out a full risk assessment studyto identify any potential hazards and isimplementing measures to minimise thepossibility of damage from waste or oil spillages.The company has taken the advice of a badgerconsultant so it can avoid damaging the animals’habitat and ensure their safety while the workcontinues.

ABB and Rugeley Power Limited areaccredited to the ISO 14001 EnvironmentalManagement Standard.

04 FFWD >> Winter 2003/4

news

A substantial contract to upgrade theoperator control system at the Medway

Power Station has been completed by ABB,working with the site engineers. The newoperator display system provides real state-of-the-art management and control facilities and is the first major upgrade to the control systemsince the plant was opened in 1997.

The dual fuel combined cycle 688MW powerstation has one steam and two gas turbines. Its owner, Medway Power, is wholly owned by Scottish and Southern Energy plc.

The power plant automation architectureprovides all the technical capabilities requiredand the display system provides a powerful andeffective interface. It offers a great many ways oflooking at the process: hierarchically structuredprocess displays, data on the health of theautomation processes and much moreinformation. In addition, historical data gathered

from the information management system isavailable to operators in the form of trenddisplays.

The tight integration of the operator displaysystems gives direct access to all informationavailable anywhere in the control system.Operators can easily investigate every functionquickly and in great detail thus reducing the timeto track any problems in the plant.

The new display system was ordered,configured and thoroughly tested in just a fewweeks. It was installed in just five days duringthe plant’s two-week summer shutdown.

As part of the contract Medway Power alsoordered a new ‘Composer’ engineering tool fromABB. This software permits changes to be madeto control strategy at site level even more quicklythan before and provides highly efficient handlingof document changes.

In visible control

Power boost for West Coast Main Line

1 Sarah Hadfield, ABB site projectmanager at Rugeley Power Station,monitors plans for site work.1

Winter 2003/4 >> FFWD 05

news

If we are to believe themass media the recent

blackouts and power outagesare the shape of things tocome. This doom and gloomscenario is constantly raisedwith very little constructivethought or interest in possiblesolutions.

ABB has been making itsglobal experience directly availableto customers on the web and,most recently, through a specialdialogue event for the technicalpress.

ABB believes that it has aunique perspective, some verypractical technical solutions and a wealth of experience to offergenerators, transmissioncompanies and industry.

The Group has launched aglobal programme to make surethat customers throughout theworld know what it can offer. The emphasis is on reliability,effectiveness and economy.

A new web portalwww.abb.com/poweroutages hasbeen launched and a special onlineissue of ABB Review published.Both these provide detailedinformation on possible solutionssuch as ABB’s own HVDC Lighttechnology, as well as mainstreamHVDC and FACTS (Flexible ACTransmission Systems).

In the UK the marketingcommunications team invited

a group of editors from leadingtechnical journals to participate in an ‘Editors’ Roundtable’.

The discussion was moderatedby former Ofgem TechnicalDirector, Brian Wharmby. ABBparticipants included TrevorGregory, UK Managing Director;Peter Jones, Network SolutionsManager; and Group technologyexpert, Carl-Axel Roseen.

US

Bridging the east/west divideA new ABB HVDC (high voltage directcurrent) transmission system links theUnited States’ eastern and westernpower grids. The $50 million ‘Rapid CityTie’, named after Rapid City, SouthDakota, carries 200MW of power andwas completed by ABB in less than 19 months. HVDC technology convertsalternating current from one grid intodirect current for transmission and thenre-converts it to AC for the other grid.

Lighting from Las to LosA 25 percent boost in the capacity of theLas Vegas-Los Angeles transmissioncorridor will be on line in time for thesummer of 2004 thanks to innovativeABB technology. While it will take years to create new generating capacity, ABB’sFlexible AC Transmission Systems(FACTS) can be implemented quickly. Separately, ABB has won a majorcontract to supply FACTS technology for the transmission network serving theSan Francisco area.

CHINA

Mass transit gears upABB has been chosen to supply mediumvoltage switchgear for the new urbanmass transit systems being built in theChinese cities of Shanghai, Guangzhou,Beijing, Shenzhen and Tianjin. The mostrecent contract, worth $18 million, is thelargest order of its kind received by ABBin China.

MIDDLE EAST

Power share will benefit developingeconomiesFour countries of the ancient Levant –Egypt, Jordan, Syria and Turkey – areusing modern ABB technologies to helpthem interconnect their national powergrids. A range of equipment includingtransformers, substations andcommunications systems will be suppliedto the national utilities who are workingtogether to bring more power to ruralareas, in particular.

MALAYSIA

A $21 million contract to rehabilitateand upgrade five 275/132kV substationsin Malaysia has been awarded to ABB.The order is part of a project by theMalaysian utility, TNB, to upgrade theelectrical infrastructure around KualaLumpur and the north of the country.

NAMIBIA

Ensuring the uptime of an 890kmpower lineA reliable power supply is absolutelycrucial to Namibia’s two main industries –mining and tourism. The availability andstability of a new 890km 400kVtransmission line from neighbouring SouthAfrica has been safeguarded thanks tothe addition of an ABB Static VarCompensator (SVC). The SVC isdesigned to provide 99.7 percentavailability on a line which wouldotherwise suffer from frequent failurescaused by extremely high and sustainedover-voltage.

A major upgrade ofpower systems at

Nottingham City Hospital(NCH) has opened the way for planned futuredevelopment on a previouslyunused area of the site. The electrical equipment has been supplied by ABBas part of a contract worthover £300,000.

ABB’s work has involved thecomplete electrical engineeringinstallation of a new distributionsubstation within a purpose builtfacility. The substation isconnected to the hospital’sexisting HV ring main system. A 1MVA 11kV/433V transformerhas been installed and space isavailable for a second transformeras demand increases.

A 1MVA standby generator is

also in place and this, togetherwith the transformer, feeds into a purpose made low voltageswitchboard complete with anASCO fast transition switchingdevice to provide seamlessswitching between mains andstandby supplies. The ASCOClosed Transition Transfer andBypass Isolation switch allowsplanned maintenance andperiodic generator testing to becarried out without interruptingthe hospital’s power supply. Otherservices provided include firealarm, small power and lighting.

According to Mick Wyer,engineer with the NCH PropertyServices Department, “ABB hasshared the benefit of its wideexperience in the world ofelectrical services. This has addedvalue to the project and helpedensure that this part of thehospital site is ready for theexpansion of services to thecommunity which will take placeover the next few years.”

A new light on blackouts

Hospital’s £300,000 power upgrade

INTERNATIONAL NEWS

06 FFWD >> Winter 2003/4

renewables

Financial modellingABB’s specialist software can evaluate the

financial and operational risks involved inundertaking an offshore windfarm project,including a full Monte Carlo analysis [1]. Theresult is a system optimised to provide the mostcost-effective combination of engineering,financial and regulatory requirements.

TransformersABB transformers convert the 690V

produced at the wind-turbine to the 33kVrequired for interconnection via the localringmain and/or an offshore substation. A drytype resin transformer [2] designed specificallyfor windpower applications can be installed inthe nacelle or tower, conventional oil-filledtransformers are also available.

ABB transformers are also found at all thekey stages in the transmission link, from

intermediary offshore and onshore 33kV/132kVsubstations to connection to the local ornational transmission grid at 275 or 400kV.

SwitchgearABB GIS and AIS switchgear meets all

windpower switching needs from MV to EHV.Where space is at a premium, such as in anoffshore substation, compact GIS switchgear [3] is the ideal answer.

Submarine power and controlcables

ABB has a long history as a globalmanufacturer and installer of submarine powercables for both AC and DC. Extruded XLPEcable provides the ideal environmentally friendlysolution for applications up to 170kV and300MVA such as the loop connections between a string of windturbines and theoffshore substation and the onshore connection.Integrated fibre optics can also provide the communications links for the controlsystems.

As well as supplying the cables, ABB offers askilled and experienced installation team whichoperates its own vessel and can bury the cables

under the seabed either by ploughing in orwater jetting [4] as well as providing mechanicalprotection where needed. ABB can alsoundertake subsea surveys.

Offshore substationsABB’s complete service for offshore

substations includes the design, layout andsupply of all 33kV and 132kV switchgear andtransformers together with standby power anddeluge systems for fire protection.

Onshore substationsABB is a world leader in the design,

installation and commissioning of GIS and AISsubstations [5] up to 400kV including thenegotiation of wayleaves and easements and allcivil engineering works.

SCADA, Industrial ITSCADA systems utilising ABB’s Industrial

IT philosophy provide the means to monitorand control all aspects of the windfarmoperation, such as adjustment of the turbineblade pitch and power output as well ascondition monitoring of bearings andmaintaining records of switchgear operations.

ABB has developed a comprehensive range of windpower infrastructuresolutions that enable power generated offshore to be brought to themainland efficiently and reliably and connected into the local or nationaltransmission grid.

Complete connection solutionsfrom offshore windfarm to the national transmission grid

2 31

ABB’s flexible windfarm connectionservice includes complete turnkey

packages from feasibility studies throughto installation, commissioning andongoing maintenance as well as thesupply of individual components.

Winter 2003/4 >> FFWD 07

renewables

SCADA also plays a vital role in meeting the protection requirements of electricalnetworks.

SVC SystemsThe introduction of national grid codes

demand that new developments such aswindfarms can demonstrate their ability to‘ride through’ any reflected fault from the grid.ABB can undertake reliability studies to assessthe potential risk and then design andmanufacture the appropriate SVC (Static VarCompensator) solution to maintain gridstability.

HVDC LightConnecting offshore windfarms to

conventional AC grids has always represented achallenge, since AC systems can be destabilisedby the variation in frequency as the wind speedchanges. HVDC Light, ABB’s high-voltagedirect current transmission system, eliminatesthis problem by converting the variablefrequency power into DC power [6].

HVDC Light can transmit power economically over long distances, withtransmission losses up to 50% lower than in AC systems, so it is ideal for offshorewindpower schemes.

Network ConnectionsABB offers a turnkey solution for the

connection of windfarm sites to the distributionor transmission network operator’s assets. By taking advantage of new legislationgoverning competition in connections, ABB can offer the design and construction of thecontestable element together with thenegotiations for, and the project managementof, the non-contestable element of suchconnections.

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new connections

Ofgem’s findings show that a totalof 414,916 electricity connections

were undertaken in the UK during thereview period June 2002 to May 2003.These comprised 252,000 low voltage,719 high voltage, 18 extra high voltage,179 distributed generation and 162,000unmetered connections.

Currently just four percent of low voltageand less than one percent of high voltageconnections are undertaken by IndependentConnection Providers (ICPs). This is despiteconsumers (house builders, service sectors, localauthorities and universities) highlightingcompetitive pricing and enhanced customerservice as two advantages of using an ICP.

Following the review, the Regulator has setup an Electricity Connections Steering Groupto promote competition in connections and isalso looking into service standards.

THE RIGHT CONNECTIONS

ABB’s new connection activities extend fromthe regulated provision of all service alterationsfor REC customers to the turnkey managementof multi-million pound competitive newconnections for the commercial and industrialmarket. Since the beginning of 2000 ourengineers have completed over 10,000 servicealterations and independently managed theconnection of over 800MW of new load fromlow voltage to 132kV.

According to Karl Young, ConnectionsBusiness Manager at ABB: “Procuring anddelivering utility connections is a major concernfor consumers both in terms of cost and projectdelivery. ABB’s success in this area is attributableto the fact that we take the problem away. We manage the interface with the host utility,reduce costs, improve cash flow, speed up theprogramme and reduce the overall project risk.Our successes at New Providence Wharf,Chelsea Bridge Wharf and BirminghamUniversity are excellent examples of this.”

NEW PROVIDENCE WHARF

The deciding factor in Ballymore Propertiesawarding ABB the contract to design and buildthe 11kV electrical distribution network forNew Providence Wharf was ABB’s capability tomeet a very tight project schedule – ‘power on’for the first two development phases in January2003.

The 8.3 acre Providence Wharf site inLondon’s Docklands will include 735 riversideapartments, a five star hotel, 500,000 sq ft ofoffice space plus retail units, restaurants andleisure facilities all requiring some 12MVA ofpower.

The 11kV distribution network for the firsttwo phases comprises a kilometre ofunderground cable which takes four incomingsupplies from LondonEnergy’s switching station at

Brunswick Wharf and distributes the power viaa 12 panel primary board to the localdistribution transformers.

CHELSEA BRIDGE WHARF

Berkeley Homes enjoyed 30 percent capitalcost savings when it engaged ABB to providethe utility connection to its new residential andcommercial development at Chelsea BridgeWharf.

To meet the site’s 6MVA supply requirement,6km of 11kV power cabling were laid from a primary substation through central London to the development site. ABB undertook theplanning, design and construction of thecomplete network including six substations.

UNIVERSITY OF BIRMINGHAM

The University of Birmingham’s new primaryelectrical substation has boosted the campus’power capability by around 70 percent as well as ensuring reliability of supply. Designed andconstructed by ABB it features ABB’s innovativeLTB Compact switchgear. This enabled a dualcircuit 132/11kV substation to be condensedinto around half the space required for aconventional design.

ABB also carried out the new HVconnection to the Selly Oak substation – theUK’s first 132kV contestable connection.

08 FFWD >> Winter 2003/4

1

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1 New Providence Wharf in Docklands. ABBmet a very tight project schedule for ‘poweron’ of the 11kV distribution network servingthe first two development phases.

2 Berkeley Homes benefited from cost savingsand hassle free delivery when it chose ABBfor the 11kV electrical distribution networkfor Chelsea Bridge Wharf.

As part of its mission to promote choice and value forcustomers, Ofgem recently carried out a review ofcompetition within the connections industry.

Getting Connected

FACTS

Winter 2003/4 >> FFWD 09

Ideally a transmission systemshould carry power up to its thermal

loading limits. This would result inmaximum utilisation of transmissionassets. However a power system iscomplex and subject to constraints suchas voltage limits, stability limits and loopflows. In practice, this means that a400kV line cannot usually be expected totransmit more than 450-500MW over any‘reasonable’ distance unless very specificmeasures are taken to safely increase thepower transfer capability.

FACTS (Flexible AC Transmission Systems)technologies are designed to remove suchconstraints and create possibilities to run thetransmission system close to its thermal limit.They are particularly suitable for applicationsrequiring rapid dynamic response, ability forfrequent variation in output and smoothlyadjustable output or fast implementation.

One of the most widely used and provenFACTS devices is the Static Var Compensator(SVC). Its fast Var (volt amp reaction) capabilitymakes it highly suitable for steady state anddynamic voltage stabilisation, dynamicbalancing of unsymmetrical loads and poweroscillation damping.

WHY SVC?

The nature of AC power flow is such thattransmission lines store energy in the form ofelectric and magnetic fields. This stored energyis reflected in flows of reactive power. In general,lightly loaded lines generate reactive power andheavily loaded lines consume reactive power.Reactive power produced or consumed bytransmission lines impacts system operatingvoltage.

An SVC has the ability to support the voltagelevel in a specific area of the power system byautomatically and instantaneously adjusting thereactive power output smoothly compared tothe reference voltage level, thus maintainingvoltage stability.

For rapid events such as when lightning hits aline section it is very important that the faultysection is disconnected and that the remaining

healthy part of the power system has the abilityto stay in service. An SVC has the ability toquickly detect and automatically adjust itsoutput for maximum support of the voltage i.e. it provides transient stability.

HOW IT WORKS

An SVC comprises standard inductive andcapacitive branches controlled by thyristor valvesconnected in shunt to the transmission networkvia a step-up transformer. Thyristor control givesthe SVC the characteristic of a variable shuntdevice.

The SVC operates by measuring the actualvoltage and automatically generating orconsuming system reactive power through itscapacitors and reactors, hence automaticallyproviding voltage and transient stability.

In terms of its steady state performance, anSVC acts much like a synchronous condenserbut with the advantage that it has no inertia,and contributes nothing to the network shortcircuit level. In comparison to switchedcapacitor banks, it can operate repeatedly and isnot encumbered by the delays associated withmechanical switching. This enables the SVC torespond very rapidly to changing networkconditions such as line or generator outagecontingencies, or loss of major loads.

APPLICATIONS

Installing an SVC at one or more suitablepoints in the network can improve transmissioncapacity by 10-50 percent through increasedtransfer capability while maintaining a smoothvoltage profile under different networkconditions. The dynamic stability of the gridcan also be improved and active poweroscillations mitigated. A further benefit is thattransmission losses are reduced in many cases.

The three principal installation points forSVCs are as follows. Close to major load centressuch as large urban areas to mitigate the effect ofdisturbances in the grid on sensitive loads and toreduce the probability of loss of load due tovoltage collapse. At critical buses for voltagecontrol and to guarantee stable and efficienttransfer of power during and immediately

following network disturbances. And, finally, atinfeeds to large industrial and traction loads forboth fast voltage control (flicker) and phaseunbalance control.

A SOLUTION FOR EVERY APPLICATION

ABB SVCs can be used for symmetrical threephase control or phase-by-phase control. The range includes:● Thyristor controlled reactors

● Thyristor controlled reactors/fixed capacitors

● Thyristor switched capacitors

● Thyristor controlled reactors/Thyristor switched capacitors

● Relocatable versions

Widely publicised power outages and the high costs of building new transmissionlines is focusing attention on making existing and new infrastructure more efficientand ensuring a high quality reliable supply. Stephen Trotter, who was appointedrecently as General Manager of ABB’s Power Systems Projects Division, explainshow Static Var Compensators can be used to extend power transfer limits andimprove power flow through effective and rapid control of reactive power.

It’s not the power IN that counts …

SVC power transmissionbenefitsAn ABB SVC can boost transmissioncapacity by 10-50 percent through:

● Stabilised voltages in weak systems

● Reduced transmission losses

● Increased transmission capacity

● Higher transient stability limit

● Increased damping of minor disturbances

● Greater voltage control and stability

● Power swing damping

In August 2003 the 45km (28 mile)330MW Cross Sound underwater

cable, linking Long Island andConnecticut, was used for the first time. It was brought on line after months ofnegotiation to help restore power afterthe massive blackout in the northeasternUnited States. Federal authorities havesince approved the continued operationof the cable which uses ABB’s HVDCLight (high voltage direct current)technology.

The underwater cable has been on the cardsfor 30 years. Its aim to provide a directconnection to the New England grid has beendogged by environmental concerns and, evenafter it was completed, it was some time beforeit could be brought online.

Addressing the environmental issue, thepossible impact of an interconnector on the

delicate aquatic ecosystem, was the opportunitythat opened the way for ABB’s HVDC Lightsolution.

GROWING DEMAND

The Cross Sound Cable project is designedto help operators in the region share theirgenerating capacity and so reduce the risk offurther blackouts. It will benefit Connecticut,New York and New England by encouragingelectricity trading and promoting competitionin the market.

The builder and owner of the project isCross Sound Cable Company, a subsidiary ofUnited Capital Investments which in turn isowned by United Illuminating Company andTransEnergie US. TransEnergie has been ABB’spartner in the project.

The route across Long Island Sound waschosen as it would have less impact on peopleand property than a landline. HVDC, as opposed

to HVAC, is well established as the preferredtechnology for this type of submarine cable.

TECHNOLOGY POWER

ABB’s HVDC Light technology comes inunit sizes up to 330MW and for DC voltagesup to +/- 150kV. It consists of converter stationsand a pair of advanced technology cables.

Unlike conventional HVDC the ABBtechnology does not rely on the AC network’sability to maintain a stable voltage and frequency.This reduces the need for reinforcement in thelocal grid and provides extra flexibility inchoosing the location of converters.

HVDC Light stations are compact, ofmodular design and blend into thesurroundings. The stations are intended forunmanned and maintenance-free operation.

Prior to burial the two 125mm diametercables were bundled and laid on the sandyseabed within a precisely defined corridor acrossLong Island Sound. A hydraulic jet plough wasused to create a trench and bury the cables up to two metres below the seabed.

Jet ploughing creates minimal damage and isextremely fast and efficient.

COMPLETION

Work was finished in mid 2002 however itwas not put into proper use until after the 2003mid-August blackouts. It was granted fullapproval for regular use at the end of August2003.

10 FFWD >> Winter 2003/4

HVDC Light

THE BIGTURN ON

After 14 months of negotiations, a $120 million underwaterpower line connecting two US states helped restore electricityto a region hard hit by two days of blackout.

HVDC vs HVAC● On cable links of 40km or more HVDC

requires lower investment. On Cross Soundtwo DC cables could be placed in one trenchas an alternative to three AC cables each ofwhich would need its own trench.

● Long AC cables produce large amounts ofreactive power, requiring shunt reactors atboth ends. This can seriously reduce theactive power capability.

● HVDC links can connect two asynchronouspower grids and are ideal where it is notfeasible to create a synchronous powerconnection.

● In an AC system it is not possible to directlycontrol the power flow while an HVDCsystem allows rapid direct control of bothdirection and quantity.

Winter 2003/4 >> FFWD 11

product roundup

ABB’s SafeRing is an SF6

insulated ring main unit forthe 12/24kV secondarydistribution networks. Thecompletely sealed system,which includes a stainless steeltank containing all the live partsand switching functions underconstant atmosphericconditions, ensures a high levelof reliability and personnelsafety and is virtuallymaintenance-free.

Typical applications includecompact secondary substations, lightindustry, wind turbines, hotels,shopping centres, office buildings,airports, hospitals, tunnels andunderground railways.

The SafeRing concept offers a choice between a switch fusecombination and circuit breakerwith relay for transformer

protection. The switch fusecombination offers optimalprotection against short circuits,while the circuit breaker with relayoption offers better protectionagainst low overcurrents. Circuitbreaker with relay is alwaysrecommended for largertransformers.

SafeRing can be suppliedcomplete with an integral remotecontrol and monitoring unit. Otheroptions include capacitive voltageindication, short circuit indicators,arc suppressor and motorisedoperation.

Available in ten differentconfigurations, SafeRing offers acomplete solution for secondarydistribution networks whencombined with ABB’s SafePlus SF6

gas-insulated compact modularswitchgear.

SafeRing is virtually maintenance free

Compact, high security MV switchgearoffers improved operator safety

The ABB AX1 air-insulated switchgear for mediumvoltage distribution offers high operator protection,

minimal maintenance and low life-cycle cost. This,coupled with its compact design, makes it ideally suitedto small spaces that need high security.

Each AX1 panel is built up from three enclosure modules. The main circuit enclosure houses the primary switchgearfunctions with all live parts (12/24kV) inaccessible from theoutside. Relay and control equipment are located within theoperating enclosure and are accessible with the switchgearenergised. The lower frame is where the power cables areconnected.

To prevent personal injury and eliminate mechanical andthermal damage to the switchgear an arc eliminator short circuitsany arc to earth within 5 milliseconds. The circuit breaker’soperating mechanism can be removed for maintenance withoutthe panel having to be taken out of service. And, because AX1uses air as the insulation medium, only the switching devicescontain SF6.

Tubular busbars ensure a robust compact design and lowsurrounding magnetic fields. with low loss coil spring contactsused for easy connection between panels.

In addition to the individual panel computers which providerelay protection, monitoring, operating, measurement,communication and interlocking functions, a single support panelfacilitates easy reprogramming/adjustments.

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back-up power

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www.abb.com

ABB helps strengthen powersupply in Alaska

Golden Valley ElectricalAssociation (GVEA) in

Fairbanks, Alaska hasenergised a new US$30-million BESS (Battery EnergyStorage System), supplied andinstalled by an ABB-ledconsortium. The BESS is ableto supply 40MW of power tostabilise the local grid andreduce its vulnerability toevents like the recent blackoutin the north eastern US andCanada.

At the heart of the world’s mostpowerful storage battery system aretwo core components. First are therechargeable Nickel-Cadmium (Ni-Cad) batteries, developed by Saft.Second is the converter, designedand supplied by ABB. Theconverter changes the batteries’ DCpower into AC power ready for usein GVEA’s transmission system.

Ensuring a reliable supply ofelectricity is essential for a regionwhere long supply lines and remoteconsumers are the rule, and wheretemperatures can drop to -51°C.At such temperatures, water pipesin homes would freeze in about

two hours if the power supplyfailed.

The BESS comprises 13,760rechargeable cells in four parallelstrings to provide a nominalvoltage of 5kV and a storagecapacity of 3,680Ah. It is able tofeed the power grid in anemergency with 40MW of power

for six to seven minutes, or 27MWfor 15 minutes. That givessufficient time to bring diesel-powered back-up generatorsonline. Other benefits includereduced emissions due to a lowerreliance on spinning reserve as wellas reactive power support andimproved power quality.

The facility, which is about thesame size as a football pitch, canultimately accommodate up toeight battery strings. This givesconsiderable flexibility to boostoutput or prolong the useful life of the system beyond the plannedoperation for 20 years.

The world’s most powerful battery energy storage system, which uses ABB technology, has begun commercial operation in Alaska. The US$ 30 million system is expected to cut power blackouts by more than 60 percent.

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