Brochure Polytransformer.qxd 29/3/05 16:32 ... - ABB …FILE/Brochure+Polytransformer.pdf · Power Transformer Brochure ... Brochure Polytransformer.qxd 29/3/05 16:32 Página 10.

The Polytransformer

The Multivoltage Substation Power Transformer

Brochure Polytransformer.qxd 29/3/05 16:32 Página 1

The PolytransformerCompact Ready for shipment andinstallation in any substation.

Multiple voltage ratings

Useful and convenient: You never know when you may need it.

3ABB The PolytransformerABB The Polytransformer2

The need for a single transformer for different transmission systems.

Change of electric power industry to a fully competitive and deregulated market has highlighted

the importance of asset management. Large power transformers represent a significant asset within

the utility delivery system. These are the most important and costly components and the critical nodes

in electricity networks.

ABB has developed a new product in thetransformer world, The Polytransformer.

This transformer is designed with multiple voltage ratings, on the HV, the LV and tertiary side,that allow it to work in substations at differentvoltages.

Impedances and MVA ratings are chosen to cover most of the applications.

Single phase and three phases units are availableIts compactness and flexibility of use make thePolytransformer the ideal universal transformer for any transmission system.

Multifunctional tools

Swiss knife multiple use Swiss knife ready for pocket.

Shell type transformer during transport.Polytransformer multiple voltage.

The Swiss Army knifeLight and compact: You carry it in your pocket.

Many tools and different applications

Useful and convenient: You never know when you may need it.



The polytransformer: Universal multi-voltage transformer.

Main features of the universal network-link transformer are:

Minimum installation dimensions to optimize substation space requirements. Minimizing total dimensions allows replacement of a widerange of existing transformers or installationin substations with limited space.

Short circuit impedance of the Polytransformer is designed takinginto consideration the impedances of existingtransformers. Parallel connectivity with otherunits is achieved by setting the appropriatetap in the on-load tap changer.

Customized Design: Your Polytransformer will bedesigned to be electrically and dimensionallycompatible with the different transformers in yourtransmission system. The design will meet yourspecifications and applicable standards.

Standardized external componentsto reduce the number of spare parts and to facilitate their availability

Multiple voltage ratings on the high voltageand low voltage side. The polytransformeris designed with internal taps providing differentvoltage combinations to allow connectionof different systems (i.e. from 345 kV to 230 kV,345 kV to 138 kV, 345 kV to 115 kV, 230 kVto 138 kV and 230 kV to 115 kV, combined with33, 26,4 and 24 kV in the tertiary). Dependingon the connection, power rating of the transformervaries. An on-load tap changer regulation is alsoprovided. The different voltage rating alternativescan be selected by changing connectionsinternally when the unit is being preparedfor shipment to a different station. The Polytransformer may be specified either for three phases or single phase execution.

Multiple voltage ratings of tertiary winding.The tertiary has internal taps to provide severalvoltage levels to match different substation needs.

Maximum power rating limited only bytransportation restrictions.

Compact design. Shell form design helps to accomplish compact shipping dimensionsproviding in addition mechanical robustness to withstand transportation and hauling loads. This way, the polytransformer can be easilyshipped to many different substations

Compact design:450 MVA, 400 kV Polytransformer ready for shipment.

Low voltage multiple taps after manufacturing.Low voltage multiple taps within design process.

Polytransformer during test

Polytransformer, a multivoltagetransformer approach, is a comprehensive product, which may be used as an universalnetwork-link transformer. This means: compact dimensions to be shipped to any substationwithin the scope and differentvoltage ratings to connectalternative transmission systems.All in one single product.



Advantages and Applications of the Polytransformer.

Based upon the described features, several applications are possible for the Polytransformers:

Spare Transformer:The Polytransformer may replace a numberof different transformers (multi-voltage,impedance compatibility, parallel connectivity),located in different substations, in a limitedtime (high transportability), without majoradjustments (standard adapted to your needs)

New substations: When you need to expand your system, the Polytransformer will fit it. It will be designedto match the requirements of your network.It can be installed permanently on-site or usedas temporary replacement of other units. Yournew system will be commissioned and runningon time. And you will know it is always available.

Valuable asset: You can also cover most of other utilities’or industries’ requirements. The Polytransformercan be rented, leased or lent to others in caseof emergency or temporary need.

Peaks of Load:The polytransformer can also be used to provideadditional power in the network during seasonalor emergency consumption peak periods. Thisreduces the risk of black outs, and will preventother installed units from being overloaded

Reduce your inventory and maintenance cost:As the Polytransformer can take the placeof different transformers, your total fleetof transformers will be reduced, with thesubsequent reduction of inventory,investments and maintenance costs.

450 MVA, 400 kVPolytransformer in service

with 400 kV / 230 kVconnection.

Do you need a Polytransformerin your network?

In ABB we can help you answer this question. Our proposal consists of three well differentiated steps:

• The first step is a technical and economicalstudy of your fleet of transformers to becarried out in a collaborative way between yourpersonnel and ABB. Our team of experts inABB will outline this study considering theelectrical characteristics of your network,shipping limitations of railways and roads, sizelimitations in your substations, your standardsrelated to equipment and control (type,location, etc.), logistics, timing available fordisassembling, transportation and installation,etc. From this study, several scenarios will beanalyzed, to maximize network coverage andminimize investments.

• Second: ABB will design and manufacture thepolytransformer that fits to your needs.

• And third, your local ABB Service will provideall necessary support for disassembling former equipment,transportation, assembling, installation andcommissioning, including voltage adjustment, oil treatment, tap changer control adjustment,etc., every time you need to move yourPolytransformer.

The result will be a polytransformer that fits anywhere in your network and will be ready to replace other criticaltransformer in a record time

Polytransformer during design process.


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A shell form design for the Polytransformer.

The optimal technical solution for the Polytransformer’s special requirements is the Shell Form concept.

There are several reasons supporting this selection:

The flexibility of winding arrangement andthe easy procedure to provide different tapconnections inherent to a shell form transformerdesign, allows multi-voltage combinations for high,low and tertiary.

The intrinsic mechanical robustness of shell formwithstands transportation and hauling loads.The Polytransformer is designed to be movedand hauled to fit into different substations.

The compact dimensions of shell form.This aspect is critical in the case of thePolytransformer to comply with transportationrestrictions.

The intrinsic flexibility of the shell form design to match existing impedances. Configuration of shell form windings allows the designer to reachpractically any level of short circuit impedancewithout adding any complexity to the construction.In a close range of impedances, parallelconnectivity can be achieved by automaticallysetting the appropriate tap in the on-load tapchanger.

A Real Case: 450 MVA, 400 kV three phase Polytransformer.

A large utility had the need of some spare transformers to be used in case of emergency in some critical

substations. Minimum objectives and requirements were: a three-phase spare unit with the maximum power

rating which could be transported easily and quickly. This would permit keeping a spare transformer readily

available for several substations.

• The utility provided ABB with the necessary information to reach anoptimum design which would fit with the maximum number of installedunits. A team of ABB experts reviewed this information and came back witha proposal that would meet these specifications, all in one singletransformer. According to this proposal, four units have been ordered up tonow with excellent results. At present some of these units are rented by theowner to other utilities.

Test Room.

The polytransformer wasdesigned as a three phase, shell form autotransformer,multivoltage 400/230, 400/138,400/110 kV, Max. power 450 MVA, with tertiary 33, 25, 4,24 kV, 50 Hz, Ynad11 connection,OFAF cooling and OLTCregulation at the neutral end (variable flux regulation)

Shell Transformer windingarrangement.

Connection diagram.



• The Polytransformer was designed to bemechanically and electrically compatiblewith other three phases transformers installedin the 400kV transmission system(up to six different designs co-existing).

• Cooling equipment was designed with oil-aircoolers to minimize the total space requiredfor installation.

• All the accessories incorporated in thisautotransformer are standard, compatiblewith accessories used in other transformersalready installed in the network, thus helpingmaintenance operations and availabilityof spare parts.

• When the Polytransformer needs to work inparallel with other units having differentregulating ranges, those have to be limited towork in the common part of the ranges. If thenumber of regulating positions is different, thetransformer could be equipped with aprogrammable PLC. This PLC can beprogrammed to control the load tap changerand to select the optimum position in everycase. It receives indication of the tap positionof the transformer to parallel. With thatinformation it selects the most suitable tapchanger position at the controlled unit and anorder is given to raise or lower the tap changerposition accordingly.

Control cabinet withprogrammable PLC.

Overview from tertiary side (oil-air coolers

in low voltage side). The polytransformer has been developed by ABB in the facility of Córdoba, Spain.

Córdoba plant.


ABB Power Technology, S.A.Escritor Conde Zamora, s/n14004 Córdoba - SpainTel.: +34 957 46 91 03 / 07Fax: +34 957 46 91 75

ABB Inc. Marketing4350 Semple Ave.St. Louis MO 63120 -USATel.: +1 314 679 4815Fax: +1 314 679 4810

www.abb.com/transformers

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We reserve the right to make technical changes ormodify the contents of this document without priornotice. With regard to purchase orders, the agreedparticulars shall prevail.

ABB does not accept any responsibility whatsoeverfor potential errors or possible lack of information inthis document.

We reserve all rights in this document and in thesubject matter and illustrations contained therein.Any reproduction - in whole or in parts - is forbiddenwithout ABB´s prior written consent.

International patent pending.


Brochure Polytransformer.qxd 29/3/05 16:32 ... - ABB …FILE/Brochure+Polytransformer.pdf · Power Transformer Brochure ... Brochure Polytransformer.qxd 29/3/05 16:32 Página 10.

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