Abb Large Power Transformer Catalogue 691045

POWER TRANSFORMERS

ABB ELEKTR‹K SANAY‹ A.fi.

ABB worldwide ABB is an electrical engineering company with global operations in approximately 1000 companies, with more than 200,000 employees all araund the world. The ABB worldwide group operation is concentrated into five business segments: • Power Plants • Power Transmission and Distrubition • Industrial and Building Systems • Transportation • Financial Services These five business segments are in turn divided into 45 business areas, each responsible for global strategies, business plans and product development. A global group of this scope offers advantages of scale in basic research, product development, low-cost manufacturing and management expertise. Yet in each country, ABB operations are local and flexible. The art of being local worldwide, having technological leadership, customer focus and commitment to sustainable growth, has placed ABB in the forefront in meeting it’s short and long term objectives. ABB Turkey ABB has been active in Turkey since 1969, in the fields of hydro and thermal power generation, power transmission and distribution, rotating machines and drive systems, rail transportation, and automation of industrial processes for Turkish industries. ABB Elektrik Sanayi A.fi. ABB Elektrik Sanayi A.fi. is located in the Kartal area on the Asian side of ‹stanbul. The main activites at the Kartal factory are: • Power Transformer production • Distribution Transformer production • Transformer Service Power transformer production at ABB Elektrik Sanayi A.fi. is one of 25 production facilities in the ABB Business Area, Power Transformers. • LV s are manufactured at Dudullu factory.

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INTRODUCTION

ABB Elektrik Sanayi A.fi. has been producing power transformers since 1969 at the Kartal Factory. During this time, ABB has been able to meet the increased rating demands and fulfill customer requirements. Power transformers from 5 MVA up to 400 MVA and 400 kV, are produced at the Kartal factory. More than half of the power transformer production is exported.

160 MVA 15.75/162 kV Step-up transformer

50 MVA 132/69/13.8 kV Autotrasformer

250 MVA 380 / 158 kV Autotransformer

40 MVA 150 ± 8 x 1.25 % / 10 ± 2 x 2.5 % kV transformer

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DESIGN

Transformers are custom made, using standardized elements and components. Computers with very well developed systems have taken over all the design and production routines. These systems and procedures are based on the acquired know-how as well as the latest findings from both Research and Development and the experience gained during production.

The specifications and individual requirements of the customer are the starting points for the design and production of each transformer. We combine the customer’s requirements with a high level of quality in the following design and production philosophy. Highly standardized working methods are applied throughout the whole product range.

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CORE

The core is built up by means of stepped sheets to form circular core cross section and 45° mitred ts at the corners. The state of the art step-lap technique is also used for further reductions on core losses and noise level. Flat and thin insulation of the electrical steel sheet makes it possible to improve the space factor with substantial improvement in losses and other no-load parameters.

Tranformer cores are manuf›actured from cold rolled grain oriented and silicon alloyed carbonless electrical steel. Super-oriented and laser treated super-oriented steels are also used in order to fulfill the customer’s low-loss and reduced noise level requirements. Core form is the general comcept for our transformers. A boltless, sophisticated core design minimizes eddy current losses and gives thermal and mechanical stability as well as low vibration and low sound level.

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are kept under pressure by flitch plates for larger cores and by tie-bolts for smaller ones. To prevent movement of core sheets during manufacture and transport, special side-s are placed at each corner.

Yoke plates are firmly pressed between core clamps to achieve the required friction forces in the corner ts. The lamination of large cores is held together by means of a semiconductive ASECOND fiberglass tape which has been wound under tension and cured to form a cylinder. For smaller cores, an epoxy-cementing technique is used. The windings

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WINDINGS

winding has a great advantage to increase series capacitances and consequently to obtain uniform transient overvoltage distribution on the winding. Helical type windings are used for most low-voltage windigs. Each turn consists of a group of conductors which are continuously transposed to reduce eddy losses.

Windings are designed to meet relevant standards and specifications in respect to short-circuit strength, temperature-rise and insulation requirements. The conductor material is paper covered high quality electrolytic copper. ›n the case where there are many strands in the conductor bunch, continuously transposed cable can be used as a winding conductor. Disc winding is used for high voltage winding. For higher voltages the interleaved form of the disc

Regulating winding is a helical type of winding and designed in such a way that each tap winding segment is evenly distributed over the entire length of the main windigs. By using such windings, the ampere-turn distribution provides an electromagnetic balance regardless of the selected tapping position. In order to reduce the leakage flux losses shunt blocks are placed on the top and bottom sides of the complete limb windig set and/or inside the tank surface.

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Winding Insulation:

Winding Production:

All the insulation materials used in the winding to form the required insulation and oil cooling ducts within the winding, are made of high quality electrical pressboard intended for use in transformers. The insulation, between the windings and between the winding to the core is of the oil-pressboard barrier system. The dielectric strength of this system is decisively better than the oil duct system with the same distance.

Specific and modern machinery and tooling is used for accurate and precise production of windings. After the winding operation is completed, the windings are dried out in the insulating material. The dried windings are compressed and height adjusted under compression. These processes will increase the dielectric withstanding capability of the insulation material and make the windings more stable and stronger against short-circuit forces.

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ASSEMBLY

submitted to a recognized testing laboratory for quality checks. As the windings can take in moisture during the assembly process, a forther drying process is applied to the complete active part, and a final pressing operation is carried out on the windings. After putting the active part into the tank, filtered and degassed new oil is filled into the transformer under vacuum. Particle reduction by circulation and fine filtering of the oil increases the dielectrical withstand capability of internal insulation of the transformer.

The windings are assembled on the core in the assembly area, which is constantly maintained clean. All connections from the windigs to the tapchanger and bushings, are made by paper insulated cables and busbars, and those are braced by pressboard profiles to provide required insulation distances between the conductors and earth, and to make them stronger against short-circuit forces. The ts are made by high frequency brazing technology and carried out by trained personnel with brazing certification. In regular intervals, some ts are

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TANK

Oil sealing is provided by an O-ring nitril rubber gasket system. Nonmagnetic steel is used around the high current carrying bushings to reduce the eddy-current losses. The surface of the tank, cover and conservator are cleaned from rust and other impurities by gridblasting, with a surface quality of at least Sa 2.5 according to Swedish Standards. The inside of the tank is covered with oil resistant paint and the outer surfaces are painted with epoxy based two-component paints.

The tank, cover and conservator are manufactured of steel plate. The complete tank together with all flanged connection is capable of withstanding hydrostatic over pressure and full vacuum. Double welding is used where the oil tightness is required. The weldings are made by qualified welders with welding certification. All the weldings are checked with a penetrant liquid and with the x-rays when necessary.

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MAIN ACCESSORIES

ON-LOAD TAP-CHANGERS

DE-ENERGIZED TAP-CHANGERS

In most of the transformers on-load tap-changers (OLTC) are used. Available types of on-load tapchangers are in-tank type, which can be built in the transformer tank and out-of-tank type, which can be installed on one side of the transformer tank. The diverter switch of the on-load tap-changer is in a separate oil compartment. The on-load tap-changer is operated by means of a motor-drive mechanism.

De-energized tap-changers are used in most of the step-up transformers and, upon customers request, in some of the step-down transformers. BUSHINGS

The bushings for voltages below 52 kV and for currents below 4500A are normally made of porcelain. For higher voltages and higher currents oil impregnated condenser type bushings which are partial discharge free up to test voltage are used. The long creepage distance requirements can be met by the shed form of anti-fog type.

Some important features of on-load tap-changers: • High-speed transition resistor type • Very short arcing time • life will be the same as the economical life of the transformer with normal operation frequency • Minimum maintenance 11

COOLING EQUIPMENT Cooling class ONAN/ONAF (OA/FA)

• Vacuum proof radiators • Shut-off valves are provided on the connection between the radiator and the transformer tank. • At ONAF (FA) cooling, the forced air stream is produced by fans with low noise level. Cooling class OFAF (FOA)

• The heat exchangers with the fans. • The oil pump is driven by a totally oil immersed motor Cooling class OFWF (FOW)

• Tube and plate heat exchangers are used • To prevent any contamination of the oil by water and/or outside moisture, each cooler is made with leakage protection, double wall or double tube.

OIL PRESERVATION SYSTEM

OIL

For large transformers and upon customers request for medium-size transformers, the conservator is provided with a rubber sack. Normally, an open conservator system is used for small and mediumsize transformers. In case of high contamination and/or high humidity at the site, the transformers are equipped with rubber sacks.

The oil used in the transformers fulfills the requirements of IEC 296.

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STANDART SUPERVISORY AND CONTROL EQUIPMENT

• Control cabinet containing ors and protective devices for cooling equipment and/or terminal blocks for the supervisory and control equipment. • Top oil temperature-indicator with up to four isolated and separately adjustable electrical s and a sensor placed in an oiltight pocket on the cover. • Winding temperature indicator (thermal image) with up to four adjustable electrical s.

• Pressure relief device with electrical .

• Gas operated relay is normally located on the pipe connection from transformer tank to conservator. The shut-off valves are placed on both sides of the relay. The relay has electrical s for gas collection and/or sudden oil rush from transformer tank to conservator.

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• Oil level indicator with electrical s for too low and too high oil levels.

• Valves for filling, draining, filtering and sampling of the oil.

• Dehydrating breather

• Pressure relay for tap changer • Bi-directional wheels, flat base or skids.

SUPERVISORY AND CONTROL EQUIPMENT (UPON REQUEST)

Following accessories can be supplied upon request. • Automatic voltage regulation • Equipment for parallel operation of on-load tap-changers • Current transformers • Cable boxes • Remote indication of instruments • Transmitter for remote temperature indication • Transmitter for remote tap-position indicator • Surge arresters mounted on a bracket placed on the transformer tank • Protective capacitors with ing brackets placed on the tank

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TESTING

All of our transformers are tested to they have been designed and constructed to withstand conditions stipulated by international and national standards.

The following routine tests are performed on the transformers in accordance with IEC and other national standards: • Winding resistance • Voltage ratio and check of phase vector relationship • Measurement of load losses and impedance voltages • Measurement of no-load losses and noload current • Dielectric routine tests • Tests on on-load tap-changers, where appropriate • Measurement of insulation resistance • Measurement of capacity and tangent of insulation loss angle. The type and special tests which are porformed on request are as below: • Temperature-rise test • Lightning impulse test • Switching impulse test • Induced over-voltage test with partial discharge measurements • Measurement of zero-sequence impedance • Measurement of acoustic sound level • Measurement of the power taken by the fan and oil pump motors

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TRANSPORTATION AND INSTALLATION

Upon request, a transformer can be transported from the factory to the installation site. Before transport of the transformer, important parts and accessories, such as bushings, conservator, cooling equipment and other minor items are dismantled and properly packed, seaworthy packing when necessary. An impact recorder is placed on the main body of the transformer for overseas transportation, upon customer request. The main body, for large and some medium-size transformers, is transported without oil and filled with dry nitrogen. The transformer oil is transported in specially treated drums. Transport and erection activites, depending on the weight and size of the transformers, are carefully planned and executed by highly qualified personnel.

Our skilled engineers and technicians carefully prepare the transformer for service operations at the installation site. All the dismantled parts and accessories are reassembled during erection. The dry nitrogen, which has been filled for transport, is sucked out, and the filtered and degassed new oil is filled in to the transformer under vacuum. A final on-site test is performed to ensure a long and troublefree operation of the transformer. Upon request, regular inspection and maintenance of the transformer can be done by our service specialists on site. Oil sample can also be taken by our service staff and chromatographic gas analysis dissolved in the oil is done to check the condition of the transformer. On service and transformer mainetance, training of the customer’s personnel can be carried out at our factory or at any site in accordance with customer requiremets.

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RESEARCH AND DEVELOPMENT

Concentrated points in research and development activities are advanced insulation systems, loss reduction, more compact transformer design and increased efficiency. To reach these goals, we benefit mainly from ABB BA Power Transformers Research and Development Center and the other research centers and laboratories within and outside ABB. Some research projects are also executed in cooperation with qualified universities. Theoretical aspects of a transformer development project are carried out by experienced engineers who have expertise in their respective fields. Results are verified by running full scale testing in order to avoid extrapolation mistakes. The development of manufacturing techniques is also a part of research and development activities. The manufacturing technique which affects the quality and reliability of a transformer is carried out in close cooperation with design, production and development engineers.

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QUALITYASSURANCE SYSTEM

Our Quality Assurance system is based upon the procedures and instructions in force within the company, from marketing and sales to site service of delivered products. The quality assurance system of ABB Elektrik Sanayi A.fi. meets ISO 9001 requirements and was certified by internationally accredited certification bodies. Our ultimate quality goal is customer satisfaction. Our products must be in conformity with customer specification.

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Power Transformers Kartal Factory Esentepe Mh. Milangaz Cad. No:52 34870 Kartal-İstanbul/TÜRKİYE Telephone : +90 216 528 22 00 e-mail : [email protected] Telefax : +90 216 353 88 07 web : www.abb.com/tr +90 216 353 94 55

Tunç Matbaac›l›k A.fi. (0212) 637 18 31 Pbx - 06/2005

1ZTR974200-1 (E)

ABB Elektrik Sanayi A.fi.