Treatment of both liquid and solid

insulation in the same process On Load process while power

transformer is energized Long lasting insulation characteristics Guaranteed results at least one year

after treatment Power transformer lifetime extension Non-Invasive technology Environmentally friendly No oil overheating No oil vacuuming Low pressure oil circulation

VIMAP R2000 ON LOAD ON LOAD REVITALIZATION OF POWER TRANSFORMERS INSULATION SYSTEM

Revitalization of Oil-Paper Insulation System

Regeneration of Insulation Oil

Dehydration of Oil-Paper Insulation

Dehydration of Insulation Oil

................ VIMAP R2000 ON LOAD

................

GUARANTEED INSULATION CHARACTERISTCS AFTER TREATMENT AND WITHIN WARANTY PERIOD OF MIN. 12 MONTHS

Depending on the condition of the insulation condition and customer demands, it is usually guaranteed that the characteristics of insulating oil after 12 months will be within the limits defined by the specification of IEC 60422, Table 3 (new oil in the new transformer, before energizing).

RECOMMENDED LIMITS FOR MINERAL INSULATING OILS AFTER INITIAL FILLING OF ELECTRIC EQUIPMENT, BEFORE ENERGIZATION- IEC 60442:2005, TABLE 3.

TEST

LIMITS

VOLTAGE (HV), kV

< 72.5 72.5 do 170 > 170

Breakdown Voltage (kV/cm) > 220 > 260 > 260

Water Content (mg/g) < 20 < 10 < 10

Neutralisation Number (mgKOH/g) < 0.03 < 0.03 < 0.03

Interfacial Tension (mN/m) > 35 > 35 > 35

Dielectric Disipation Number - tgδ < 0.015 < 0.015 < 0.010

Oxidation Stability According IEC60296 (for unused oils)

Particles (ISO 4406) - - 9/6 to 10/7

VIMAP R2000 ON LOAD Revitalization of oil-paper insulating system

Revitalization of power transformer insulation includes the following: PHYSICAL-CHEMICAL REGENERATION OF INSULATING OIL

Reclamation/ restoration of all insulating oil characteristics DEPTH PURFICATION AND DEHYDRATION OF SOLID INSULATION

Water and all ageing products are polar compounds and are adsorbed by VIMAP adsorbents. Phenomenon of diffusion is used to ensure depth purification and drying of solid insulation. By constant removal of all polar compounds from insulating oil, non-equilibrium between solid and liquid insulation is maintained. It ensures migration of polar compounds from cellulose to oil. Constant maintenance of this non-equilibrium by purification and drying of insulating oil ensure migration of polar compounds from solid to liquid insulation, i.e. provide depth purification and drying of solid insulation.

VIMAP R2000 On-load Revitalization

400/121/22 kV, 250 MVA, Bacau Sud, Romanian power grid company, 2010

tg δ of total insulation Insulation resistance Water content in solid

insulation

tg δ of insulating oil Neutralization/Acid number Interfacial tension Dielectric strength Water content in insulating oil Particles

Regenerated oil as good as unused

VIMAP R2000 adsorption columns

Remain adsorbed: - Oxidation products - Water

Extracting from oil-cellulose insulation: - Oxidation products - Water

Polar compounds migrate from cellulose to oilat

Adsorption of polar compounds

from insluating oil

VIMAP R2000 ON LOAD ................

................

Criteria which define right moment for insulation revitalization

Revitalization at appropriate time insures maximum power transformer lifetime increase and its reliability on the network. Since cellulose depolimerization is irreversible process, late revitalization has limited results. Depending on the moment when revitalization is done, power transformer lifetime could be prolonged from 10 to 25 years.

Based on our experience and according to IEC, IEEE and other international regulations and standards, following insulation characteristics border values are recommended when revitalization should take place.

CHARACTERISTIC UNIT VOLTAGE (LV)

≤ 72.5 72.5-170 170-400 ≥ 400

Water content in solid insulation (20°C) % Max. 2.5 2.5 2.0 2.0

Water content in oil (20°C) ppm Max. 15 15 15 10

Dielectric Strength kV/cm Min. 200 200 200 220

Total Neutralization (acid ) number (TAN) mgKOH/g Max. 0.15 0.10 0.10 0.10

Interfacial Tension (IT) mN/m Min. 25 25 30 32

Dielectric dissipation number (tgδ) 90°C x 10-3

Max. 60 60 60 60

IT/TAN - Min. 166 250 300 320

Degree of cellulose polimerisation (DP) - Min. 600 600 600 600

Year change DP (Δ DP) * - 50 50 40 30

Our Technology

VIMAP Technology is based on use of synthetic adsorbents which main characteristic is high capacity in adsorption of all polar molecules, which occur as a result of oil and cellulose degradation process.

Granulated synthetic adsorbents attract water, acids, peroxides, furans, furaldehydes, ketones etc. and permanently hold them on active surface in their pores.

Operation principle is very simple- insulating oil continually circulates from power transformers through columns with synthetic adsorbent where polar molecules are trapped.

Unlike other technologies that are very demanding and require oil vacuuming and oil overheating, our technology allows us to perform treatment while transformer is energized, because none special condition is required,

Because of that our equipment can be used for the purpose of preventive maintenance, which is achieved by continuous on-load treatment of insulation oil.

Saturated adsorbents can be reactivated hundreds of times till full oxidation, in the REACT2000 process, resulting in in only two combustion products- CO2 and H2O, which are harmless for environment.

Since all VIMAP processes of oil and paper insulation system treatments as described above are free of exhaust gases therefore we can conclude that VIMAP technology is virtual 100% clean in complete, making it environmentally most friendly of all technologies available nowadays.

Modular configuration of columns with adsorbents is enabled in order to optimize the size of our machinery and reaction speed of adsorbent with oil and to rationalize adsorbent change intervals.

ADVANTAGES OF VIMAP R2000 TECHNOLOGY

COMPARING TO OIL REPLACEMENT

No new oil required Ressource friendly Depth cellulose insulation purification Depth cellulose dehydration Long term stability of revitalized oil Transformer continuously filled with oil Transformer continuously in operation Simple equipment connection No waste oil Cleaning of active part Long period gurantees on achieved results

COMPARING WITH CLASSIC TREATMENTS AND FACTORY REPAIR

(oil spray, thermo-vacuum, natural adsorbents):

On Load operation Non-invasive process No oil overheating No power transformer vacuuming Long lasting results Extension of power transformer lifetime Increased power transformer reliability on the network Simplicity in operation Environmentaly friendly technology No disposal of waste oil Long period gurantees on achieved results

................ VIMAP R2000 ON LOAD

................

0

100

200

300

400

500

600

700800

900

1000

0 10 20 30 40 50

Non-Revitalized Insulation Aging

Revitalized Insulation Aging

Deg

ree

of D

e-Po

limer

izat

ion

(DP)

Transformer Lifetime (Years)

Revitalization

Lifetime Extention

DP valued of 150-200 indicates end of transformer lifetime

Source: ABB

- POWER TRANSFORMER LIFETIME EXTENTION

- INCREASED OPERATION RELIABILITY ON THE NETWORK

VIMAP D.O.O. Brace Jerkovic 137, 11000 Belgrade, Serbia

tel.: +381 63 257853, fax: +381 11 24 69 724 office@vimap-technics.com, www.vimap-technics.com

SLOWING DOWN CELLULOSE

AGEING

TOTAL INSULATION

REVITALIZATION

Power Transformer Lifetime is Defined by the Lifetime of Cellulose

Power transformer lifetime could be extended for more than 15 years depending on treatment timing

Differences Between Transformer Insulation System Treatments

Derived technologies from VIMAP R2000:

VIMAP OREG2000 Regeneration of Insulating Oil

VIMAP IDEH2000 Dehydration of Oil-Cellulose Insulating System

VIMAP ODEH2000

Dehydration of Insulating Oil

Technology Transfer We offer complete transfer of our technology, products and ’’know-how’’

Our products:

VIMAP PORTABLE Device for dehydration of insulating oil

VIMAP IDEH PORTABLE Device for on-load dehydration of oil-cellulose insualting system

VIMAP RCIM

Equipment for continual revitalization of oil-cellulose insulating system

VIMAP RCID

Equipment for continual dehydration of oil-cellulose insulating system VIMAP VRA2000

Mobile plant for reactivation of synthetic adsorbents

SYNTHETIC ADSORBENTS

Dehydration of Insulation Oil

It is the most basic treatment of transformers and it includes removal of water from oil only. Problem with this process is that results achieved do not last for long time. Since more than 95% of water in power transformer is located in cellulose, soon after oil dehydration is finished water from cellulose starts to migrate back to the oil, resulting in the same water content in oil few months later as it was before.

Dehydration of Oil-Paper Insulation System

This process includes dehydration of both oil and cellulose. Results after treatment remain for a long time in terms of water content but other aging products in oil-cellulose insulation system remain unaffected. Problem is that it takes much more time to dehydrate cellulose then oil. Therefore many invasive and complicated technologies are not suitable for this treatment as they often require long lasting transformer shutdown which is not acceptable for transformers owners. Synthetic adsorbent based technologies permit on-load treatments while the transformer is in operation.

Regeneration of Insulation Oil

This process consists of removal of all oxidation products from the oil. The same as insulation oil dehydration results of this process are temporary because soon after oil regeneration, water and oxidation products (polar molecules) start to migrate from cellulose back to the oil. Insulating oil regeneration can be performed by synthetic adsorbents only or in combination of natural adsorbents with some other dehydration technology.

Revitalization of Oil-Paper Insulation System

This is the most complex process of all others and includes water and all polar compound removal from oil-paper insulating system. Process consists of oil dehydration and regeneration and at the same time cellulose dehydration and depth purification. Only after this treatment it is possible to give guarantees for achieved results for a few years and to significantly prolong power transformer lifetime. After such treatment oil quality should be acc. to IEC 60422, table 3. (recommended limits for mineral insulating oils after initial filling of electric equipment, before energizing).