Frankfurt (Germany), 6-9 June 2011 SINGH– US – Session 1 – 0952 Dry-type Transformer for Pole Mounted Application

Frankfurt (Germany), 6-9 June 2011 ABB dry-type transformers  Market and technology leader, providing three complementing technologies from 60 kVA to 63 MVA up to 72.5 kV and with on-load tap changer  More than 35 years experience  Proprietary technology and R&D departments RESIBLOC ® Vacuum cast coil Open wound

Frankfurt (Germany), 6-9 June 2011 Our value proposition – Dry Transformers Safety – reliability – low losses  Safety for people and property - no fire hazard or explosion risk  Hundred thousand-fold proven  Intrinsically environmental-safe New high-tech product line for ultra-efficient dry-type transformers: “EcoDry” New 72.5 kV voltage class dry-type transformer for ultimate safety New IP00 pole mount dry-type transformer PoleDry for avoiding soil contamination and copper theft -

Frankfurt (Germany), 6-9 June 2011 Dry pole mount transformer The motivation for the development  Risks for oil leakage, theft and related soil contamination  Not attractive for copper theft  Safety for people and environment  Suitable for water and environment protection areas  Compact transformer, with comparable dimension and weight as oil-filled Pole mounts

Frankfurt (Germany), 6-9 June 2011 Dry-type IP00 pole mount 100kVA / 15 kV  VCC coils, realized with cycloaliphatic epoxy for outdoor applications  Solid insulation between HV and LV  Integrated bushings and off-load taps  Stacked core with corrosion protection  Used advanced simulation tools to realize dielectric design Integrated bushings mould design Advanced dielectric simulations

Frankfurt (Germany), 6-9 June 2011 Testing- Routine Dielectric Results Dimensions (LxWxH): mm 1200 x 613 x 1198 Lightning impulse/ AC 95kV Passed AC Withstand 38kV Passed Sound power level53 dB(A) PD-level 130% nominal voltage) <10 pC (after pre-stressing to 200%) Temperature rise+45°C (25°C ambient) NEW !

Frankfurt (Germany), 6-9 June 2011 Core corrosion resistance  All structural steel part are made of stainless steel or Aluminum with no welding joint.  1000 hrs. of corrosion test for magnetic steel (stacked core samples)  Standards used DY991 and DY2101 Stacked core samples after 1000hrs. of salt fog testing (a) reference, uncoated sample (b) successful, coated sample. (a) (b)

Frankfurt (Germany), 6-9 June 2011 Testing- Accelerated Aging- Salt fog Chamber Test Voltage [U/Uo, kVrms] [Uo=8.7 kVrms] Total Ageing Time [Hours]

Frankfurt (Germany), 6-9 June 2011 Testing- Outdoor- KIPTS  The installation is placed around 30 m from the Atlantic Ocean in Western Cape of South Africa  Almost one year of energized PoleDry transformer confirmed robustness of materials and design Energized Dry Pole mount transformer in South Africa

Frankfurt (Germany), 6-9 June 2011 Conclusions  Dry-type transformer for pole mount application without enclosure  Increases safety and avoids oil or copper theft  Complies with IEC  Solid insulation between HV and LV, cycloaliphatic outdoor epoxy  Corrosion resistant coating for core  Dielectric simulations confirm the internal and external design  Lab and outdoor testing show superior performance under extreme environments 3D-drawing showing single pole installation (from HV side) of PoleDry with HV- Delta connection.