New EasyDry® transformer bushings Holger Hoffmann, Area Sales Manager MICAFIL Bushings, Johannesburg, May 2013

The paper-free solution

© ABB Group May 8/ 9, 2013 | Slide 2

Transformer condenser bushings

ABB recognized customer needs for a new bushing technology that would…

…preserve the safety and performance benefits of the traditional RIP bushings

oil-free and fully dry explosion proof and fire resistant high thermal strength, temperature class 120°C low dielectric losses partial discharge free excellent mechanical strength transportation, storage and assembly at any angle practically maintenance free

Why a new technology?

© ABB Group May 8/ 9, 2013 | Slide 3

Transformer condenser bushings

…while providing new customer benefits like

significantly easier and more economic long-term storage

easier and simpler bushing handling during transport, assembly and disassembly

shorter purchasing cycles optimised value for money less capital bound for maintenance of strategic

reserve/ stock

Why a new technology?

© ABB Group May 8/ 9, 2013 | Slide 4

Transformer condenser bushings

ABB utilized our vast experience in high voltage technology Corporate Research Centers in:

Switzerland, Sweden, Poland, India Bushing production expertise in:

Switzerland, Sweden, USA and Brazil Cutting-edge simulation tools for epoxy and silicone

molding process optimization Design for assembly methodology and production process

optimization (single piece flow)

How did ABB develop the new technology?

© ABB Group May 8/ 9, 2013 | Slide 5

Transformer condenser bushings

The new bushing technology is called

Resin Impregnated Synthetics (RIS)

The bushing product family is called EasyDry ®

How the new bushing technology is named?

© ABB Group May 8/ 9, 2013 | Slide 6

Transformer condenser bushings

RIS Field grading: Al-foils Insulation material: Filled epoxy resin Spacer material: Synthetic fabric

RIP Field grading: Al-foils Insulation material: Epoxy impregnated paper Spacer material: Paper

RBP Field grading: Al-foils Insulation material: Epoxy coated paper Spacer material: Paper

OIP Field grading: Al-foils/conductive ink Insulation material: Oil impregnated paper Spacer material: Paper

RIS Technology – the next step in bushing technology!

© ABB Group May 8/ 9, 2013 | Slide 7

RIS Condenser bushing

Compact and light bushing design Completely free of oil and paper Avoidance of moisture absorption Elimination of external insulator

components and filler material Superior mechanical, thermal and

electrical properties Same field grading as with RIP

bushings

What is the technical achievement?

© ABB Group May 8/ 9, 2013 | Slide 8

RIS Condenser bushings

Condenser core is wound out of synthetic fabrics

Al-foils used as condenser layers inside the wound core

Condenser core is impregnated with filled epoxy resin and molded into final shape

Silicone sheds are molded directly onto the condenser core

Final assembly of shielding electrode etc.

Routine testing

What are the main manufacturing steps?

© ABB Group May 8/ 9, 2013 | Slide 9

RIS Condenser core materials

Synthetic fabric prevents condenser core from humidity uptake

Open structure of synthetic fabric allows to use filled epoxy resin for impregnation

Inorganic mineral fillers yield to excellent mechanical, electrical and thermal properties of the epoxy resin condenser core

Synthetic fibers and epoxy resin

© ABB Group May 8/ 9, 2013 | Slide 10

RIS Condenser core production

Condenser Core based on synthetic fibers is molded into final shape

Time intensive drying is not needed anymore

Mechanical shaping (milling) is not necessary

Humidity uptake is physically limited

Minimized manufacturing process steps

© ABB Group May 8/ 9, 2013 | Slide 11

RIS Technology

Humidity in condenser core increases dissipation factor

Stable dissipation factor means no humidity uptake

Used RIS materials have very low saturation level

Highest bushing safety and reliability in all climatic environments

Significant operational advantage no humidity uptake

0

0.5

1

1.5

2

2.5

3

0 50 100 150 200

RIS

RIP

Dissipation factor as function of storage time Dissipation factor [%]

Storage time [d]

Results for Test at 40°C / relative humidity of 95% Source: ABB Switzerland Ltd.

© ABB Group May 8/ 9, 2013 | Slide 12

RIS Technology outdoor silicon insulation

Silicone sheds are directly molded on condenser cores

Minimal number of interfaces between different materials

Lowest material consumption

Silicone molding process is done inhouse

Inhouse process control for entire bushing

Dependence on external suppliers is significantly reduced

Process long term proved for different ABB high voltage products

Directly molded on condenser core

© ABB Group May 8/ 9, 2013 | Slide 13

RIS Technology

1. Copper terminal

2. Clamp to fix terminal

3. Silicon outdoor insulator

4. Mounting flange

5. Measuring tap

6. Condenser core

7. Extension for current transformer

8. End shield

EasyDry® product family

5

3

2

1

8

4

7 6

© ABB Group May 8/ 9, 2013 | Slide 14

EasyDry® product family

Easy to use, maintenance free: Inspection free Transportation/ assembly/

storage at any angle No humidity uptake during

storage

Excellent thermal and electrical properties Partial discharge free up to

double service voltage High thermal endurance

(class E, 120°C) Low dielectric losses (tan δ <

0.35 %)

The easy way of bushing

© ABB Group May 8/ 9, 2013 | Slide 15

EasyDry® bushings

Classification: dry, fine capacitive graded,

paper free, resin molded bushing

Minimum ambient temperature: - 40 °C

(- 60 °C on request)

Altitude of installation: ≤1000 m

(1800 m on request)

Pollution level: very heavy (31 mm/ kV)

Mounting angle: vertical down to horizontal

Standards IEC 60137 (2008)

IEEE C57.19.00 and C57.19.01

Common specifications

© ABB Group May 8/ 9, 2013 | Slide 16

Application: oil insulated transformers Type designation: DMB-OA Rated voltage: 24 – 170 kV BIL: 150 – 750 kV Rated current: 800 – 3,150 A Conductor types: cable bolt, removable or fixed solid rod Outdoor insulator: silicone rubber

EasyDry® bushings Application and range

© ABB Group May 8/ 9, 2013 | Slide 17

RIS Technology – EasyDry® bushings

You will get a dry bushing which provides maximum safety and reliability at the highest technical characteristics

Long-term storage is significantly easier and more economic

Transport, assembly and disassembly easier and simpler

Purchasing cycles are much shorter Optimised value for money Less capital bound for maintenance of

strategic reserve or intermediate stock Lowest impact on environment during

manufacturing, operation and disposal

Customer benefits summary

© ABB Group May 8/ 9, 2013 | Slide 18

Questions and discussion

© ABB Group May 20, 2013 | Slide 19