Increasing Transformer Reliability by Smart Bushing

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  • Increasing Transformer Reliability by SMART Bushing

  • OVERVIEW TECHNOLOGIES

    Types RBP OIP RIP RIS RIF

    Insulation Srbp Paper+Oil Paper+Epoxy Synth+Epoxy Glass+Epoxy

    Tan 0.7 0.4 0.4 0.35 0.3

    Pressure Nil Yes Nil Nil Nil

    Life 25 40 40 50 50

    Population 8 % 80 % 10 % 1 1

    PD high

  • FAILURE ANALYSISEUROPE

    45%

    7%

    1%

    17%

    3%

    26%

    1%

    Windings

    Lead exit

    Insulation

    Bushing

    Core

    Tapchanger

    Others

    50% >400kV

    RD2

  • Slide 3

    RD2 Ramachandran Damodaran, 05-08-2016

  • ROOT CAUSE ANALYSIS

    80% leakage (OIP Bushings )

    13% deterioration of insulation

    7% mechanical damage (mainly

    porcelain insulators)

  • WEAK LINKS

    Water accumu

    late

    High RPN

  • Summary of IMPROVEMENTSBY PROBLEM SOLVING + FMEA

    LOWEST RPN ON SEALING- ALL JOINTS UNDEROIL

    LOWEST RPN ON CONDUCTOR- CASTINGS WELDING

    RISK REDUCED AT TOP CONNECTION- 3 NOS TAPPED HOLES

    HEAT SINK FOR HOTSPOT- SOILD TOP TERMINAL

    CURRENT SHARE EQUALLY- PLANETARY + SINGLE PIECE

    ELCTROPLATING DEFECTS- ELECTROLESS

    We understand and We care

  • SOME CASE STUDIES

    NO WELDING better conductance

    INTEGRAL terminal thermal performance

    ElectrolessNickel

  • SOME CASE STUDIES

    JOINTS ABV OIL LVL

  • SOME CASE STUDIES

    JOINTS ABV OIL LVL

  • AGEING of BUSHING

    High ambient temperatures & temperature changes

    High & frequent load cycles (e.g. pump storage power plants)

    Overvoltage/transients (switching, lightning, harmonics)

    Leakage moisture ingress

    Oil leakage (OIP only) loss of insulation/dielectric properties

    Corrosive contaminants in oil (for OIP only)

    Capillary cracks (RBP types)

    Partial discharges

  • SMART PLANS

    Step 1: Identify & Clustering Bushing Fleet

    Voltage level

    Current level

    Technology

    Age

    Type of transformer

    Importance of substation

  • SMART PLANS

    Step 2: Risk Assessment of Installed Bushing Fleet

    Based on Age

    Site Measurements

    - Tandelta + Capacitance

    - thermography

    - Dissolved Gas Analysis-oil sampling

    - Partial Discharge limited by background noice

    < 1% OK1`2%..??>2%..ICU

  • Step 3: Definition of Bushing Style to Replace Installed Fleet

    Step 4: Set Up Risk-Based Replacement Schedule

    Step 5: Execution of Bushing Fleet Replacement Strategy

  • THANK YOU

  • OIL + PAPER INSULATION

    Oil Impregnated Paper (OIP)

    Century Old Proven need Long Process time

    Need Monitoring of oil level + Quality

    Moisture settles down at most stressed part

    Failure may lead to a devastating fire

  • RIP IS POPULARMANY

    APPLICATIONS

  • RESIN + PAPERRESIN + PAPERRESIN + PAPERRESIN + PAPER

    Dry type Resin Impregnated Paper (RIP)

    A big relief against the nuance of oil

    But RESIN do not marry PAPER well

    Long Process time to remove water from paper

    SLOW Impregnation of RESIN to Paper

    PAPER absorb moisture STORAGE in store

    RIP is BETTER than OIP but not the BEST

    being fully dry and pressure-free;

    featuring a higher temperature class;

    being partial-discharge free;

    having low dielectric losses;

    being fire resistant, and;

    having outstanding mechanical properties

  • SEARCH FOR Alternative to RIP..

    ABBMICAFIL

  • RESIN INFUSED GLASS

    Most proven FRP system Resin Infused Glass widely

    accepted from Boat to Aircraft

    Superb Electrical and Mechanical properties

    Popular for Polymer INSULATORS, Wind Mill etc..

    Factory tested values retain life Long

    P.Keith Ellis ..IEEE ex.chairman

    .seen many failures of RIP leading fireif you need a safer bushing for transformerlook in to fiberglass impregnated Glass.

  • RESIN +GLASS

    Safer, no risk of fire and explosion.

    Totally maintenance-free, low cost of ownership.

    Superior resistance to mechanical and thermal stresses.

    Environmentally friendly no risk of toxic leakage.

    Sealed and impervious to water and pollution.

    Real time tracking for unmatched peace of mind.

  • MGCPCORE

    TRENCH

  • BETTER with POLYMER HOUSING

  • TRANSFORMER BUSHINGSTRANSFORMER BUSHINGSTRANSFORMER BUSHINGSTRANSFORMER BUSHINGS

    No Grading

    with Grading