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in situ-GRIP®

This special program is a complete and comprehensive rotor in situ generator assessment. Minimal disassembly of the generator is required; thus, the generator never becomes the critical path of the outage unless an outage is planned specifically to address major maintenance on the generator.

Features:

  • Turbine Generator Stator (TGS) Visual and Borescope Inspection (as accessible):
    • TGS Frame (for indications of arcing, oxidation, weld cracks, and other evidence of accelerated aging or damage).
    • TGS Connection Ring Assembly (for indications of mechanical dusting or greasing, loose or missing blocks, corona activity, and other evidence of accelerated aging or damage).
    • TGS End Windings (for indications of contamination, mechanical dusting or greasing, loose or missing blocks, corona activity, and other evidence of accelerated aging or damage).
    • TGS Core Iron (for indications of “fretting”, movement of core bolts, lamination looseness, or any other evidence of accelerated aging or damage).
    • TGS Slot Wedge System (for indications of mechanical dusting or greasing, loose and migrating wedges and/or slot fillers, or any other evidence of accelerated aging or damage).

 

  • Turbine Generator Stator (TGS) Electrical Testing:
    • Armature Winding Copper Resistance Measurements.
    • Armature Winding Insulation Resistance Testing.
    • Armature Winding Polarization Index Testing.
    • Armature Winding DC High Voltage Testing:
      • Stepped Voltage Testing.
      • Maintenance Proof Testing (test voltage to be determined by findings of low voltage testing and approved by customer).
    • Power Factor Dissipation and Tip-Up Testing with corona camera examination.
    • Electromagnetic Core Imperfection Detection (El CID) Testing utilizing the ARGIS robot and an IRIS Power EVOLUTION™).
    • Wedge Tightness Mapping (utilizing the ARGIS robot and an IRIS Power SWA™).
    • Stator Slot RTD Resistance Measurement.
    • Stator Slot RTD Insulation Resistance Testing.

 

  • Turbine Generator Rotor (TGR) Visual and Borescope Inspection (as accessible):
    • Retaining Rings (for indications of surface pitting, oxidation, and/or cracks, movement or fretting against fits, electrical arcing, or any other evidence of accelerated aging or damage).
    • Main Field End Windings (for indications of contamination, copper elongation, deformation, or cracking, migration or turn or ground insulation components, or any other evidence of accelerated aging or damage).
    • Rotor Body Wedges (for indications of looseness and/or fretting, electrical arcing, or any other evidence of accelerated aging or damage).
    • Rotor Body Forging (for indications of cracking, arcing, overheating, or any other evidence of accelerated aging or damage).

 

  • Turbine Generator Rotor (TGR) Electrical Testing:
    • Main Field Winding Copper Resistance Measurement.
    • Main Field Winding Insulation Resistance Testing.
    • Main Field Winding Polarization Index Testing.
    • Main Field Winding AC Impedance Testing.
    • Main Field Winding AC Pole Drop Testing (as accessible).
    • Main Field Winding Recurrent Surge Oscillograph (RSO) Testing.

 

  • Turbine Generator Exciter Visual and Borescope Inspection (as accessible):
    • Exciter Windings (for indications of contamination, armature band condition, overheating, or any other evidence of accelerated aging or damage).
    • Collector Ring Assembly or Brushless Exciter Assembly (for indications of contamination, looseness and/or fretting, arcing and/or burning, excessive wear, or any other evidence of accelerated aging or damage).
    • Brush assembly (for indications of contamination, worn insulators, carbon brush condition, or any other evidence of accelerated aging or damage).

 

  • Turbine Generator Exciter Electrical Testing:
    • Brushless Exciter Armature Insulation Resistance Testing.
    • Brushless Exciter Stationary Field Insulation Resistance Testing.

 

Benefits:

  • Reveals partial discharge activity and deterioration in windings, blocking and stator wedge tightness condition, which would be otherwise obstructed with the rotor-in.
  • Record of stator core lamination condition.
  • Record of rotor retaining ring, wedge and rotor body condition.
  • Essential documentation to establish a trend report to monitor future deterioration.
  • Turn-Key and Field Based.
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