ABB-LEAP for IM

LEAP - Life Expectancy Analysis Program

“For Electrical Rotating Machines”

Marcio GennariMarcio GennariABB BrazilABB BrazilAutomation ProductsAutomation ProductsMachines Service OsascoMachines Service Osasco

LEAP LEAP -- IntroductionIntroduction

�� ABB India (excellence center in insulation studies) with over 40ABB India (excellence center in insulation studies) with over 40 years of experience in years of experience in the field services and Manufacturing of Electrical Rotating Machthe field services and Manufacturing of Electrical Rotating Machines, have developed ines, have developed several innovative and patented tests and technologies for assesseveral innovative and patented tests and technologies for assessing the current sing the current physical condition of the machine. physical condition of the machine.

�� LEAP is a special LEAP is a special bouquet of electrical testsbouquet of electrical tests that is able to identify failure that is able to identify failure mechanisms in stator insulation system of Motors and Generators mechanisms in stator insulation system of Motors and Generators (AC / DC) therefore (AC / DC) therefore achieving the Maximum Operational Reliability.achieving the Maximum Operational Reliability.

-- Contamination / charge storageContamination / charge storage-- Coils / wedges loose in slotsCoils / wedges loose in slots-- Voids within main insulationVoids within main insulation-- Partial DischargesPartial Discharges-- Aging / insulation material degradationAging / insulation material degradation-- Calculate the remaining life of the insulation systemCalculate the remaining life of the insulation system-- Planning the maintenance actions (short / long term)Planning the maintenance actions (short / long term)

�� ““Finger PrintFinger Print”” from stator insulation system:from stator insulation system:

LEAP is not just a package of inspections; it is a systematic aLEAP is not just a package of inspections; it is a systematic approach to pproach to managing machine maintenance.managing machine maintenance.

LEAP LEAP –– Machine Life CurveMachine Life Curve

Thermal, Electrical, Ambient and Mechanical stresses act on materials and components of an electric machine, leading to a process of degradation - represented by the blue curve as areduction of strength with time. When operating stresses – bothtransient and steady state - in the red curve, exceeds thestrength, failure is imminent.

LEAP is all about drawing the red and blue curves.

What makes LEAP special, is its ability to relate the developmenWhat makes LEAP special, is its ability to relate the development of defects to the t of defects to the dimension of time with a life expectancy analysis, that enables dimension of time with a life expectancy analysis, that enables its direct its direct integration into a maintenance plan.integration into a maintenance plan.

LEAP LEAP –– Machines testedMachines tested

�� August 2002 August 2002 -- August 2006August 2006

358 Electrical Rotating Machines only in Brazil !!!358 Electrical Rotating Machines only in Brazil !!!

Turbine Generator – Synchronous Generators/ Motors – Induction Motors

Slip Ring Motors – Hydro Generators - DC Machines

OUTPUT RATE 300 kW to 250 MW

LEAP Tests LEAP Tests –– General InformationGeneral Information

�� Can be applied in Machines from any Manufacturer (due large ABBCan be applied in Machines from any Manufacturer (due large ABB India Database)India Database)

�� Time for data collection approximately 10 hours with the equipmTime for data collection approximately 10 hours with the equipment stopped ent stopped (off line tests)(off line tests)

�� Not necessary open covers / machine for data collectionNot necessary open covers / machine for data collection

�� Only access to the terminal box (disconnect exit cables / powerOnly access to the terminal box (disconnect exit cables / power cables)cables)

�� Non destructive tests, due Maximum Voltage Test = Phase to GrouNon destructive tests, due Maximum Voltage Test = Phase to Ground Voltage)nd Voltage)

THE IEEE AND EPRI SURVEY FINDINGS

ON MOTORS AND GENERATORS FAILURES

Failure Estatistics Failure Estatistics –– IEEE and EPRI SurveyIEEE and EPRI Survey

33%

6% 5% 5% 3%

11%

37%

10%7%4%2%

8%8%

61%

0%

10%

20%

30%

40%

50%

60%

70%

Bearin

gSta

tor W

indin

gShaf

t/Couplin

g

Rotor

Exter

nal Dev

ices

Brush

es/S

liprin

gUnsp

ecifi

ed

Failure during operation

Failure initiators identified during inspection / traditional tests

Failure Estatistics Failure Estatistics –– Insurance CompanyInsurance Company

Bearing / Shaft /Bearing / Shaft / CouplingCoupling

Rotor windingRotor winding

Stator core (sheet plates)Stator core (sheet plates)

Stator windingStator winding

Others (diodes, excitation system etc)Others (diodes, excitation system etc)

Source: Allianz Insurance, Germany (1996Source: Allianz Insurance, Germany (1996--1999), VDE Colloquium, June 28, 20011999), VDE Colloquium, June 28, 2001

Survey Survey –– ConclusionsConclusions

�� Bearings fail frequentlyBearings fail frequently

�� Windings also share a significant failure rateWindings also share a significant failure rate

�� Very few winding failures are detected in maintenance (8.3%) as Very few winding failures are detected in maintenance (8.3%) as against the total failure of 33% in normal operationagainst the total failure of 33% in normal operation

This indicates deficiency in traditional tests to detect stator This indicates deficiency in traditional tests to detect stator winding problems and achieve Operational Liability in Machinewinding problems and achieve Operational Liability in Machine

Insulation system: A complex structureInsulation system: A complex structure

�� MICA: material used to retard the failureMICA: material used to retard the failure�� Various process applied during coil manufacturing:Various process applied during coil manufacturing:

–– Resin (preResin (pre--impregnated tapes)impregnated tapes)

–– VPI, global VPI (vacuum pressure impregnation)VPI, global VPI (vacuum pressure impregnation)

–– Old Machines: mica splittings, asphalt shellacOld Machines: mica splittings, asphalt shellac

All materials and structure are subjected to stresses and aging All materials and structure are subjected to stresses and aging !!!!

One More reason to explain the One More reason to explain the needs for accurate Diagnostic needs for accurate Diagnostic techniques !!!techniques !!!

BEFORE GOING FOR THE DIAGNOSTIC TESTS

LETS HAVE A LOOK AT THE FAILURES

Failures manifestationFailures manifestation

DelaminationDelamination / deterioration of insulation/ deterioration of insulation


Partial Discharges in slot Partial Discharges in slot regions / stress grading systemregions / stress grading system

Damage due to excessive looseness and Damage due to excessive looseness and rubbing of coil with core (loose wedges)rubbing of coil with core (loose wedges)


ContaminationContamination

Arrhenius curveArrhenius curve


Coils / wedges loose in slotsCoils / wedges loose in slots

Where the problem is located ?Where the problem is located ?

LEAP indicates which machine component needs maintenance activitLEAP indicates which machine component needs maintenance activitiesies�� Cleaning the endwindings regions or slotCleaning the endwindings regions or slot

�� ReRe--wedging stator (customer can plan for acquire wedges)wedging stator (customer can plan for acquire wedges)

�� ReRe--taping tasks in slot exits / Repair stress grading systemtaping tasks in slot exits / Repair stress grading system

�� Indicate when insulation reached critical levels (and then a reIndicate when insulation reached critical levels (and then a rewinding or acquisition of a spare coils is needed)winding or acquisition of a spare coils is needed)

�� LEAP LEAP alsoalso is is indicatedindicated for new machines (to for new machines (to detectdetect possiblepossible problemsproblems in in manufaturingmanufaturing taskstasks))

LEAP Package of testsLEAP Package of tests

�� LEAP Level IILEAP Level II

1) DC Absorption Test 1) DC Absorption Test

2) Tan Delta and Capacitance analysis2) Tan Delta and Capacitance analysis

3) Partial Discharges analysis 3) Partial Discharges analysis

4) Non Linear Behavior analysis 4) Non Linear Behavior analysis

-- Contamination / charge storageContamination / charge storage-- Coils / wedges loose in slotsCoils / wedges loose in slots-- Voids within main insulationVoids within main insulation-- Partial DischargesPartial Discharges-- Aging / insulation degradationAging / insulation degradation-- Remaining life of the insulation Remaining life of the insulation -- Planning the maintenance actionsPlanning the maintenance actions

�� LEAP Level ILEAP Level I-- Operational Hours.Operational Hours.-- Number of stops / startsNumber of stops / starts-- Stator winding temperatures (Arrhenius Curve)Stator winding temperatures (Arrhenius Curve)

�� LEAP Level III and IVLEAP Level III and IV-- Stress analysis with FEA (Finite Element Analysis)Stress analysis with FEA (Finite Element Analysis)

Case studie Case studie -- 11

�� August 2004 August 2004 –– Customer Power Plant Customer Power Plant

Turbine Generator HITACHI 75 MWTurbine Generator HITACHI 75 MW

ABB in April 2003 performed the Analysis, and the report ABB in April 2003 performed the Analysis, and the report presented some risks in the machine due high contamination presented some risks in the machine due high contamination in endwindings and slot section, because the contaminants in endwindings and slot section, because the contaminants were blocking the ventilation ducts and also the type of were blocking the ventilation ducts and also the type of contaminants were conductive. We also identify contaminants were conductive. We also identify contamination in slot portions, so was necessary remove the contamination in slot portions, so was necessary remove the rotor from stator. The wedges system was ok, so were not rotor from stator. The wedges system was ok, so were not necessary to acquire spare wedges.necessary to acquire spare wedges.

Even with the condition of the Generator, Report said that the machine could still operate for more one year, but to get more Operational Liability in the machine, after one year a MAJOR INSPECTION should be planned.

I will present a short video (2 minutes)


�� June 2005 June 2005 –– LEAP On Board LEAP On Board –– Oil Rig Platform Oil Rig Platform

03 BBC Synchronous Generators 12.5 MVA 03 BBC Synchronous Generators 12.5 MVA –– 13.8 kV13.8 kV

LEAP ReportLEAP Report: : High amount of contamination in windings (also spread in slot High amount of contamination in windings (also spread in slot sections), oil contaminants ingress in insulation system, overhasections), oil contaminants ingress in insulation system, overhauling within 1 uling within 1 year (cyclic cleaning in workshop), insulation not aged, wedges year (cyclic cleaning in workshop), insulation not aged, wedges / coils tight in / coils tight in slots, high surface PD due carbonized oil. slots, high surface PD due carbonized oil.

CustomerCustomer’’s actions action: : Decided to send the 03 machines to ABB Workshop Decided to send the 03 machines to ABB Workshop Osasco (1 machine each 4 months) to perform Major overhauling, iOsasco (1 machine each 4 months) to perform Major overhauling, including ncluding rotor inspections, rewinding rotor poles, replacing rotor coil srotor inspections, rewinding rotor poles, replacing rotor coil supports and upports and implementations of new labyrinth seals system (to avoid further implementations of new labyrinth seals system (to avoid further ingress of ingress of oil in endwindings).oil in endwindings).


�� April 2006 April 2006 -- ABB Field Team removing 01 Machine and ship to ABB ABB Field Team removing 01 Machine and ship to ABB OsascoOsasco WorkshopWorkshop


�� April 2006 April 2006 –– Machine in ABB Machine in ABB OsascoOsasco WorkshopWorkshop


�� March 2006 March 2006 –– Oil Refinery Customer Oil Refinery Customer -- BBC Generator 12.5 MVABBC Generator 12.5 MVA

March 10, 2006March 10, 2006 -- Flash over in V / W phase terminal, customer called ABB to Flash over in V / W phase terminal, customer called ABB to evaluate insulation stator condition (after stresses) and check evaluate insulation stator condition (after stresses) and check if machine if machine could be put in operation.could be put in operation.

March 12, 2006March 12, 2006 –– LEAP Data Collection (Report sent in March 15,2006) LEAP Data Collection (Report sent in March 15,2006)

V phase shows inherent weakness and it is likely stressed. EitheV phase shows inherent weakness and it is likely stressed. Either the level r the level of contamination is high or the insulation strength has weakenedof contamination is high or the insulation strength has weakened slightly slightly for this phase.for this phase.

The nonThe non--linear patterns for V and W phases are very similar and differenlinear patterns for V and W phases are very similar and different t from other phases. The patterns show a general even harmonic from other phases. The patterns show a general even harmonic dominance but the 15th harmonic component dominance but the 15th harmonic component

Expected degradation due to overheating in between V and W phaseExpected degradation due to overheating in between V and W phases. s. Also some residual effects are suspected at the terminations (slAlso some residual effects are suspected at the terminations (slot exits)ot exits)


�� LEAP Report Recommendations:LEAP Report Recommendations:

The results indicate that the unit is contaminated to a significThe results indicate that the unit is contaminated to a significant extent along the endwindings with oil/carbonized ant extent along the endwindings with oil/carbonized oil and dust type contaminants.oil and dust type contaminants.Also the flash has possible resulted in additional thermal stresAlso the flash has possible resulted in additional thermal stresses particularly in V and W phases.ses particularly in V and W phases.

It is recommended to open up the machine for overhauling (at earIt is recommended to open up the machine for overhauling (at earliest) liest) –– is not advisable operation of the is not advisable operation of the unitunit. .

The main areas of maintenance are as under:The main areas of maintenance are as under:Carry out the thorough cleaning of the machine especially along Carry out the thorough cleaning of the machine especially along the endwinding areas followed by drythe endwinding areas followed by dry--outoutThe slot exits portions need to be inspected for presence of conThe slot exits portions need to be inspected for presence of contaminants at the terminations and overheating taminants at the terminations and overheating marks and insulation degradation or burning.marks and insulation degradation or burning.

The corresponding reThe corresponding re--taping of the leads to the bushings may be correspondingly repaitaping of the leads to the bushings may be correspondingly repairedred..

Even with information regarding the machine conditions customer Even with information regarding the machine conditions customer decided to put the decided to put the machine in operation............machine in operation............


�� Only 4 days of operationOnly 4 days of operation…………………………(failure in V/W phase):(failure in V/W phase):

Customer ship the machine to ABB Osasco WorkshopCustomer ship the machine to ABB Osasco Workshop…………


�� Machine in Workshop Machine in Workshop OsascoOsasco::

� Rotor balancingRotor balancing�� Installation and commissioning (Sept. 2006)Installation and commissioning (Sept. 2006)

� Stator rewindingStator rewinding��Rotor rewinding (catastrophic failure)Rotor rewinding (catastrophic failure)


�� June 2006 June 2006 –– Mining Plant Mining Plant

Ball Mill Ball Mill –– GE GE –– Synch. MotorSynch. Motor

4085 4085 cvcv –– 4.160 V 4.160 V -- 19781978

LEAP Report:LEAP Report: Even machine operating in an Even machine operating in an aggressive environment , the general condition aggressive environment , the general condition of the stator insulation system is good.of the stator insulation system is good.

ABB also calculated the remaining life (thermal ABB also calculated the remaining life (thermal only) from machine and we found a remaining only) from machine and we found a remaining life of 47.565 equivalent hours (corresponds to life of 47.565 equivalent hours (corresponds to 5.47 years) 5.47 years) –– 80% of Reliability in Life 80% of Reliability in Life information.information.

No maintenance actions is necessary for this No maintenance actions is necessary for this insulation system for the next 10.000 operating insulation system for the next 10.000 operating hours (or 1 year).hours (or 1 year).

LEAP: A value propositionLEAP: A value proposition

�� Optimizes Maintenance PlanningOptimizes Maintenance Planning of Electrical Machines by moving from Time Based of Electrical Machines by moving from Time Based Maintenance to Condition Based Maintenance.Maintenance to Condition Based Maintenance.

�� Provides an opportunity for Life Extension of machines, which wProvides an opportunity for Life Extension of machines, which would lead to increased ould lead to increased earnings capability and earnings capability and greater Return on Investmentgreater Return on Investment..

�� Facilitates decision makingFacilitates decision making: A single occasion of measurements is sufficient to enable shor: A single occasion of measurements is sufficient to enable short t and long term maintenance plans, repairand long term maintenance plans, repair--runrun--replace decisions.replace decisions.

�� Focuses on essential maintenanceFocuses on essential maintenance, and machines that are vulnerable, to, and machines that are vulnerable, toreduce downtime at lower risk levelsreduce downtime at lower risk levels

�� Provides important Provides important ““lifetime lifetime ”” inputs for more inputs for more realistic estimates of Life Cycle Costsrealistic estimates of Life Cycle Costs

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ABB-LEAP for IM