ABB LEAP Customer presentation, PG Service, BU Motors and Generators

Stator Winding-Condition & Lifetime

assessment

© ABB Group

May 13, 2013 | Slide 2

ABB LEAP

ABB LEAP - Benefits for customer

Motivation to perform LEAP

Failures statistic

Consequences of stator failure

Basic LEAP Theory

LEAP levels and measurements

LEAP versus traditional measurements

LEAP report

LEAP case studies

Overview

© ABB Group

May 13, 2013 | Slide 3

ABB LEAP

ABB LEAP (Life Expectancy Analysis Program) is

unique diagnostic tools for motors and generators

which

assesses the condition of the stator winding

insulation,

evaluates the remaining life of the stator winding

insulation

Site measurements are performed by trained personnel

in the ABB Service Center network and the data

analyzed at the ABB LEAP Center of Excellence at

Mumbai

Service is performed by Local ABB Service Providers

Benefits for customers ABB LEAP creates optimized maintenance plans

that helps our customers to

minimize unplanned downtime

extend motors and generators lifetime

boost return on investment

reduce operating risks

Introduction

© ABB Group

May 13, 2013 | Slide 4

Failure Statistics – IEEE and EPRI

Failures observed in motor during normal operating condition

Failure identified in motor when carrying out activities such as:

• Preventive Maintenance

• Condition Monitoring

37%

33%

6% 5% 5% 3%

11%

61%

8% 8%

2% 4%

7% 10%

0%

10%

20%

30%

40%

50%

60%

70%

© ABB Group

May 13, 2013 | Slide 5

Stator Failure Consequences….

What is the time for repair ?

What are the costs involved in a complete stator replacement or rewinding ?

What are the losses related to production due the stator failure

Downtime cost

© ABB Group

May 13, 2013 | Slide 6

Factors influencing stator winding life Age, voltage, speed, operation

Total Failure Rate Vs Age

0

1

2

3

4

5

6

7

0-5 5.1-10 10.1-15 15.1-20 20.1-25 25.1-

Age (Years)

%

0

0.2

0.4

0.6

0.8

1

1.2

1.4

%

2 4 6 8 10

Pole Number

%wdg. Failure Rate

Series1

00.5

11.5

22.5

33.5

%

3000-

5000

6000 6600-

10500

11000-

13800

Voltage(Volts)

%wdg Failure Rate

Series1

0

0.5

1

1.5

2

2.5

%

1 or less More than 1

No of Starts/day

Wdg Failure Rate

© ABB Group

May 13, 2013 | Slide 7

Stress

Strength

Failure Transients

Residual Life

Premature Failure

Time

Str

ess,

str

ength

Basis of LEAP

Stress & Strength vs Time

© ABB Group

May 13, 2013 | Slide 8

Adv. 2: Increase in Life

Stress

Strength

Failure

Transients

Residual Life

Adv. 1: No Premature Failure

Condition assessment and taking

suitable actions at this point.

Life Expectancy Analysis

The Benefits

© ABB Group

May 13, 2013 | Slide 9

LEAP

The levels…

© ABB Group

May 13, 2013 | Slide 11

LEAP Measurements

Can be applied on

Machines from any

Manufacturer

Time for data collection

approximately 4 hours with

machine stopped (off line

tests)

Not necessary to open

covers / machine for data

collection

Only need access to the

terminal boxes

Non destructive tests

General Information

© ABB Group

May 13, 2013 | Slide 12

LEAP Measurements

DC Measurements

PDCA-Polarization De-

polarization current

analysis

AC Measurements

Tan delta(Tan δ)

/Capacitance analysis

Partial discharge (PD)

NLIBA-Non linear

insulation behavior

analysis

DC measurements

gives more

information on the

surface of the

insulation

AC measurements

gives more

information on the

volume of insulation

Standard Package

© ABB Group

May 13, 2013 | Slide 13

LEAP measurements

DC Measurement By measuring leakage and

absorption current, PDCA

test helps quantify and

identify location of charge

storage within the machine

Identifies contamination

even when IR, PI values

are “acceptable”

Determines state of winding

insulation, ageing,

contamination etc

AC Measurement Confirm the results from DC

Measurements

Assess the condition of

Corona protection shield

Determine the extent of de-

lamination or void content in

terms of a percentage of

discharging Air Volume to

Insulation Volume

Assess condition of the

Stress Grading system at

slot ends

Trend Ageing effects

DC measurements:

Conventional IR,PI

values may be

satisfactory even for

highly contaminated

windings

AC measurements:

Conventional

measurement

interpretation is

based on trend

Salient points

Q3

Q1, Q2

© ABB Group

May 13, 2013 | Slide 14

LEAP Vs Traditional measurement

Traditional measurement looks at values such as IR, PI, Tan δ, whereas LEAP looks from point of strength aspects of insulation

Trend of data required in traditional analysis. With LEAP finger print can be established with one set measurement

65-72% of failures are related to Thermal (aging) and Ambient reasons which may not be detected by measurements that rely only on partial discharges. ABB’s measurements and analysis focuses also on detection non-partial discharge related problems

Analysis software is UNIQUE and parameters derived from analysis can be utilized in Life Expectancy Calculations

Can be related to time and shall be integrated into the Maintenance Plan

How is it different?

© ABB Group

May 13, 2013 | Slide 15

LEAP

Provides condition assessment of stator winding

Helps make short term maintenance plan

Provides remaining lifetime of stator winding

Helps make long term maintenance plan

Provides recommendation

What maintenance needs to be done

When maintenance needs to be done

What winding areas to attend

When to perform rewinding or buy new stator

Reports

© ABB Group

May 13, 2013 | Slide 16

LEAP

Compliments maintenance planning of electrical machines

Helps extend life of machine by suggesting correct

maintenance at appropriate time leading to better return of

investment

Facilitates decision making in short and long run

Provides lifetime inputs to make realistic calculation of

lifetime costs

Benefits to customer

© ABB Group

May 13, 2013 | Slide 17

LEAP Cases

• 11 MW, 11KV, 1500 rpm

Synchronous motor

• Purpose of test: • The motor was in operation for

69,000 hours with no outage. LEAP

Standard carried out to determine

the need for L3 or Level 4

Inspection.

• On-line pd alarm had appeared

• Results PDCA test:

IR- 2310 Meg ohm

PI- 2.02 (Limits)

Q1(%) – 9.63 (<7%)

Q2 (%) – 11.30 (<10%)

Q3 (%) – 44.54 (< 20%)

Key findings

LEAP Standard indicated

presence of oil/carbonized

contaminants

predominantly on the

overhangs

Recommendation

Open the end covers and

clean end windings. No

immediate need of

overhaul with rotor

removal

Benefits

Optimized maintenance

planning

Contamination

© ABB Group

May 13, 2013 | Slide 18

LEAP Cases

• 725 KW, 6.6KV, 990 rpm

• Sector

• Petrochemical Industry

• Purpose of test:

• Routine shutdown

checks

• Results

• Performed LEAP

Standard

• Evidence of Slot PD

recorded from PD

pattern

Key findings

• Substantial erosion of

corona protection field

indicated

Recommendation

• Customer advised to

open the machine and

re-impregnate the

windings with resin

Benefits

• Life extension

Insulation wear

© ABB Group

May 13, 2013 | Slide 19

LEAP Cases

• 400 MW, 23KV, 2 pole

Generator

• Sector

• Power Plant

• Purpose of test:

• To validate health

condition since machine is

in operation for 20 years

• Results

• Performed LEAP Premium

• Tests done:

• LEAP Standard

• Wedge deflection

• Bump test

Key findings

Looseness in wedges and

end windings

Recommendation

Customer advised to do

re-wedging and implement

new tie ups between coil

and support structure.

Benefits

Life extension

Lifetime optimization

62

64

66

68

70

72

74

76

78

160 170 180 190 200 210 220 230 240 250 260 270 280 290 300

Str

ess/T

en

sil

e S

tren

gth

(M

Pa)

Equivalent Operating Hours ( x 1000 )

LIFE ESTIMATION

Present Equivalent Operating Hours

Equivalent Operating Hours at Intersecting Points

Stress Developed (9240 psi or 63.66 MPa) 167413 285800

Remaining Life (118387 eq. hrs)