Doble Engineering Company 1

INSITE

Circuit Breakers Presentation IEEE/PES Pittsburgh, PA

11/11/99 A. Wilson/Doble Engineering Company

DAU

Recordings

Communication Network

INSITE Server

Doble Engineering Company 2

INSITE

Diagnostics For Substation Apparatus

Diagnostics NOT Data

Circuit Breakers Transformers Bushings

Doble Engineering Company 3

Power Factor Rate of Change Power Factor Rate of Change

(4/21/98 - 5/07/98)

1 26 51 76 101 126 151 176 201 226 251 276 301 326 351

Hourly recording #

PF ra

te o

f cha

nge

[%/m

onth

]

High Change Alert

Medium Change Alert

Low Change Alert

Doble Engineering Company 4

Feature Analysis EXPERT SYSTEM ALERT! Generator

Data Archive Browser

INSITE Server

Recordings

Multiple Locations-One Remote Server

Client Communications FAX ALERTS!

LAN

Recordings

One Substation-One Local Server

Expandable Up To 63 DAUs

Telephone Communication

Network

Telephone Communication

Network

Doble Engineering Company 5

CIGRE Failure Analysis Study Control Circuits Major Failures - 30% Minor Failures - 20%

Main Contacts Major Failures - 15% Minor Failures - 10%

Motion Major Failures - 12% Minor Failures - 6%

Ancillary Equipment Major Failures - 31% Minor Failures - 28%

Doble Engineering Company 6

Circuit Breaker Measurements

Control Circuits 52-A and 52-B Auxiliary Contact Status Trip and Close Coil Currents

Main Contacts Trip and Close Coil Currents Phase Currents A,B, and C

Insulation Bushings - PF and Capacitance

Motion Breaker Mechanism-Total-Travel, Over-Travel, Rebound, and Velocity

Ancillary Equipment Motor Current Pressure - SF6, Air Tank, or Hydraulic Heater Status Temperature - Ambient, SF6 Tank, or Cabinet

Doble Engineering Company 7

Identified Problems/Failures

Control Circuits (2) Fails to Trip on Command Fails to Close on Command Control Circuit Performance

Main Contacts Current Interruption/Initial Performance Contact Erosion Re-strike

Insulation (3) Deteriorated Insulation Change in PF/Capacitance

Motion (2) Mechanism Performance - Lubrication, Damping, and Binding

Ancillary Equipment (15) Performance - Stored Energy, Pressure,Motor and Heaters

Doble Engineering Company 8

Contact Malfunction Breaker Type: Air-Blast Multi-Interrupter Breaker Four of the interrupting contacts along with the isolating contacts did not operate initially

0 50 100 150 200 250 300 350 400 450 500-10

0

10

20Trip Coil Currents

0 50 100 150 200 250 300 350 400 450 500-10

0

10

20

Am

ps

0 50 100 150 200 250 300 350 400 450 500-10

0

10

20

ms

9

Contact Malfunction Total Trip Coil Time for each phase. 130+ operations in a 3 year period. The spike indicates the pole disagreement on Phase B.

01/01/97 01/01/98 01/01/99 01/01/000

50

100

150

200

250

300

Time

ms

Total Time - Trip Coils

Phase B Stuck

Doble Engineering Company

Doble Engineering Company 10

Contact Malfunction The trace of Phase B indicates re-ignition of current

0 50 100 150 200 250 300 350 400 450 500-1000

0

1000

Phase Currents

0 50 100 150 200 250 300 350 400 450 500-1000

0

1000

Am

ps

0 50 100 150 200 250 300 350 400 450 500-1000

0

1000

ms

Doble Engineering Company 11

Interrupting Time of the Main Contacts Varies slightly with load current. Repeatable. The interrupting time did not indicate pole disagreement

01/01/97 01/01/98 01/01/99 01/01/0010

12

14

16

18

20

22

24

26

28

30

Time

ms

Current Interruption Time

Doble Engineering Company 12

Motion Future analysis may have to incorporate seasonal adjustments

Jan Apr Jul Oct Jan Apr Jul 7.888

7.889

7.89

7.891

7.892

7.893

7.894

7.895

7.896

7.897

7.898

Time

Inch

es

SF6 Breaker

Doble Engineering Company 13

SF6 Pressure (Hourly)

10

11

12

13

14

15

16

17

18

12/2

2/98

12/2

4/98

12/2

6/98

12/2

7/98

12/2

8/98

12/2

9/98

12/3

0/98

12/3

1/98

1/1/

99

1/2/

99

1/3/

99

1/4/

99

1/5/

99

1/6/

99

1/7/

99

1/8/

99

Data Points

PSI

"Compensated"

"Uncompensated

3 day alert

20 hr alert

Low pressure alarm

LP Alarm and Final Alert Level

Doble Engineering Company 14

Motor Recording Belt Slipping

Doble Engineering Company 15

INSITE Diagnostics

Linked To: Failure Statistics Reliability Maintenance

Using: Statistics within Context of Limits Compensation for Operating Conditions

To Give: Conditioned Based Maintenance

Doble Engineering Company 16

Conclusion

Breakers have extremely repeatable functionality.

INSITE sensors are robust and sensitive enough.

Diagnostics must be focused