0 10 20 30 40 50 60

Years

Fa

ilure

ra

te %

Without monitoring With monitoring

Infant

mortality

Steady

state

Worn Out

Replacement deferral

Acceptable level

of failure rate

Without

monitoring

With

monitoring

Hydran Data - May 23, 2010

0

50

100

150

200

250

0:0

7

1:3

7

3:0

7

4:3

7

6:0

7

7:3

7

9:0

7

10:3

7

12:0

8

13:3

8

15:0

8

16:3

8

18:0

8

19:3

8

21:0

8

22:3

8

Hydran Gas Level

H2O PPM Level12:23

13:08

Transformer Tripped

Due to Bushing Failure

At 11:56

H2 Hydrogen Nearly all fault conditions, low energy PD

CH4 Methane Oil overheating between 200 and 500ºC

C2H6 Ethane Oil overheating between 300 and 500ºC

C2H4 Ethylene

Oil overheating over 500ºC, possible formation of carbon particles

C2H2 Acetylene High energy arcing, oil overheating over 800ºC, strong formation of carbon particles, metal melting

CO Car. Monoxide Paper insulation overheating

CO2 Carbon Dioxide Severe oil oxidation, paper degradation

O2 Oxygen Oxidation, leak

HYDROGEN H2

METHANE CH4

ETHANE C2 H6

ETHYLENE C2 H4

ACETYLENE C2 H2

GA

S C

ON

ST

ITU

EN

TS

250 750 1000 1250 1500 1750 500

Fault Temperature ( C )

2000

SF6 density monitoring alerts staff of gas leaks. Can reduce the release of potent greenhouse gas. Loss of SF6 can result in failure to extinguish arc.

Contact Ω change indicates wearing of current carrying contacts

B/O Oil DGA. Look for dark oil, contact metals such as silver, copper and tungsten

Mechanism Timing 70% of breaker failures are due to mechanism

Doble Testing Determines breaker bushing insulation break down by measuring Power Factor /Capacitance. Look for changes over time

Site Inspections: operation counts, leaks

Use GE C60 relay functions for breaker monitoring Arcing Current i²t: Interrupter Life Measurement Restrike detection can indicate mechanism or interrupter problems immediately after they happen. This can save catastrophic breaker failure

Partial Discharge Surveys: Detects breakdown of insulation in windings, bushings, etc. Done by exception following DGA evidence

Infrared Surveys: Detects loose terminals, blocked radiators, hotspots on transformers, CTs, PTs. Part of regular substation checks

Doble Testing measures physical changes to the transformer winding and bushing insulation Readings are compared to nameplate data and trends

Online gas monitoring: GE Hydran measures two key gases, CO (paper) and H₂ (PD)

Continuous Bushing monitoring: Doble IDD measures insulation characteristics Local and remote indication via IP connection

Kelman Transfix measures 8 key gases. Regular sampling dependant on results.

Transformers

Circuit Breakers

Substation Equipment Condition Monitoring

Michael Anderson, P.Eng

Location of Transformer Failure

Main tank

LTC

Bushing

Cooling system

Other

Data Historian Cascade Asset Management Health Analysis Database Weighted Algorithms Asset Health Score