t 1 transformer insulation oil sensing system

September 2011

Transformer Insulation Oil

Sensing System

0

Unique Sensing Solution

www.snsrevolution.co.kr

Sensor & System Technology

Doc T-1

http://www.snsrevolution.co.kr/

1

Core Technology

“Carbon Nano-Tube (CNT) Sensor”- Unique Technology”

CNT

Features

CNT has characteristics such as nanometer diameters,

cylindrical structures

Chemical features to absorb and desorb by molecular

unit and far larger surface compared to volume

Application Technology

Major contents of oil, “HYDROCARBONS” undergoes chemical changes by heat

and light, generating combustible gases such as CH4, C2H2, C2H6, C2H4, C3H8

H2 and combustible gases are absorbed in the surface of CNT sensor, making

conductance changed. The measured conductance difference will then be

converted into PPM value.


2

Core Technology

Measuring Gas

CNT Sensing Mechanism • Electrons being adsorbed onto the nanotube surface

• Generating electron transfers

• Changing CNT charge carrier density (and thus resistance)

Electron donating or withdrawing molecules


3

CNT Oil Sensor

- Excellent sensing performance in oil

- Reaction through direct contact with oil ; Additional equipment not required for extracting gas

and degraded materials

- Low cost due to simplified system

- Secured “Unique Technology for CNT Paste”

- Developed “Low Cost Process Technology”

- “Application Technology” to analyze various oils; Transformers

Auto vehicles

Edible oils for food


4

Outline of Sensing System

TCG

&

Degradation

status

Wire

&

Wireless

Inspection

+

Diagnosis

+

Management

Safety

&

No accidents

Measurement;

Total Combustible Gas(TCG),

Degradation status of

insulation oil using CNT sensor

Integrated monitoring functions

utilizing wire-wireless data

transmission system

Preventing accidents and

securing safety by analyzing

transformer status in a real-

time manner

Enhanced efficiencies facilitating;

Inspection,

Diagnosis,

Management of Transformers

Solutions


5

Insulation Oil Degradation

Degradation Phenomena : Thermal degradation by operation in a high temperature

Gas


Affecting mechanical

strengths in

substation facilities

Increased

vibrations

Generated

combustible gas

Caused

dielectric breakdown

Accelerated by overload operation

6

Criteria


Gases Normal Caution Abnormal Danger

H2 Under 400 401∼800 Over 800 -

C2H2 Under 20 21∼60 61~120 120 or more

C2H4 Under 200 201∼500 Over 500 -

CH4 Under 250 251∼750 Over 750 -

C2H6 Under 350 351∼750 Over 750 -

C3H8 Under 250 251∼750 Over 750 -

TCG Under 1,000 1,001∼2,500 2,501~4,000 4,000 or more

Increased amount

of TCG - -

Over 2,000ppm/year

from “Caution”

Over 3,000ppm/year

from “Abnormal”

Insulation Oil Degradation

Insulation oil analysis method ; Judging abnormality by TCG amount and amount of each gas

7

Comparison with other products

Comparison

Div. HYDRAN CALISTO TRUE GAS OTS Series

Manufacturer GE SYPROTEC

CANADA

MORGAN SCHAFFER

CANADA

SERVERON

USA

SNS Revolution

Korea

Main functions • To monitor dissolved gas of

transformer insulation oil

• To monitor abnormal gas

and moist of Transformer

• To analyze dissolved gas of

transformer insulation oil

• To analyze degradation of

insulation oil

• To measure dissolved gas of

transformer insulation oil and

degradation

Gas, components

to be monitored

H2,CO,C2H4,C2H2

(composition value of 4 gases) H2, moist

H2,CO,C2H4,C2H2,

C2H6,CH4,CO2,O2

Detection of total combustible

gas amount in transformer

insulation oil

Analysis method Gas amount H2 gas and moist amount Combustible gas amount Oil degradation and Combustible

gas amount

Price Expensive Expensive Expensive Inexpensive

Far more competitive in “Price” than competitors’

No “Maintenance & Operation”

“Real-Time” base 24 hours monitoring system


Additional equipment not required for extracting gas in oil → saving cost

8

Comparison

Div. HYDRAN CALISTO TRUE GAS OTS Series

Merits

• Instant site monitoring

• Continuous monitoring and

recording major gases

• Monitoring 4 Tr at the same

time

• Site installation type

suitable for monitoring trends

• Easy maintenance

• Analyzing causes of

each pattern

• Site measuring/analysis

possible

• Analyzing various gases

• Easy installation at site

• Integrated diagnosis system

with sensors installed in each Tr

(Max. 255 Trs)

• Additional equipment not

required for extracting gas →

Low cost

• No maintenance & operation

• Tr capacity is not limited ;

Multi applicable for large Tr,

pole Tr, ground Tr

Demerits

• Required equipment to

convert liquid into gas

• Required new column for

replacing or recalibrating due

to residual gas of the

previous analysis

• Required replacing sensor

rather frequently

• Measuring dissolved

gas amount not possible

• Only measuring H2 and moist

• Required skilled analyzer

• Real Time monitoring not

possible

• Expensive equipment

• Lack of data reliability

when analyzing 2 or more

Tr in parallel

• Required site data

accumulation

• Analysis of each gas not

possible (※)

Comparison with other products

(※) According to international regulation, ASTM D 3612, only total combustible gas amount is measured

for analyzing transformer insulation oil status.


9

Introduction of system

OTS-1000 / OTS-2000 Major Component

Sensor module body for insulation oil

degradation detection

Materials for installation

Real-time monitoring system


10


Specification

Main Sensor Module

CNT Oil Sensor

Data Transmission parameters

1. Degradation status of insulation oil

2. Total Combustible Gas(TCG) amount

3. Temperature and time

Data transmission

1. Wire or wireless online communication

2. Long-term data accumulation; more than 10 years

3. Diagnosing insulation oil status & alarm

function installed in the system; LED lights

OTS-100 / OTS-2000


11

Transformer

System Flow – Transformer oil degradation sensing


OTS-2000


12

Wire/Wireless

Communication

< Web Server >

Users

Internet

< Transformers > < SNS Sensing System >

<OTS-2000>

Type A

Type B

Type C

System Configuration


<OTS-100>


13


1. Sensor module / Case

2. Materials for installation

3. Real-time program

Introduction of OTS-2000

Main Sensor Module Cabon Nano Tube(CNT) Oil Sensor

Data transmission factor Time, oil degradation & TCG, temperature

Measured range TCG, accelerated degradation status of insulation oil

Measured gas TCG: H2, C2H2, C2H4, CH4, C2H6, CO (based on ASTM D3612 criteria)

Diagnosis method Diagnosing transformers status by analyzing data patterns measured (Daily, weekly, monthly, total change amount)

CNT Sensor End Of Line (EOL) 15 years or more

Warranty 3 years

Operation temperature 0 ~ +120 ℃

Operation height 4,000M or less

Size (Width×Height×Depth) 400×500×200mm

Weight 15 ~ 22Kg

Case material STS 304 or AL5005

Case surface treatment Power coating

Oil circulation pump Solenoid pump: 500~700ml/Min.

Oil pipe 3/8" OD copper steel or stainless steel

Length of oil pipe Sucking: 2 ~ 20M, Outflow: 2 ~ 20M

Power 85 ~ 260 VAC, 50 ~ 60 Hz, 350W

Communication RS485, RS232, Ethernet,, Wi-Fi

Data save period 10 years (6 times of diagnosis per a day)

Diagnosis of abnormality Diagnosis function installed for abnormality of sensor, pump, circuit

Software NMS Program

Technical Specification Configuration

14

Integrated System Configuration

Diagnosis program 1 - NMS (Network Management System)

※ General Figure

Transformer Oil Sensing Management System Logo

Monitoring

Sensing

Setting

Statistics

Administrator

setting

Notice


Abnormal

15


Diagnosis program 3

Monitoring – Warning List Logo

Monitoring

- Warning List

- Sensing Result

- Equip. status

Sensing

Setting

Statistics

Administrator setting

Notice Trans 37

Temp. 58.2℃

Sensor 1 0.0001

Sensor 2 0.0001

Sensor 3 0.0001

Trans 38

Temp. 58.2℃

Sensor 1 0.0001

Sensor 2 0.0001

Sensor 3 0.0001

Trans 39

Temp. 58.2℃

Sensor 1 0.0001

Sensor 2 0.0001

Sensor 3 0.0001

Abnormal : Oxygen factory → Section 4 → Transformer No. 37


16


Diagnosis program 5

Logo

Monitoring

- Warning List

- Sensing Result

- Equip. status

Sensing

Setting

Statistics

Administrator setting

Notice

Abnormal : Oxygen factory → Section 4 → Transformer No. 37 → Abnormal Temp.

Monitoring – Warning List

Trans 37 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Oil OK OK OK OK OK OK OK OK OK OK OK OK OK OK chk chk

Temp. 30 33 34 32 35 36 35 34 33 32 31 30 32 33 35 35

Device OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK

Door CLD CLD CLD CLD CLD CLD CLD CLD CLD CLD CLD CLD CLD CLD CLD CLD

Comm. OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK


17

Comparison on test result between “Analyzed gas value” and

“Measured value by CNT oil sensor”

General

Failures of power transformers are detected through

Analyzing gases in insulation oil, using Gas

Chromatography (GC) equipment.

GC is very expensive and has its limitations in

establishing on-line analyzing net-work.

HOWEVER

To verify reliability of CNT oil sensor by a comparison test between

“Analyzed gas value” and “Measured value by CNT oil sensor


18

Test outline

Place

Insulation Gas analysis laboratory of EIC

technology Dept, POSCO Gwangyang Steel Mill

Performed by

EIC technology Dept, POSCO

Smart Grid Team, RIST

SNS R&D




19



Test result

Reliability of CNT oil sensor module was verified

and confirmed which has reacted accurately

corresponding to change of combustible gases.

※ Refer to Annex 1 Research Institute of Industrial Science & Technology(RIST) test report


20



Conclusion

CNT oil sensor module

Reacting

Detecting

It was confirmed that CNT oil sensor module

employing CNT reacted accurately corresponding to

change in density of combustible gases regardless

of temperature of insulation oil.

It was verified that CNT oil sensor module has

detected total amount of combustible gases

(six kinds of gases, H2, CH4, C2H6, C2H2, C2H4

and CO) and it was thus confirmed that CNT oil

sensor is very effective to diagnose transformer oil

degradation status.


21



Conclusion

Compact system

Easy to monitor and handle

Not expensive

Having advantageous merits in constructing on-line monitoring net work

which can prevent failure accidents of power transformers

Minimizing transformer maintenance costs

It is verified that CNT oil sensor is ;


Thank You - End of Document -

22


23

Annex 1

RIST Test Reports(1/5)


24

Annex 1



25

Annex 1



26

Annex 1



27

Annex 1



28

Annex 2

Analysis data - Transformer insulation oil

Assessment of CNT oil sensor analysis test

Sensing Rate of CNT Sensor

Oxid

atio

n S

tab

ility

[mgK

OH

/g]

Die

lectric

Stre

ngth

[KV

]

※ MICHANG OIL IND.CO.,LTD Analysis Data 2008.01


29

Annex 2

Analysis – Characteristic of transformer insulation oil

Assessment of CNT oil sensor analysis test

Replacement criteria

(Sensing Value)


30

Annex 3 - Insulation Oil Degradation

Components area Degradation phenomenon

Trf

Parts Material Types Impact Indicators

Iron core Iron core

insulation

Manila paper ,

pressboard Thermal degradation

Decrease in mechanical strength,

increase in vibration

Occurring variation of noises and

vibrations

Winding wire

Conductor

insulation Kraft paper

Thermal degradation

Partial discharge

degradation

Pyrolysis of insulating material

1. Decrease in mechanical

strength

┌ Dielectric breakdown

└ Increase in vibration

2. Generation of combustible gas

1. Occurring variation of

dissolved oil gas

2. Decrease in degree of poly-

merization of insulating

paper

3. Decrease in mechanical

strength of insulating paper

Winding wire

insulation

Kraft paper,

pressboard

Coil support Woods,

pressboard

Lead wire

Conductor

insulation Kraft paper

Lead support Woods,

pressboard

Thermal degradation, a

bsorption of partial

discharge degradation

┌Decrease in dielectric strength

└Generation of partial discharge

→Generation of combustible gas→

Dielectric breakdown

1. Dielectric breakdown

voltage

2. Variation of oil gas

3. Increase in moisture in oil

4. Dielectric breakdown

voltage

5. Variation of acid value

Insulation oil Electric

insulation oil

On-load

tab changer

Insulation oil Electric

insulation oil

Contact Copper, Copper

alloy

Abrasion,

corrosion

(copper sulfide)

Damage to contact surface

Increase in contact resistance

Overheating and melting loss

1. Number of change-over

2. Contact resistance

3. Contact status

4. Operating torque

Insulation oil-filled transformers


31

Increase of transformer temperature

Increase of temperatures in transformer and cooling system

Winding

wires

Iron cores

Heat generated from

iron cores and winding

wires by no-load or

load losses when

transformers are operated

Difference between

ambient and the

transformer temperature

is defined as increase of

transformer temperature

In case of oil-filled

transformers, generated

heat is emitted through

insulation oil



32

Gases generated in abnormal status

Abnormal phenomena Major gases

Overheated

insulation oil

Low temperature

(Over 300℃) Ethane(C2H6), Methane(CH4), Ethylene(C2H4)

Middle temperature

(300~700℃) Methane(CH4), Ethylene(C2H4), Ethane(C2H6)

High temperature

(Over 700℃) Ethylene(C2H4), Methane(CH4), Ethane(C2H6)

Overheated solid insulator

(Over 200℃) Carbon monoxide(CO), Carbon dioxide(CO2), Methane(CH4)

ARC during insulation

(Over 1,000℃)

Acetylene(C2H2), Hydrogen(H2), Ethylene(C2H4),

Methane(CH4)

CORONA during insulation

(Over 1,000℃)

Hydrogen(H2), Acetylene(C2H2), Ethylene(C2H4),

Methane(CH4)

Degradation of insulation materials and insulation

oil Carbon dioxide(CO2), Carbon monoxide(CO)

Carefulness is required when even tiny amount of Acetylene(C2H2) is

detected as it is the gas generated by pyrolysis such as arc and discharge

and it thus makes a drastic development of degradation



33

Type of gases in abnormality transformer

Transformers

Solid insulator

Insulation oil

Carbon

monoxide/

Carbon dioxide

Acetylene/

A lot of Hydrogen

Methane/

Ethane/

Ethylene

Dielectric breakdown of solid

insulator caused by abnormality of

coil and lead wire

• Arc, corona between

conductors

• Discharge from sharp edge of

high voltage zone

• Overheating at bare conductor

• Hot spot caused by mal-

connection at joints

Craft insulating paper,

Press Board etc.

200℃

200~800℃

Over

1,000℃

Decomposition by natural degradation under 100℃



34

Annex 4

GE energy data - Trf. oil degradation detection

Source : Power Transformer Life Extension Through Better Monitoring, GE Energy

Real Time Monitoring of

Thermal Degradation

• Reduce Power Outages :

Quality power supply

• Accident Prevention

→ reduce economic losses

• Efficient system maintenance


35

Estimate annual values from

monitoring system

$ 38,325 -$ 16,590 = $21,735.

※ Estimated losses by a damaged

transformer

Losses without proper

monitoring system: $38,325

(100%)

Losses with proper

monitoring system installed:

$16,590 (43%)

Source : Power Transformer Life Extension Through Better Monitoring, GE Energy


Annex 4

GE energy data - Trf. oil degradation detection

t 1 transformer insulation oil sensing system

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