Post on 04-Dec-2021
4
T P S - I 600 MW
T P S - I EXPN 420 MW
T P S - II 1470 MW
T P S - II EXPN 500 MW
NTPL – TUTICORIN 1000 MW
BARSINGSAR 250 MW
TOTAL CAPCITY 4240 MW
THERMAL POWER STATIONS
Elimination of
“Frequent tripping of High voltage overhead lines”
in Township Administration
Title of our Case study Presentation on…
LEADER : SHRI. R ARUL DURAIACM/ELEC /TA
DY.LEADER : SHRI. K BALASUNDARAMJE/ELEC/TA
MEMBERS : SHRI. R SETHURAMANSR.FOREMAN/ETM/TA
SHRI. R SANKARSR.FOREMAN/ETM/TA
SHRI A MOHAMMED SADHIK BASHAfOREMAN/ETM/TA
76
QC
Meeting
Details
Frequency Alternate Saturday
Duration One Hour
Total Hours Spent for this project 18 Hrs.
Attendance 97%8
OUR MOTTO : STRIVE for EXCELLENCE
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789
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11
12
PLAN
DOCHECK
ACTION
PROBLEM SOLVING METHOD
We follow …Q C F I’ s - TWELVE STEP METHOD
P D C A DEMING WHEEL
9
Problem Identification
Problem Selection
Root cause Analysis
Problem Analysis
Finding Causes
Foreseeing Probable Resistance
Trial Implementation
Months
Date of Initiation :
01.10.2017
Date of Trial Implementation:31.03.2018
1
2
3
4
5
6
7
8
9
10
Solution Development
Problem Definition
Data Analysis
Standardization , Follow-up & Review
Date of Regular Implementation:01.07.2018
2017 2018
NOV
Regular Implementation
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12
10
Ste
ps
OCT DEC JAN FEB MAR APR MAY JUN JUL
Performance check
SL NO
PROBLEM DESCRIPTION CATEGORY
1 FREQUENT FAILURE OF DISTRIBUTION TRANSFORMERS
B
2 FREQUENT FAILURE OF SINGLE PHASE PREVENTORS
A
3 DRASTIC INCREASE IN POWER CONSUMPTION C
4 WASTAGE OF ENERGY –NON RESIDENTIAL BUILDINGS, PARKS ETC
C
5 CURRENT TRANSFORMERS FAILURE C
6 FREQUENT HT CABLE JOINT FAILURES A
7 PROBLEMS DURING MAINTENANCE OF OLD KIOSKS B
8 PROBLEMS DURING MAINTENANCE OF MOCB’S A
9 TREES FALLING LT OHT LINES B
LIST OF PROBLEMS IDENTIFIED THROUGH BRAIN STORMING
1210
SL NO PROBLEM DESCRIPTION CATEGORY
10 FREQUENT FAILURE OF MCCB’S IN LT PANELS A
11 FEEDERS TRIPPING DUE TO ENTRY OF REPTILES
A
12 OIL LEKAGE IN OLD 33 K.V C.T’S IN SUB-STATIONS
A
13 FREQUENT FAILURE OF 40W T.L IN ST.LIGHTS A
14 FREQUENT REPLACEMENT OF CEILING FANS A
15 POOR EARTHING IN RB’S&NRB’S C
16 MAINTENANCE PROBLEM IN AIR BREAK SWITCHES IN F.P’S
B
17 REDUCTION IN DOWN TIME OF 11K.V.BREAKDOWN
A
18 MAINTENANCE OF PROTECTION SYSTEM B
LIST OF PROBLEMS IDENTIFIED THROUGH BRAIN STORMING
13 1
1
SL NO PROBLEM DESCRIPTION CATEGORY
19 LUGS BURNING IN TRANSFORMERS A
20 OIL FILLING IN DIST TRANSFORMERS B
21 FREQUENT FAILURE OF SPRING CHARGING MECHANISM IN MOCB’S
A
22 LOW VOLTAGE IN TAIL ENDS C
23 AVAILABLITY OF VEHICLES DURING BREAKDOWNS
B
24 PROBLEMS DUE TO LIGHTNING STROKES C
25 ELECTRIC SHOCKS DUE TO SEEPAGE OF WALLS C
26 ERRORS IN ENERGY METER READINGS B
27 LONGER TIME TAKEN IN BACK FEEDING ARRANGEMENTS
A
LIST OF PROBLEMS IDENTIFIED THROUGH BRAIN STORMING
14 12
SL NO
PROBLEM DESCRIPTION CATEGORY
28 FREQUENT FAILURE OF HT SUPPLY IN 11kv FEEDER
B
29 FREQUENT FAILURE OF MONOBLOC PUMPS A
30 DRASTIC INCRESE IN POWER CONSUMPTION IN NRB’S
C
31 ENERGY CONSERVATION IN NRB’S C
32 STREET LIGHTS IN BLOCK-24 & BLOCK-17 AREAS C
33 FREQUENT LT CABLE JOINT FAILURES A
34 PROBLEMS DURING MAINTENANCE OF OLD F.P’S B
35 PROBLEMS DURING MAINTENANCE OF BOCB’S A
36 TREES FALLING 33K.V OHT LINES B
LIST OF PROBLEMS IDENTIFIED THROUGH BRAIN STORMING
15 13
SL NO PROBLEM DESCRIPTION CATEGORY
37 FREQUENT FAILURE OF FEEDER SWITCH IN LT PANELS
A
38 FEEDERS TRIPPING DUE TO EARTH FAULTS A
39 OIL LEKAGE IN OLD 33 K.V P.T’S IN SUB-STATIONS A
40 FREQUENT FAILURE OF LOUVERS IN ST.LIGHTS A
41 FREQUENT REPLACEMENT OF REGULATORS A
42 EARTH LEKAGE RB’S& INRB’S C
43 MAINTENANCE PROBLEM IN HORN GAP UNITS IN F.P’S
B
44 FREQUENT PROBLEMS IN HIGH TENSION CONDUCTORS
C
45 FAILURE OF INSULATORS IN OHT LINES B
LIST OF PROBLEMS IDENTIFIED THROUGH BRAIN STORMING
16 14
SL NO PROBLEM DESCRIPTION CATEGORY
46 COPPER FLATS DAMAGING IN TRANSFORMERS A
47 OIL LEAKS IN DIST. TRANSFORMERS B
48 FREQUENT FAILURE OF INDICATION BULBS IN MOCB’S
A
49 LOW VOLTAGE IN RB’S C
50 AVAILABLITY OF MANPOWER DURING BREAKDOWNS
B
51 PROBLEMS DUE TO BIRDS IN FP’S C
52 ELECTRIC SHOCKS DUE TO UN SAFE ACTS C
53 PROBLEM IN ENERGY METER READINGS B
54 NON AVAILABLITY OF RING MAIN SYSTEM IN E2 C
LIST OF PROBLEMS IDENTIFIED THROUGH BRAIN STORMING
1715
SL NO PROBLEM DESCRIPTION CATEGORY
55 COPPER FLATS THEFT IN TRANSFORMERS A
56 COPPER FLAT THEFT IN DP & FP A
57 FREQUENT FAILURE OF LED BULBS IN ST.LIGHTS A
58 FREQUENT FAILURE OF LED BULBS IN NRB'S A
59 PROBLEM IN OPERATION OF BOREWELL PUMPS
A
60 REMOVAL OF VEGETATION IN FP & DP AREAS C
61 PROBLEM IN IDENTIFYING LT CABLE JOINTS A
62 FREQUENT FAILURE OF ENERGY METERS B
63 NON AVAILABLITY OF RING MAIN SYSTEM IN LT DISTURIBUTION
C
LIST OF PROBLEMS IDENTIFIED THROUGH BRAIN STORMING
1816
A B C CATEGORISATIONof 63 IDENTIFIED PROBLEMS
0
5
10
15
20
25
30
A B C19
30 26
7
PROBLEM IDENTIFICATION
CAN BE
SOLVED
BY USNEEDS
HELP
NEEDS
MANAGEMENT
APPROVAL
Step 1
Identified Problems for further Analysis
1. Linear Heat Sensing Cable Healthiness ensuring modifica
2. Emergency Back up of Contactor logic panel.
3. Frequent tripping of HV feeders4. Provision of Siren in Auto for Bunker high level set.
5. Elimination of Mechanical Limit Switch Problems in Stacker Hoist.
Identified 5 Problems:
22
PROBLEM SELECTION
Step 2
Q-Quality C- Cost D-Delivery S- Safety WE – Work Environment
Problem Selection Matrix
Sl.No.Case Studies EASY DELAY
WEPRIORITY
1Elimination of Mechanical Limit Switch
Problems in Stacker.YES YES YES NO YES YES YES
2Linear Heat Sensing Cable Healthiness
ensuring modification . YES NO YES NO YES YES YES
3 Frequent tripping of HV feedersYES YES YES YES YES NO YES
4 Emergency Back up of Contactor logic
panel. YES NO YES YES NO YES YES
5Provision of Siren in Auto for Bunker high
level set.YES YES YES NO YES YES NO
1
4
2
5
3
No
Delay
23
Problem Selected:
Frequent tripping of HV feeders
PROBLEM SELECTION
Step 2
To ensure 100% availability of supply to public
To avoid equipment damage.
To improve work environment
To improve our problem solving skill & User-friendly atmosphere.
GOAL:
Current Objectives
OCT 2017
JUNE 2018
FINDING OUT SUITABLE SOLUTION to SOLVE FREQUENT TRIPPINGS of HV
Feeders 28
Step 3
PROBLEM DEFINITION
sh
hat is the problem ?
here is the problem ?
Step 4
ho identified this problem ?
hen does it occur ?
ow much is the severity?
Frequent tripping of HV feeders
In the overhead line cut points of posts
Public & Maintenance team
When birds bring metal objects or wet
Flesh of snakes, etc
Heavy & Costly damage to electrical equipments which will lead to power failure
30
PROBLEM ANALYSIS
31
Reasons for Feeder trippingNo. of
Complaints% age
Cum. %
age
Birds crossing the lines (A) 46 61.33% 61.33%
Earth fault due to birds / squirrel (B) 8 10.6% 72.0%
Line to line short(C) 6 8.0% 80.0%
Lightning arrestor failure (D) 5 6.67% 86.67%
Insulator failure(E) 4 5.3% 91.97%
Tripping due to transformer(F) 2 2.66% 94.63%
CT/PT failure(G) 2 2.66% 97.29%
Heavy Lightning spikes(H) 1 1.33% 98.62%
Deposit of dust over insulators(I) 1 1.33% 100.0%
DATA Collection based on Logbook for 8 months
from Jan 2017 to Aug 2017
Step 4
Total 75 100%
PROBLEM ANALYSIS
Sl.No
Possible Causes Sl. No
Possible Causes
1. Protection Tripping 13. Dropper Tension
2. CT Failure 14. Gear box problem
3. PT failure 15. Ageing of conductor
4. Breaker IR value failure 16. Sag of conductors
5. Lightning Arrester failure
6. Bird Dropping Flesh & Metel Wires
7. Over Head line
8. Falling of Trees
9. Dusty atmosphere
10.
Moloperation
11. Poor workman ship
12. Wrong connections
33
FREQUENT TRIPPING OF HV INSULATORS
Step 5
GEMBA OBSERVATIONS
IDENTIFICATION OF CAUSES
MACHINE
(Control panel)
MATERIAL
PROCESS
Frequent Tripping ofHV FeedersIn OH line
Poor workman ship
Bird Dropping Flesh & Metal Wires
CT Failure
Maloperation
Protection Tripping
Falling of Trees
Over Head linePT failure
Breaker IR value failure
Sag of conductors
Dropper Tension
Dusty atmosphere
Ageing of conductor
34
MAN
Step 5
Lightning Arrester failure
Wrong connections
VALIDATION OF CAUSES
CAUSES TO CHECK VALIDATION RESULT REMARKS
Data collection Insignificant
Observation Insignificant Not valid
Observation Insignificant Not valid
Observation/ Discussion Insignificant Not valid
Observation/ Discussion Insignificant Not valid
CAUSES TO CHECK VALIDATION RESULT REMARKS
Bird Dropping Flesh & Metal Wires
Data collection Significant To be analyzed
Over Head line By inspection Insignificant Not valid
Falling of trees Test & Trial Insignificant Not valid
Dusty atmosphere By inspection Insignificant Not valid
Protection failure
CT Failure
Lightning arrestor Failure
Breaker IR value failure
PT Failure
36
Step 6
VALIDATION OF CAUSES
CAUSES TO CHECK VALIDATION RESULT REMARKS
By inspection Insignificant Not valid
Poor workmanship By inspection Insignificant Not valid
Wrong connections Data Collection Insignificant Not valid
Maloperation
Material
CAUSES TO CHECK VALIDATION RESULT REMARKS
Dropper tensionBy inspection
Not Significant Not valid
Ageing of conductors
Data CollectionNot Significant Not valid
Sag of conductorsBy inspection
Not Significant Not valid
37
Step 6
MACHINE
(Control panel)
MATERIAL
PROCESS
Frequent Tripping ofHV FeedersIn OH line
Poor workman ship
Bird Dropping Dropping of Flesh & Metal Wires by Birds
Maloperation
Over Head line
38
MAN
Step 5
Wrong connections
Why Why Analysis Power Supply disturbance in Neyveli
Township
Why ?Tripping of 33 KV incoming feeders
WhyTripping due to Earth fault
Why ??
39
Step 6
ROOT CAUSE :
EARTHING OF LIVE CONDUCTOR DUE TO BIRDS
DROPPING METAL / FLESH
43
Step 8
Suggestions
By Our TeamPossibility
Cost
InvolvedMaintenance
Trouble
shooting-
Time
REMARKS
Under ground 33kv cable may be changed.
Possible Very High Minimum Minimum
Rejected due to
cost
Regular patrolling oflines
Notpossible
More Time
ConsumingMaximum More Rejected
Insulating type cross arms may be erected
Not Possible Very highMinimum
VeryMinimum
Rejected
Insulation of cut point jumper in double / treble poles
Possible
Minimum(Due to In-
House
Design)
Minimum Very
Minimum Accepted
Insulation of cut point jumpersAccepted
44
Step 8
Sl.
No.
Description of
WorkTime
Taken
Done
by
Co-
ordination
Target
DateCompleted
by
01Material
Requirement List 2 Shifts RS RAD 17.02.18 15.02.18
02Collect the HT / HV
insulation Tape from
Our division Store
1 Shift RSR RAD 28.02.18 25.02.18
03 Getting Line
Clearance
30
minutesKBS RAD 12.03.18 10.03.18
04Earthing the
structure30
minutesKBS RAD 12.03.18 10.03.18
05Insulating the
jumper with HV Tape30
minutesRS MSB 23.03.18 20.03.18
06Return of LC &
Normalisation5 mnutes KBS RAD 29.03.18 31.03.18
Share
The Responsibility
46
ACTIVITY PROBABLE RESISTANCE
ACTION TAKEN TO OVERCOME RESISTANCE
Insulating the cutpoint jumperswith HV tape
Will it be safe and withstand 33 KV?
Checked for insulation and perfectly working in the field conditions and replaceable.
Will it be a disturbance to other equipments?
It occupies no space and hence No disturbance.
Will it affect the safety of the system? No. The tape is designed for 33 KV cable
joints and hence no problem
Whether easily replaceable and sufficient spares available?
Yes, ensured.
Step 9
TRIAL
IMPLEMENTATION
The Implementation are …….
1. Each feeder will have atleast 10 cut
points
2. Onecut point in the 33 KV Black Feeder between SSII and SSI was insulated with HT tape by 27.03. 2018
3. Two cutpoints in the 11 KV – E4 feeder was also insulated with HT tape
48
Step 10
49
Reasons for Feeder trippingNo. of
Complaints% age
Cum. %
age
Birds crossing the lines (A) 0 61.33% 61.33%
Earth fault due to birds / squirrel (B) 0 10.6% 72.0%
Line to line short(C) 6 8.0% 80.0%
Lightning arrestor failure (D) 5 6.67% 86.67%
Insulator failure(E) 4 5.3% 91.97%
Tripping due to transformer(F) 2 2.66% 94.63%
CT/PT failure(G) 2 2.66% 97.29%
Heavy Lightning spikes(H) 1 1.33% 98.62%
Deposit of dust over insulators(I) 1 1.33% 100.0%
DATA Collection based on Logbook for 3
months from Apr2018 to Jun 2018
Step 10
Total 20
Performance check after trial implementation
51
REGULAR IMPLEMENTATION
DATE OF REGULAR IMPLEMENTATION 01.07.2018
1. Modification was carried out at the full length of Black feeder.
2. Informed our division. Drawings updated.
Step 11
Problem Identification
Problem Selection
Root cause Analysis
Problem analysis
Finding Causes
Foreseeing Probable Resistance
Trial Implementation
Months
1
2
3
4
5
6
7
8
9
10
Solution Development
Problem Definition
Data Analysis
11
12
OCT
2018201752
Standardisation
Follow-up & Review
Regular Implementation
Trial Follow-up & Review
Step 11
NOV DEC JAN FEB MAR APR JUNMAY JUL
1. 33 KV black feeder was normal in
all aspects.
FOLLOW-UP REVIEW
ACKNOWLEDGEMENT
SL.NO
Department Workinvolved
Acknowledgement
1 Operation In charges of Sub stations
Operation Very good
2 Our Head of Department & Division Colleagues
Maintenance
Very good
54
Step 12
FOLLOW-UP REVIEW
55
AIM
1.To ensure 100%
availability of supply to
public
2.To avoid equipment
damage.
3.To improve work
environment
4.To improve our problem
solving skill & User-friendly
atmosphere.
ACHIEVED
1. Ensured by elimination of
tripping due to birds
dropping metal / flesh
2. Avoided
3. Greatly improved.
4. Greatly improved.
AA Chart
Step 12
Cost of HT tape for 1 meter = Rs. 100
Modification cost (For one system)
56
Step 12
Modification Cost for each
cutpoint = Rs 100
Modification Cost for One feeder
(10 cut points) = Rs 1000
Uninterrupted power supply,damage to
Electrical equipments and stress and fatigue to
Maintenance crew was eliminated
57
0
2
4
6
8
10
Team Sprit
Communiation Skill
Knowledge in QCmethodologies
Problem Solvingability
Presentation Ability
Poor Satisfactory
2 4 6 8 10
Good Very Good Excellent
Radar Chart
Step 12
0