Frequent Tripping of HV Feeders - Amazon Web Services

SmartTA QC

Electrical Township Maintenance

Township Administration

NLC India Ltd, Neyveli

Mine

2

Solar

Wind Mill Thermal1

3

NLC India Ltd,Neyveli

A “Navratna” Public Sector Enterprise

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…

6

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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5

6

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

11

12

10

Ste

ps

OCT DEC JAN FEB MAR APR MAY JUN JUL

Performance check

Step 1

Problem Identification 11

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


13 1

1


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


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


15 13


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


16 14


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


1715


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


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

Step 2

Problem Selection 20

21(FROM 30 ‘A’ CATEGORY PROBLEMS)

PROBLEM SELECTION

Step 2

VENN DIAGRAM

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

Step 3

Problem Definition 24

25

PROBLEM DEFINITION

Definition of the Problem

27

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

Step 4

Problem Analysis 29

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

Step 5

32Identification of Causes

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

Step 6

35Finding out the Route Causes

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


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


By inspection Insignificant Not valid

Poor workmanship By inspection Insignificant Not valid

Wrong connections Data Collection Insignificant Not valid

Maloperation

Material


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

Step 7

DATA ANALYSIS ON

ROOT CAUSE40

41

Step 7

Step 8

Solution Development42

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

Step 9

Foreseeing Probable

Resistance45

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

47

TRIAL IMPLEMENTATION AND

PERFORMANCE CHECK

Step 10

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

Step 11

Regular

Implementation

50

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

Step 12

Follow-up & Review

53

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

58

Step 12

TOOLS

&

TECHNIQUES

A P

DC

Radar

Chart

02040

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Frequent Tripping of HV Feeders - Amazon Web Services