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BNERI

Reliability Indices

Measurement Reliability Indices Measurement for three 11 kV

and 66 kV substations in Brunei Darussalam

(PWR 01)

NUR SABIQAH HAJI ROSLI

Draft dated 27th May 2015 i

ACKNOWLEDGEMENT

I would like to express my deepest appreciation to all those who provided me the possibility to complete

this report. I would also like to acknowledge with much appreciation the crucial role of Robinson Goh,

Hajah Zuriyati and Haziqah Nordin, the staff of Department of Electrical Services in the Distribution

Department, who provided their power outages and Single Line Network data to complete this Reliability

Indices Measurement project.

A special gratitude I give to our supervisor, Chief Researcher of Power Department, Dr. Arvind K S

Chaudhary, whose contribution in stimulating suggestions and words of encouragement helped me to

coordinate this project especially in writing this report.

Draft dated 27th May 2015 ii

EXECUTIVE SUMMARY

One of the Key Performance Indicators (KPI) under the Energy White Paper 2014 is to reduce the number

of power outages by 2035, which is in line with Wawasan 2035. Therefore, quantitative reliability

indices measurement such as System Average Interruption Duration Index (SAIDI) and System Average

Interruption Frequency Index (SAIFI) has been calculated for three 11 kV and 66 kV substations in

Brunei Darussalam.

In this study, IEEE Guide for Electric Power Distribution Reliability Indices (IEEE Std 1366-2012) is

used as the methodology and only unplanned and sustained interruptions are taken into account to provide

consistency in all four districts, to review and improve current reliability and performance of distribution

system in Brunei Darussalam. To further improve the performance of distribution system, design and

implementation of Smart Grid technologies can be utilized in Brunei Darussalam

Draft dated 27th May 2015 iii

Table of Contents

ACKNOWLEDGEMENT ............................................................................................................................. i

EXECUTIVE SUMMARY .......................................................................................................................... ii

1. INTRODUCTION .................................................................................................................................... 1

1.1 Scope of Work .................................................................................................................................... 1

2. ACRONYMS ............................................................................................................................................ 2

3. GLOSSARY ............................................................................................................................................. 3

4. POWER SYSTEM RELIABILITY .......................................................................................................... 4

4.1 Background ......................................................................................................................................... 4

4.2 SYSTEM AVERAGE INTERRUPTION DURATION INDEX (SAIDI) ......................................... 5

4.4 Distribution System ............................................................................................................................ 8

5. METHODOLOGY IEEE GUIDE ............................................................................................................ 9

5.1 Factors that cause variation in reported indices .................................................................................. 9

5.2 Outages that should not be taken into account when calculating indices ......................................... 10

5.3 Example of using MED definition to identify Major Event. ............................................................ 10

5.4 Sample System to calculate SAIDI and SAIFI with no MED .......................................................... 11

5.5 Catastrophic Days ............................................................................................................................. 12

5.6 List of data requested from DES for both 11 kV and 66 kV substations .......................................... 13

6. SYSTEM RELIABILITY CALCULATION FOR BRUNEI DARUSSALAM. .................................... 14

6.1 Step Restoration ................................................................................................................................ 14

6.2 Analysis of three 11 kV substations in Brunei Darussalam .............................................................. 17

6.2.1 SAIDI calculation for 11 kV substations ............................................................................ 18

6.2.2 SAIFI calculation for 11 kV substations ............................................................................. 22

6.3 Analysis of three 66 kV substations in Brunei Darussalam. ........................................................... 23

6.3.1 SAIDI calculation for 66 kV substations ................................................................................... 23

6.3.2 SAIFI ................................................................................................................................... 28

7. POWER OUTAGE ................................................................................................................................. 29

7.1 Causes of power outages. .................................................................................................................. 29

7.1.1 Weather related power outages. ..................................................................................................... 29

7.1.2 Faulty Equipment ........................................................................................................................... 30

7.1.3 Overcurrent .................................................................................................................................... 30

7.1.4 Flashover transformer .................................................................................................................... 30

7.1.5 Animal Contacts ............................................................................................................................. 30

7.1.6 People induced including: pole and overhead contacts and underground digging ........................ 30

Draft dated 27th May 2015 iv

7.1.7 Short Circuit ................................................................................................................................... 30

7.1.8 Electrical Trees ....................................................................................................................... 30

7.2 Examples of power outages (historical blackouts). ..................................................................... 31

8. CONCLUSION ....................................................................................................................................... 32

9. FUTURE WORK .................................................................................................................................... 33

References ................................................................................................................................................... 34

Appendix ...................................................................................................................................................... A

Appendix 1: Power Outages for 2014 and 2013 ...................................................................................... A

Appendix 2: List of required data for accurate calculation of SAIDI and SAIFI ................................... W

Draft dated 27th May 2015 1 of 34

1. INTRODUCTION

More than half of Brunei Darussalam’s revenue comes from the energy sector. The Energy White paper

has outlined three strategic goals to realize Brunei Darussalam’s energy vision. One of the Key

Performance Indicator (KPI) is to reduce the number of power outages by 2035, in line with the goals of

Wawasan 2035 [1].

The main aim of this project is to provide electric power distribution reliability indices, namely System

Average Interruption Duration Index (SAIDI) and System Average Interruption Frequency Index (SAIFI),

to benchmark DES (Department of Electrical Services) and chart improvements used in all utilities

worldwide. As well as to identify root causes of power outages in Brunei Darussalam.

The reliability indices of electric power distribution will follow a set of methodology outlined in IEEE

Guide for Electric Power Distribution Reliability Indices [2] to ensure the indices obtained are consistent

with best practices in the Power Industry.

1.1 Scope of Work

Understand existing distribution equipment and protection philosophy. This includes the

understanding of IEEE Std. 1366-2012 methodology (and other standards Department of

Electrical Services (DES) used) and consultation from DES personnel.

Gather information from DES. Conduct survey at a few substations and their feeders. Create and

understand scenarios given by DES.

Obtain and analyze the data given to calculate SAIDI (in minutes) and SAIFI.

Compare the results obtained for SAIDI and SAIFI with DES.

Write report on SAIDI and SAIFI results and peer review.

Execution plan (Gantt chart) is attached at the back of this report.


2. ACRONYMS

SAIDI System Average Interruption Duration Index

SAIFI System Average Interruption Frequency Index

DES Department of Electrical Services

MIS Main Intake Station


3. GLOSSARY

Customer A metered electrical service point for which

an active bill account is established at a

specific location.

Interruption The total loss of electric power on one or

more normally energy conductors to one or

more customers connected to the distribution

portion of the system.

Interruption Duration The time period from the initiation of an

interruption until service has been

restored to the affected customers.

Major Event An event that exceeds the reasonable design

and or operational limits of the electric

power system.

Major Event Day (MED) A day where the daily SAIDI index exceeds

a Major Event Day (MED) threshold value.

Interruptions which occur on MED should

be separately analyzed.

Momentary Interruption The brief loss of power delivery to one or

more customers caused by opening and

closing operation of an interrupting device.

Usually less than 5 minutes.

Outage The loss of ability of a component to deliver

power.

Planned Interruption The loss of electric power to one or more

customers that results from a planned

outage.

Reporting period The time period from which interruption

data is to be included in the reliability index

calculations.

Sustained Interruption Any interruption not classified as a part of a

momentary event. Interruption which lasts

more than 5 minutes.

Total number of customers served The average number of customers served

during the reporting period. If a different

customer total is used, it must be clearly

defined in the report.


4. POWER SYSTEM RELIABILITY

4.1 Background Electric power system is one of the most important and complex systems created by human. It comprises

countless facilities and structures, systems and subsystems, components and equipments and interactions

between all [3]. It was also reported that more than 50% of reliability depends on the performance of

distribution system [3]

Electric power has become an essential part of humans’ lives up to an extent that it is impossible to live

without electrical power. This stresses the importance of power system reliability. Reliability of power

system is mainly concerned with customer interruptions, thus, it is a subset of power quality [4].

In this report, two main power system reliability indices are looked into, particularly SAIDI (System

Average Interruption Duration Index) and SAIFI (System Average Interruption Frequency Index).

Additional index such as CAIDI (Customer Average Interruption Duration Index) can also be derived

from the initial indices.

There are mainly two main types of interruptions, sustained and momentary. Where sustained interruption

is closely related to reliability issue (more than five minutes), and momentary interruptions as power

quality issue (usually less than five minutes) [2,4].

Figure 1: shows Power Quality Subset [4]


4.2 SYSTEM AVERAGE INTERRUPTION DURATION INDEX (SAIDI)

The System Average Interruption Duration Index (SAIDI) indicates the sum duration of interruption for

the average customer during a predefined set of time [2]. The unit used to measure SAIDI is in minutes

or hours of interruption. The equation used to measure SAIDI is given in Eq. (1)[2].

ServedCustomersofNumberTotal

onInterruptiofMinutesCustomerSAIDI

(1)

To calculate the index, Eq (2) can be used, where ri is restoration time for each interruption event, Ni

stands for number of interrupted customers for each sustained interruption event during a reporting

period, NT is total number of customers served for the area and CMI stands for customer minutes of

interruption [2].

TT

ii

N

CMI

N

NrSAIDI

(2)

Figure 2 shows Unplanned SAIDI for various countries, including exceptional event [5].


Figure 3 shows Unplanned SAIDI for various countries, excluding exceptional events [5]

From Figures 2 and 3, it can be observed that due to the elimination of exceptional events, the SAIDI

decreases.


4.3 SYSTEM AVERAGE INTERRUPTION FREQUENCY INDEX (SAIFI)

The System Average Interruption Frequency Index (SAIFI) shows how frequently the average customer

experiences a sustained interruption over a predefined period of time. The equation used to calculate

SAIFI is (Eq 3) [2].

ServedCustomersofNumberTotal

dInterrupteCustomersofNumberTotalSAIFI

(3)

To calculate the index, Eq (4) can be used. Where CI is customers interrupted [2],

TT

i

N

CI

N

NSAIFI

(4)

Figure 4 shows Unplanned SAIFI for various countries, including exceptional event [5].


Figure 5 shows Unplanned SAIFI for various countries, including exceptional event [5].

4.4 Distribution System

The distribution system is the final stage in delivering electrical power to consumers. An ordinary

distribution system consists of step – down transformer with various lengths (a few hundred meters to

several kilometers), so the voltage can be stepped down to distributed levels for industrial, commercial

and residential users [9].


5. METHODOLOGY IEEE GUIDE In order to accurately develop indices of a power system reliability measurement, IEEE Std 1366-2012

was used as a methodology, so as to obtain consistent results amongst utilities in the region.

A Major Event Day (MED) is an identified day in which the daily system SAIDI exceeds a threshold

value called TMED. Thus, the SAIDI index obtained will be consistent regardless of size of utility and any

anomaly (MED value) which may lead to a higher SAIDI value is analyzed separately and removed from

indices calculation.

A TMED value is typically obtained at the end of each reporting period (one year) for use during the next

reporting period as follows [2]:

Obtain daily SAIDI values for five years, which ends on the final day of the last entire reporting

period.

Only include days which have SAIDI/day value which can contribute in calculation of TMED, i.e

exclude days where interruptions did not occur.

Take the natural log of each daily SAIDI value in the data set

Find alpha, the average of the log of the data set

Find Beta, the standard deviation of the log of the data set.

Compute the MED threshold, using Eq. (5) [2]

)5.2( eTMED (5)

Any day with daily SAIDI greater than the threshold value Tmed that occurs during the subsequent

reporting period is classified as MED.

5.1 Factors that cause variation in reported indices There are various factors that can cause difference in the indices reported by different utilities. Some

examples are in [2];

Level of automated data collection

Geography

System design

Data classification


It is highly essential to classify performance for each day in the data set to be analyzed as either day-to-

day or MED; false decision may occur when this important step is not performed, as MED may disguise

overall daily performance.

5.2 Outages that should not be taken into account when calculating indices

There are several types of outages that should not be included when calculating the indices, such as [2]:

Interruptions that occur as a result of outage on customer – owned facilities

Loss of supply from another utility

Planned interruptions

Momentary interruptions

These interruptions are not included in calculation of SAIDI and SAIFI as to provide uniform and

consistent policy in all four districts. Furthermore, the calculation is done to review and improve current

performance of unplanned events.

5.3 Example of using MED definition to identify Major Event.

The following example shows the calculation of

Daily SAIDI

MED threshold, TMED

Identification of MEDs and calculation of adjusted indices.

Table 1 shows selected data for all interruptions which occur on a certain day for a utility which serves

2000 customers

DATE TIME DURATION

(MIN)

NUMBER OF

CUSTOMERS

INTERRUPTION

TYPE

July 15, 1995

18:34:30 20.0 200 Sustained

July 15, 1995

18:38:30 1.0 700 Momentary

July 15, 1995

18:42:00 513.5 400 Sustained

Table 1 shows Interruption data for July 15, 1995.


For July 15, 1995, daily SAIDI (assumption: a 2000 customer utility) is given in Eq (6):

min7.1042000

)4005.513()20020(

SAIDI

5.4 Sample System to calculate SAIDI and SAIFI with no MED

Table 2 below shows an extract from one utility’s customer information system (CIS) database for feeder

7055 [2], which serve 2000 customers with a total load of 4MW. In this sample system, Circuit 7055 is a

representation for the “system” where the indices are to be calculated. Furthermore, the “system” consists

of all the circuits together in a region for a whole company.

Date Time off Time on Circuit Number of

Customers

Duration

(min) Load kVA

Interruption

type

Jan 17 121220 12:20:30 7055 200 8.17 800 S

Feb 15 18:23:56 18:24:26 7055 400 0.5 1600 M

Mar 13 00:23:10 01:34:29 7055 600 71.3 75 S

Apr 24 23:17:00 23:47:14 7055 25 30.3 4000 S

May 27 09:30:10 09:31:10 7055 2000 1.0 500 M

June 22 15:45:39 20:12:50 7055 90 267.2 2100 S

July 19 08:20:00 10:20:00 7055 700 120 1800 S

Aug 31 17:10:00 17:20:00 7055 1500 10 3000 S

Sep 3 10:15:00 10:55:00 7055 100 40 200 S

Table 2: An example of interruption data for a utility

Note: S – Sustained Interruption, M – Momentary Interruption

Equations (2) and (3) should be used to calculate the annual indices, using the data shown in Table 2,

assuming there were no MEDs in the data.

min11.862000

)10040()150010()700120()902.267()253.30()6003.71()20017.8(

SAIDI

61.12000

10015007009025600200

SAIFI


5.5 Catastrophic Days

It is assumed that, when calculating the daily SAIDI and the 2.5β method, the distribution of the natural

log values will look like a Gaussian distribution (a bell-shaped curve) [2]. Events such as hurricanes or ice

storms typically result in abnormally higher daily SAIDI values, and these events are called “catastrophic

events”, and have a slim probability of happening [2].

It is typical for catastrophic event, which leads to higher SAIDI values to exist in data sets and this will

cause relatively small outward shift in the resulting reliability metric trends [2]. Thus, measures have been

taken to identify and process catastrophic, in order to remove the effect it has on reliability metric trends

[2].

Furthermore, when catastrophic events are not taken into account, this may cause a huge increase in the

events identified as MEDs. It was also proposed that catastrophic events should be processed and

determined on an individual company basis by regulators and utilities itself, as no universal solution has

been devised to achieve acceptable results [2].


5.6 List of data requested from DES for both 11 kV and 66 kV substations 2013 2014

Data Requested

Mentiri

Substation

Beribi

Substation

Kuala

Belait

Substation

Mentiri

Substation

Beribi

Substation

Kuala

Belait

Substation

Date of power

outage

Duration of power

outage

Number of

customers

interrupted

Number of

customers served

Step restoration

information

Stages

required to

restore

power

Duration to

restore

power at

each stage

Number of

customers

restored at

each stage

Causes of outage


6. SYSTEM RELIABILITY CALCULATION FOR BRUNEI

DARUSSALAM.

6.1 Step Restoration When power outages occur, power is not always fully restored in one stage, but, it takes a series of stages

to restore power to all interrupted customers, this process is called step restoration. A sample calculation

is shown below to illustrate how SAIDI is calculated when step restoration takes place. It is also

important to know the duration of outages during restoration and number of customers restored at a

particular restoration time to accurately calculate SAIDI.

Figure 6: Single line network representation


Figure 6 shows a representation of single line network. A sample case of step restoration can be broken

down into a few steps as follow:

When a fault occurs at X, Breaker number 1 opens and isolates the fault. Operation on Breaker

number 1 also opens the load break switch (LBS) of substations A, B, C and D. At this point,

outage of power occurs at A, B, C and D

Operator is sent to site to locate the Fault Circuit Indicator (FCI) which identifies the fault

location path.

1. LBS at A1 is closed to restore partial power. Since load at substation A is restored, then

A2 is closed.

2. Operator arrives at substation B, checks the FCI and closes LBS B1 to restore partial

power. Since the load at substation B1 is restored, then B2 is closed.

3. Operator arrives at substation C, checks the FCI and closes LBS C1 to restore partial

power. Since the load at substation C1 is restored, then C2 is closed.

4. Operator arrives at substation D, checks the FCI and closes LBS D1 to restore partial

power. Since the load at substation D1 is restored, and then D2 is closed but due to the

presence of fault, power is not restored back to the affected customers, and fault is

detected. This fault is then isolated and reported by operator.

Permanent repairs are completed, and power to all customers is restored. The outage event is

concluded.

One example of step restoration took place in Kuala Belait on the 28th of March 2014; the number of

customers restored at each restoration was not known in detail. Thus, percentages of customers restored

are used to illustrate how the amount of customers initially restored affects the SAIDI value.

Three sample cases are tabulated to calculate SAIDI where the percentages of customers restored are

varied.

The three sample cases are:

In Table 4: Equal number of customers is restored in four separate restoration times (25%).

In Table 5: More customers are restored in the first 20 minutes (75%)

In Table 6: Remaining 75% of customers restored after 80 minutes.

Scenario orders numbered 1-4, in Tables 4, 5 and 6 represent the steps (stages) taken to close each LBS

(A B, C and D – refer to Figure 6), locate the fault and restore power back to interrupted customers


Scenario

Order

% of

customers

restored

Customers

restored

Customers

remaining

interrupted

Time

off

Time

on

Interruption

duration

(min)

Customers

interrupted

(CI)

Customer minutes

of

interruption(CMI)

- 0% 0 3144 - -

1 25% 786 2358 12:00 12:20 20 786 15720

2 25% 786 1572 12:00 12:40 40 786 31440

3 25% 786 786 12:00 1:00 60 786 47160

4 25% 786 0 12:00 1:20 80 786 62880

100% 3144 - - - - 3144 157200

SAIDI in

mins

50

Table 4: Sample step restoration with equal number of customers at each stage

Scenario

Order

% of

customers

restored

Customers

restored

Customers

remaining

interrupted

Time

off

Time

on

Interruption

duration

(min)

Customers

interrupted

(CI)

Customer minutes

of

interruption(CMI)

- 0% 0 3144 - -

1 75% 2358 786 12:00 12:20 20 2358 47160

2 10% 314 471 12:00 12:40 40 314 12576

3 10% 314 157 12:00 1:00 60 314 18864

4 5% 157 0 12:00 1:20 80 157 12576

100% 3144 - - - - 3144 91176

SAIDI in

mins

29

Table 5: Sample step restoration where 75% of customers are restored in the first 20 minutes


Scenario

Order

% of

customers

restored

Customers

restored

Customers

remaining

interrupted

Time

off

Time

on

Interruption

duration

(min)

Customers

interrupted

(CI)

Customer minutes

of

interruption(CMI)

- 0% 0 3144 - -

1 5% 157 2987 12:00 12:20 20 157 3144

2 10% 314 2672 12:00 12:40 40 314 12576

3 10% 314 2358 12:00 1:00 60 314 18864

4 75% 2358 0 12:00 1:20 80 2358 188640

100% 3144 - - - - 3144 223224

SAIDI in

mins

71

Table 6: Sample step restoration where 75% of customers are restored in the last 20 minutes

From the SAIDI values obtained from Table (4), Table (5) and Table (6) above, it can be observed that

SAIDI value is smaller when the first batch of customers restored are higher (29 mins from Table 5).

Meanwhile, when the remaining 75% of customers are restored after 80 minutes, the SAIDI value

increases to 71 minutes and when equal number of customers restored takes place at each restoration

time, the value of SAIDI lies in between 71 and 29 minutes, that is 50 minutes.

In conclusion, when the distribution of customers restored and the number of customers restored at each

restoration time are not known, it can be seen that, the SAIDI value lies more towards the time when the

largest number of customers are restored at.

6.2 Analysis of three 11 kV substations in Brunei Darussalam

To carry out the calculation to estimate the SAIDI and SAIFI for Brunei Darussalam, three 11 kV

substations have been analyzed, which are:

Kuala Belait Substation

Mentiri Substation

Beribi Substation


6.2.1 SAIDI calculation for 11 kV substations To develop the estimates of SAIDI for the three 11 kV substations, a few parameters were looked into in

the power outages data provided by DES (Appendix 2), as mentioned in previous chapter (Chapter 5).

The parameters are:

If restoration of power occur in full or in steps (step restoration)

If Major Event Day (MED) is involved (outage which will increase the SAIDI value – typically

due to natural disasters where outages can last for days)

A few step restoration scenarios were identified in Kuala Belait outages in year 2014 and 2013 (no step

restoration identified in Beribi and Mentiri). The identified step restoration outages are highlighted in

Appendix 2. Further breakdown on calculation of SAIDI for step restoration is laid out below (Tables 7-

11). The calculation of SAIDI which involves step restoration cannot be done accurately as the number of

customers restored at a particular restoration time is not known in detail.

Moreover, due to unavailability of five historical years of data, calculation of MED threshold, as per

reference from IEEE Std 1366-2012 [2] cannot be performed. Thus, in this calculation, it is assumed that

equal number of customers are restored at each restoration time.

KB outage on 22/06/2013

Scenario

order

% of

customers

restored

Customers

restored

Customers

remaining

interrupted

Time off Time on

Interruption

duration

(min)

customers

interrupted

(CI)

Customer

minutes of

interruption

(CMI)

- 0% 0 50 - - - -

1 50% 25 25 7:00 AM 9:40 AM 160 25.00 4000

2 50% 25 0 7:00 AM 10:45

AM 225 25.00 5625

TOTAL 100% 50 - - - - 50.00 9625

Table 7: Step restoration calculation for power outage in KB on 22/06/2013


KB outage 03/08/2013

Scenario

order

% of

customers

restored

Customers

restored

Customers

remaining

interrupted

Time off Time on

Interruption

duration

(min)

customers

interrupted

(CI)

Customer

minutes of

interruption

(CMI)

- 0% 0 3309 - - - -

1 50% 1655 1655 11:30 AM 4:00 PM 270 1655 446715

2 50% 1655 0.00 11:30 AM 10:00

PM 630 1654.50 1042335

TOTAL 100% 3309 - - - - 3309.00 1489050


KB Outage 20/01/2014

Scenario

order

% of

customer

s

restored

Customers

restored

Customers

remaining

interrupte

d

Time off Time

on

Interruption

duration

(min)

customers

interrupted

(CI)

Customer

minutes of

interruption

(CMI)

- 0% 0 8867 - - - -

1 33% 2956 5911 6:20 PM 7:03 PM 43 2956 127093

2 33% 2956 2955 6:20 PM 8:55 PM 155 2956 458127

3 33% 2955 0.00 6:20 PM 10:40

PM 260 2955 768471

TOTAL 100% 8867 - - - - 8867 1353692



Scenario

order

% of

customers

restored

Customers

restored

Customers

remaining

interrupted

Time off Time on

Interruption

duration

(min)

customers

interrupted

(CI)

Customer

minutes of

interruption

(CMI)

- 0% 0 4445 - - - -

1 50% 2223 2222 12:15

PM 5:00 PM 285 2223 633412

2 50% 2222 0.00 12:15

PM 5:25 PM 310 2222 688975

TOTAL 100% 4445 - - - - 4445 1322387



KB Outage 28/05/14

Scenario

order

% of

customers

restored

Customers

restored

Customers

remaining

interrupted

Time off Time

on

Interruption

duration

(min)

customers

interrupted

(CI)

Customer

minutes of

interruption

(CMI)

- 0% 0 3144 - - - -

1 33% 1048 2096 11:37 AM 1:15 PM 98 1048 102703

2 33% 1048 1048 11:37 AM 5:15 PM 338 1048 354224

3 33% 1048 0.00 11:37 AM 6:00 PM 383 1048 401384

TOTAL 100% 3144 - - - - 3144 858311


To calculate the SAIDI values for Kuala Belait, Mentiri and Beribi; the number of customers served at

each is defined in Table 10, this information is obtained from DES.

Venue Number of customers served Description

Kuala Belait 19121 Total number of accounts in

KB

Mentiri *84167 Total number of accounts in

Brunei Muara

Beribi *84167 Total number of accounts in

Brunei Muara

Table 12: Number of customers served

*NOTE: No detailed information on the number of customers served in Mentiri and Beribi, thus total

number of accounts in Brunei Muara is used.

Upon calculation of customer minutes of interruptions (CMI) for respective 11 kV substations for year

2013 and 2014 (Appendix 2), SAIDI values were calculated and have been tabulated in Figures 7a and 7b

as shown below.


Figure 7a: SAIDI chart for 11 kV substations

Figure 7b: SAIDI chart for 11 kV substations - with step restoration analysis


6.2.2 SAIFI calculation for 11 kV substations

Estimate of SAIFI is carried out for the three substations mentioned earlier. It is observed that the value of

SAIFI for Kuala Belait and Mentiri increases from 2013 to 2014, this is possibly due to deteriorating of

the equipment for example excess lightning, storm and animal contact.

Figure 8: SAIFI chart for 11 kV substations


6.3 Analysis of three 66 kV substations in Brunei Darussalam. Three representative 66 kV substations have also been analyzed to obtain the SAIDI and SAIFI values,

which are:

Kuala Belait Substation

Mentiri Substation

Beribi Substation

6.3.1 SAIDI calculation for 66 kV substations

To develop the estimates of SAIDI for the three 66 kV substations, a few parameters were looked into in

the power outages data provided by DES (Appendix 2), as mentioned in previous chapter (Chapter 5).

The parameters are:

If restoration of power occur in full or in steps (step restoration)

If Major Event Day is involved (outage which will increase the SAIDI value – typically due to

natural disasters where outages can last for days)

A few step restoration scenarios were identified in Kuala Belait outages in the year 2014 and 2013. From

the data given by DES, there were no recorded outages in 66 kV substations Mentiri for year 2014 and

Beribi for the year 2014 and 2013. Further breakdown on calculation of SAIDI for step restoration is laid

out below (Tables 13- 21). The calculation of SAIDI which involves step restoration cannot be done

accurately as the number of customers restored at a particular restoration time is not known in detail.

Thus, in this calculation, it is assumed that equal number of customers are restored at each restoration

time.

KB Outage on 04/06/2014

Scenario

order

% of

customers

restored

Customers

restored

Customers

remaining

interrupted

Time off Time on

Interruption

duration

(min)

customers

interrupted

(CI)

Customer

minutes of

interruption

(CMI)

- 0% 0 9561 - - - -

1 50% 4781 4780 1:30 PM 1:55

PM 25 4781 119512

2 50% 4780 0 1:30 PM 2:35

PM 65 4780 310732

TOTAL 100% 9561 - - - - 9561 430245




Scenario

order

% of

customers

restored

Customers

restored

Customers

remaining

interrupted

Time off Time

on

Interruption

duration

(min)

customers

interrupted

(CI)

Customer

minutes of

interruption

(CMI)

- 0% 0 9561 - - - -

1 33% 3187 6374 11:15 AM 12:45

PM 90 3187 286829

2 33% 3187 3187 11:15 AM 1:23

PM 128 3187 407936

3 33% 3187 0 11:15 AM 1:47

PM 152 3187 484424

TOTAL 100% 9561 - - - - 9561 1179189



Scenario

order

% of

customers

restored

Customers

restored

Customers

remaining

interrupted

Time off Time on

Interruption

duration

(min)

customers

interrupted

(CI)

Customer minutes

of interruption

(CMI)

- 0% 0 9561 - - - -

1 50% 4781 4780 10:19 PM 10:50

PM 31 4781 148195

2 50% 4780 0 10:19 PM 11:23

PM 64 4780 305952

TOTAL 100% 9561 - - - - 9561.00 454147

Table 15: Step restoration calculation for power outage in KB on 07/08//2014


Scenario

order

% of

customers

restored

Customers

restored

Customers

remaining

interrupted

Time off Time on

Interruption

duration

(min)

customers

interrupted

(CI)

Customer

minutes of

interruption

(CMI)

- 0% 0 742 - - - -

1 25% 186.00 556.00 6:37 AM 8:57 AM 140 186 26040

2 25% 185.00 371.0 6:37 AM 9:45 AM 188 185 34780

3 25% 185.00 186.00 6:37 AM 10:55 AM 258 185 47730

4 25% 186.00 0 6:37 AM 12:56 PM 379 186 70494

TOTAL 100% 556 - - - - 742 179044




Scenario

order

% of

customers

restored

Customers

restored

Customers

remaining

interrupted

Time off Time on

Interruption

duration

(min)

customers

interrupted

(CI)

Customer

minutes of

interruption

(CMI)

- 0% 0 180 - - - -

1 33% 60.00 120.00 10:50

AM 12:45 PM 115 60.00 6900

2 33% 60.00 60.0 10:50

AM 2:10 PM 200 60.00 12000

3 33% 60.00 0 10:50

AM 6:09 PM 439 60.00 26340

TOTAL 100% 180 - - - - 180 45240



Scenario

order

% of

customers

restored

Customers

restored

Customers

remaining

interrupted

Time off Time on

Interruption

duration

(min)

customers

interrupted

(CI)

Customer

minutes of

interruption

(CMI)

- 0% 0 6235 - - - -

1 50% 3118 3118 1:15 PM 2:05 PM 50 3118 155875

2 50% 3118 0 1:15 PM 2:57 PM 102 3118 317985

TOTAL 100% 6235 - - - - 6235 473860


KB Outage 18/07/13

Scenario

order

% of

customers

restored

Customers

restored

Customers

remaining

interrupted

Time off Time on

Interruption

duration

(min)

customers

interrupted

(CI)

Customer

minutes of

interruption

(CMI)

- 0% 0 13158 - - - -

1 50% 6579 6579 8:37 PM 9:00 PM 23 6579 151317

2 50% 6579 0 8:37 PM 9:38 PM 61 6579 401319

TOTAL 100% 13158 - - - - 13158 552636



KB outage 02/08/2013

Scenario

order

% of

customers

restored

Customers

restored

Customers

remaining

interrupted

Time off Time on

Interruption

duration

(min)

customers

interrupted

(CI)

Customer

minutes of

interruption

(CMI)

- 0% 0 6279 - - - -

1 33% 2093.00 4186.00 10:48 PM 12:21 AM 93.00 2093 194649

2 33% 2093.00 2093.0 10:48 PM 12:52 AM 124.00 2093 259532

3 33% 2093.00 0 10:48 PM 1:26 AM 158.00 2093 330694

TOTAL 100% 6279 - - - - 6279 784875



Scenario

order

% of

customers

restored

Customers

restored

Customers

remaining

interrupted

Time off Time on

Interruption

duration

(min)

customers

interrupted

(CI)

Customer

minutes of

interruption

(CMI)

- 0% 0 116 - - - -

1 50% 58 58 10:00

AM 11:14 AM 74 58 4292

2 50% 58 0 10:00

AM 11:45 AM 105 58 6090

TOTAL 100% 116 - - - - 116.00 10382


Upon calculation of customer minutes of interruptions (CMI) for respective 66 kV substations for year

2013 and 2014 (Appendix 2), SAIDI values were calculated and have been tabulated in Figures 9a and 9b

as shown below.


Figure 9a: SAIDI chart for 66 kV substations

Figure 9b: SAIDI chart for 66 kV substations with step restoration calculation


6.3.2 SAIFI

SAIFI calculations have been carried out for the three substations mentioned earlier. It can be observed

that the SAIFI values for Kuala Belait and Mentiri decrease from 2013 to 2014. Since, there were no

recorded outages in Beribi for the two consecutive years, the SAIFI value remains zero.

Figure 10: SAIFI chart for 66 kV substations


7. POWER OUTAGE

Power system outage means a failure of part of the power supply system for example transformer out of

service, an open breaker when it should be closed, and a line down [6], a power outage consequentially

will lead to a number of consumers being in an absence of electrical energy for a duration of time [3].

Power outage can last a few hours up to several days, and this may greatly impact businesses,

manufacturers (in downtime and lost production) [8], and hospitals.

7.1 Causes of power outages.

There are several reasons that may contribute to power outages, such as weather – related outages (i.e

lightning, rain) and other outages caused by man and animals. While it is possible to identify the causes of

power outages, absolute future power outage prevention is highly unlikely to take place, but it can be

minimized up to a certain degree.

Weather related power outages

Faulty equipment – faulty underground cable

Overcurrent – trip

Flashover transformer

Animal contacts

People induced including – pole and overhead contacts underground digging [9]

7.1.1 Weather related power outages.

A large number of power failures and outages are caused by natural weather such as thunderstorm, high

winds, snow, ice and even dust [7]. In Brunei Darussalam, the occurrence of lightning and thunderstorm

is highly frequent, thus, this can be categorized as one of the main causes of power outages in this

country. Power outages are mainly caused by damage from trees falling on electrical lines and poles,

especially on longer transmission lines which carry bulk power [8], thus circuit breakers or other

protective equipment shut off power flow [13]


7.1.2 Faulty Equipment

Faulty underground cable has also been identified as one of the reasons for power outages in Brunei

Darussalam.

7.1.3 Overcurrent

Overcurrent occurs when excessive electric current flows through a conductor, which may dangerously

lead to excessive generation of heat and cause failure in equipment. Thus, circuit breakers trip to shut off

power flow.

7.1.4 Flashover transformer

This happens when power lines touch each other or the ground, and consequently lead to short circuit and

an arc or a flashover.

7.1.5 Animal Contacts

Animals such as monkeys and squirrels may climb on certain pieces of equipment (transformers and

fuses), which consequently causes the equipment to shut down [13].

7.1.6 People induced including: pole and overhead contacts and underground

digging

Pole and overhead contacts during maintenance and excavation work by contractors may accidentally hit

underground cables, thus, directly affecting power supply [9].

7.1.7 Short Circuit

Short circuit happens when an electric current travels a different path from the planned one in an

electrical circuit [7]. Due to the excessive electric current, this may lead to circuit damage and

consequentially fire and explosion.

7.1.8 Electrical Trees

Electrical treeing is a scenario which affects high power installations such as high power cables and

transformers [7]. Partial electric discharges may form in the equipment due to impurities or mechanical

defect used in high voltage installations [7]. If the fault goes undetected, this can lead to constant

degradation of the equipment and finally result in a major breakdown – power loss [7]


7.2 Examples of power outages (historical blackouts).

Power outages are common in this modern world, but its adverse effects have played a major role in

trying to improve the electrical power system. Some power outages have affected thousands of people,

and lasted for a couple of days, in which, this has led to further economic losses.

Brazil and Paraguay (10 November 2009)

This outage occurred due to natural event; where continuous heavy rain and strong winds had caused a

number of transformers to short circuit and consequentially shutting all 20 turbines in the hydroelectric

power plant due to sudden fall of power demand. This incident has put a halt to subways operations, and

most of Brazil’s phone network collapsed. This outage has affected about 87 million people, and lasted

from 25 minutes to 7 hours [10].

India (2 January 2001)[cite]

A technical failure, more specifically, failure of substation in Uttar Pradesh has caused a widespread

of power outages which affected major hospitals, treatment plants, and pumping stations. As a result

from this failure, millions of people were affected as the water supply broke down. The outage has

also caused chaos in train and land operations. This disruption has affected 226 million people, and

lasted for 12 hours and economic losses were estimated to be USD 110million [10].

USA (North – East) + Canada (Central) 14 August 2003.

A large area of Midwest and Northeast United States and Ontario, Canada suffered from power

outages due to human error, lack of maintenance and total equipment break down. The power outage

lasted for four consecutive days and 50 million people were affected. A total economic loss of USD 6

Billion was also recorded. [10]

From the list of examples of outages, it can be observed that reliability of electrical power system plays a

major role in everyday life. A power outage may last from a few hours to a few days, and the economic

loss a country has to endure during this period can reach billions of dollars. Thus, it is important to put

emphasis on reliability of power system, to benchmark and simultaneously improve the electrical power

system supplied to consumers.


8. CONCLUSION

Reliability indices measurement for SAIDI and SAIFI has been carried out for three 11 kV and 66 kV

substations in Brunei Darussalam which are Kuala Belait, Mentiri and Beribi substation. Different types

of interruptions were looked into, and to provide consistent policy to all four districts, only sustained and

unplanned interruptions are included to review and improve current reliability performance.

In the event of widespread of power outages, restoration of power needs to be done in stages (steps).

Thus, step restoration sample calculation has been outlined to calculate SAIDI more effectively, by

varying the number of customers restored per stage since the number of customers restored at each stage

is not known in detail. A few causes of power outages have also been identified in Brunei Darussalam

such as weather – related causes (lightning and thunderstorms), faulty equipment, and animal contacts.

Furthermore, collection of more data (five years of data) would enable the study of the reliability trend of

SAIDI and SAIFI numbers. Specific power outages could also be identified such as problematic circuits

or failing of specific equipment, thus, further corrective action can be taken to benchmark DES to other

utilities worldwide.

This power failure may affect a large number of people and may greatly impact businesses,

manufacturers, hospitals and cause economic losses; thus, improving power reliability is of utmost

importance.


9. FUTURE WORK

From the SAIDI and SAIFI calculations developed for Brunei Darussalam, a few measures can be taken

to improve the accuracy of the calculations, such as having a more detailed record of power outages. DES

is currently doing a remarkable job at recording power outages across Brunei Darussalam; further

addition on the number of customers restored at each restoration stage would greatly increase the

accuracy of SAIDI and SAIFI calculation.

One of the causes of prolonged power outages in Brunei Darussalam is due to the delay in mobilization of

personnel to affected areas. Further design improvement of distribution systems using Smart Grid

technologies [13] would identify fault location, and enable personnel to reach the affected area faster,

thus, a decrease in time to normalize the power outage [11] and a reduced SAIDI number.

Furthermore, implementation of advanced intelligent real–time communications-based load shedding

schemes can be employed to minimize the number of customers interrupted by matching actual loads to

required loads to be shed [14]. Typically, pre–determined feeders regardless of actual load (based on peak

loading conditions) are selected to shed the required loads.

Assume priority order for load shedding is Feeder 1, Feeder 2, Feeder 3 and finally, Feeder 4. Assume

that the required load shed in stage 1 under frequency is 8 MW. Assuming peak loading for Feeder 1,

Feeder 2, Feeder 3 and Feeder 4 is 2, 3, 5 and 8 MW, respectively. During the requirement for under

frequency load shedding, the actual loading is 1, 2, 3 and 6 MW respectively. This conventional scheme

will result in a total of 12 MW; 4 MW greater than what is necessary. Thus, the utilization of intelligent

load shedding [14] would only select Feeder 2 and Feeder 4 to total 8 MW and unnecessary load shedding

can be avoided and a better SAIDI and SAIFI number achieved.


References

[1] Energy Department, Prime Minister’s Office, Energy White Paper, Bandar Seri Begawan: Energy

Department, Prime Minister’s Office, 2013.

[2] IEEE Guide for Electric Power Distribution Reliability Indices, IEEE Std 1366-2012, 2012.

[3] Marko Cepin, “Assessment of Power System Reliability: Methods and Applications”, London:

Springer. [Online].

[4] Richard E. Brown, “Electric Power Distribution Reliability”, 2nd

edition, USA: CRC Press, 2008

[Online]

[5] Council of European Energy Regulators, “CEER Benchmarking Report 5.1 on the Continuity of

Electricity Supply”, CEER, Brussels, Belgium, REF: C13-EQS-57-03, 2014 [Online].

[6] H. Lee Willis, “Power Distribution Planning Reference book”, 2nd

edition, USA: New York: Marcel

Dekker AG, 2004.

[7] “The Many Causes of Power Failures” Internet:

http://www.dieselserviceandsupply.com/Causes_of_Power_Failures.aspx, [Apr. 31, 2015]

[8] Richard J. Campbell “Weather – Related Power Outages and Electric System Resiliency”,

Congressional Research Service, 2012.

[9]“ Distribution Feeder Principles” Internet:

https://www.gedigitalenergy.com/multilin/resource/Feeder/UniFlip_Publication/document.pdf [Date

accessed]

[10] “Power Blackout Risks”. Internet:

https://www.allianz.com/v_1339677769000/media/responsibility/documents/position_paper_power_blac

kout_risks.pdf

[11] “ How the Smart Grid Makes Restoration Faster and Easier for Utilities” Internet:

http://www.silverspringnet.com/outage/pdfs/SilverSpring-Whitepaper-Outage.pdf

[12] “Causes of Power Outages” Internet: https://www.duke-energy.com/north-

carolina/outages/causes.asp

[13] “ Smart Grid Investments Improve Grid Reliability, Resilience, and Storm Responses”

https://www.smartgrid.gov/sites/default/files/doc/files/B2-Master-File-with-edits_120114.pdf

[14] Farrokh Shokooh, et. Al. “An Intelligent Load Shedding (ILS) System Application in a Large

Industrial Facility,” in Proc. Industry Applications Conference, 2005, pp. 417-425, vol. 1.

http://www.dieselserviceandsupply.com/Causes_of_Power_Failures.aspx

https://www.gedigitalenergy.com/multilin/resource/Feeder/UniFlip_Publication/document.pdf

https://www.duke-energy.com/north-carolina/outages/causes.asp

https://www.duke-energy.com/north-carolina/outages/causes.asp

Draft dated 27th May 2015 A

Appendix

Appendix 1: Power Outages for 2014 and 2013 Kuala Belait Outages for 2014 (for 11 kV substation)

Date Description Action Taken Time off Time on Duration of

Interruptio

n in mins

Affected area No. of

custo

mers

affecte

d

Customer

minutes of

interruption

07-

01-14

Transformer tripped at

substation Telekom

Fault was due to bushing

HT terminal yellow phase

which leaked. Temporary

power supplied through

gengset. Transformer was

replaced by SEC

Mashibah at 8.00 am and

power supply is

normalized.

7.45pm 9.30pm 105

2 210

20-

01-14

Faulty underground cable

from substation Jalan A until

X22

Found out that MIS Setia

Di-Raja TAMCO (panel

10) and MIS Hospital

(Panel 3 – Panglima 1)

tripped.

Sg Tujoh and Mumong

received power at 7:03

PM.

Jln Panglima and Jalan

Maulana received power

at 8:55PM.

JlnPandan received power

at 10:40 PM

6.20pm 10:40pm 260 PekanBelait

Kg Pandan

RPN Kg Pandan

Pandan 3&4

Pandan 6

Kg Mumong Utara

Kg Mumong Selatan

Mumong (postpaid)

JalanSetiaDiraja

8867 1353692

31-

03-14

Incoming panel number 2

from SetiaDiraja tripped on

o/c at MIS BatuTiga

Overcurrent trip triggered,

open bus section to

distribute loading.

7:00pm 7:28pm 28 Pandan 6

Kg Pandan

4473 125244

Draft dated 27 May 2015 B

RPN Kg Pandan

JalanMaulana

JalanMaulana,

SgPandan

11-

05-14

Faulty underground cable

from in between substation

Pandan 5 and Substation

Wisma Yakin

Power supply given from

S/S Kerma Negara to S/S

Wisma Yakin at 5:00PM.

Power supplied from S/S

Batu 2 to S/S Pandan 5 at

5:25 PM

12:15pm 5:25pm 310 Kg Pandan

RPN Kg Pandan

JalanMaulana

JalanMaulana,

SgPandan

4445 1322387

28-

05-14

RMU flashover at substation

H3 Spg 15 Pandan 5

Trip at TAMCO MIS

SetiaDiraja Panel 5 and

found RMU flashover at

S/S H3.

Normalised affected area

at 1:15 PM.

Temporary power given

to Spg 15 at 5:15 PM.

Spg 29 and Spg 80-22

received power supply at

6:30 PM.

Repairs of RMU started at

6:00 PM and ended at

12:50 AM.

11:37 PM 6:00 PM 98

JalanMaulana

JalanMaulana, Sg.

Pandan

Kg Pandan

RPN Kg. Pandan

Pandan 3&4

3144 858311

09-

07-14

1000KVA transformer

flashover at substation H21

Spg 2431-3

Temporary power supply

given through gengset

from 8:00 PM until 2:50

AM. Power normalized

back at 3:00 AM.

5:00 pm 8:00 pm 180 JalanMaulana

JalanMaulana,

SgPandan

Pandan

Kg. Pandan

RPN Kg. Pandan

3092 556560

Draft dated 27 May 2015 C

21-

07-14

Panel 5 Panaga Fuji to circuit

Kuala Balai trip on

overcurrent

Switch on again.

Intermittent fault.

9:30 am 11:15 am 105 Kg Kuala Balai 169 17745

31-

07-14

Panel number 5 to circuit

Kuala Belait trip on

overcurrent at MIS Panaga

Switch on again.

Intermittent fault.

7:00 pm 7:15pm 15 Kg Kuala Balai 169 2535

09-

08-14

Panel number 5 Fuji to

circuit Kuala Balai trip on

overcurrent at MIS Panaga

Switch on again.

Intermittent fault.

5:45pm 7:30 pm 105 Kg Kuala Balai 169 17745

02-

11-14

Fault 800KVA transformer at

substation Buruh housing

Temporary power

supplied through 500

kVA started at 4:20 PM.

2:45pm

4:20pm

95 Kg Mumong Utara

Kg Mumong Selatan

Mumong (postpaid)

3627 344565

09-

12-14

ERM feeder (Substation

SekolahPersediaan Arab to

Substation Mumong A) trip

due to BSP contractor

(seismic project) hit

underground cable (blue

phase) between substation

Jati 6 and Jati 7.

Affected areas normalized

at 3:20 pm.

2:07 pm

3:20 pm 73 Kg Mumong Utara 2582 188486

Kuala Belait Outages for 2013 (11 kV substation)


Interruptio

n in mins


custo

mers

affecte

d

Customer

minutes of

interruption

31-12-13 Received complaint from

144 informing low voltage

Low voltage found at S/S

w7 and S/S Batu 4 due to

66 kV transformer at MIS

Panaga low tapping and

changed tapping from 6 to

9.

10:00 PM 12:00 AM 120 JalanMaulana

JalanMaulana

(postpaid)

901 108120

Draft dated 27 May 2015 D

02-01-13 Flashover of transformer at

substation Jati 1 Spg 120-

48-35-9

Changed to a new

transformer. Temporary

power supplied using two

gengset.

5:00 PM 12:00 AM 420 STKRJA area, SPG

120-48-35-9, SPG

120-48-35-10 and

JalanDipa Negara

189 79380

04-03-13 Faulty underground cable

from human work?

Isolated faulty cable

between MIS Batu 3 until

S.S Eng Hong. Supplied

power through ring.

9:30AM 12:05 PM 155 JalanMaulana

JalanMaulana

(postpaid)

JalanPandan 1

JalanPandan 2

JalanPandan 3

Pandan 7

Pandan 8

1305 202275


from MIS BT.3 to

substation Eng Hong

Power supplied via

alternative circuit.

8:50 AM 9:31 AM 41 JalanSingaMenteri

Pandan 8

667 27347


between MIS Panaga to

Substation Kuala Balai

Power supplied from 4

gengset at S/S Kuala Balai.

9:40 AM 6:30 PM 530 JalanSingaMenteri

Kuala Balai

545 288850

26-04-13 Power cut off Power cut off due to

animal contact on jumper

HT cable and aerial cable,

which caused breaker at

Panel Bandaran to get

tripped. Switched off

supply to S/S SgDuhon and

switched breaker back on

at MIS SetiaDiraja.

4:25 PM 4:45 PM 20 Jalan Sungai Duhun 7 140

22-6-13 Power cut off Found RMU 2R2T (ABB)

flashover at s/s Kuala Balai

A. Temporary power

supplied using 4 gengset.

7:00 AM 10:45 AM 225 Jalan Kuala Balai 50 11250

13-07-13 Power cut off Found out transformer

1000Kva tripped at S/S

8:18 AM 9:45 AM 87 309 26883

Draft dated 27 May 2015 E

Kuala Balai E HjTalip.

Switched back on, and

normalized affected area.

16-07-13 No power Found faults at station

transformer. Temporary

power supplied using

mobile generator.

7:50 PM 10:45 PM 175 1 175


due to human work??

Found out underground

cable from Jati 7 to S/S

penapisan najis 1 (JKR)

faulty and a trip at MIS

Panaga. Isolated faulty

underground cable and

found out more faults at

cable from S/S Mumong to

package unit (RMU) at

S/S. Power supply

normalized at 4:00 PM

except Spg 284 Mumong,

power supplied through

generator at S/S Saluran

najis at 10: 00 PM

11:30 AM 10:00 PM 630 JalanSingaMenteri

Pandan 8

Mumong B

Kg Mumongutara

Mumong (postpaid)

3309 2084670

26-08-13 Power cut off Checked and found out

transformer No. 3 tripped

due to overcurrent at MIS

Setia DiRaja Siemen.

Transformer switched back

on and normalized affected

areas.

1:45 PM 3:30 PM 105 Pekan KB

Kg Pandan

RPN Kg Pandan

JlnMaulana, SgPandan

(postpaid)

Pandan 3&4

Pandan 6

5210 547050

27-08-13 Power cut off 1000 kVA transformer

tripped at S/S Jalan Patai.

Transformer switched back

on.

4:00 PM 4:30 PM 30 JlnPetai

LubokNipah

56 1680

14-10-13 Power cut off Electricity tripped at

TAMCO Panel 5 at MIS

10:50 AM 12:26 PM 96 JalanSetiaPahlawan 217 20832

Draft dated 27 May 2015 F

Setia Di Raja. Found out

there was a flashover at

termination in RMU in S/S

Pejabat Elecktrik.

Normalised affected areas.

JalanSgSatu

Pandan 5

Pandan 6

Beribi Outages for 11kV substation 2014


Interruptio

n in mins


custome

rs

Affected

Customer

minutes of

interruption

30-03-14 Substation Jalan Jasmin

Beribi

Feeder T tripped.

The RMU oil type (Long

&Crowfort).

Change to RMU (Brush

Hacker Siddley)

2:00 PM 3:30 PM 90 Jalan Jasmin Kg

Beribi

17 1530

21-04-14 Overcurrent due to load

transfer

Transferred load and

energized one by one by

considering the load.

9:00 AM 11:32 AM 152 Baiduri Bank

Kg Kiarong

Kg Beribi

Kg Kiulap

5496 835392

22-05-14 MIS Telanai P#13

tripped and indicated

earthfault and

overcurrent.

HV underground yellow

phase faulty.

12:30 AM 1:50 AM 80 Spg 493, Spg 2,

Flat E, SgSunda

Housing

New Housing Kg

Beribi

75 10500

21-09-14 MIS Beribi Industry

Phase 1 P#4 tripped to

ERM Beribi Industry 3

and indicated earthfault.

3:00 AM 4:30 PM 90 Light Beribi

Industrial area

5 450

Draft dated 27 May 2015 G

22-09-14

HV cable faulty

transformer to ERM.

HV cable blue phase

faulty from ERM Beribi

Industry 3 to substation

Industry 5 faulty

11:30 AM 12:00 AM

30

Light Beribi

Industrial Area

5 150

15-10-14 Overcurrent 6:47 PM 8:47 PM 120 Kg Jansak

Kg beribi

Royal Escot Housing

Smart Beribi

JalanBunga Jasmin

Beribi

JalanDamuan

Mentiri Housing area

3298 395760

Beribi Outages for 11kV substation on 2013

Date Description Action Taken Time off Time on Duration

of

Interrupt

ion in

mins


custome

rs

affected

Customer

minutes of

interruption

03-02-13 TX 300 kVA tripped.

Check and found oil level

empty. Energise and

tripped.

Isolate and earth for

testing. Found LV side

faulty (TX)

04:40 PM 5:50 PM 70 Spg 199

JalanPermaisuaraBerib

i PAP Noraian

12 840

24-04-13 Panel 12 tripped to ERM

Beribi 1. Megger and

found HV cable from S/S

Beibi Industry 2 to S/S

Beribi Industry 3 faulty.

(Yellow and Blue phases

Isolated and earthed the

fault.

09:38 AM 10:47 AM 69 Bangunan Bina Block

A, B & C Beribi

Industry

100 6900

Draft dated 27 May 2015 H

faulty)

08-05-13 MIS Beribi Industry Fasa

1 P#3 tripped and

indicated earthful and

overcurrent. Isolate and

megger. Found HV cable

from S/S Spg 466 to S/S

Government Cooperative

Store (BINA) Beribi

faulty.

Isolated and earthed the

fault.

06:45PM 8:00 PM 75 Bangunan BINA,

PerindustrianFasa 1,

Spg 466 and Spg 456

Kg Beribi

34 2550

29-06-13 TX 1000 kVA tripped. Check and energized. 12:00 AM 12:30 AM 30 Industry Beribi 100 3000

01-07-13

TX 1000 Kva tripped,

check and found the TX

faulty.

Isolate and earth. 09:40AM 10:09 AM 29

KilangPlastikPerindust

rianBeribi,

BombaBeribi Industry

100 2900

03-07-13 P#19 tripped to MIS S1

Kiarong and indicated

overcurrent.

Energise P#2 & P#19 to

balance load.

11:05 AM 11:50 AM 45 Kg Tungku

Kg Kiarong

Gadong

Kg Beribi

6305 283725

06-07-13 Trip from overcurrent

and third phase detach

from MIS Beribi Industry

PH#12 & S/S ERM

Industry Ringan 1 P#7 –

HV cable faulty from S/S

#2 to S/S #3 & S/S #3 to

S/S #4.

09:00 AM 09:25 AM 25 Beribi Industry and

Block C

13 325

Draft dated 27 May 2015 I

18-08-13 TX 800 Kva tripped.

Intermittent tripped.

08:40 AM 09:00 AM 20 PerindustrianBeribi 1 15 300

19-08-13 Feeder MIS Telanai P#11

& P#5 tripped and

indicated earthfault.

Found HV cable from

MIS Beribi Industry 1

P#11 to MIS Telanai

P#11. (2 phases faulty)

09:30 PM 11:37 PM 127 Kg Jangsak

Kg Telanai

Kg Beribi

Beribi Industry

3944 500888

02-09-13 Complaint TX tripped at

Sph 456 Kg Beribi.

Found HV cable from

S/S 456 Kg Beribi to S/S

Spg 424 Kg Beribi.

03:30 AM 04:45 AM 75 Spg 456, Spg 424, Kg

Beribi

61 4575

28-09-13 TX 1000 kVA tripped. Checked and energized 10:35 AM 11:30 AM 55 Gardenia Factory

Beribi Industry

1 55

08-10-13 TX 800 kVA tripped Checked and energized. 08:15 AM 09:00 AM 45 Gardenia Factory 1 45

08-10-13 TX 800 kVA tripped. Checked and energized. 09:45 AM 10:00 AM 15 Gardenia Factory 1 15

12-10-13 TX 800 kVA tripped. Checked and energized

release the protection

wiring (relay).

08:20 AM 09:00 AM 40 Gardenia Factory 1 40

21-11-13 66/11 Kv Beribi P#5

tripped to MIS Kiulap 1

and MIS Spg 32 tripped

to MIS Kiulap P#8 MIS

Kiulap 1 to MIS Spg 32

Isolate and earth. 04:15 AM 07:00 AM 165 Hua Ho Kiulap,

KomplexSetiaKenang

an,

151 24915

Draft dated 27 May 2015 J

Kiarong P#9 flashover. Hotel Kiulap and

Kiulap Mall

03-12-13 Feeder T tripped and

checked. Energised and

found TX 800 kVA

faulty.

Isolate and earth. 01:20 PM 02:00 PM 40 Flat F14 Kg Beribi 6 240

Draft dated 27 May 2015 K

Mentiri Outages for 11kV substation for 2014


of

Interrupt

ion in

mins


custome

rs

affected

Customer

minutes of

interruption

23-03-14 Feeder TX1 incomer

tripped P#4. Intermittent

fault (animal trespassing

the aerial cable)

Open all the outgoing

feeder and close the

incomer – Intermittent

tripped (animal contact)

01:20PM 03:09PM 111 PerpindahanMentiri

Mentiri

SgBesar

Kapok

Kg Salar

Buloh

BatuMarang

Bukit Sebangin

PengkalanSibabau

3429 380619

27-05-14 Feeder incomer TX1

tripped and found relay

faulty. Intermittent

tripped (relay faulty)

06:55AM 07:58AM 63 Kg Salar

Kg Mentiri

PerpindahanMentiri

SgBuluh

Bukit Sebangin

Kg Kapok

SgBesar

3122 196686

04-07-14 Incomer feeder tripped

because SF6 gas is low.

Close bus section. 04:32 PM 06:18PM 166 Kapok

Tanah Jambu

SgBuloh

4448 738368

Draft dated 27 May 2015 L

Mentiri

23-07-14 Incomer 66/11Kv Mentiri

TX1 tripped at 11Kv

PANEL 8. Isolate P#8. –

Intermittent tripped.

Close bus section 08:43AM 09:16AM 33 Kg Mentiri

Kg SgBesar

Sungai Buloh

Tanah Jambu

Mentiri

4084 134772

19-10-14

Feeder T tripped check

and found the feeder

pillar vandalized.

09:20AM 0935AM 15

Street Lighting and

Pump Mentiri

2 30

Mentiri Outages for 11 kV substation for 2013


of

Interrupt

ion in

mins


custome

rs

affected

Customer

minutes of

interruption

11-03-13 MIS Mentiri P#10

tripped to S/S Spg 444

SgBesar and indicated

overcurrent. Test and

found S/S Opp Klinik Sg

Besar RMU NEI

flashover at T feeder.

Isolate and earth.

Requested for a generator.

01:20AM 02:25 AM 65 Kg Mentiri

Kg Sungai Besar

886 57590

05-04-13 Feeder TX2 incomer

tripped at 11kV feed to

MIS Mentiri and

indicated overcurrent. –

11:45PM 02:00 PM 132 Perumahan Kg Mentiri

Kg Sungai Bunga

KlinikSgBesar

1585 209220

Draft dated 27 May 2015 M

Aerial cable termination Kg SgBesar

Kg Mentiri

28-05-13 Incomer panel at GIS

Mentiri TX2 tripped and

S/S Spg 444 tripped

overcurrent. Found S/S

Spg 444 termination

flashover. – Termination

HV cable flashover

06:20PM 07:50PM 90 PerpindahanMentiri

Kg PengkalanSibabau

Kg Mentiri

SgBungadan Golf

1476 132840

22-06-13 TX 500 kVA tripped. –

Intermittent tripped

Checked and energise.

RMU MG cover remove

need to install back.

03:40PM 04:27 PM 47 PerkhidmatanAwamK

elabMentiri

4 188

Kuala Belait outages for 66kV substation for 2014


of

Interrupti

on in mins


custome

rs

affected

Customer

minutes of

interruption

30-05-14 Transient fault

– could be due

to lightning

strikes ,

momentary

tree and animal

contact

Seria #2 feeder tripped at LPS

66kV S/S at 8:08am with ARC

operated but failed to operate.

21Distance Zone B, Phase & Earth

fault, 86B lock out protection relay

activated, total load loss of 18MW.

Attempt to reenergize the feeder

was succesfully at 8:23am, thus

normalizing all affected areas.

8:08 AM 8: 23 AM 15 Half of Seria and

Kuala Belait areas

9561 143415


– could be due

to lightning

strikes ,

momentary

tree and animal

Seria #1 feeder tripped at LPS

66kV S/S at 1:30pm with ARC

operated but failed to operate,

21Distance Zone 1, C, Phase &

Earth fault locator, 86B lock out

protection relay activated, total load

1:30 PM 02:35 PM 65 Half of Seria and

Kuala Belait areas

9561 430245

Draft dated 27 May 2015 N

contact loss of 22MW. Attempt to

reenergize the feeder was

succesfully at 1:55pm, but tripped

at Anduki 66kV S/S. Seria #1

feeder was successfully reenergized

at 2:35pm at Anduki 66kV S/S,

thus normalizing all affected areas

21-07-14 Bus coupler A

tripped due to

under frequency

relay activated

whilst Seria # 2

feeder tripped

by the

activation of

load shedding

protection and

further

investigation on

GTG #12

tripping

11:15 AM 01:23 AM 128 Half of Seria and

Panaga and Belait

areas

9561 1179189

07-08-14 Bad weather/

Lightning

Transmission Unit received

information from KB Engineer that

Seria #1 feeder tripped at LPS at

10:19pm. Attempt to reenergize

the feeder succesful at 10:50pm but

only registered 15MW of load and

KB areas still without power

suspected Slimpole #1 feeder at

Panaga 66kV S/S tripped. Delay at

LPS was due to phase

discrepancies relay unable to be

reset remotely, so SIC needed to go

to yard to manually reset at LCC.

KB Engineer and Personnels

normalized KB from Panaga

(Slimpole #1 feeder) at 11:23pm,

thereby normalizing all affected

areas


Panaga and Belait

areas.

9561 454147

Draft dated 27 May 2015 O

28-08-14 Load shedding

activated –

feeder at Seria #

2 tripped

Seria #2 feeder tripped at LPS at

12:44pm with Main and Back up

Lock Out Relay operated and a load

loss of 28MW. Attempt to

reenergize the feeder succesfully at

12:55pm, thereby normalizing all

affected areas.


Panaga and Belait

areas

9561 105171

26-11-14 Animal contact Seria #2 feeder tripped at LPS at

1:37pm with 86A & 86B Lock Out

Relay operated and a load loss of

27MW. Transmission Unit just

informed of feeder tripped at

1:45pm Attempt to reenergize the

feeder successfully at 1:54pm,


areas.


Panaga and Belait

areas

9561 152976

Kuala Belait outages for 66kV substation for 2013


of

Interrupti

on in mins


custome

rs

affected

Customer

minutes of

interruption

06-02-13 Suspected

transformer

winding fault

The supplies were normalized vide

Tx#3 Pauweltrafo on Line #1 by

transferring load at Panaga 11kV

MIS Tamco at 4:15pm, Thus

normalizing the affected areas.

3:20 PM 4:15 PM 55 Panaga

PerumahanMumong

JalanMaulana

PerpindahanPandan 8

Batu 4

Perumahan Kg

Panaga

3081 169455

Draft dated 27 May 2015 P

20-03-13 Animal contact The feeder was successfully

reenergized at 8:57am, thus

normalizing Sg Liang areas.

Bukit Puan areas normalized at

9:45am .Rampayoh areas

normalized at 10:55am. All

affected areas were normalized by

this time.

Bukit Puan to Rampayoh 66kV

circuit was successfully

reenergized at 12:56pm.

6:12 AM 08:57 AM 165 Part of Sg Liang area

Whole of Bukit Puan

Rampayoh

Labi areas

742 179044

25-04-13 Lightning

strikes

Seria #1 feeder tripped at Anduki

66kV S/S after ARC succesfully at

LPS 10:21pm. Attempt to

reenergize Seria #1 feeder was

succesfully at 11:07pm by KB

District Engineer. All affected

areas were normalized by this time

10:21 PM

11:07 PM 46 Half of Seria

Panaga

Kuala Belait areas

6279 288834

29-04-13 Lightning

strikes

Seria feeder #2 was tripped with

21Distance Zone 1 A&C, lock out

86A, 86C, LoLr relay protection

operated as per inform by LPS SIC

at 6:35pm.

Attempet to reenergize Seria

feeder#2 was successfully at

6.47pm with initial load of 11MW.

All supplies were normalized by

this time

6:35 PM 06:47 PM 12 Half of Seria

Panaga

Kuala Belait areas

6279 75348

20-06-13 Unknown Manually opening circuit breaker

and both isolator switch at Bukit

Puan. Affected areas normalized

vide by closing the N/O point 11

kV RMU at Luagan Lalak intake

station.

10:50 AM 01:15 AM 195 Whole of Bukit Puan

Rampayoh

Labi areas

180 45240

Draft dated 27 May 2015 Q

30-06-13 Wrong wiring

connection

Tx#1 tripped with OLTC oil level

trip flag protection relay operated at

7:50am. Attempt to reenergize

back Tx#1 was failed as relay flag

cannot be reset. All affected areas

were normalized by energized Tx#2

and load transfer at Anduki 11kV

MIS. 9:45am. Tx#1 was inspected

and test on the next day and found

out that OLTC oil level ALARM

flag at Tx#1 cubicle at switchyard

wiring wrongly connected to OLTC

oil level Trip flag at relay room

6:55 AM 08:50 AM 115 Areas of Anduki

Third ABDB

batillion

PerpindahanLumut

SgTali

1307 150305

02-07-13 Lightning

thunderstorm in

KB areas

Seria #1 feeder tripped with phase

and Earth fault locator, 21 Distance

Zone A protection relay operated at


Seria #1 feeder was successfully at

2:05pm with initial load of 5MW.

A total loss of 19MW after tripped

still unknown. Upon checking KB

#1slimpole feeder at Panaga was

tripped. Feeder was successfully

reenergized at 2:57pm. All affected

areas were normalized by this time.

1:15 PM 02:57 PM 102 Whole of Anduki

Half of Seria

KB areas

6235 473860

09-07-13 Fallen tree onto

overhead line

conductors

Telisai #1 incoming feeder tripped

at 2:30pm as per inform by KB

District Engineer at 2:45pm. The

Telisai #1 feeder was succesfully

reenergized back after feeder

tripped. Attempt to reenergize back

Labi feeder, Sg Liang to Bukit

Puan segment was successfully by

manually Open Circuit Breaker at

Sg liang and Circuit Breaker &

both Isolator Switch at BukitPuan .

The affected areas were normalized

vide 11kV RMU at Terunan intake

station at 4:57pm. The suspected

fault, Bukit Puan to Rampayoh

segment was reenergized back at

3:11pm on Thursday 11th July

2:30 PM 4:57 PM 147 Areas at Sg Liang

Whole of Bukit Puan

Kg Sg Mau

Rampoyah

Labi areas

847 124509

Draft dated 27 May 2015 R

2013 after surveying done and

checking the resistance on the Red,

Yellow and Blue phases of the

Overhead line segment

18-07-13

Intermittent

fault –

momentary tree

contact,

lightning strikes

and animal

contacts

Pasir Puteh #1 feeder tripped at


Pasir Puteh #1 feeder was

successful at 9:00pm. At the same

time Panapar#1 feeder at Pasir

Puteh 66 kV S/S also tripped.

Attempt to normalized from

SCADA was failed with operation

block indicated. An attempt to

reenergize the feeder at 9:38pm

was successful by DES Tutong. All

affected areas were normalized by

this time.

8:37 PM 09:38 PM 61 Areas at

mukimTanjong Maya

Perpindahan Bukit

Beruang

Kg Bukit Beruang

MukimTelisan

Sg Liang

Whole of JalanLabi

areas

Part of Serambangun

MukimLamunin

MukimRambai

Penapar

MukimUkong areas

13158 552636

24-07-13 Overhead line

overload

Seria #1 feeder at Anduki 66kV S/S

was tripped at 3:12pm. Attempt to

reenergize the feeder at Anduki

66kV S/S was successfully at

4:00pm.

3:12 PM 04:00 PM 48 Areas at Panaga and

Kuala Belait

288 13824

02-08-13 Animal contact Anduki #2 feeder at Seria 66 kV

S/S tripped at 10:48pm. Attempt to

reenergized failed at 11:15pm,

indicate a present of permanent

fault between Seria to Panaga and

Panaga to KB segment. The survey

was done with the help of

contractor but no possible fault was

found. The affected areas were

normalized at 12:21pm for Seria

10:48 PM 01:26 PM 158 Half of Seria

Panaga

One third of Kuala

Belait areas

6279 784874

Draft dated 27 May 2015 S

areas, Panaga areas at 12:52am and

KB areas at 1:26am, thus

normalizing all the affected areas.

02-08-13 Transient fault Telisai#1 feeder at Pasir Puteh 66

kV S/S tripped approximately at

4:18pm with 21D Zone 1, A G, Red

Phase to Ground. Attempt to

reenergized the feeder was

successful at 5:16pm. All affected

areas were normalized by this time.

4:18 PM 05:16 PM 58 Whole of Bukit Puan

Rampayoh areas

Sg Liang

Lumut areas

8689 503962

03-08-13 Unknown Tx#1 at Bukit Beruang 66 kV S/S

tripped approximately at 9:22am

with 87T Differential protection

relay activated indicated a fault on

the transformer. The supplies were

normalized vide 11kV Bukit

Beruang MIS by closing the Bus

Section at 10:18am. The

transformer was measured and

tested but no possible fault was

found. Tx#1 was successful

reenergized back at 12:55pm

4:10 PM 05:06 PM 56 Kg Bukit Beruang

Perpindahan Bukit

Beruang

Bukit Beruang

Primary School

2040 114240

07-08-13 Contractor

accidentally

excavated 66kV

underground

cable

Panapar Slimpole #1 feeder at

Panapar 66 kV S/S tripped at

approximately 10:40am with 21D

Zone 1, A, B, C. All supplies were

normalized vide 11kV MIS

Lamunin by closing the bus section

at 11:48am. An attempt to

reenergized the feeder was

successful at 3:30pm and put the

feeder on soak, by isolating the

Panapar to Lamunin underground

cable feeder.

5:38 PM 06:46 PM 68 Areas at Panapar

Kg Ukong

Bukit Barun Water

Treatment Plant

Layong Water raw

Kg Layong

Kg PangkalanTangsi

1075 73100

20-08-13 Weather related

outage

Lumut #1 feeder tripped at 2:55pm

with 21Distance Zone 1

Protection relay activated and a

total load loss of 9MW.

8:20 AM 08:29 AM 9 Areas at Mile 8

Kilanas Pump Station

Kg Jangsak

2796 25164

Draft dated 27 May 2015 T

Attempt to reenergize Lumut #1

feeder was successfully at 3:04pm,

therefore normalizing all affected

areas.

Kg Lamunin

Kg Managah

Kg Bukit Sulang

Kg PangkalanTangsi

Bukit Barun Water

Treatment Plant

Kg Layong

07-11-13 Treee fallen

onto the

overhead line

conductor and

snapped.

A complained received at 10:00am,

no electrical supply at MukimLabi

areas. Upon checking Labi feeder at

Sg Liang tripped at Earth fault

protection relays operated with total

load loss of 2MW. Attempt to

reenergize back Sg Liang to Bukit

Puan feeder segement was

successfully at 11:14am,

normalizing Bukit Puan areas. All

supplies were normalized by

11:45am by closing N/O point at

Terunan RMU.

10:00 AM 11:45 AM 105 Whole Bukit Puan

Rampayoh areas

116 10382


– animal

contact,

lightning strikes

and momentary

tree contact

Seria #2 feeder at LPS 66 kV S/S

tripped at 10:15am with 21 trip

Zone 1, Distance

protection relays, operated with a

total load

loss of 19MW. An attempt to

reenergize the feeder at 10:25am

was successful, thus normalizing all

affected areas. Survey of the

overhead transmission line was

done on the same day but no fault

was found.

10:15 AM 10:25 AM 10 Half of Seria, Panaga

and Kuala Belait

areas

6279 62790

Draft dated 27 May 2015 U

Mentiri Outages for 66 kV for 2013.


Interruption

in mins


custome

rs

affected

Customer

minutes of

interruption

16-6-13 Transient faut –

momentary tree

contact on the

overhead

conductors /

lightning

Attempt to reenergize the Muara

#B feeder was successfully done at

6:18pm after DTCB Mentiri#B at

Muara was switched OFF.

Mentiri#B was switched ON,


areas.

2:20 PM 4:20 PM 120 Parts of Kg Serasa

Kg Sabun

Kg Kapok

2915 349800

08-08-13 Bad weather,

lightning during

the feeder

tripped

Muara #B feeder at Mentiri 66 kV

S/S tripped at 1:06pm with 21D

Zone 1, L2 & EF protection relay

activated. An attempt to reenergize

back the feeder was successful at

2:00pm, thus normalizing all the

affected areas.

1:06 PM 2:00 PM 54 Areas at Muara Port

Kg Sabun

Kg Serasa

PerpindahanMeragan

g

PekanMuara

3616 195264

19-08-13 Intermittent

fault

Muara #B feeder at Mentiri 66 kV

S/S tripped at 2:40pm with 21D

Zone 1, L2 & EF protection relay

activated. An attempt to reenergize


4:30pm, thus normalizing all the

affected areas.

2:40 PM 04:30 PM 110 Areas at Muara Port

Kg Sabun

Kg Serasa

PerpindahanMeragan

g

PekanMuara

3616 397760

Draft dated 27 May 2015 V

20-08-13 Fallen tree

branches onto

the overhead

line

Labi feeder at Sg Liang 66 kV S/S

tripped at 8:20am with 51

overcurrent protection relay

operated. An attempt to reenergize


9:58am, thus normalizing all the

affected areas.

8:20 AM 9:58 AM 98 Whole of Bukit Puan

Rampayoh Labi areas

180 17640

Draft dated 27th May 2015 W

Appendix 2: List of required data for accurate calculation of SAIDI and SAIFI

Required Data 2015 2016

General Data

Total number of customer served

in supply area

Date of outage

Type of interruption

Beginning and end of

interruption

All kind of interruption (classify

as momentary, sustained or

planned)

Unusual interruptions (lasts for

days)

Consequences

Number of customers

affected/interrupted

Affected area

How is the power restored?

Step restoration or full

restoration

If step restoration is involved,

state:

The stages

Duration of restoration

time for each stage

Number of customers

interrupted and restored

at each stage.

Cause of interruption

Draft dated 27th May 2015 X

Planned

Unplanned

Natural disaster (weather- related

)

Human behavior

Operational cause

External cause

Other causes

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