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Substation Types

ID Substation Type No.

1 33/11 kV substations 8

2 66/33 kV substations 2

3 66/11 kV substation (total)

Connected to power plant

LILO (big)

LILO (small)

City type

Tail feed type

132

2

20

33

63

14

4 220/66 kV substations

Connected to power plantOthers

25

520

Total 167

Note: Cut off date December 2013

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Substation Survey

Following substations were survey during data collection stage:

Substation Substation

Embassy Hawar

Manama Rifaa

Rifaa PS Sitra Local

Madinat Hamad Mahazza

Waterfront Zinj

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Criteria for ACA - Substations

Following criteria is used for substation assessment:Criteria Criteria

Age Technology transfer of equipment

Capability of increasing load demand Operational experiences related to faults

and failuresPhysical condition of transformers,

switchgear and cables

Maintenance records related preventive,

regular and emergency

Impact of ambient temperature &

seasonal variations

Condition of inner components (viz. Oil,

SF6 gas, protection relays, etc.)

Condition of protection, control andmonitoring system

Availability of spares

Expansion plans for the switchgear Accidents such as fire, flood or lightning

etc.

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Failure Causes- Switchgear

Causes for the failure of the switchgear are:Cause Cause

Age and number of operations SF6 gas leakages

Mechanical problems Frequent short circuit tripping

Malfunctioning of protection Failure due to improper cabletermination

Insulation failure Failure on VT & CT

Overloading Technology transfer & spares availability

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Failure Causes- Transformers

Causes for the failure of the transformers are:Cause Cause

Reduction in dielectric strength (due to

lightning and switching impulses)

Loose connections

Reduction in mechanical strength Design drawbacks related to material andworkmanship

Reduction in thermal integrity (due to

heating or overloading)

Oil contaminations

Moisture Reduction in electromagnetic integrity

(due to over excitation and over loading)

Fire/Explosion Flood

Insulation Failure Improper maintenance/operation

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Failure Causes- Cables

Causes for the failure of the cables are:Cause Cause

Ambient temperature Lightning impulses and other system

induced over voltages

Overload current beyond rating Excessive tension

Moisture and chemicals in contact Mechanical damage

Poor temporary splices Type of back fill around direct buried

cables or ducts

Switching operations Fire accidents

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Classification for ACA

Classification based on Age

Substation Age Age by 2015 No. Units Percentage

33/11 kV >45 years 2 1.2

33/11 kV, 66/33 kV >40 years 4 2.4

33/11kV, 66/33 kV, 66/11 kV >35 years 15 9

66/11 kV, 220/66 kV >30 years 22 13.2

66/11 kV, 220/66 kV >25years 13 7.8

66/11 kV >20 years 3 1.8

66/11 kV, 220/66 kV >15 years 6 3.633/11kV, 66/11 kV, 220/66 kV

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EPC for RefurbishmentNormal Temp. winding

(55K)

Above normal temp but

below hot spot Temp

Above hot spot temp

(68 K)Hidd (3) Al Dur (3) Rifaa (2)

Rifaa (1) Al Areen (3) Busaitin (1)

Amwaj (3) Al Madinah (3) Jasra (2)

BFH (3) Buquwwah (3) Madinat Hamad (1)

Busaiteen (1) Busaitin (1) Umm Al Hassam (3)

Dahiyat Al Seef (1) Dahiyat Al Seef (2) Waterfront (3)

Khaleej Al Bahrain (3) Embassy (3)

Marsa Al Bahrain (3) Hawar (3)

Shamal Al Ali (3) ITN (3)

Sitra BSP (1) Jasra (1)

Madinat Hamad (2)

Manama BSP (3)

Sitra BSP (2)

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EPC for Replacement

1. MOCBs of substations Sitra PS and Umm Al Hassam are to be replaced with SF6.2. Electromagnetic relays are to be replaced with numerical relays stage by stage.

3. All 220 kV LPOF cables are to be replaced with XLPE.

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EPC for Retirement

66/33 kV SubstationManama BSP Muharraq N

33/11 kV Substation

Bank Hoora

Manama South Manama Town

Hospital Manama BSP

Muharraq C Muharraq N