rapid metro gurgaon report
TRANSCRIPT
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RAPID METRO GURGAON LIMITED
(Power system distribution)
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Acknowledgement I sincerely thank to IL&FS Corporation for giving me the chance to intern in Rapid Metro
Gurgaon Limited. I also sincerely thank to Mr. Harish Srivastav (HOD of electrical department),
Mr. Rajesh Kanan, Mr. Neeraj and Mr. Jagmohan for their full guidance and support.
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Contents 1 Introduction .......................................................................................................................................... 5
2 Definitions ............................................................................................................................................. 6
3 General overview .................................................................................................................................. 7
3.1 System boundary .......................................................................................................................... 7
3.2 Utility in feed /RSS ........................................................................................................................ 8
3.2.1 Power supply ......................................................................................................................... 8
3.3 11kv power supply to TSS/ASS ...................................................................................................... 8
3.4 11kv power supply equipments .................................................................................................... 9
3.4.1 11kv cable system: ................................................................................................................ 9
3.4.2 TSS cum ASS at sikanderpur station: ..................................................................................... 9
3.4.3 ASS at DLF phase 2 station .................................................................................................... 9
3.4.4 ASS at belvedere tower and mall of India ............................................................................. 9
3.4.5 TSS/ASS at gateway tower, DLF phase 3 and depot ........................................................... 10
3.4.6 Technical particulars of 11kv circuit breakers .................................................................... 10
3.5 Traction System........................................................................................................................... 10
3.5.1 Traction transformers ......................................................................................................... 10
3.5.2 Rectifiers ............................................................................................................................. 10
3.5.3 750V DC switchgear ............................................................................................................ 11
3.5.4 3rd rail .................................................................................................................................. 11
3.5.5 Sectioning ............................................................................................................................ 12
3.6 Auxiliary power system ............................................................................................................... 12
3.6.1 11kv cable network ............................................................................................................. 12
3.6.2 Auxiliary substation ............................................................................................................. 13
4 ASS/TS ................................................................................................................................................. 14
4.1 Auxiliary substation ..................................................................................................................... 14
4.1.1 Overview ............................................................................................................................. 14
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4.2 11kv cable network ..................................................................................................................... 14
4.3 ASS types ..................................................................................................................................... 14
4.4 Traction substation ..................................................................................................................... 15
4.4.1 Overview ............................................................................................................................. 15
4.4.2 Traction substation ............................................................................................................. 15
4.4.3 750V DC switchgear ............................................................................................................ 16
4.5 ASS & TSS equipment .................................................................................................................. 17
4.5.1 11kv switchgear .................................................................................................................. 17
4.5.2 Dry type transformers ......................................................................................................... 34
4.5.3 Rectifier transformer(1900KVA) ......................................................................................... 36
4.5.4 High speed breakers............................................................................................................ 38
4.5.5 Rectifier ............................................................................................................................... 39
4.5.6 Short circuit device ............................................................................................................. 40
4.5.7 Negative return panel ......................................................................................................... 41
4.5.8 By pass load breaker switch panel ...................................................................................... 42
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1 Introduction
Rapid Metro Rail Corporation is the organization responsible for Building, Operating and
Maintaining the Metro Rail Public Transport in Gurgaon. The operations of Rapid Rail
Metro System began in year 2012. This system provides a transport solution for areas in
and around Cyber city, DLF phase 2, DLF phase 3 & NH-8, providing connectivity to
Delhi Metro at Sikanderpur.
The technologies used to develop and operate the metro system are latest and provide lots
of opportunities for students to learn the latest market developments in terms of
technology and helps students decide their future career path.
RMGL comes under Infrastructure Leasing& Financial Services Limited (IL&FS), one of
India’s leading infrastructure development and finance companies.
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2 Definitions 1. Bond: - An electrical connection in the conductor rail, traction return circuit or in a signaling
track circuit.
2. Circuit Breaker: - A device designed to open automatically when current above a pre-
determined level flows through it. The circuit breaker can also open and close device remotely.
3. Current collector shoe:-Device on motor coach of rolling stock which presses from the bottom
on the conductor rail to complete the circuit between conductor rail and train.
4. Insulated Joint: - It separates the from two traction sub-station.
5. Traction power controller: - The person who controls the supple to the electric traction
system and who is responsible for all switching operations, isolation and switch outs.
6. Operation control center (OCC):- The isolation of the apparatus and staff that operate the
remote control equipment/SCADA associated with the electric traction system.
7. Emergency isolated section: - the area isolated in an emergency. This does not include
abutting sections.
8. Power block: - The action of causing one or more electrical sections or sub-stations of the
conductor equipment to be isolated
9. Live: - having a voltage by being charged with electricity
10. Stringer system: - in a maintained sheet, a system of overhead electricity supply which can
be manually connected to a DC traction unit
11. Return circuit: - the traction return rail and cables back through which the electricity flows
from the electric trains to the substation
12. Section: - conductor rail equipment between two circuit breakers or a circuit breaker and the
termination point of the conductor rail
13. Section gap:- place where one section end and the next one starts
14. Portable SC device:- a locally operated device that when operated converts the conductor
rail and traction return rails to stop the conductor rail being accidently made live during a
planned isolation
15. Substation: - A building or compound is containing electrical equipment that supplies
electricity to conductor rails and for other purposes.
16. Receiving substation:- The 11kv power supply received from electricity board is receiving
substation
17. Traction substation(TSS):- The 11kv supply received is stepped down and converted to DC
750V supply and fed to 3rd rail
18. Auxiliary substation:- The 11kv supply is stepped down to 415V A/C supply for supplying for
lightening etc
19. Switchgear: - switchgear is the combination of electrical disconnects
switches, fuses or circuit breakers used to control, protect and isolate electrical
equipment. Switchgears are used both to de-energize equipment to allow work to
be done and to clear faults downstream. This type of equipment is directly linked to
the reliability of the electricity supply.
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3 General overview
RMGL is India’s first fully privately owned and operated metro. Rapid metro covers a distance of
6.2km. It starts at Sikanderpur, crossing below the DMRC alignment, goes straight on the median of
the road taking a turn behind the line from phase 2 to mall of India and beyond that up to phase 3
and then connects back to phase 2 on single line section. The section b/w Sikanderpur and phase 2
stations is double tracked, while remaining station are served with a single track loop.
A depot is b/w mall of India and DLF phase 3 station
3.1 System boundary
The project has been divided into various systems and subsystems. Work has been allotted to
various contractors and sub contractors as per their eligibility and expertise criteria.
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3.2 Utility in feed /RSS
3.2.1 Power supply
Power supply is obtained at Sikanderpur and DLF phase 2 stations. The power is transmitted
through a double ring main cable.
In feed-1
66kv substation
Sector-44 sector-56
Sector-28, 66/11kv HVPL substation
In feed-2
66kv substation Dundahera sector-56
DLF-Q block, 66/11kv HVPNL substation
DLF phase-2 station
11kv bulk power supply arrangement
3.3 11kv power supply to TSS/ASS
The 11kv power supply received at Sikanderpur and DLF phase 2 stations is feed to other station through
double ring network in RMGL project.
Each TSS and ASS is provided with two separate 11kv bus bar, connected to ring main-1 and ring main-2.
Further each bus bar feeds one rectifier transformer and one auxiliary transformer in case of TSS cum
ASS, and one auxiliary transformer in case of ASS. Both the rectifier as well as auxiliary transformer are
connected to 11kv bush bar and are sized to meet the entire load of sub-station thereby providing 100%
redundancy. Thus complete system is capable of being operated at the designed headway with one in
feed 11kv supply.
Sikanderpur station
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All the incoming as well as outgoing feeders at Sikanderpur and DLF phase 2 stations are provided with
11kv circuit breakers. However, ring main switches at other stations are 11kv load brake switches of the
same rating as circuit breaker. The outgoing feeders for rectifier transformers and auxiliary transformers
at all TSS/ASS are provided with circuit breaker. In case of any fault on the ring main cables, the feeding
circuit breakers at Sikanderpur/DLF phase 2 stations will trip and isolate the complete ring main. The
other healthy ring main will feed the entire system without any operational constraints.
3.4 11kv power supply equipments
3.4.1 11kv cable system:
The 11kv in feed cable is fire retardant, low smoke, single core cable with circular stranded aluminum
conductor, XLPE insulated, copper screen, inner sheath, flat wire armoring and FRLS outer sheath. Cross
linking is by “Dry curing” process. The size of cable is 185 sq mm. there are two cables per phase and
thus 6 single core cables connect grid sub-station with the TSS/ASS. Two cables per phase are required
to increase the life of wire and in case of fault in one wire other one can be used.
R
Y
B
3.4.2 TSS cum ASS at Sikanderpur station:
10 nos. of 11kv circuit breaker present at Sikanderpur station. In addition to one circuit breaker, two
circuit breaker feed the two ring mains and the other two circuit breakers provide interconnection with
the other in feed ASS at DLF phase 2. One circuit breaker which is normally open (NO) serves the
purpose of interconnecting the two 11kv bush bars and provide in feed from the adjoining ASS, when
closed, in case the in feed is lost at this sub-station. The other four circuit breakers feed the two rectifier
transformers and auxiliary transformers.
3.4.3 ASS at DLF phase 2 station
8 circuit breakers are present here. . In addition to one circuit breaker, two circuit breaker feed the
two ring mains and the other two circuit breakers provide interconnection with adjoining Sikanderpur
TSS/ASS. The two circuit breakers feed auxiliary transformers. One circuit breaker which is normally
open (NO) serves the purpose of interconnecting the two 11kv bus bars and provides in feed from the
adjoining ASS, when closed, in case the in feed is lost at this sub-station.
3.4.4 ASS at belvedere tower and mall of India
4 nos. of 11kv load break switches for the two ring mains and two circuit breakers for auxiliary
transformers.
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3.4.5 TSS/ASS at gateway tower, DLF phase 3 and depot
Presence of 4nos. of load break switches for two ring mains out of which one works as a coupler switch
in “normally open” state for ring mains. In addition, four nos. of circuit breakers are provided, two for
rectifier transformers and two for auxiliary transformers
3.4.6 Technical particulars of 11kv circuit breakers
It is a 3 pole metal enclosed and gas insulated. The rating of circuit breaker is 630A. The switch gear
vessel is filled with SF6 gas and insulated. The rated short time with stand current is 20kA for one
second.
3.5 Traction System
There are 3 nos. of traction substation along main line and one in depot. The traction and auxiliary
substation are shared in one common room in RMGL line.
Each traction station has following equipment:-
Traction transformers
Rectifier
Return line panel
DC switchgear
Short circuit device(SCD)
SCD installed at every station to check the potential rise b/w return rail and structural earth
Conductor rails carry electricity at 750V DC. The conductor rails are supported by insulators above the
track.
Traction system collects and converts power from 11kv to 750V DC. Electricity is supplied to 3rd rail via
DC switchgear located inside traction substation along main line
At each substation transformers and rectifiers convert the AC high voltage supply to DC. This is then fed
to 3rd rail via circuit breakers
Running rails are utilized as a return for the 750V DC traction system.
3.5.1 Traction transformers
These transformers are installed in the technical rooms for power supply of TSS, each within a separate
compartment area nearby the rectifier.
These transformers convert the 3 phase supply to 6 phase supply of 585V AC
3.5.2 Rectifiers
They are present nearby to traction transformers. They convert the 585V AC voltage to 750V DC and
then fed to 3rd rail.
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3.5.3 750V DC switchgear
The Sitras DSG switchgear is metal enclosed, factory-assembled and type-tested. Supply from rectifier is
supplied to 3rd rail via switchgear.
3.5.4 3rd rail
Electric power is supplied to the train by this 3rd rail. It is manufactured from a high conductivity
aluminum allow which is able to supply the train current without large voltage drop and thus energy
losses are very less. The aluminum is fitted with a wearing surface made of stainless steel. It is formed
into two sections and is fixed to the aluminum by welding the two sections together providing a good
electrical and mechanical bond to the aluminum.
Gaps are provided in the conductor rail at:
Points and crossings
Track crossings
Other locations for sectioning purposes
3rd rail present everywhere except at depot. Stringer system is used to power trains at depot.
Stringer line
Highlights of the system:-
Designed for a speed of 90kmph
3rd rail system installed near the track
Bottom part of the rail at 160mm from track level
Fully PVC cover over 3rd rail
Expansion joints b/w 80mts of 3rd rail
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Conductor rails supported at a regular interval of 5.88mts
750V DC GRP insulators
3.5.5 Sectioning
In RMGL project 3rd is divided into 5 sections along the main line by 3 TSS.
Within one TSS of the main line single track, the segregated 3rd rail sections of the track is in both
directions and for double track it is supplied with separated feeders. The sections of 3rd rail between two
adjacent substations will be supplied from both TSS
3.6 Auxiliary power system
Here auxiliary power is supplied for equipments like lifts, elevators, etc. at 415V AC.
Auxiliary power system is divided into subsystems
3.6.1 11kv cable network
Power is received at Sikanderpur and DLF phase 2 station from Q block and sector-28
respectively and then distributed to all stations through double ring network
This ring is kept open at MOI by keeping one breaker at NO position. In case of fault NO position
switch closes and power to healthy sections is restored
The cables have been designed to cater the loading under worst conditions
Following two sizes of cables are used:-
o 11kv 1CX185 sq mm Al cable, incomer from RSS/in feed sub-station to ASS at
Sikanderpur and phase 2
o 11kv 1CX150 sq mm Al cable, ring main feeder b/w ASS
66/11kv Chakkarpur in
feed station
DLF phase 2 ASS Sikanderpur ASS
66/11kv Q block
In feed station
Belvedere tower ASS
Gateway
tower TSS
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DLF Phase 2
3.6.2 Auxiliary substation
It supplies power for individual stations. Two ASS’s are present at each station which are connected to
two ring main.
Mall of India ASS Depot TSS
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4 ASS/TS
4.1 Auxiliary substation
4.1.1 Overview
Used for fulfilling the demand of power supply for lifts, escalator, fans, etc in each station. The load
demand required is 415V.
In RMGL, the power is received at 11kv from substations and reaches to Sikanderpur and DLF phase
2 stations, and from there they distribute through by ring topology.
4.2 11kv cable network
The 11kv power is distributed from receiving substation to auxiliary substation through 11kv cable
network
Power is received at Sikanderpur and DLF phase 2 stations and distributed to all stations by
ring network. Each station has two 2 ASS
The cables have been designed to cater the loading under worst conditions
Following two sizes cables are used:
11kv 1CX185 sq mm incomer from RSS to TSS at SIK and phase 2 station
11kv 1CX150 sq mm ring cable b/w ASS, auxiliary and traction transformer feeder
4.3 ASS types
Auxiliary substation caters to the auxiliary power demand of each individual. Each station has 2 ASS.
Apart from 6 stations, there are 2 auxiliary substations at depot
ASS can be classified as:
Type A: 2X300 KVA
Type B: 2X400KVA
Type C: 2X500KVA
Type D: 2X1000KVA
Each auxiliary substation consist of following equipments
11kv switchgear
11kv/415V auxiliary transformer
RTU
ACDB/DCDB
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4.4 Traction substation
4.4.1 Overview
Used for supplying power to the trains for movement. There are 3 nos. of TSS along main line excluding
one TSS in depot. TSS and ASS are shared in one common room in RMGL line
Each TSS consists of following equipments:-
Traction transformer
Rectifier
Return line panel
DC switchgear
Short circuit device
Short circuit device (SCD) is installed at all station for monitoring the Potential rise b/w return rail and
structural earth
In TSS system, the AC power is converted to 750 DC and passed to 3rd rail via DC switchgear
At each substation transformers and rectifiers convert the AC high voltage supply to DC, This is then fed
to the conductor rails through circuit breakers and ground level insulated cables.
Running rails are utilized as a Return for the 750V DC traction system. The return rail among the two is
identified after visioning with signalizing contractor.
4.4.2 Traction substation
The transformers are installed in the technical rooms for power supply for power supply to TSS, each
within a separate compartment area nearby the rectifier and shall be suitable to operate under the
ambient condition
Traction transformers are provided in the traction substation in order to convert the 3 phase system to
the medium voltage power supply to 585V with six phases as AC input of the traction rectifiers
The total requirement for the traction load is being met through installation of two rectifier transformer
at all traction substations
The 12 pulse rectifier is of the type Siemens. The traction power supply rectifier is naturally of two 3
phase bridges connected in series forming the 12 pulse rectifier
Station Type Transformer ration
Sikanderpur ASS/TSS with in feed 2X1900KVA
Gateway tower ASS/TSS 2X1900KVA
Depot ASS/TSS 2X1900KVA
DLF phase 3 ASS/TSS 2X1900KVA
Rectifiers are installed at:-
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Station Type No of transformers
Sikanderpur ASS/TSS with in feed 2
Phase 2 ASS with in feed X
Belvedere tower ASS X
Gateway tower ASS/TSS 2
Mall of India ASS X
Depot ASS/TSS X
Phase 3 ASS/TSS 2
Each rectifier is fitted into a sheet-steel cubicle with open top and bottom, front doors, back and side
covers. It is fixed using non-tracking insulating supports. Venting slots are provided in the lower half of
the front doors.
4.4.3 750V DC switchgear
The Sitras DSG DC switchgear is metal enclosed, factory-assembled and type-tested. The circuit breaker
panels are constructed as withdrawals unit racks without disconnectors
The equipment of the DC switchgear is installed in standard sheet metal enclosure with the following
features:-
Draw-out type high speed circuit breaker
Front door for operators safety
Insulated against structure earth
Frame fault protection
Clear arrangement of operation devices and induction
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Local and remote control and annunciation
Low maintenance and long life time
No separate isolating switches required
The DC switchgear comprises the following units
Incoming panel
Section feeder panel
Coupling panel
Stringer panel
Load break switch panel
4.5 ASS & TSS equipment
4.5.1 11kv switchgear
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Switchgear is the combination of electrical disconnects switches, fuses or circuit
breakers used to control, protect and isolate electrical equipment. Hermetically welded
switchgear vessel, made of stainless steel, with welded in bushings for connections and
mechanical components.
Insulating gas SF6
Maintenance free
Climate-independent
Three position switch-disconnector with load-break and make-proof earthing function
4.5.1.1 General description
In RMGL project 11kv switchgear is classified into four types, they are:-
Type –D switchgear (located at Sikanderpur station)
Type –C switchgear(located at DLF-2 station)
Type-B switchgear(located at DLF-3 and gateway tower station)
Type-A switchgear( located at mall of India and belvedere tower station)
Detailed description:-
Type –D switchgear:-
This switchgear in RMGL project is meant for 11kv with traction transformer. This type D
switchgear comprises of 10 panels
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Panel Purpose
+K01,+K02 To the station auxiliary transformers
+K02, +K09 To the station rectifier transformers
+K03 Ring cable belvedere tower
+K04 Ring cables phase 2
+K05 Bus sectionalizer
+K06 Ring cable phase 2
+K07 RSS 1 utility in feed
+K08 Ring cable belvedere tower
Type –C switchgear
These are meant for 11kv in feed with auxiliary transformer substation. It comprises of 8 panels
Panel Purpose
+K01, +K08 To the auxiliary transformers
+K02, +K05 Ring cable Sikanderpur
+K03 Ring cable phase 3
+K07 Ring cable phase 3
+K04 Bus sectionailizer
Type 2 circuit breaker:-
1. Ready for service indicator
2. ON pushbutton for circuit breaker
3. Actuating opening for DISCONNECTING three position disconnector
4. Control gate/locking device for 3 position disconnector
5. Actuating opening for earthing
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6. Position indicator for earthing switch
7. Position indicator for disconnector
8. Control gate/locking device for circuit breaker
9. Feeder designation label
10. Socket of capacitive voltage detecting system
11. Actuating opening for ”spring charging” at the circuit breaker
12. Position indicator for circuit breaker
13. Operation counter
14. Off pushbutton for circuit breaker
15. Indicator for the circuit breaker closing and opening springs(not charger/charger)
This circuit breaker feeder type 2 consists of disconnector switch and circuit breaker. The disconnector is
an off load switch and it can be operated only by manual operation through handle. The circuit breaker
spring charging can be operated by handle and also motorized automatic operation through an external
110kv DC supply. The on and off operation of the circuit can be done by mechanically through push
button and as well as electrically through relay. It is used as a ring feeder. Present at Sikanderpur and
DLF phase 2 stations. B
Type 1.1 Circuit breaker:-
1. Ready for service indicator
2. Off pushbutton for circuit breaker
3. Actuating opening for disconnecting 3 position disconnector
4. Control gate/locking device for 3 position disconnector
5. Actuating opening for earthing
6. Position indicator for earthing switch
7. Position indicator for disconnector
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8. Socket of capacitive voltage detecting system
9. Indicator for the circuit breaker closing spring
10. Operation counter
11. Position indicator for circuit breaker
12. Feeder designation label
13. On pushbutton for circuit breaker
14. Actuating opening for “spring charging” at the circuit breaker
15. Rating plate
This circuit breaker feeder type 1.1 consists of disconnector switch and circuit breaker. The disconnector
is an off load switch and it can be operated only by manual operation through handle. The circuit
breaker spring charging can be operated by handle and also motorized automatic operation through an
external 110kv DC supply. The on and off operation of the circuit can be done by mechanically through
push button and as well as electrically through relay. It is used as a ring feeder. Present at Sikanderpur
and DLF phase 2 stations.
Operating mechanism
a) Indicator and control elements
1. Short circuit/earth-fault indicator
2. On/off pushbutton for motor operating mechanism
3. Local/remote switch for motor operating mechanism
4. Ready-for-service indicator
5. Off pushbutton(transformers feeder only)
6. Spring “charged/not charged” indicator
7. Feeder designation labels
8. On pushbutton
9. Actuating opening for spring charging
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10. Manual operation for the mechanism of the earthing function closed/open
11. “fuse tripped” indicator
12. Manual operation for the mechanism of the load-break function closed/open
13. Control gate/locking device
14. Socket of capacitive voltage detecting system
15. Position indicator for earthing switch
16. Position indicator for disconnector
17. Rating plate
b) Operating the 3 position switch-disconnector
Operation with tools
Standard single-layer operation with black handle and coding as universal lever
Alternative 1: One operating lever with red handle for earthing and de-earthing and one operating
lever with black handle for load breaking
Alternative 2: Single-lever operation via anti-reflex lever with and without coding
All operation levers are available in short and long design. The long operation lever is equipped with
an additional spacing tube
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1->setscrew
Remove setscrew to get an anti-reflex lever
Operation for CLOSING (spring operated mechanism)
Check ready for service inductor
Remove padlock 5
Push control gate 4 upwards to release the switching gate and hold it tight
Insert operating lever 6 and move straight to CLOSED position
The switchgear is energized
Remove operating lever. The control gate moves to the center position automatically
Refit padlock at desired position
The locking device of the switching gate can be padlocked in all three switching positions
Operation for OPENING (spring operated mechanism)
Check for ready-for-service indicator -1
Remove padlock -5
Push control gate-4 upwards to release the switching gate, and hold it tight
Insert operating lever -6 and move straight to OPEN position
The switchgear is de-energized
Remove operating lever. The control gate to the center position automatically
Refit padlock at desired position
Operation for CLOSING (stored-energy mechanism)
Check ready-for-service indicator-1
Remove padlock -5
Push control gate-4upwards to release the switching gate and hold it tight
Insert operating lever-6 and move straight to the switch position
Remove operating lever. The control gate moves to the center position automatically
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The switchgear is prepared for CLOSING
ACTUATE on PUSHBUTTON-3
The switchgear is energized and the spring energy store for CLOSING is not
charged
Refit padlock at desired position
The locking device of the switching gate can be padlocked all three switch
position
Operation for OPENING (stored –energy mechanism)
Check ready-for-service indicator -1
Remove padlock-5
Actuate OFF pushbutton-2
The switchgear is de-energized and the spring energy store for OPENING is not
charged
Refit padlock at desired position
The locking device of the switching gate can be padlocked all three switch positions
Operation for EARTHING switch CLOSED
Check ready for service indicator-1
Remove padlock-5
Operate control gate-4 downwards to release the switching gate, and hold it tight
Insert operating lever and move straight to the switching position
The switchgear is earthed
Remove operating lever. The control gate moves to the center position automatically
Refit padlock at desired position
The locking device of the switching gate can be padlocked in all three switch
positions
Operating for earthing switch OPEN
Check ready for service indicator-1
Remove padlock -5
Operate control gate-4 downwards to release the switching gate, and hold it tight
Insert operating lever-6 and move straight to the switching position
The switchgear is de-energized
Remove operating lever. The control gate moves to the center position automatically
Refit padlock at desired position
The locking device of the switching gate can be padlocked in all three switch position
c) Operating vacuum circuit breaker type-2
Possible switching operations:
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Manual local operation, i.e. at the panel itself
Electrical remote operation, e.g. from the control center
Automatic operation from the installed protection equipment, e.g. SIPROTEC
o Avoid no-load switching as this can damage circuit-breaker type-2
o After charging the spring energy store, close circuit-breaker type-2 first, and then open
it
If the circuit-breaker is equipped with a motor operating mechanism, the closing and opening
springs are charged automatically after applying auxiliary voltage. The circuit-breaker can be
closed via a closing pulse supplied by the closing coil
If the circuit-breaker is operated manually, the closing and opening springs must be charged
annually
The circuit-breaker can be closed and opened with the pushbuttons
The opening spring is charged together with the closing spring
The control elements of the circuit-breaker are located at the panel front in the upper control
board
Closing the Circuit Breaker type-2 ‘Locally’
How to close the circuit-breaker depends on the equipment of the switchgear panel. There are two
versions of circuit-breaker operating mechanisms:
Stored-energy spring mechanism manually with handle
Stored-energy spring mechanism with motor
Closing with stored energy mechanism
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Actuate the ‘ON’ pushbutton
The circuit is closed
Opening the circuit breaker type -2 ‘Locally’
Actuate the ‘OFF’ pushbutton
The circuit is open
Closing the three-position disconnector in the circuit breaker panel type -2
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Push the control gate of the disconnector upwards. The actuating opening for the disconnector
is free. Only possible with the circuit-breaker in OPEN position
Insert the operating lever and turn 70 degree clockwise.
Remove the operating lever
The control gate of the disconnector moves to the center position automatically. The actuating
opening is closed
The disconnector is closed
Opening the three position disconnector in the circuit breaker panel type-2
Push the control gate of the disconnector downwards. The actuating opening is free
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Insert the operating lever and turns 55 degree clockwise
Remove the operating lever
The control gate moves to the center position automatically. The actuating opening is closed
The circuit-breaker panel is earthed
Position disconnector in the circuit breaker panel type-2: De-activating the EARTHED
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Insert the operating lever and turns 55 degree counter-clockwise
Remove the operating lever
The control gate moves to the center position automatically. The actuating is closed
The circuit-breaker panel is de-earthed
d) Operating the vacuum circuit breaker type 1.1
Possible switching operation:
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Manual local operation
Electrical remote operation e.g. from the control center
If the circuit breaker is equipped with a motor operating mechanism, the closing spring is
charged automatically after applying auxiliary voltage. The circuit breaker can be closed via a
closing pulse supplied by closing coil
Spring must be charged for the circuit breaker to be operated manually
Circuit breaker can be operated using pushbutton
1. Ready for service indicator
2. Off pushbutton for circuit breaker
3. actuating opening for disconnecting three position disconnector
4. Control gate/locking device for 3 position disconnector
5. Actuating opening for earthing
6. Position indicator for earthing switch
7. Position indicator for disconnector
8. Socket of capacitive voltage detecting system
9. Indicator for the circuit breaker closing
10. Operating counter
11. Position indicator for circuit breaker
12. Feeder designation label
13. On pushbutton for circuit breaker
14. Actuating opening for “spring charging” at the circuit breaker
15. Rating label
Closing the circuit breaker type 1.1”locally”
Two methods:-
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Stored-energy spring mechanism manually with handle
Stored-energy spring mechanism with motor
Closing with stored energy mechanism
Spring must be charged
Push “on” button
Circuit breaker is in closed position
Circuit breaker is in closed position
Opening the circuit breaker type 1.1 “locally”
Push “on” button
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Circuit breaker come in open position
Charging the spring energy store manually
The closing spring is charged automatically after applying control voltage. It is charged manually
by using lever
The opening for the lever is located top-left at the control board
Protective cap is removed
Insert the hand crank
Lever is turned clockwise until the “spring charged” indication appears in the inspection
window
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Remove the lever
The circuit breaker is charged and now it can be closed and opened again
Closing the three position disconnector in the circuit breaker panel type 1.1
Push the control gate of the disconnector downwards
Lever is inserted and rotated 70 degree clockwise
Operating lever is removed and the control gate comes back to center position
automatically. Disconnector is closed
The disconnector is closed
Opening the three position disconnector in the circuit breaker panel type 1.1
Control gate is pushed upward
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Lever is inserted and turned 70 degree anti-clockwise
Remove operating lever
The control gate comes automatically back to center position
The disconnector is open
4.5.2 Dry type transformers
4.5.2.1 General description
Station Type Rating
Sikanderpur ASS/TSS with in feed 2X500KVA
Phase 2 ASS with in feed 2X400KVA
Belvedere towers ASS 2X300KVA
Gateway tower ASS/TSS 2X300KVA
Mall of India ASS 2X300KVA
Depot ASS/TSS 2X300KVA
DLF phase 3 ASS/TSS 2X300KVA
4.5.2.2 Storage
They must be kept in a dry, well vandalized room, free from explosion hazard
4.5.2.3 Protection of dry type transformers
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Transformer protection
rating Primary secondary additional
Up to 900KVA load break switch with trip coil MCCB/ACB for each winding temperature
Or circuit breaker with IDMT type feeder indicator with alarm & trip
Over current & earth fault relay contact
1000KVA & circuit breaker with IDMT type MCCB/ACB for each winding temperature
Above over current & earth fault relay feeder indicator with alarm & trip
contact
4.5.2.4 WTI (winding temperature indicator) setting
Self cooled transformers have recommended setting for ALARM and TRIP
Alarm Trip
WTI 130 deg C 140 deg C
For forced cooled transformers fans start at 120 deg C
4.5.2.5 Insulation resistance (IR)
As a safe general rule the following values may be considered as satisfactory
Rated voltage KV Min safe IR in mega ohms at 30 deg C
Voltage of meggar (V)
33/22 500 2500
11/6.6 250 1000
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4.5.3 Rectifier transformer (1900KVA)
Rectifier transformer steps down the bulk 33KV power supply for the rectifiers to get 750V DC supply for
3rd rail. Presence of two rectifiers at all traction substations and one rectifier in NS corridor.
4.5.3.1 Transformer protection
The transformer must be protected from effects by overcurrrent. The winding and core
temperature sent to control center by SCADA.
Alarm at 130 deg Celsius
Trip at 150 deg Celsius
4.5.3.2 Connections
I. Coupling
Transformers connections on LV and HV side must not exert strain on the terminals and
must have enormous space to prevent excessive heating.
II. Ground connection
To ensure a solid core ground, transformers have copper straps embedded in the core
laminations and securely connected to the lower flame
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III. Tap connection
Before tapping transformer must be discharged. Tapping is done on HV side (primary)
because voltage per turn is high in large transformer thus change of one turn in LV side
causes a large voltage regulation.
IV. Bus connection
When transformer terminals are connected with bus duct, it is necessary to use flexible
transformer with bus duct is connected directly without flexible bus bar, transformer
may cause damage to bus duct or increase of noise
Contact plates must be cleaned for oxidation for good connection.
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4.5.4 High speed breakers
4.5.4.1 Description
Front view of high speed circuit breaker
4.5.4.2 High speed circuit breaker- operation
It is usually controlled by the built-in sitras PRO digital protective unit controller controlled
by a PLC
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4.5.5 Rectifier
It supplies 750V DC power to 3rd rail. The diodes are three phase bridge connection in 12 pulses
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4.5.6 Short circuit device
This device is installed at every station to check the potential rise b/w ground and 3rd rail. If the
voltage comes above 60V, the contractor closes and opens only if the current is reduce to a
determined level. If the voltage comes above 120V the information is sent to SCADA and
contractor remains in closed position and opens only when reset
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4.5.7 Negative return panel
The negative return current from the rails is collected by this negative return panel.
Following dia. shows collection of negative current from rails
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4.5.8 By pass load breaker switch panel
In DEPOT when the power gets down then by pass load breaker switch panel is used to get
power from 3rd rail.
Both disconnector and load break switch are present.
In open state the OFF button shows steady light, whereas in close state the OFF button flashout
and ON button glows
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End of report