rapid metro gurgaon report

RAPID METRO GURGAON LIMITED

(Power system distribution)

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.

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

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

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.

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.

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.

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

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.

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.

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

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

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

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

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:-

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

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

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

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



+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

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:-



3. Actuating opening for disconnecting 3 position disconnector






9. Indicator for the circuit breaker closing spring

10. Operation counter



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

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




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

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


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


The switchgear is prepared for CLOSING

ACTUATE on PUSHBUTTON-3

The switchgear is energized and the spring energy store for CLOSING is not

charged


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


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



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



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:

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

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

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

Insert the operating lever and turns 55 degree clockwise


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

Insert the operating lever and turns 55 degree counter-clockwise


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:

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



3. actuating opening for disconnecting three position disconnector






9. Indicator for the circuit breaker closing

10. Operating counter



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:-

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

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

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

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

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

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

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.

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

4.5.5 Rectifier

It supplies 750V DC power to 3rd rail. The diodes are three phase bridge connection in 12 pulses

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

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

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

End of report

rapid metro gurgaon report

Engineering