ACKNOWLEDGEMENTS Like any metropolitan railway system, KOLKATA METRO is also a vast application of innovative technology & engineering. The lesions, taught in U.G. electrical engineering curriculum, are found applied in each parts of power distribution, ventilation, signaling, rolling stock etc. throughout the system. Fortunately getting a chance to watch inside of this complex system, We have seen that how the theoretical lessons deal with the practical scenarios. We, therefore, convey our heartily gratitude and thanks to Kolkata Metro Railway Authority for giving us to refurbish our theoretical Learning with first hand practical experiences. We would like to thank the following officials for spending their valuable time on account of our on-site visiting. The Dept. In-Charge and Technicians of 1. 2. 3. 4. 5. 6.
Belgachia AV Kalighat AV JD park PD MSS(Basdroni) PD Noapara Rolling Stock Traction Power Control
Signature and seal of the Depot Incharges where on site training were given. I hereby declared that ,ARDHENDU PAL, student of JADAVPUR UNIVERSITY, had attended the scheduled vocational training programme 2014,conducted by Kolkata Merto Railways at my depot under my supervision.
i.
___________________ (SSE at Jatin Das Park PD Station)
ii.
___________________ (SSE at Belgachia AV Depot)
iii.
___________________ (SSE at Kalighat AV Depot)
iv.
___________________ (SSE at MSS Basdroni PD depot)
………………………………
Signature of the trainee
COMPANY PROFILE:The Kolkata Metro or Calcutta Metro (Bengali: কলকাতা মে া) is a metro system serving the city of Kolkata and the districts of South 24 Parganas and North 24 Parganas from DumDum near Netaji Subhas Chandra Bose Air Port, Kolkata to Kavi Subhash station near Patuli, the busy North-South axis of Kolkata over a length of 25.135 kms . It is the first Underground metro railway system in India. The network consists of one operational line (Line 1) and one under construction (Line 2), with four further lines in various stages of planning. It was the first such form of transport in India, opening for commercial services in 1984. It is the 17th zone of the Indian Railways system. Presently, 270 services are being run on normal weekdays to carry about 5.43 lakhs of passengers on an average per day with peak volume touching 6.90 lakhs on certain days.
The heaven of polluted, noisy Kolkata is under its land,i.e.,the Kolkata metro where anyone can discover cigerette butts,packets of pan mashala,poly bags, constant blow horn of undisciplined street cars suddenly vanished. Kolkata metro stations The Kolkata Metro, the Underground Mass Rapid Transit Urban Railway network in Kolkata, India. It was the first underground railway to be built in India, with the first operations commencing in October, 1984 and the full stretch that was initially planned being operational by February, 1995. Currently, there is only one line, the North-South Corridor. In the future, there will be five other metro lines. Stations 1. 2. 3. 4. 5. 6.
KaviSubhash (New Garia) ShahidKhudiram KaviNazrul Gitanjali Masterda Surya Sen Netaji
7. MahanayakUttam Kumar 8. RabindraSarobar 9. Kalighat 10.Jatin Das Park 11. Netaji Bhavan 12.Rabindra Sadan 13.Maidan 14.Park street 15.Esplanade 16.ChandniChowk 17.Central 18.Mahatma Gandhi Road 19.Girish Park 20.ShobhabazarSutanuti 21.Shyambazaar 22.Belgachhia 23.Dum Dum 24.Noapara
FUTURE PROSPECT OF METRO STATIONS: Line 1 (North-South Metro) Kolkata metro Railway,the oldest metro in India Line 1 has a total length of 28 kilometres (17 mi) serving 24 stations of which 15 are underground. It has a combination of elevated, ground-level and underground lines and uses five and a half feet (1.67metres) of Indian gauge, a broad gauge rolling stock. It was the first underground railway to be built in India, with the first trains running in October 1984, and the full stretch that had been initially planned was completed and operational by February 1995. On 28 December 2010, it became the 17th zone of the Indian Railways.[4] The New Delhi Metro, which opened in 2002, is the second such urban metro rail network in India. It had benefitted from the expertise gained during the Kolkata metro construction. In being the country’s first metro and constructed as a completely indigenous process, the Kolkata Metro was more of a trial-and-error affair, in contrast to the Delhi Metro, which has also seen the involvement of numerous international consultants. As a result, it took nearly 23 years to completely construct a 17 km underground railway.[2]
Line 2 (East-West Metro) East-West West Metro, a 48745.8 rupees ( ) (US$779.9) project to connect Kolkata with Howrah by an underwater metro line was given the go-ahead go ahead by the central [5] government. The length will be 14.67 km (8.9 km underground and 5.77 km elevated). This line will be constructed and maintained by a separate body named Kolkata Metro Rail Corporation (KMRC). However, in January 2011 KMRC and the entire East West (EW) metro corridor, was taken over by the Ministry of Railways from the Ministry of Urban development and the state government of West Bengal. Now the EW Metro's majority stake is with the Indian Railways and the remainder is as a loan from the Japan Bank for International Cooperation Cooperation. The West Bengal government had earlier appointed Delhi Metro Rail Corporation Limited to conduct a feasibility study of the project, after which the government had to then put the project on hold due to funding issues. The underwater metro plan was thought of when the first metro service was inaugurated in Kolkata in 1984 by former Prime Minister Indira Gandhi. The route is to cover 12 stations and go under the river through a tunnel. The foundation stone was laid on 22 February 2009. The construction of line 2 started in March 2009. The East-West East West Metro will run from Salt Lake Sector 5 (in the east) to Howrah Maidan (in the west). Trains will be air conditioned, and underground stations will be equipped with platform screen doors. It will run on standard (4 ft 8.5 in or 1,435 mm) gauge, unlike line 1, which runs on broad (5 ft 6 in or 1,676 mm) gauge. Between Mahakaran and Howrah Station, Station the metro will run 1,500 ft (460 m) under the Hooghly River — the first underwater metro in India. The line will be elevated between Salt Lake Sector 5 and YuvaBharatiKrirangan,, and the remaining stretch will be underground. Transfer stations will be located at Sealdah and Howrah. The first phase is planned to be operational in September 2015. Line 3 (Joka-B.B.D. B.B.D. Bagh Metro) A 16.72 km long metro line from Joka (in extreme South Kolkata) and BBD Bagh (in central Kolkata) is under construction.[citation needed] It is being built by RVNL and the tender has gone to Simplex Infrastructures. Proposed stations on this route: 1. Joka
2. Thakurpukur 3. Shilpara (Sakherbazar) 4. Barisha (BehalaChowrasta) 5. Behala Bazar 6. Taratala 7. Majerhat 8. Mominpur 9. Kidderpore 10.Hastings 11.Park Street (Intersection with Line 1) 12.Dharamtala 13.Mahakaran[Dalhousie) (Intersection with Line 2) The proposed Esplanade station will not to be the same as that of Line 1 (NorthSouth Metro) but a completely different station. Park Street will serve as an interchange between Line 3 and Line 1. Line 4 (Noapara-Barasat Metro) The project to build an 18.5 km line from Noapara to Barasat via NetajiSubhas Chandra Bose International Airport is sanctioned and construction work has commenced. The proposed stations on this route are 1. 2. 3. 4. 5. 6. 7. 8. 9.
Noapara (Intersection with Line 1) Dum Dum Cantonment Jessore Road Airport (Intersection with Line 6) Birati New Barrackpore [ Mother Teresa ] Madhyamgram Hridaypur BarasatLine 6 (New Garia-Airport Metro)A connection between New Garia and the Airport (32 km) via E M Bypass, Saltlake and Rajarhat has started; it will help to reduce travel time between the southern fringes of Kolkata to NetajiSubhas Chandra Bose International Airport. The work on this New Garia-Airport line was inaugurated by Mamata Banerjee on 7 February 2011 with a project deadline of six years.[10] The link between KaviSubhas (New Garia) and the airport, to be set up at a cost of Rs4 billion, will have 24 stations with the terminal Airport station being an underground one.
The stations, as declared of now, will be named after eminent personalities.[10]
1. New Garia (Intersection with Line 1) 2. Satyajit Ray Film and Television Institute 3. Mukundapur 4. Kalikapur 5. Ruby Hospital 6. VIP Bazar 7. Bantala 8. Science City 9. Beliaghata 10.Chingrighata 11.Nicco Park 12.Salt Lake Sector V (Intersection with Line 2) 13.Technopolis 14.Bidhan Nagar 15.Sub CBD-1 16.CBD-1 17.Kalkhetra 18.New Town 19.Convention Center 20.Sub CBD-2 21.Titumir 22.RabindraTirtha 23.VIP Road 24.Airport (Intersection with Line 4)
Power Supply, Air-conditioning & Ventilation and Other General Electrical Assets: The activities are distributed in four sections: Power Supply Distribution and Third Rail. Air-Conditioning, Ventilation, False Ceiling & Lighting. Escalators & Lifts Pumps and general assets. Power Supply Distribution and Third Rail: 33kV Power Supply is received from CESC at three Receiving Substations (RSS) viz. Shyambazar, Central &Jatin Das Park. 33KV supply is extended from Shyambazar&Jatin Das Park RSS to Masterda Surya Sen (Bansdroni) RSS. The voltage is stepped down to 11 KV and fed to 15 nos. Traction substation and 34 nos. Auxiliary substations located at stations & mid points. All the Receiving Substations are interconnected through 33 kV cable network and all the Traction & Auxiliary Substations are interconnected through 11 kV cable network to maintain power supply in case of failure of power supply at any of the RSS. In the Traction Substations (TSS), 11 kV is stepped down to 604 Volts, rectified to 750 Volts D.C. and fed to 3rd rail for traction purpose. In the Auxiliary Substations (ASS), 11 kV is stepped down to 415 Volts for lighting, Air conditioning and Ventilation, Pumps, Escalators, Signalling and Telecommunication etc. In addition to the 33kV sub-stations mentioned above, there are two receiving sub-stations, one at Metro Rail Bhawan and another at Belgachhia, where power from CESC is received at 6 kV, basically for commercial/domestic loads. 3rd rail between Noapara and KaviSubhash is fed at 15 Traction Substations with average spacing of 1.8 Km. From Traction Substations, 750 Volts D.C. is fed to 3rd rail through DC High Speed Circuit Breakers and cables. Power Supply is controlled through SCADA system from centralised Traction Power Control located at 4th floor of Metro Bhawan.
Routine maintenance of these assets is done departmentally. Major repair/replacement work is carried out by contractual agencies as per requirement. SCADA system is maintained by M/s. ABB, Bangalore through AMC. Air Conditioning, Ventilation and Lighting: All 15 underground stations of Kolkata Metro are equipped with ventilation and air-conditioning system. There are 149 no. ventilation fans working as supply or exhaust fans. The supply fans deliver fresh and cool air to station premises and tunnel sections, where as the exhaust fans remove air from under platform and mid tunnel points. The centralised type station air conditioning system consists of water cooled chillers, cooling tower, cooling coils and associated ducting. The AC plant capacity for each station ranges from 600 TR to 1200 TR. As per DMRC's recommendations, the use of air washery has been discontinued thereby achieving energy saving. In lieu, dry type filters have been installed. Fluorescent tubes are used for station and tunnel illumination. The switching of lighting system is done through SCADA system as per need during commercial & non-commercial hours. Out of 23 stations, 7 stations are provided with Energy Efficient Light (T-5). Emergency Lighting system is provided with battery backup.All the 15 underground stations are provided with aluminium false ceiling with perforation for minimising noise level inside the station. Mural lighting has been provided at stations for beautification purpose. Routine maintenance of Air Conditioning system is done through outsourcing whereas routine maintenance of Ventilation and lighting system is done departmentally. Escalators & Lifts: 64 nos. escalators in service have been installed at 20 stations. Of these, 21 nos. are for carrying passengers from platform to mezzanine and 14 nos. from mezzanine to surface. 20 nos are from concourse to platform and vice-versa. 5 nos. at Dum Dum station & 2 nos at KaviSubhash, are meant for carrying passengers from ground level to platform and vice-versa and 2 escalators are installed at Tollygunge subway.
Two escalators are under erection at Jatin Das Park station and two more are under supply. Twenty-five more escalators will be provided at different stations under sanctioned work to facilitate passenger movement. Two nos. of escalators have been erected at KaviSubhash station (for Eastern Railway platform). In the underground section no passenger lift has been provided. In the elevated section (Netaji – KaviSubhash) lifts have been provided between concourse level and platform level for physically challenged and aged person. Three no service lifts are provided at maintenance depots and nine no. passenger lifts are provided at Metro Rail Bhavan and residential complexes. One patient lift has been provided at Hospital. Three more lifts are under provision at New Hospital under construction at Tollygunge. Routine maintenance of lifts and escalators are outsourced.
Pumps and Other General Service Assets: There are 117 Dewatering Pumps of different capacities installed in sump pits at different locations to pump out seepage water, effluent of toilet, sanitary effluent etc. and discharged into Municipal sewer. All these pumps are made “ON” and “OFF” automatically by water level controller. There are 44Tube well Pumps of different capacities installed at different locations to meet water required for platform cleaning, drinking, fire fighting etc. Presently only 25 Tube-well Pumps are working, remaining has dried up. Periodical maintenance and performance checking of pumping system is done for reliable service. Routine maintenance of pump is done departmentally and repair activity is outsourced. Other assets include passenger amenity items like water coolers & illuminated signage, approximately 20,000 tube light fittings, fans, battery and battery chargers, UPS, window and split air conditioners, service sub stations, colony and service buildings etc.
Power Requirement: The Contract Demand for the different receiving sub-stations is as under. Name of the RSS Shyambazar Central Jatin Das Park Metro Rail Bhawan
Voltage 33 kV 33 kV 33 kV 6 kV
Belgachhia
6 kV
Contract Demand 6.5 MVA 12.0 MVA 9.0 MVA 0.4 MW (commercial) 0.11 MW (domestic)
POWER SUPPLY & DISTRIBUTION SYSTEM OF METRO RAILWAY, KOLKATA
RECEIVING SUBSTATION (RSS): The entire alignment of Dum Dum-Kavi Subhas is fed at 33kV,50 Hz 3phase AC from the local electrical supply company like CALCUTTA ELECTRIC SUPPLY CORPORATION’S (CESC) main grid network.There are four 33kV receiving stations for metro at the following locations(1) CENTRAL in the Northern sector. (2) SHYAMBAZAR in the Northern sector. (3) JATIN DAS PARK in the Southern sector. (4) MASTERDA SURYA SEN in the Southern region. Shyambazer and Central receiving substation y being fed normally by two independent 33kV feeders from two independent from two independent sources of CESC. Jatin Das Park is fed by 3 independent sources. Masterda Surya Sen receiving substation is fed by two 33kV feeders, one drawn from shyambazer& other from Jatin Das Park. Furthermore, there is also interconnections at 33kV through tunnel and underground cables between Central, Shyambazer, Jatin Das Park and Masterda Surya Sen. Thus, so far as receiving the power supply is
concerned every receiving station has two independent sources (except JPK which has three)& interconnections at either end so that even second degree failure of power supply, which does not effect the train operation. AUXILLIARY SUBSTATION (ASS): An Auxilliary Substation is used for supplying power for escalators, lighting in tunnels and stations, pumps for sippage water drain etc. Here the voltage is stepped down from 11KV/415 V 1 MVA transformers. All the RSS and TSSare essentially ASS. Apart from RSS/TSS mentioned above, Kolkata metro has ASS at Shovabazar, M.G. Road, ChadniChowk, Esplanade, Maidan, NetajiBhavan, Kalighat. Air Conditioning, Ventilation and Lighting: • All 15 underground stations of Kolkata Metro are equipped with ventilation and air-conditioning system. There are 149 no. ventilation fans working as supply or exhaust fans. The supply fans deliver fresh and cool air to station premises and tunnel sections, whereas the exhaust fans remove air from under platform and mid tunnel points. • The centralised type station air conditioning system consists of water cooled chillers, cooling tower, cooling coils and associated ducting. The AC plant capacity for each station ranges from 600 TR to 1200 TR. As per DMRC's recommendations, the use of air washery has been discontinued thereby achieving energy saving. In lieu, dry type filters have been installed. • Fluorescent tubes are used for station and tunnel illumination. The switching of lighting system is done through SCADA system as per need during commercial & non-commercial hours. Out of 23 stations, 7 stations are provided with Energy Efficient Light (T-5). Emergency Lighting system is provided with battery backup.All the 15 underground stations are provided with aluminium false ceiling with perforation for minimising noise level inside the station. Mural lighting has been provided at stations for beautification purpose. • Routine maintenance of Air Conditioning system is done through outsourcing whereas routine maintenance of Ventilation and lighting system is done departmentally.
Escalators & Lifts: • 64 nos. escalators in service have been installed at 20 stations. Of these, 21 nos. are for carrying passengers from platform to mezzanine and 14 nos. from mezzanine to surface. 20 nos are from concourse to platform and vice-versa. 5 nos. at Dum Dum station & 2 nos at KaviSubhash, are meant for carrying passengers from ground level to platform and vice-versa and 2 escalators are installed at Tollygunge subway. • Two escalators are under erection at Jatin Das Park station and two more are under supply. Twenty-five more escalators will be provided at different stations under sanctioned work to facilitate passenger movement. • Two nos. of escalators have been erected at KaviSubhash station (for Eastern Railway platform). • In the underground section no passenger lift has been provided. In the elevated section (Netaji – KaviSubhash) lifts have been provided between concourse level and platform level for physically challenged and aged person. Three no service lifts are provided at maintenance depots and nine no. passenger lifts are provided at Metro Rail Bhavan and residential complexes. One patient lift has been provided at Hospital. Three more lifts are under provision at New Hospital under construction at Tollygunge. Pumps and Other General Service Assets: • There are 117 Dewatering Pumps of different capacities installed in sump pits at different locations to pump out seepage water, effluent of toilet, sanitary effluent etc. and discharged into Municipal sewer. All these pumps are made “ON” and “OFF” automatically by water level controller. • There are 44Tube well Pumps of different capacities installed at different locations to meet water required for platform cleaning, drinking, fire fighting etc. Presently only 25 Tube-well Pumps are working, remaining has dried up. • Periodical maintenance and performance checking of pumping system is done for reliable service. Routine maintenance of pump is done departmentally and repair activity is outsourced. • Other assets include passenger amenity items like water coolers & illuminated signage, approximately 20,000 tube light fittings, fans, battery and
battery chargers, UPS, window and split air conditioners, service sub stations, colony and service buildings etc.
Mid Section Substation:Mid Section Substation is fed by two 11kV feeders from 11 kV bus of two consecutive stations in the middle of which the substation resides. The 11 kV line is stepped down to 415V(AC) by 315 kVA transformers and the power flows through a circuit breaker whose capacity is to withstand 1600A current. Mid Section Substation is generally used to feed the AC and Ventilation System . It is used to feed station intake fans, under Platform exhaust fans, tunnel intake fans, dewatering pumps, Lighting in the tunnel and the switchyard. A TYPICAL MID SECTION SUBSTATION..
TRACTION SUBSTATION( TSS) 11kV cabling system has been distributed throughout the main tunnel for traction supply. So far as traction supply is concerned, each traction substation is being fed from two different receiving stations. A traction substation (TSS) steps down 11kv voltage to 604 V using transformers. Using diode rectifier arrangement 604 v ac voltages is converted to near about 750 v DC supply. From the positive bus of DC supply four feeders are connected to the third rail,one across each end of the neutral section for up and down lines. Afifth feeder arrangement is provided to provide supply to a particular section in case of failure of corresponding feeder.The negative bus of DC supply is connected to over voltage protection device (OVPD) to trip the circuit in case of over voltages. Normally the third rail section is being fed at both ends at 750 V DC. Even if one receiving station is completely switched off, i.e. switching “OFF” the third rail supply, the other supply for the same section is fed from the nearest TSS & other receiving stations will always be “ON”. This ensures that incase of ‘first’ degree failure either at 33kv system/equipment or 11kv cabling/equipment or 750V equipment/cabling, the concerned third rail zone will be always get power supply from the other TSS. Thus in no case, train movement is jeopardized. As usual to the DC traction distribution, allsubstations are operated in parallel. There is no provision of track cabin. Due to lower voltage and higher traffic density, the distance between the substations is small (around 1.5 km). The spacing of the substation is fixed on the basis of the voltage drop for ultimate load. The minimum voltage permitted at the far end in the worst case is 525 V DC. At every receiving station, there are 16 MVA, 33/11 kV, 3 phase delta star connected transformers, which stepped down the incoming voltage to 11kv. From there, 11kv cabling system has been restored throughout the main tunnel for traction supply.
PROTECTION SCHEME Kolkata metro is very much dependent on uninterrupted electric supply and measures must be taken so that the long electrical network can withstand any faulty condition. Metro railway use vacuum type, air type, DC high speed and SF6 circuit breakers in accordance with various relays like earth fault, overload, under voltage, OVPD relays etc. It also uses positive and negative is are isolators which are either hand driven or motor driven. The breaker
capacity for CESC side is 1200A and that for auxiliary and mid-section substation is 1600A.Besides dislocation 110 batteries are used to generate a 220V DC and feed the relay coils so that corresponding breaker can close and power can be brought from outside to maintain the service. In normal case CTs are used to supply the relay coils. PTs are used to measure voltage of different buses. According to modern technology for a three phase line to overcurrent relay is used to detect overcurrent or earth fault in any phase supply or receiving of power another feeder supplies Masterda Surya Sen station. The 33kV power is received to the 33kV power is received to the 33kv bus through the circuit breakers. There are 3no.s of 33kV buses connected the bus couplers. It is so designed that only 3 of the total 5 breakers can operate at a time for receiving power as there is no arrangement of parallel operation. PTs are connected to the buses to measure their voltages. After that the 33kV is stepped down to 11kV and supplied to the 11kV bus through the circuit breakers. There are two no’s of 33/11kV transformers which is of 16 MVA rating. This 11kV line is divided for two purposes, such as (1) Traction (2) auxiliary substation feeding. The 11kV line is stepped down to 604 volt AC by four set of 11 kV/604 V (2.3 MVA) transformers which is in term is guided to the rectifier panel. This is called a Traction Substation. There are 4 number of rectifier panel each of which has 60 no.s of silicon diodes. After rectification 750 volt DC is generated. This voltage is guided to the +Ve bus through +Ve isolator and the negative section is guided to the negative bus through negative isolator. The +ve bus 750 V DC is guided to the third rail through 5 feeders. 4 of which work regularly and one is kept standby in case of power failure. They are guided by high speed DC circuit breaker. The 5th feeder has 4 parts, 2 of them supplies the up and down section of TOLLYGUNGE end. One part of 11 kV is supplied to mid section substation and other is supplied to Auxiliary substation. Auxiliary substation is used for supplying power to escalators, fans, lights, pumps, signaling etc. The LT side of 415v AC auxiliary substation is coupled with cables for proper insulation. 415v is achieved by stepping down 11 kV to 415 v by 1MVA transformers. Mid section substation is used to supply the AC ventilation system. CTs and PTs are used for measuring purpose. CTs are also used to feed the different relays that are present in the Substation. Substation uses 3 core cable for 33 kV side. Protection Scheme for various POWER SYSTEM components are given below:
(1) 33 KV Incoming Feeders (a) Inverse time over current and earth fault protection. (b) Pilot Wire Translay feeder protection in conjunction with surge proof inter trip receive relay (c) Instantaneous Voltage relay protection for over voltage and under voltage.
(2) 33KV Bus Section (a) High impedance circulating current differential protection relay in conjunction with trip relays. (b) Instantaneous voltage relay protection for over voltage and under voltage.
(3) 33KV Transformer (a) Differential Protection. (b) Combined Inverse Time over current and Earth Fault Relay. (c) Low Oil level Alarm, Buchholz relay, Oil temperature and winding temperature alarm and trip.
(4) 11KV Bus Section (a) Instantaneous voltage relay protection for over voltage and under voltage.
(5) 11KV AC/750V DC rectifier transformer (a) Instantaneous over current and earth fault relay. (b)Neutral displacement relay. (c) Winding temperature alarm and trip.
(6) 750V DC Rectifier
(a) Fuse protection for each string. (b) Reverse current protection. (c) 3 phase over current with instantaneous high set relay. (d) 2 phase over current and one phase earth fault relay.
(7) DC HSCB and Isolator Panel (a) di/dt relay for short circuit protection. (b) Frame leakage relay. (c) Under voltage relay. (d) DC cable insulation failure relay.
(8) DC Negative Isolator Panel (a) Voltage operated contactor set to operate whenever voltage difference between DC negative and substation earth exceeds 90V.
(9) 11KV/415 v auxiliary Transformer (a) Combined inverse time over current and Earth fault relay on both primary and secondary side. (b) Buchholz relay, oil temperature alarm and trip.
BANSDRONI ( MASTERDA SURYA SEN)(_RSS) Information about different protection scheme used in BANSDRONI METRO STATION: 1. Relay protection system. 2. Circuit breaker. 3. Transformer. TRANSFORMER A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors – the transformer coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying EMF in the secondary winding. This effect is called inductive coupling.
DIFFERENT TYPES OF TRANSFORMER USED IN THIS TRACTION SYSTEM: 1. Oil type transformer. 2. Dry type transformer. (1). Oil type transformer: Transformer oil is usually a highly- refined mineral oil that is stable at high temperatures and has excellent electrical insulating properties. It is used in oil-filled transformers, some types of high voltage capasitors, and circuit breaker. Its function are to insulate, suppress corona and arcing, and to serve as coolant.
RELAY USED IN PROTECTION SYSTEM: The relays is the element that senses an abnormal condition in the circuit and commands the operation of the breaker. They can be classified in a number of ways:
According to the quantity sensed: current, voltage, active power, reactive power, impedance relays
According to the tripping: instantaneous trip, delayed trip, inverse timecurrent response According to the operating principle: electromagnetic relays, induction relays, thermal relays, static or digital relays
More general classification distinguishes two types of relays:
1. Electromechanical relays 2. Digital relays
Currently, electromechanical relay in all its forms is being replaced by static, digital and numerical relays, each change bringing with it reductions and size and improvements in functionality. In most types (except digital relays) the relays contacts are closed by a moving part which senses a force proportional to the current (or other sensed quantity) in the circuit. A restraining force produced by a spring or other means sets the threshold above which the relay operates. In a protection relay, the term "static" refers to the absence of moving parts to create the relay characteristic. Compared to static relays, digital relays introduced A/D conversion of all measured analogue quantities and use a microprocessor to implement protection algorithm. The distinction between digital and numerical relays rests on points of fine technical detail, and is rearly found in areas other than protection. They can be viewed as natural developments of digital relays as a result of advances in technol
BELGACHIA AV Informations about (1) (2) (3) (4)
Lighting Battery Ventilation AC Plant
LIGHTING : Generally two types of lighting systems are used – (1) Commercial (2) Non commercial In non commercial system comparative less number of lights are used than that of in commercial system.Lighting arrangement depends upon the Illumination level inside and outside the tunnel & platform. Illumination : Outside illumination level – 1400 to 1500 LUXLUX level inside the tunnel depends upon the polar curve.Inside illumination level – 150 LUXLUX level at the entry of the tunnel (gate) – 400 LUX Diameter of tube lights :At preliminary days diameter of tube light usually was 12 mm. It caused more cross-sectional area between the tube gap. It is evident that molre cross-sectional area causes more losses which in turn provide less efficiency. But when the diameter has been reduced to 8 mm lesser amount of losses as well as more Efficiency has been produced. So now a days tube lights having 8 mm diameter are usually used. But very recently much more modification has been made and T-5 system (tube lights having 5mm diameter) is used. Modification : Modification in lighting has been done on the basis of CARBON CREDIT.Carbon credit is the phenomena in which according to the location of any area the limit of carbon exhaustion is specified.Carbon exhaustion means exhaustion of CO2 . Heat radiation causes CO2 formation. It has to be kept in mind that there should not be any heat radiation in lighting system used in
metro railway. For this purpose, CFL bulbs are used, not ordinary bulbs. Lighting Arrangements:
STATION
50 % OF LIGHTS
50 % OF LIGHTS
POWER IS SUPPLIED BY A SOURCE IN RIGHT END
25 % OF LIGHTS POWER IS SUPPLIED BY A SOURCE IN LEFT END
25 % OF LIGHTS
GET POWER SUPPLY BY A DC SOURCE AT TIME OF POWER FAILURE
BATTERY: In tunnel section we use PLANT-TYPE batteries in lighting system. These are Exide batteries containing Lead-Acid. Technical specifications of plant-type batteries:Standard rating – 30 Volts DC, 75 AH, at 27 °C when discharged in 10 hours with final voltage per cell not less than 1.85 volts. Cell voltage – The nominal voltage of a single cell shall be not less than 2 Volts at the beginning of the charging. The trickle charging voltage per cell shall be within2.25 volts to 2.3 volts. The boost charging voltage per cell shall be within 2.35 volts to 2.75 volts. At the end of the charging, cell shall be floated easily around 2.25 volts without causing adverse corrosion or loss of water. Charging current – Trickle charging current shall be between 60 mA to 180 mA. Boost charging current shall be within following limits: (a)Starting Rate : 10 Amp (b)Finishing Rate : 5 Amp Total minimum input requirement during initial charging shall be around 480 to 500 AH. Fully charged battery shall accept about 1 mA/AH or less current under float application. Configuration- YKP21 EXIDE For maintenance purpose discharging should be low in this type of battery. With plante-type battery quick recharging is possible. Plante-type batteries are used in 4 sections: (a)DCDB- dc distribution box (b)MCCB- Modulated case circuit breaker Miniature circuit breakers are used below 100A and Modulated Case circuit breakers are used between the range from 10A to 2000A. So, MCCB is capable for higher currents. The rated current for air circuit breaker, used in metro railway is 400A. DCDB is capable at the time of power failure.
ACB for input
MCB
MCCB
To load via 6 way SPN DB
3- phase load
VENTILATION : Ventilating is the process of “changing” or replacing air in any space to provide high indoor air quality. Ventilation is used to remove unpleasant smells and excessive moisture, introduce outside air, to keep platform & train interior air circulating, and to prevent stagnation of the interior air. Ventilation includes both the exchange of air to the outside as well as circulation of air within the platform & train interior air circulating, and to prevent stagnation of the interior air. Ventilation includes both the exchange of air to the outside as well as circulation of air within the platform & train. It is one of the most important factors for maintaining acceptable indoor air quality in platform & train. Platform Air Intake = (30+30) M3 =60 M3 Tunnel Air Intake = 50 M3 (Platform+Tunnel) Intake = (60+50) M3 =110 M3
UNDER Platform Exhaust (by exhaust fan)= 25 M3 So, Total Intake = (110-25)M3 = 85 M3 Mid point tunnel is used to exhaust 80 M3 of total air intake and rest 5 M3 of air intake is considered as platform leakage.The exhausted air passes away and leaves the system through ducts used in the mid point tunnel. Ventilation Fan: Ventilation fan is belt driven. So, the belt is called Wedge Belt. Also, the power is transmitted through this wedge.As air is passing through both the inlets of the fan, so it is called Double Inlet Fan. This fan vibration is axial type, so it is called Axial Fan. ‘V’ shaped belt is used in the pulley which is used in the fan. The total air intake for the fan having 75 HP efficiency is 50 M3 and that is for the fan having 125 HP efficiency is 80 M3. A purely star-delta auto starter is used in 3 – phase, lap winded Induction Motor used in fan.In ventilation fan normally Top Discharge is used but somewhere Bottom Discharge is also used.The phenomena of static pressure are used in ventilation fan.Static Pressure – The pressure of the water, lifted by air on that air level is called static pressure. At the time of intake the static pressure in the fan is 100 mm3 At the time of exhaust the static pressure in the fan is 50 mm3.
AC PLANT : The basic operation of an AC plant is as follows – (a)The hot water is passed through an ORIFICE into the CHILLER. Here sudden expansion occurs and therefore the hot water evaporates to form gas. (b)Then the chilled gas or air is passed through a COMPRESSOR where temperature & pressure both are high. (c)After this the compressed air is passed through the CONDENSOR. Here the air faces high pressure & low temperature. Therefore the air becomes liquefied and is passed through the chiller again.
(d) Hot water from the condenser is passed to the COOLING TOWER. Hence it cools down and the cold water is passed through the condenser. Thus the water circulation never stops. This is the overall AC PLANT arrangement discussed above. The unit TONAGE is used in AC plant arrangement. TONGE – The capacity of the system to convert 1 tone of water of 0°C into 1 tone of ice of 0°C in 24 hours. Panel Box : Star connection: at the time of starting with the current is high. Delta connection: when the motor gets started (after 25 ms). Condenser : Return liquid = 91.7° F Leaving liquid = 96.7° F Chiller : Leaving liquid = 54° F Return liquid = 60.4° F Evaporated pressure = 45.4 PSIG Compressor : Differential oil pressure = 88.3 PSIP Discharge pressure = 137.4 PSIG DISCHARGE TEMPERATURE = 120.4° F Water hardness = 10p.p.m to 15 p.p.m
KALIGHAT AV Informations about AC and Ventilation System:
OUTSIDE WATER
MOTOR
COMPRESSOR
CONDENSOR
CHILLER
EXPANSION VALVE
CHILLER TANK (WATER) COOLING COIL(HEAT EXCHANGING) WARM WATER TANK To reduce the temperature of stations underground Metro Railway has installed AC and ventilation system that not only cools the ambient but also
reduce the temperature of the lower part of the rail engines. To obtain these tasks 3 types of fan are installed: 1) Station intake fans 2) Tunnel intake fans 3) Under platform exhaust fans are used. There are a total of 75 AC plants(7 of which are in Kalighat Metro station, capacity 90 tons per unit). AC plant fan capacity for station end in Kalighat Metro is 60 m3 and for tunnel end is 40 m3. The motors use star delta starters and for station end the capacity is 150 HP (at 120 A) and for tunnel end is 60 HP (at 75 A) at speed of 1400 rpm. There are 139 nos. of ventilation fans out of which 61 nos. are exhaust fans and 78 nos. are stations intake fans of various capacities from 25 m3/s to 90 m3/s installed in the underground metro zone. The ac plants take water and it is passedto the compressors by motors. The compressed air is condensed by the condensers which has freon22 outside and water inside. The condensed water is passed to the chiller which has Freeon22 inside and water outside for cooling. The cooled water is passed to the chiller tank by expansion valves. Another set of fans create suction and ambient hot air enters the ac plant successively filtered by 20 micron and 10 micron filters and the hot air exchanges heat with the cold water in the cooling coil. The water becomes warm and passed to the warm water tank and then again to the chiller for cooling. This cycle persists until the ambient temperature falls below 28° C and the humidity level is below 65 %. The cool air is passed to the station by station intake fans. The tunnel intake fans in the mid section substations is used as ventilation. The under platform exhaust fans cool the lower portion of engine.
Traction Power Control(TPC):As metro railway system spreads over several kilometers under densely populated area,localized power control and switching arrangements causes much trouble for efficient transportation. We need a instant and continuous data server which will show instantaneous condition of each relay,circuit breaker, isolator , power supply diverter,ct,vt, employed throughout route.And also a workstation for remote controlling of those protecting diverting, measuring devices, i.e., acting as a master computer. The SCADA system is best option for this remote controlling. SCADA (supervisory control and data acquisition) is a system operating with coded signals over communicate on channels so as to provide control of remote equipment (using typically one communication channel per remote station). The supervisory system may be combined with a data acquisition system by adding the use of coded signals over communication channels to acquire information about the status of the remote equipment for display or for recording functions. It is a type of industrial control system (ICS). Industrial control systems are computerbased systems that monitor and control industrial processes that exist in the physical world. SCADA systems historically distinguish themselves from other ICS systems by being large-scale processes that can include multiple sites, and large distances. Common system components A SCADA system usually consists of the following subsystems: • Remote terminal units (RTUs) connect to sensors in the process and convert sensor signals to digital data. They have telemetry hardware capable of sending digital data to the supervisory system, as well as receiving digital commands from the supervisory system. RTUs often have embedded control capabilities such as ladder logic in order to accomplish boolean logic operations. • Programmable logic controller (PLCs) connect to sensors in the process and converting sensor signals to digital data. PLCs have more sophisticated embedded control capabilities, typically one or more IEC 61131-3programming languages, than RTUs. PLCs do not have telemetry hardware, although this functionality is typically installed alongside them. PLCs are sometimes used in place of RTUs as
field devices because they are more economical, versatile, flexible, and configurable. • A telemetry system is typically used to connect PLCs and RTUs with control centers, data warehouses, and the enterprise. Examples of wired telemetry media used in SCADA systems include leased telephone lines and WAN circuits. Examples of wireless telemetry media used in SCADA systems include satellite (VSAT), licensed and unlicensed radio, cellular and microwave. • A data acquisition server is a software service which uses industrial protocols to connect software services, via telemetry, with field devices such as RTUs and PLCs. It allows clients to access data from these field devicesusing standard protocols. • A human–machine interface or HMI is the apparatus or device which presents processed data to a human operator, and through this, the human operator monitors and interacts with the process. The HMI is a client that requests data from a data acquisition server. • A Historian is a software service which accumulates time-stamped data, boolean events, and boolean alarms in adatabase which can be queried or used to populate graphic trends in the HMI. The historian is a client that requests data from a data acquisition server. • A supervisory (computer) system, gathering (acquiring) data on the process and sending commands (control) to the SCADA system.
Description of SCADA System: SCADA system is based on microprocessor based state-of-the-art technology. It consists of a number of high performance computer systems situated in RCC room with microprocessor based Remote Terminal Units (RTU) installed in geographically disbursed terrain in harsh environment near Railway track. The architecture of the SCADA system is depicted inthe following schematic “SCADA SYSTEM CONFIGURATION DIAGRAM”. The high end microcomputers are connected over a high speed tightly coupled LAN architecture.
The backbone of the RCC system is a LAN, which consists of: 1) Two supervisory computers (SC1 & SC2) with identical configuration, working in 100% fault tolerant hot standby mode. 2) Two front end computer system (F1 & F2) with auto-switch and MODEM for managing data communication with RTUs and Supervisory computers. 3) Two Work Stations (WS1 & WS2) consisting of six view terminals (V1-V3 and V4-V6) connected through 8 port unmanaged HUB.
4) 6 Nos. 19” Large screen Video display terminals.The LAN is implemented using ETHERNET standard. Thecomputers are connected in STAR topology using a 10 port unmanaged HUB. The connections are done in a radial manner through UTP CAT V cable. The cable is terminated on both side using RJ45 connector. The network works in TCP IP mode using 10 Mbps serial communication with the CSMA.CD (carrier sense multiple access with collision detection) media technique.The complete system along with their peripherals and devices are installed at RCC. The Supervisory computers are connected to the RTU’s in a multi drop fashion for continuous polling. The proprietary protocol is based on IEC 870-5. The RCC to RTU communication happens over a single four wire communication channel. The Supervisory computer running the SCADA software would interrogate and acquire the field signals from individual RTU on a query basis through dedicated communication channel. The collected information are available for display on the view terminals and the Work Station’s video screen. Powerful Graphical User interface software allows display of the status of the entire topography covered. Multicoloured display allows for easy recognition of alarm conditions. The operators working on the work station issue the appropriate commands which are relayed to the RTUs via the active Supervisory computers. All RTUs are microprocessor based, designed to acquire data from TSS, SP, SSP and capable of providing TRIP and CLOSE signals to the respective feeders according to the TPC’s choice. The configuration of RCC room with various sub-systems and computers and outline of the software architecture are described below:Each Supervisory Computer has following configuration :• Latest Intel Processor based CPU • 4 GB RAM • 15” Monitor • 104 Keys Key Board • Mouse • 200+ GB Hard Disk Drive with EIDE disk controller. • Back Up drives
• One serial and one parallel interface • 10 / 100 MBPS Ethernet LAN interface. The system consists of two Supervisory computers ofidentical configuration. Hot stand by is implemented through these two computers. While SC1 is working as Master the SC2 is working as Slave. Supervisory computers workas a centralized data server and its main tasks are as follows :Functions of Active/Master Computer (SC1) • Receives data from RTU’s via the Front End Processors • Maintains data base for all signals from all RTU’swith date and time stamp • Accepts queries from Work Stations • Makes the requested data available to the Work Station. • Takes care of log printing. • This computer works as Master.While SC1 works as the master the SC2 works as slave and watching the various transactions taking place in the network. Functions of Standby/Slave Computer (SC2) • Slave computer works in hot-stand by mode • Maintain identical database with SC1 • Slave computer continuously monitor the health of the Master • In case of failure the slave computer configures itself as active through intelligent auto switching with updated data base/ message so that fault can be attended Front End Processor (F1 and F2)Front-End Processors (F1 & F2) are also working in hot-standby mode and connected to the LAN. FEPs are connected to the different RTU communication line via modem. Following are the details: The front-end processor manages the data communication between the RTUs and master station. It handles the total communication protocol and distributes
data to the supervisory computer via high bandwidth LAN bus. Through a serial port the FEPs are connected to the RTU communication lines via modem. The two modems are connected back to back and attached to their respective F1 & F2. The system consists of two Front End Processor each having following configuration. One modem is always connected to the active FEP which controls the RTU communication channel when the other modem is held back in stand by mode. Each front end processor has following configuration: • Latest Intel Processor based CPU • 4 GB Dynamic RAM • 1 Serial port and one parallel port • 10 /100 Mbps Ethernet LAN card. Work Station (WS1 & WS2) Work Station software provides the complete Man Machine Interface (MMI). Each work station consists of PCs with 19” SVGA colour monitors connected to the LAN. The operator can view the updated status of the Breaker/ Interrupter. Operator can also issue command via mouse or key board connected to each of the six terminals. Following are the details configuration of the WorkStation. • Latest Intel Processor based CPU • 4 GB Dynamic RAM • 1 Serial and 1 parallel port • 10 / 100 Mbps Ethernet LAN card • One DOT MATRIX Printer • Three terminals each supporting 19” color monitor,key board and mouse. The primary task of Work Station software is to display the status of the system. It has following components: • Three adjacent control station with fixed and variable data
• Full section with all devices • Tabular Displays • Alarm List • Event List • Systems Alarms • Trend chart • Bar Graph • Message Pad Work Station software handles the following commands: • It accepts command from keyboard and mouse, generate TELECOMMAND and then send to appropriate RTU. It also accepts command for EDA (enable or disable), Auto re-closing of devices, Feed extension and Auto fault localization. • It receives tele-signals and changes the status ofthe devices by changing the original position and color. • It activates HOOTER and ALARM in case of emergency. • It generates periodic reports. Other features include: • Real-time data display for all part of the power system in full-colour, userconfigurable system graphics mode. • Automatic detection, annunciation, display and logging of alarm conditions. • Extensive data acquisition capabilities provide automatic retrieval and disk archival of waveform capture data, wave form recorder data and data logging from remote devices. • Power quality analysis using high speed waveform capture data, Display waveforms, %THD, K-Factor, Crest Factor and histograms.
• Fault or swell/sag analysis using display of waveform recorder. Display multiple input phases of 12 to 36 – cycle waveforms with zoom and pan capability. • View all data logs on screen or use archived data with standard database applications. • Detailed graphical display of load trends. Remote Terminal Unit (RTU) The RTU is a microprocessor based remote control and data acquisition system that interfaces field signals acquired from a process to a host computer. The RTUs are located in scattered way over a long distance near Railway track under harsh environment. The basic functions performed by RTU are as follows: a) Processing of control commands received from the host computer for control action. b) Acquire data and processing and transmission of information about the local process to the host computer. c) Control all devices internal to the RTU. The basic structure of RTU hardware is based on a system bus, which is identical for all types of equipment. It forms the backbone of both the electrical and mechanical designs. The entire data exchange between the CPU and peripheral modules takes place through the microprocessor bus, which physically form a back plane. RTU consists of a 16-bit, 32KB CMOS RAM, 32K EPROM, 1 serial communication port, analog input modules with 8 – bit ADC, digital input modules with optical isolation and as a self contained unit with power supply and cooling.
