Power Supply Arrangements at Sub-Stations
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Questions and Answers

What is the primary voltage for the feeders that are used to support the overhead equipment for traction?

  • 25 kV (correct)
  • 27.5 kV
  • 23.75 kV
  • 30 kV

What is the permissible voltage variation range for the bus bars at the grid sub-station?

  • $27,500 V$ to $23,750 V$ (correct)
  • $23,000 V$ to $29,000 V$
  • $20,000 V$ to $27,500 V$
  • $25,000 V$ to $30,000 V$

How is the single-phase traction load managed to prevent unbalance in the 3-phase grid system?

  • By cyclic tapping across different phases (correct)
  • By reducing the voltage to lower levels
  • By using transformers
  • By using only one phase for traction

Which component ensures that the voltage does not exceed 27.5 kV at the feeding post?

<p>Transformer settings (B)</p> Signup and view all the answers

What is the maximum allowable instantaneous voltage unbalance at the point of common coupling in the grid supply system?

<p>5% (D)</p> Signup and view all the answers

What type of operation is the traction sub-station designed for?

<p>Remote operation (B)</p> Signup and view all the answers

What connects one end of the secondary winding of the transformer at the sub-station?

<p>Buried rail (D)</p> Signup and view all the answers

What is the maximum speed allowed when the runners of the section insulator assembly are not installed in the first one-third of the span?

<p>80 km/h (C)</p> Signup and view all the answers

What kind of structures are used to ensure mechanical independence of the overhead equipment (OHE) for each track?

<p>Independent structures (C)</p> Signup and view all the answers

What is the maximum speed potential for an OHE designed with a span of 72 m and a tension of 1000 kgf in both contact and catenary wires?

<p>160 km/h (D)</p> Signup and view all the answers

What precaution is necessary when approaching an unwired track with an electric locomotive?

<p>A diesel engine must be used to pull the locomotive (A)</p> Signup and view all the answers

What should a driver be ready to do when approaching a neutral section indicated by warning boards?

<p>Open the DJ (Disconnector Junction) (B)</p> Signup and view all the answers

What is indicated about electric traffic during a power block on both OHE sub-sectors?

<p>Electric traffic must be suspended until power is restored. (A)</p> Signup and view all the answers

What is the purpose of static type voltage regulators in the railways?

<p>To maintain voltage fluctuations within + 5%. (A)</p> Signup and view all the answers

Where are static type voltage regulators typically installed?

<p>Inside dedicated kiosks or rooms based on load positions. (B)</p> Signup and view all the answers

What is the duty of the Traction Power Controller (TPC) during his shift?

<p>To monitor and maintain continuity of power supply. (A)</p> Signup and view all the answers

What kind of emergency provision can be found at large stations?

<p>Standby diesel generator sets installed by S&amp;T. (A)</p> Signup and view all the answers

How often is the Remote Control Centre (RCC) manned?

<p>24 hours a day. (B)</p> Signup and view all the answers

What is the maximum duration a power block is likely to last?

<p>One hour at a time. (A)</p> Signup and view all the answers

Which of the following personnel is in charge of switching operations on the railway system?

<p>The Traction Power Controller (TPC). (D)</p> Signup and view all the answers

What arrangement is suggested for authority communication during a power block?

<p>Close liaison with Section Controllers. (A)</p> Signup and view all the answers

What is the purpose of staggering the contact wire in OHE systems?

<p>To allow the pantograph to sweep across the current collecting strips. (B)</p> Signup and view all the answers

What defines a regulated OHE system?

<p>It incorporates automatic tensioning mechanisms. (A)</p> Signup and view all the answers

How far apart are uninsulated overlap spans in OHE systems?

<p>200 mm. (A)</p> Signup and view all the answers

What is the role of section insulators in OHE systems?

<p>To isolate adjacent elementary sections from each other. (D)</p> Signup and view all the answers

Why are insulated overlaps provided in OHE systems?

<p>To prevent arcing and ensure safety. (A)</p> Signup and view all the answers

What is the maximum distance OOHE conductors can be terminated with an overlap?

<p>1.5 Km. (C)</p> Signup and view all the answers

What factor typically dictates the spans adopted for catenary support intervals?

<p>Degree of curvature. (D)</p> Signup and view all the answers

What happens when pantographs transition between OHE systems?

<p>They can cause sparks if not designed correctly. (C)</p> Signup and view all the answers

What is the length of overlap in insulated overlaps in OHE systems?

<p>500 mm. (C)</p> Signup and view all the answers

At what speed are section insulator assemblies designed to be effective?

<p>120 km/h. (B)</p> Signup and view all the answers

What is the primary purpose of the Emergency Control Circuit?

<p>To facilitate quick communication between traction maintenance gangs and TPC. (A)</p> Signup and view all the answers

Where are emergency telephone socket boxes installed?

<p>Along the track at specific intervals and near important posts. (A)</p> Signup and view all the answers

Which of the following is NOT a purpose of walkie-talkie sets in maintenance depots?

<p>To interact with passengers. (C)</p> Signup and view all the answers

Who primarily operates the Emergency Control Circuit?

<p>TPC (Traction Power Control). (D)</p> Signup and view all the answers

What is the role of Hot Line Communication?

<p>To establish a connection between headquarters and electric loco sheds. (D)</p> Signup and view all the answers

What interval is recommended for placing emergency telephone socket boxes along the track?

<p>Every 0.75 to 1 km. (B)</p> Signup and view all the answers

Which of the following is a function of the independent inter-communication circuit?

<p>To facilitate local communication among Section Controllers and Chief Controller. (C)</p> Signup and view all the answers

Which personnel are equipped with portable emergency telephones?

<p>Train crew, maintenance gangs, and Station Masters. (C)</p> Signup and view all the answers

What is a key benefit of providing walkie-talkie sets in maintenance depots?

<p>Improving efficiency and productivity during maintenance and breakdowns. (A)</p> Signup and view all the answers

Which of the following roles is NOT involved in the Hot Line Communication circuit?

<p>Traffic Control Officers. (B)</p> Signup and view all the answers

What is the standard capacity of the transformers typically installed at traction sub-stations?

<p>21.6 MVA (ONAN)/30.2 MVA (ONAF) (C)</p> Signup and view all the answers

Which arrangement describes when the Railway owns certain circuit breakers at sub-stations while the Supply Authority manages all other equipment?

<p>Railway owns feeder circuit breakers but not transformers (A)</p> Signup and view all the answers

How is continuity of power supply ensured at traction sub-stations?

<p>Through dual power sources or double circuit transmission line (A)</p> Signup and view all the answers

What is a typical distance between traction sub-stations along electrified sections?

<p>35 to 50 km (A)</p> Signup and view all the answers

Which of the following explosion prevention measures is commonly installed at traction sub-stations?

<p>Rapid fault isolation equipment (A)</p> Signup and view all the answers

How does the Railway receive its power supply if it runs its own transmission lines?

<p>From a single 3-phase power supply point near the grid sub-station (D)</p> Signup and view all the answers

What is the role of the Traction Power Controller regarding the 25 kV feeder circuit breakers?

<p>To operate feeder circuit breakers remotely (D)</p> Signup and view all the answers

What is the main function of the Emergency Control Circuit in the railway system?

<p>To facilitate the communication between traction maintenance gangs and TPC during emergencies (A)</p> Signup and view all the answers

Which personnel are typically provided with portable emergency telephones?

<p>Train crew, maintenance gangs, and Station Masters (C)</p> Signup and view all the answers

What interval is recommended for the placement of emergency telephone socket boxes along the railway track?

<p>Every 0.75 to 1 km (D)</p> Signup and view all the answers

What purpose do walkie-talkie sets serve in maintenance depots?

<p>To enhance communication during power blocks and maintenance activities (D)</p> Signup and view all the answers

What does the Hot Line Communication circuit primarily connect?

<p>Divisional HQ traction loco controller to electric loco sheds and senior officials (D)</p> Signup and view all the answers

What is the purpose of a 'Neutral Section' in the overhead equipment system?

<p>To ensure that pantographs do not bridge different phases (B)</p> Signup and view all the answers

What is referred to as a 'sub-sector' in the overhead equipment management?

<p>A section that can be isolated by opening interruptors alone (D)</p> Signup and view all the answers

Why are warning boards placed in advance of the neutral section?

<p>To alert drivers to open the locomotive circuit breaker (D)</p> Signup and view all the answers

What are 'interruptors' used for at feeding posts?

<p>To control supply to individual lines (C)</p> Signup and view all the answers

What feature does a sectioning and paralleling post (SP) provide?

<p>It marks the boundary of two zones with different power phases (B)</p> Signup and view all the answers

What type of isolators are provided for electric loco running sheds?

<p>Isolators with earthing device in the 'off' position (B)</p> Signup and view all the answers

How are 'elementary sections' created in the overhead equipment system?

<p>Using off-load type manually operated isolator switches (A)</p> Signup and view all the answers

What does the term 'earthing heels' refer to in the context of overhead equipment?

<p>Devices used to ground the overhead equipment safely (A)</p> Signup and view all the answers

What is the expected functionality of manually operated interrupters at watering stations?

<p>To enable local power disconnection and earthing (C)</p> Signup and view all the answers

What is the role of the bridging interruptors in the overhead equipment system?

<p>To allow one feeding post to supply power beyond its sectioning post. (A)</p> Signup and view all the answers

What type of equipment is typically installed to protect each sub-sector from voltage surges?

<p>Lightning arresters (C)</p> Signup and view all the answers

How many interruptors are normally provided at each Sub-Sectioning Post (SSP) in a double track section?

<p>Three (B)</p> Signup and view all the answers

Where is the 25 kV AC supply tapped to ensure a reliable supply of 240V?

<p>At each wayside station for CLS and level crossings more than 2 km from a station (B)</p> Signup and view all the answers

What is the primary purpose of auxiliary transformers installed at posts?

<p>To supply AC at 240 V, 50 Hz for lighting and signaling (B)</p> Signup and view all the answers

What occurs with the bridging interruptors under normal operation conditions?

<p>They are normally kept open. (D)</p> Signup and view all the answers

What type of posts are occasionally used for sectioning but do not support paralleling of tracks?

<p>Sub-Sectioning Post (SS) (D)</p> Signup and view all the answers

What provides accommodation for remote control equipment and other essential devices?

<p>Masonry cubicle (D)</p> Signup and view all the answers

What is typically monitored at switching stations using potential transformers?

<p>Power supply to each sub-sector (B)</p> Signup and view all the answers

What is the role of lightning arresters in the sub-sector equipment?

<p>To protect against voltage surges (D)</p> Signup and view all the answers

What is the primary purpose of the Traction Loco Control circuit?

<p>To manage the movements of electric locomotives and EMU stock (A)</p> Signup and view all the answers

Which circuit is primarily responsible for train movements within a section?

<p>Train Control/Section Control (C)</p> Signup and view all the answers

What type of communication does the Traction Power Control circuit focus on?

<p>Power supply and switching operations (A)</p> Signup and view all the answers

Which personnel primarily operates the Dy.Control Telephone circuit?

<p>Deputy Controller (D)</p> Signup and view all the answers

What is a key benefit of having multiple independent telephone circuits in electrified railway sections?

<p>To enable quick communication and coordination (A)</p> Signup and view all the answers

Which circuit is specifically used for continuous monitoring of wagon movements?

<p>Stock Control Telephone (A)</p> Signup and view all the answers

Which of the following offices is NOT connected to the Train Control/Section Control circuit?

<p>Stock Control Offices (B)</p> Signup and view all the answers

For managing all power supply communications, which circuit is utilized?

<p>Traction Power Control (D)</p> Signup and view all the answers

Which of the following statements accurately describes the role of the Section Controller?

<p>Directing train movements within their jurisdiction (B)</p> Signup and view all the answers

The connections for the Traction Loco Control circuit include which of the following?

<p>Electric Loco Sheds and Important Station Masters (A)</p> Signup and view all the answers

Flashcards

Transformer Step-Down Voltage

Transformers reduce grid voltage to 25 kV for traction overhead equipment (OHE).

25 kV Feeders

Carry power from substations to feeding posts near tracks, each controlled by a single-pole circuit breaker.

Voltage Regulation Limits

Bus bar voltage at substations must vary between 23,750 V and 27,500 V (+10% and -5% from 25,000V).

Transformer Tappings

Adjust secondary winding voltage to maintain 27.5 kV at feeding posts, avoiding exceeding this value.

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Single-phase Traction Load

Causes voltage unbalance in the 3-phase grid, potentially affecting power generation and equipment.

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Voltage Unbalance Limits

Instantaneous unbalance ≤ 5%, 2 hours ≤ 3%, continuous ≤ 2%, at the grid supply system's common coupling point.

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Cyclic Tapping at Substations

Power for single-phase traction is tapped across different phases at adjacent substations in a sequence to maintain voltage unbalance within limits.

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Power Block on OHE

Situation where power is cut off on both OHE sub-sectors used for signal supply, often due to maintenance or an issue.

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Signal Supply Outages

Interruption of power supply to signalling system, leading to traffic suspensions.

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Portable Generators

Temporary power source used at wayside stations during power block events on OHE.

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Standby Diesel Generators

Large stations might have permanent diesel generators as a back-up power source for specific critical situations.

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Voltage Fluctuations

Variation in AC 240V supply caused by fluctuating traction load.

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Static Voltage Regulators

Equipment to keep voltage fluctuations under control, ensuring stability in the 240V supply.

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Remote Control Centre (RCC)

Centralized location where all critical switching operations at traction substations are controlled continuously.

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Traction Power Controller (TPC)

Person in charge of maintaining power continuity throughout the entire system at RCC.

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Section Controllers

Personnel responsible for train operations on electrified sections and in constant contact with the TPC.

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Emergency Control Circuit

A circuit enabling traction maintenance and train crews to quickly contact the TPC in emergencies, also for train accidents

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Hot Line Communication

A dedicated communication circuit linking HQ, divisional HQ, traction loco controllers, and electric loco sheds

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Walkie-Talkie Sets

Communication devices for OHE maintenance depots, facilitating communication during maintenance and breakdowns, especially during power blocks.

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Emergency Telephone

Portable phones that plug into emergency socket boxes along tracks, used for communication with the TPC.

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TPC

Train Protection Centre.

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Power Blocks

Periods when power is cut off to certain sections of track for maintenance.

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Divisional Officers

Senior staff at train divisions (e.g., Sr.DEE/TrD, Sr.DEE/OP).

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Maintenance Depots

Locations for maintaining overhead electric traction lines.

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Walkie Talkie Communication purposes

Used to communicate about the power block start/end, guide/direct work during power block, and confirm cancellation

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Inter-communication circuit

Independent communication circuit between Section Controllers and the Chief Controller for local communication.

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Section Insulator Runners Facing Direction

When the runners of the section insulator assembly are in the facing direction, and not installed within the first one-third of the span, the speed limit must be 80 km/h.

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Mechanical Independence of OHE Track

Separate structures support each track's overhead line equipment (OHE), preventing issues on one track from affecting others.

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Flexible Head-Span

A cross catenary wire system used in large yards to maintain multiple catenaries and contact wires at the correct heights.

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Maximum OHE Span Speed Potential

An Overhead Line Equipment with a 72-meter span, 10mm presag, and 1000 kgf tension in wires, is designed for a maximum speed of up to 160 km/h.

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Unwired Track Warning

Certain loops/sidings lack OHE wiring. Warning signals/boards are necessary to avoid damage to locomotives and OHE for trains entering these areas.

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Staggered Contact Wire

The contact wire is positioned in a staggered pattern to ensure even wear on pantograph current collectors.

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Overlap Spans (OHE)

OHE conductors are connected in segments, often 1.5km long, with overlapping sections to allow smooth pantograph transitions.

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Uninsulated Overlaps

Two conductors are connected electrically through jumpers. Conductor separation is 200mm.

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Insulated Overlaps

Two OHE systems are separated by 500mm and typically bridged with interrupters, except at neutral sections.

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Regulated OHE

OHE with automatic tensioning, typically used on main lines for reliable current collection.

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Unregulated OHE

OHE without automatic tensioning, used for less important lines due to cost effectiveness

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Section Insulator Assembly

Insulation between sections of OHE, ensuring no arcing when pantographs traverse crossovers.

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Pantograph Glide Distance (Curves)

The pantograph sweeps across the contact wire 300 mm on one side on curves.

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Pantograph Glide Distance (Straight Runs)

The pantograph sweeps across the contact wire 200 mm on either side of the center line on straight runs.

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Conductor Overlap Interval

OHE conductors are terminated and overlapped approximately every 1.5 km.

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Power Supply Arrangements

Methods for delivering 25 kV, 50 Hz single-phase power to electrified railway sections.

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Duplicate Supply

Ensuring uninterrupted power supply to traction substations by using two sources or a double circuit transmission line.

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Traction Sub-station

Location where high-voltage power is transformed to a lower voltage for rail traction.

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Single-phase transformers

Used at traction substations for transforming power; normally two are installed.

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EHV (Extra High Voltage)

Very high voltage electrical power lines, typically used for transmission purposes.

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25 kV

The voltage of single-phase electricity used for electric traction.

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Standby Transformer

A transformer that is kept in reserve and readily available to take over operation if the active transformer fails.

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Neutral Section

A section of overhead equipment (OHE) that prevents pantographs from bridging different phases of 25 kV power while transitioning between sub-stations.

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Sub-sector

The shortest section of OHE that can be isolated by opening interruptors.

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Elementary Sections

Smaller sections within a sub-sector, isolated by manually operated isolator switches.

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Switching Station Interruptors

Devices used to isolate sections of OHE, often rated at 600A.

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Feeding Post (FP)

A location where power is supplied to the overhead equipment (OHE) on one side.

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Sectioning and Paralleling Post (SP)

A post marking the boundary between two zones fed from different sub-stations.

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OHE Sectioning

Dividing overhead equipment into smaller segments for easier maintenance and fault isolation.

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Alternative Feeding Arrangements

Backup power supply options in large yards for reliability and to avoid power outages.

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Electric Loco Running Sheds

Places where electric locomotives are housed and maintained, requiring specific isolation.

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Neutral Section Location

Neutral sections are located on tangent tracks away from signals and crossings to ensure high coasting speeds, preventing train stalls.

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Paralleling Interruptor

A device at 'SP' posts that connects the overhead lines (OHE) of up and down tracks in a double-track section.

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Bridging Interruptors

Allow feeding posts to deliver power further along the tracks if the primary supply is disrupted.

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Sub-Sectioning and Paralleling Post (SSP)

A post with interruptors that divide a double track section and connects up and down tracks.

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Sub-Sectioning Post (SS)

A post, similar to an SSP, for dividing the OHE into sections, but without paralleling capability.

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Lightning Arresters

Devices that protect each sub-sector from voltage surges caused by lightning.

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Auxiliary Transformers

Provide 240V AC power for signalling and operational lighting at posts and intermediate points.

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Potential Transformers

Monitor the power supply to each sub-sector at switching stations using voltage measurements.

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25 kV/240V auxiliary transformer

Transforms 25kV OHE power to 240V AC power for railway signalling and operational lighting.

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Power Supply at Level Crossings

Special arrangements are in place for reliability of 240V AC power supply for level crossings beyond 2km from stations.

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Emergency Control Circuit

Enables traction maintenance and train crews to contact the Train Protection Centre (TPC) quickly in emergencies, including accidents.

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Hot Line Communication

Dedicated communication circuit linking headquarters, divisional headquarters, traction controllers, and electric loco sheds.

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Walkie-Talkie Sets

Used by OHE maintenance depots for clear communication during maintenance, breakdowns, and power block procedures.

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Walkie-Talkie Communication Purposes

Used for communicating power block schedules, directing work during power blocks, and confirming cancellations during OHE maintenance.

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Inter-communication circuit

Independent communication circuit between Section Controllers and the Chief Controller for local communication.

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Railway Communication Facilities

The systems used for communication within railway operations, particularly on electrified sections.

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Train Control/Section Control Circuit

A circuit used by Section Controllers to manage train movements within their area, connecting with signal cabins, offices, and yards.

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Dy. Control Telephone

A circuit operated by the Deputy Controller for general traffic direction, connecting with important stations, yards, and signal cabins.

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Stock Control Telephone

Circuit monitored by the Stock Controller, for wagon movement control, connecting with yard masters and important stations.

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Traction Loco Control

Circuit for AC traction, operated by the Traction Loco Controller to manage electric locomotives and EMUs, connecting with sheds and divisional officers.

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Traction Power Control

AC traction circuit handling TPC-related communications regarding power supply, switching, and permits.

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Multiple Independent Telephone Circuits

Multiple circuits crucial for efficiency in electrified sections by allowing quick communication and coordination between railway branches.

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Alternative Telephone Channels

Backup communication options in case of failure of a telephone circuit, needed for emergency situations.

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Underground Cables/Microwave

Used for aerial telecommunication lines to mitigate interference caused by 25kV single-phase AC traction.

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Indian Railways Telecommunication Manual

A reference guide for detailed technical information on railway telecommunication circuits.

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Study Notes

Power Supply Arrangements at Sub-Stations

  • 25 kV, 50 Hz single-phase power supply for electric traction is derived from the grid system of State Electricity Boards.
  • Sub-stations are located approximately 35-50 km apart (or less depending on traffic and load) along electrified sections.
  • Four primary arrangements exist for power supply:
    • Supply Authorities provide 220/132/110/66 kV EHV at the sub-station.
    • Railways receive 3-phase power from the Supply Authority, maintain their own transmission lines, and operate sub-stations.
    • Supply Authority owns all EHV and 25 kV equipment, except 25 kV feeder circuit breakers owned by the Railways.
    • Supply Authority owns all EHV and 25 kV equipment, except 25 kV feeder circuit breakers operated remotely by the Traction Power Controller (TPC).

Duplicate Power Supply

  • Double circuit transmission lines or dual power sources ensure uninterrupted power supply in sub-stations.
  • Protective equipment isolates any fault in transmission lines or sub-station equipment quickly.
  • Normally, two single-phase transformers (21.6/30.2 MVA capacity) are used to step down the grid voltage to 25 kV and feed traction equipment.
  • 25 kV feeders carry power from sub-stations to feeding posts, controlled by circuit breakers with protective devices.

Voltage Regulation

  • Permissible busbar voltage variation at the grid sub-station is +10% and -5% (27,500 V to 23,750 V).
  • Transformer tappings regulate voltage at the feeding posts (maximum 27.5 kV).
  • Multiple transformer circuits on the secondary side include a transformer circuit breaker and feeder circuit breaker with associated double pole isolators.

Feeding and Sectioning Arrangements

  • 3-phase supply systems from power authorities create supply imbalances affecting generators and other equipment.
  • Voltage unbalance at the point of common grid coupling should not exceed 5% (instantaneous) or 3% (continuous).
  • Tapping off single-phase traction power from grid phases at substations (in a cyclic order) helps reduce imbalance.
  • Overhead equipment systems in adjacent sub-stations are electrically separated by "neutral sections."
  • Switching stations and other equipment segment 10-15 km sections of overhead equipment (OHE), facilitating rapid isolation for maintenance.
  • Alternative feeding arrangements are provided for yards and electric loco-running sheds.
  • Automatic switching mechanisms on some sections allow flexible power supply (e.g., for watering stations or for maintenance on OHE).

Feeding Posts (FP)

  • Each feeder supplies OHE on one side of the feeding post through interruptors.
  • Two-track lines require four interruptors at each post.

Sectioning and Paralleling Posts (SP)

  • Located midway between feeding posts (marking neutral sections).
  • Connect adjacent substations for better load distribution.

Sub-Sectioning and Paralleling Posts (SSP)

  • Provided between FP and adjacent SPs, typically with three interruptors.
  • Help to divide sections of OHE into smaller segments.
  • May include interruptors or other switch gear to help divide up the section into sub-sectors.

Other Equipment at Switching Stations

  • Essential equipment: Lightning arrestors, auxiliary transformers (240 V AC), potential transformers, controls, and communication equipment.
  • All of this equipment safeguards transmission lines and monitors the power grid, protecting against potential damage.

Power Supply for Signaling

  • 240V AC supply is made available at railway stations and other locations through auxiliary transformers.
  • Locations include the side of tracks, level crossings, and installations.

Remote Control and Communication

  • Remote Control Centre (RCC) manages circuit breakers and related switch gear in sub-stations.
  • One or more Traction Power Controllers (TPCs) operate switching functions during each shift.
  • Continuous communication between TPCs and Section Controllers maintains power supply and train operations.
  • Telecommunication lines (now largely underground cable/microwave) are necessary to accommodate the electrification.

Overhead Equipment (OHE)

  • Catenary and contact wire system (cadmium copper/aluminum alloy).

  • Grooved contact wire with a specific cross-section (equivalent copper section of 157 mm²) and is supported by droppers.

  • Looping lines, sidings, yards use a simpler OHE design with lower contact wire specifications than main lines.

  • Contact wire height varies based on temperature and gauge.

  • Spans for structures supporting OHE vary based on track straightness; larger spans used in straight sections/smaller spans in curved sections.

  • The contact wire is properly staggered to ensure consistent pantograph contact/uniform wear.

  • Two types of overlap spans.

Special Warning Signals

  • Visual cues indicating neutral sections (and when they're being used), helping drivers to operate safely and smoothly.
  • Warnings are used for unwired tracks, or when the OHE ends.

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Related Documents

Indian Railways AC Traction Manual Volume 1 PDF

Description

This quiz explores the various power supply arrangements at sub-stations, specifically focusing on electric traction systems. It covers the distances between sub-stations, the roles of supply authorities, and the strategies for ensuring a reliable power supply. Gain insights into the technical aspects that keep the electric railways running smoothly.

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