SUBMITTED BY :

DEEPAK MEHRA ( ECE )

SUMMER TRAINING PROJECT

ON

“TECHNICAL ANALYSIS OF POWER GRID’S TELECOM

SYSTEM”

CARDINAL OBJECTIVES OF THE ORGANIZATION :

The Corporation has set following objectives in line with its mission and its status as "Central Transmission Utility"

Undertake transmission of energy through Inter-State Transmission System Discharge all functions of planning and coordination relating to Inter-State  

Transmission System with-      (i) State Transmission Utilities;      (ii) Central Government;      (iii) State Government;      (iv) Generating Companies;      (v) Regional Electricity Boards;      (vi) Authority;      (vii) Licensees;      (viii) Transmission Licensees;      (ix) Any other person notified by the Central Government on this behalf.

Exercise supervision and control over the Inter-State Transmission System To participate in long distance Trunk Telecommunication business ventures.

TELECOM NETWORK :

…………………………………………

TECHNOLOGIES

PRESENTLY

TECHNOLOGIES :

TELECOMMUNICATIONS

OPTICAL FIBERS

PDH (plesiosynchronous Digital Hierarchy)

SDH (Synchronous Digital Hierarchy

WDM (Wavelength Division Multiplexing)

ADSS (All Dielectric Self Supporting Fiber Optic)

MPLS (Multi-Protocol Label Switching)

TELECOMMUNICATION :

Telecommunication is the transmission  of messages, over significant distances, for the purpose of communication. In earlier times, telecommunications involved the use of visual signals, such as smoke, , signal flags, and optical heliographs , or audio messages via coded drum beats , , or sent by loud whistles.

A Basic Elements Of A telecommuncation system

It consists of three primary units , namely :

I. A transmitter  that takes information  and converts it to a signal.

II. A transmission medium, also called the "physical channel" that carries the signal. An example of this is the “free space channel".

III. A reciever that takes the signal from the channel and converts it back into usable information.

A Diagrammatic representation of the telecommuncation system ….

OPTICAL FIBERS…..

What Are Fiber Optics ?

Long thin strands of pure glass about the size of human hair.

Arranged in bundles called optical cables.

Used to transmit light signals over long distances. Light is kept in the core of the optical fiber by total

internal reflection.

What is an Optical fiber?

An optical fiber is a waveguide for light.

It consists of :

CORE : Inner part where wave propagates.

CLADDING :Outer part used to keep wave in core.

BUFFER :Protective coating over the fiber.

JACKET :Outer protective shield over the cable.

An Optical Fiber….

Manufacturing Of Optical fibers.

Materials

Glass optical fibers are almost always made from silica, but some other materials, such as fluuorozirconate , fluoroaluminate, and chalcogenide glasses as well as crystalline materials like sapphire, are used for longer-wavelength infrared or other specialized applications. Silica and fluoride glasses usually have refractive indices of about 1.5, but some materials such as the chalcogenides can have indices as high as 3. Typically the index difference between core and cladding is less than one percent.

Plastic optical fibers (POF) are commonly step-index multi-mode fibers with a core diameter of 0.5 millimeters or larger. POF typically have higher attenuation coefficients than glass fibers, 1 dB/m or higher, and this high attenuation limits the range of POF-based systems.

Types Of Optical Fibers … SINGLE MODE FIBER MULTI MODE FIBER

Plesiosynchronous Digital Hierarchy (PDH)….

The Plesiosynchronous Digital Hierarchy (PDH) is a technology used in telecommunication networks to transport large quantities of data over digital transport equipment such fiber optic  and microwave radio systems. PDH is typically being replaced by synchronous digital hierarchy (SDH) or synchronous optical networking (SONET) equipment in most telecommunications networks.

Block Diagram Of PDH …

Synchronous Digital Hierarchy(SDH)

Synchronous Optical Networking (SONET) or Synchronous Digital Hierarchy (SDH) are standardized multiplexing protocols that transfer multiple digital bit streams over optical fibers using lasers or light emitting diodes (LEDs). Lower rates can also be transferred via an electrical interface. The method was developed to replace the plesiosynchronous digital hierarhy (PDH) system for transporting larger amounts of telephone  calls and data  traffic over the same fiber wire without synchronization problems. SDH (Synchronous Digital Hierarchy) is an international standard for high speed telecommunication  over optical/electical networks which can transport digita signals in variable capacities.

THIS IS WHAT AN SDH LOOKS LIKE.

SDH Evolution…

S.D.H. evolution is possible because of the following factors :

(i) Fibre Optic Bandwidth : The bandwidth in Optical Fibre can be increased and there is no limit for it. This gives a great advantage for using SDH.   (ii) Technical Sophistication : Although, SDH circuitary is highly complicated, it is possible to have such circuitary because of VLSI technique which is also very cost effective.   (iii) Intelligence : The availability of cheaper memory opens new possibilities.   (iv) Customer Service Needs : The requirement of the customer with respect to different bandwidth requirements could be easily met without much additional equipment. The different services it supports are :   1. Low/High speed data. 2. Voice 3. Interconnection of LAN 4. Computer links 5. Feature services like H.D.T.V. 6. Broadband ISDN transport (ATM transport)

Wave length Division Multiplexing (WDM)

In fiber optic communication, wavelength-division multiplexing (WDM) is a technology which multiplexes multiple optical carrier signals on a single optical fiber by using different wavelenghts (colours) of laser light to carry different signals. This allows for a multiplication in capacity, in addition to enabling bidirectional communications over one strand of fiber. A WDM system uses a multiplexer at the transmitter to join the signals together, and a demultiplexer  at the receiver to split them apart. WDM systems are popular with telecommunication companies because they allow them to expand the capacity of the network without laying more fiber.

WDM..

Types Of WDM.

Namely :

Dense wavelength Division Muliplexing.(DWDM)

Coarse Wavelenght Division Multiplexing.(CWDM)

Multi-Protocol Label Switching

MPLS is a packet-forwarding technology which uses labels to make data forwarding decisions. With MPLS, the Layer 3 header analysis is done just once (when the packet enters the MPLS domain). Label inspection drives subsequent packet forwarding. MPLS provides these beneficial applications:

• Virtual Private Networking (VPN)• Traffic Engineering (TE)• Quality of Service (QoS)• Any Transport over MPLS (AToM)

MPLS

POWERGRID’S USP

UNIQUE SELLING PROPOSITION

Powergrid’s USP in the telecommunication business is mainly the OPGW technology which is extensively being used in the country only by powergrid. It was very fascinating to learn about this distinct modern technology which I witnessed here while training in powergrid’s telecommunication department.

OPGW (OPTICAL GROUND WIRE)

An optical ground wire (also known as an OPGW or, in the IEEE standard, an optical fiber composite overhead ground wire) is a type of cable that is used in the construction of electric power transmission and distribution lines. Such cable combines the functions of grounding and communication. An OPGW cable contains a tubular structure with one or more optical fibers in it, surrounded by layers of steel and aluminium wires. The OPGW cable is run between the tops of high-voltag eelectricity pylons. Theconductive  part of the cable serves to bond adjacent towers to earth ground, and shields the high voltage conductors from lightning strikes.

OPGW

….

The optical fibers within the cable can be used for high-speed transmission of data, either for the electrical utility's own purposes of protection and control of the transmission line, for the utility's own voice and data communication, or may be leased or sold to third parties to serve as a high-speed fiber interconnection between cities.

ADSS

All Dielectric Self SupportingFiber Optic Cable

ADSS cable is the short form for All-dielectric Self-supporting Optical Cable. The “All Dielectric Self Supporting”(ADSS) cable is designed for aerial self supporting application at short ,medium and long span distances.ADSS cable offers a rapid and economical means of deployment by cable television operators telephone companies and power utilities.ADSS fiber optic cable is loose tube stranded; the tubes are filled with water resistant filling compound. The tubes are stranded around fiber reinforced plastic .

ADSS fiber cables with the following characteristics: 

1. ADSS cables can be installed without shutting off the power. 

2. ADSS cables are excellent AT performance. The maximum inductive at the operating point of AT sheath can reach 12kV.

3. ADSS is light weight and small diameter reducing the load caused by ice and wind and the load on towers and back props.

4. The ADSS cable is of large span length and the largest span is over 1000 meters.

SCADA / EMS

SCADA stands for supervisory control and data acquisition. It generally refers to an industrial control system: a computer system monitoring and controlling a process .SCADA, A collection of equipment that will provide an operator at remote station with sufficient information to determine the status of a particular piece of equipment or an entire substation or power plant.

AND Cause actions to take place regarding that equipment

or facility without being physically present.

A SCADA System usually consists of the following subsystems:

A Human Machine Interface or HMI is the apparatus which presents process data to a human operator, and through this, the human operator monitors and controls the process.

A supervisory (computer) system, gathering (acquiring) data on the process and sending commands (control) to the process.

Remote Terminal Units (RTUs) connecting to sensors in the process , converting sensor signals to digital data and sending digital data to the supervisory system.

Facility processes occur both in public facilities and private ones, including buildings, airports, ships, and space stations. They monitor and control HVAC, access, and energy consumption

SCHEMATIC DIAGRAM OF SCADA / EMS

Remote Terminal Unit (RTU)

The RTU connects to physical equipment. Typically, an RTU converts the electrical signals from the equipment to digital values such as the open/closed status from a Switch or a Valve, or measurements such as pressure, flow, voltage or current. By converting and sending these electrical signals out to equipment the RTU can control equipment, such as opening or closing a switch or a valve, or setting the speed of a pump.

A Remote Terminal Unit..

MY EXPERIENCES AND FACTS

DURING THE PERIOD FROM 14TH JUNE 2010, THE FOLLOWING DEPARTMENTS WERE VISITED FOR GAINING KNOWLEDGE ABOUT THE ROLES AND RESPONSIBILITY OF THE ORGANIZATION

NLDC , KATWARIA SARAI .

LD&C DEPARTMENT :

NLDC,KATWARIA SARAI

NLDC , KATWARIA SARAI : NATIONAL LOAD DESPATCH CENTER (NLDC) is the apex load dispatch center of our country responsible for power system monitoring with special emphasis on inter-regional power exchange. it requires data from all the five regional load dispatch centers namely NRLDC,SRLDC,WRLDC and ERLDC. State of the art EMS/SCADA systems are provided at NLDC integrated with all RLDC’S in multi level hierarchy configuration so as to equip the system operators for efficient management of power system operations . a wide band communication network based on SDH technology and OPGW cables is in place to provide connectivity of NLDC with RLDC’S for reliable communication system to facilitate voice and data exchange.

National Load Dispatch Centre (NLDC) has been constituted as per Ministry of Power (MOP) notification ,New Delhi dated 2nd March 2005 and is the apex body to ensure integrated operation of the national power system. 

LOAD DISPATCH AND COMMUNICATION DEPT.

This Department is responsible for carrying out engineering functions of projects related with SCADA/EMS and communications project being implemented by the organization. It was instrumental in timely implementing multi level hierarchical load dispatch centers namely ULDC projects in all the regions for the first time in country . These projects covers state of the art SCADA/EMS systems and communication network based on SDH technology and opgw cables. This department is also responsible for rendering consultancies not only to India but also overseas like Afghanistan , Bhutan , UAE etc.

CONTROL HIERARCHY

INTRODUCTION OF ULDC(Unified load dispatch center)

The Unified Load Despatch and Communication  (ULDC) scheme has been conceived to Operate & Control the regional power grid in a unified, well-coordinated and integrated manner using modern computerised load despatch facilities and a hierarchical network of Control  Centres along with adequate Telecommunication facilities with the objective to improve & strengthen the Indian Power System.   

  In 1992, the Government of India (Dept. of Power) entrusted

the responsibility of implementing the Unified Schemes of Load Despatch& Communication to POWERGRID in all the regions in consultation with the constituent states.

CONCEPT OF SMART GRID

A smart grid delivers electricity from suppliers to consumers using two-way digital technology to control appliances at consumers' homes to save energy, reduce cost and increase reliability and transparency. It overlays the ELECTRICITY DISTRIBUTION GRID with an information and NET METERING system. A smart grid includes an intelligent monitoring system that keeps track of all electricity flowing in the system. It also incorporates the use of SUPERCONDUCTIVE TRANSMISSION  for less power loss.

BENEFITS OF SMART GRID

Integrate isolated technologies: Smart Grid enables better energy management.

Proactive management of electrical network during emergency situations.

Better demand supply / demand response management.

Better power quality. Reduction in carbon emissions. better energy management

A FUTURISTIC VIEW OF SMART GRID

GOALS OF SMART GRID.

In principle, the smart grid is a simple upgrade of 20th century power grids which generally "broadcast" power from a few central power generators to a large number of users, to instead be capable of routing power in more optimal ways to respond to a very wide range of conditions, and to charge a premium to those that use energy during peak hours. A smart grid includes an intelligent monitoring system that keeps track of all electricity flowing in the system. It also incorporates the use of Superconductive lines for less power loss, as well as the capability of integrating renewable electricity such as solar and wind.

Power Grid’s Existing Telecom Vendors

TELECOM VENDORS FOR OPGW CABLE:

▪ Furukawa▪ BGR energy Systems▪ Anixter International Inc.▪ LS Cables

FOR UNDERGROUND FIBER CABLE:

TCIL ITI HFCL