Hvdc transmission by pankaj chaudhary

A SEMINAR ON

“HVDC TRANSMISSION”BACHELOR OF TECHNOLOGY

IN

ELECTRICAL & ELECTRONICS ENGINEERINGSUBMITTED

BY

PANKAJ CHAUDHARY R.N. - 24823

UNDER THE SUPERVISION OF

ARUNESH DUTT (H.O.D)

NEHRU GRAM BHARATI UNIVERSITY, ALLAHABAD

DEPARTMENT OF ELECTRICAL & ELECTRONICS ENGINEERING SANJAY GANDHI INSTITUTE OF ENGINEERING & TECHNOLOGY

With the increasing of requirement of electrical power supply the facilities have to be increased,in that transmission plays an important role.

Here hvdc (high voltage direct current) transmission plays major role in power transmission.

First hvdc transmission linked between gotland and mainland in sweden in 1954.

The hvdc transmission has many advantages over hvac transmission.

HIGH VOLTAGE DIRECT CURRENT


HVDC stands for high voltage direct current and is today a well-proven technology all over the world.

Two a.c systems having different frequencies can be linked up together by means of hvdc link.

HVDC technology is used to transmit electricity over long distances.

Losses are less in d.c transmission while comparing to a.c transmission.

Only two conductors are required for d.c with positive and negative polarities.

D.C overhead lines or cables are less expensive.

D.C lines are useful for long distances above 500km.


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Converting transformers.

Converter bridge.

Surge arresters.

Smoothing reactors.

Filters(a.c and d.c).



THYRISTOR BASED HVDC SYSTEM VERSUS HVAC SYSTEM: Costs for converter stations in hvdc is more

than the hvac substations. Operation maintanance costs are less in hvdc transmission. The figure shows cost break down.

HVDC lines occupies less place when compared to a.c .

D.C lines or cables are less expensive than a.c cables.

Sychronisation of two a.c power supplies.

HVDC does not transmit short circuit in case of faults and disturbances.

Power transmission can be done with out intermediate taps.


Long distances bulk power transmission.

Under ground or under water cables.

Asynchronous interconnection of two a.c power supplies.


The difficulty of breaking d.c currents which results in high cost of d.c currents.

Inability to use transformers to change voltage levels.

High cost of conversion equipment.

Complexity of control.


Rihand-delhi and chandrapur-padghe were the first long distance hvdc projects in India.

In 1990 ,rihand-delhi (singrauli) thermal power complex with a combined power generation of Several thousand mw was put in to service.it covers over a distance of 814 km.

In 1998, the 1500 mw transmission chandrapur-padghe was put in to service.it covers over distance of 736 km.


With the hvdc systems,the power flow can be controlled rapidly and accurately as to both power level and the direction.this possibility is often used in order to improve the performance and efficiency of connected a.c networks.

Using hvdc to inter connect two points in a power grid, in many cases is the best economic alternative, and further more it has excellent environmental benefits.


The hvdc technology (high voltage direct current) is used to transmit electricity over long distances by overhead transmission lines or submarine cables.

HVDC overland links are usually bipolar, on overhead lines. compared to ac, dc transmission has several advantages.


1.C.L.wadhwa ‘electrical power systems'-third edition

2. I.J.nagrath and d.p.khotari 'power system engineering

3. S.S. vadhera 'power system analysis and stability 4. Soni gupta bhatnagar 'power system engineering

5. K.R.padiyar ‘hvdc power transmission systems'


Hvdc transmission by pankaj chaudhary

Engineering

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