This document summarizes a seminar report on HVDC transmission lines. It introduces HVDC transmission and explains the types of DC links. It discusses India's use of HVDC including its first and largest HVDC systems. It compares the cost of AC and DC transmission and describes how HVDC is incorporated into AC systems. It outlines the equipment used at converter stations and lists the technical, economic, and stability advantages of HVDC transmission. It also discusses some problems with HVDC transmission and concludes that HVDC offers alternatives to increase power system stability and flexibility.

1. SEMINAR REPORT
ON
HVDC TRANSMISSION LINE
Submitted by
Ankit Mankotia
AAEE0016A/10
Dept. of EEE

2. CONTENTS
• INTRODUCTION
• TYPES OF DC LINK
• HVDC IN INDIA
• COMPARISON
• C0NVERTER STATION EQUIPMENT
• INCORPORATING HVDC INTO AC SYSTEM
• C0NVERTER STATION EQUIPMENT
• ADVANTAGES
• PROBLEMS
• CONCLUSION

3. INTRODUCTION
• Now a day large amount of block of power are
needed to be transmitted.
• There arises some technical problem of
transmitting to such a long distance using ac.
• In the view of draw backs of ac the HVDC
transmission has come into picture

4. • The first DC link was set up in 1954 in
between Swedish main land and the
island of Gotland
• The use of an HVDC link in an ac system
requires converter station at each end of
the line

5. Types of dc link
Monopolar
Bipolar
Homopolar

6. Monopolar link

7. Bipolar link

8. HVDC IN INDIA
• In India presently 6 HVDC systems are in operation.
• India- Pioneer developer of HVDC since 1990 with the first
HVDC set up of 1000MW 814Km Rihand-Dadri line
between U.P & Rajasthan.
• 2000MW 1440Km Talcher-Kolar link is biggest so far
connecting four states-orissa, andhra pradesh , tamilnadu
and karnataka.
• In march 2000,Power-grid(largest power transmission
utility of India) awarded a new long distance HVDC
transmission project to SIEMENS, Germany.
• More greater plans are cooking to add 1lakh MW of power
by 2012 in which HVDC will play vital role to transmit
these powers to all corners of India.

9. Facts and figure
Data of Rihand-Dadri line Data of Talcher-Kolar line

10. Comparison between the price of AC
and DC transmission

11. Incorporating HVDC into AC system
• Two terminal DC link point to point
transmission.
• Back to back DC link.
• DC line in parallel with AC link.
• Multi-terminal DC link.

12. Converter station equipment
• Thyristor valves
• Converter transformer
• DC reactor
• Harmonic filtering equipment
• Control equipment
• Reactive power compensation

13. ADVANTAGES
Advantages of
dc transmission
Technical
Advantages
Economic
Advantages

14. Technical Advantages
• Reactive power requirement
• System stability
• Short circuit current
• Fast change of energy flow
• Lesser corona loss and radio interference
• Greater reliability
• No limit in transmitted distance

15. Economic advantages
• DC lines and cables are cheaper than ac lines
or cables.
• The towers of the dc lines are narrower,
simpler and cheaper compare to the tower of
the ac lines.
• Line losses in a dc line are lower than the
losses in an ac lines

16. Problems
• The design of grounding electrodes for low
cost of installation and maintenance
• Location and screening of electrodes so that
ground current cause negligible electrolytic
corrosion of buried and immersed mettalic
structures.

17. Conclusion
HVDC offers powerful alternative to increase
stability of a power system as well as to improve
system operating flexibility and loss reduction. Our
simulations have shown that HVDC lines can be
used for oscillations’ damping and improvement of
the system stability. When a HVDC line is in parallel
with an AC-line, the AC-line can transfer more
power because of the damping control. With
damping control the AC line can transfer more
power than with no damping control.