This Presentation show the latest trends in the Transmission of High Voltage Direct Current with interesting video..

1. HVDC
Transmission

2. Introduction & History
 HVDC stands for High Voltage Direct Current. HVDC
transmission is an efficient technology designed to deliver
large amount of electricity over long distances with negligible
losses.
 The world’s first commercial HVDC link situated between
the Swedish mainland and the island Gotland was delivered
by ABB.

3. Basic Transmissions of HVDC
 Back to Back Transmission.
 Point to point Overhead line Transmission.
 Point to point Underground Cable Transmission.
 Point to point Sub marine Transmission.

8. Needs for HVDC
 The losses which occurs in the systems are comparatively
low at all the stages (i.e) at generation , transmission &
distribution level.
 The losses at transmission level can be highly reduced by
HVDC transmission.

9. Comparison of HVAC and HVDC
 Conventionally power transmission is affected through
HVAC systems all over the world.
 HVAC transmission is having sever limitations like, line
length , uncontrolled power flow, over/low voltages during
lightly / over loaded conditions, stability problems, fault
isolation etc…
 But HVDC have low transmission losses and it requires
only two conductors.

10. Cont…

11. HVDC in India
HVDC LINK CONNECTING REGION CAPACITY (MW)
Vindyachal North –West 2 x 250
Chandrapur West – South 2 x 250
Vizag – I East – South 2 x 250
Sasaram East – North 2 x 250
Vizag – II East – South 2 x 250

12. Parameters needed
 If DC is used in transmission, there need to be an inverter
and the converter units.
 Because the power generating stations is always
generates Alternating Current.
 Also the primary domestic appliances are designed to
work on AC only.
AC-DC conversion : Rectifier
Transmission : DC
DC-AC conversion : Inverter

13. 6 pulse Rectifier

14. Rectifier’s Waveform…

15. Transmission
 While transmitting the DC there are 3 types of links.
Types of DC links
Monopolar
Bipolar
Homopolar

16. Monopolar Links
 It uses only one conductor.
 Due to negative polarity, no corona effect occurs.

17. Bipolar Links
 It have two conductors.
 Junction between the conductors are grounded.
 Can carry half the rated load, if fault occurs in one pole.

18. Homopolar Links
 It has two conductors are in same polarity (Usually
negative).
 The return path for such a system is through ground.

19. Inverter Circuit
The combinational circuit which converts DC-AC is referred as
Inverter Circuit.

20. Advantages of HVDC
 Technical Advantage
System stability.
less Corona Loss and no skin effect.
Greater Reliability.
Economical Advantages
Line cost is less.
Tower Construction is narrow.

21. Cont…

22. Disadvantages
 Power loss in conversion, switching and control.
 Expensive inverters.
 The high-frequency constituents found in direct current
transmission systems can cause radio noise in
communications lines that are situated near the HVDC
transmission line.

23. Conclusion
 Recent studies indicate that HVDC systems are very reliable.
 Very large investments Eg. In China and India shows that High
Voltage Direct Current will very important in the future,
especially in big and new-industries countries.

26. By
Abuthahir T
Arumugam A