i've made this presentation for my purposes bt if it can help out someone else too then i'll b happy more than for myself. i think these slides help you a lot to understand the concepts of HVDC transmission.And may be you like the way i present it.....

2. High Voltage DC Transmission
Subject
Power Transmission
Engineering

3. Presented By
Arsalan Ali
Arslan Tariq Arslan
Ghafoor
Khayyam
Shah
FA15-EPE-002
FA15-EPE-003
FA15-EPE-021
FA15-EPE-031
FA15-EPE-040
Roll
NO:
Nasir
Mehmood

4. High Voltage DC Transmission

5. CONTENTS
HVDC Definition
Components of HVDC
Preference of HVDC
Types of link HVDC
Advantages & Disadvantages
Applications of HVDC
Conclusion

6. What is HVDC ?
HVDC technology is used to transmit electricity over
long distances by overhead transmission lines or
submarine cables.

7. Components of HVDC Transmission Systems
Converters
Smoothing reactors
Harmonic filters
Reactive power supplies
Electrodes
DC lines
AC circuit breakers

8. Diagram of HVDC components

9. Harmonic
filters
Converters
Perform AC/DC (rectifier) and DC/AC (inverter)
conversion . It consists of bridges and transformer
Smoothing
reactors
They are high reactors with inductance as high as
1 H in series with each pole.
They decrease harmonics in voltages and
currents in DC lines
Prevent current from being discontinuous for
light loads
They are Used to reduce harmonics (in voltages and
currents) caused by converters which generate
harmonic
These harmonics may cause overheating of capacitors

10. Reactive
power supplies
Electrodes
DC lines
Under steady state condition, the reactive power
consumed by the converter is about 50% of the
active power transferred
For a strong AC power system, this reactive
power is provided by a shunt capacitor.
Electrodes are conductors that provide connection
to the earth for neutral.
They have large surface to minimize current
densities
They may be overhead lines or cables.
DC lines are very similar to AC lines

11. AC circuit
breakers
They used to clear faults in the transformer
and for taking the DC link out of service

12. WHY WE PREFER HVDC TRANSMISSION ?
Less losses (no inductance, capacitance).
Cost of transmission medium & long is less
Maintenance & operation cost is low.
Initial cost is high but overall cost is low
than ac .
DC lines are useful for long distances above
500km.

13. Types of HVDC
links
Bipolar
CONFIGURATION
Classification

14. Monopolar
It uses one conductor.
The return path is provided by ground or water.
Use of this system is due to cost considerations.
Due to –ive polarity, no corona effect occurs.

15. Bipolar
Bipolar HVDC has two conductors.
Junction b/w the conductors is grounded.
Can carry half the rated load, if fault occurs in one pole.

16. Homopolar
It has two conductors each having same polarity,
usually negative
The return path for such a system is through ground.

17. Advantages of HVDC
Economic
Advantages
Technical
Advantages

18. TECHNICAL ADVANTAGES
System stability
less Corona Loss and no skin effect
The voltage regulation problem is much less
serious for DC
Line controlled power flow is possible very
precisely.
No restriction on line length as no reactance in
DC

19. ECONOMIC ADVANTAGES
DC lines and cables are cheaper than AC lines
or cables.
Towers of the DC lines are narrower, simpler
and cheaper.
Line losses are less and increases efficiency.
Less material is required and cheaper.

20. DISADVANTAGES
Power loss in conversion, switching and
control.
Expensive inverters.
Converters have limited overload
capacity.
Higher losses in static inverters at
smaller transmission distances.

21. HVDC Applications in Pakistan
“Matiari Lahore” is the Pakistan’s first HVDC long distance project
among the Pakistan and China state ministry.
It covers over a distance of 878km from Matiari ( Sindh) to Nankana Sahib
District near Lahore. (approx. 4000 MW at 660 kV ) from coal plant.
1000 MW from Taftan to Quetta through a 500 KV,HVDC
transmission line, under discussion (from IRAN).
Proposed 500 MW from India through a 400 KV AC
transmission line and a back-toback HVDC converter in
Pakistan, estimated construction time 24-30 months.

22. CONCLUSION
HVDC offers powerful alternative to increase stability of a
power system, with it power flow can be controlled rapidly
and accurately.
Use of HVDC to interconnect two points in a power grid, it
has excellent environmental benefits.
Very large investment for example in China and Pakistan
shows that HVDC very important in future especially in big,
new industrial countries

24. THANK YOU