HVDC PPT

1. HVDC TRANSMISSION

2. CONTENT
INTRODUCTION
WHY DC
TRANSMISSION
COMPARISON
(AC/DC)
COMPONENTS
HVDC SUBSTATION
LAYOUT
TYPES OF HVDC
SYSTEM
EXISTING HVDC IN
INDIA
DRAWBACKS
APPLICATION CONCLUSION

3. INTRODUCTION
 A high voltage, direct current(HVDC) electric power
transmission system(also called a power super highway)
uses direct current for the bulk transmission of electric
power.
 It’s especially useful for long distance and underwater
power transmission.
 The longest HVDC link in the world is the Rio Madeira link
in Brazil(2*±600kV,3150MW)
 In India, the longest HVDC link is the Talcher-Kolar
transmission link(1450km long) of 500kV,with a rated
capacity of 2500MW.

4. WhyDCTransmission
Losses are less
Two conductors are required
Less expensive
Can be used for long distance and
undersea transmission

5. ComparisonbetweenACandDCTransmission
Lower overall
investment cost
for point to point
transmission.
Less conductor
cost due to
absence of skin
effect.
Losses are less as
dc has only active
power.
DC Higher
investment cost.
Higher conductor
cost as three
phases have to
be supported.
Losses are more
as ac has both
active and
reactive power.
AC

6. COMPONENTS
CONVERTERS
CONVERTER TRANSFORMER
FILTERS
REACTIVE COMPENSATION
(SHUNT CAPACITOR)
DC CABLE

7. HVDC SUBSTATION LAYOUT

8. ►MONOPOLAR LINK
►BIPOLAR LINK
►HOMOPOLAR LINK
Types Of
HVDC
System
HOMOPOLAR
BIPOLAR
MONOPOLAR

9. MONOPOLAR LINK
 A monopolar system has only one conductor with
ground as return conductor and it is usually of a
negative polarity.
 It is suitable in submarine systems where sea water
can be used as return path.

10. BIPOLAR LINK
 A bipolar system has two conductors, one of positive
and other of negative polarity.
 The ground point is maintained at the mid-potential.
Each terminal of a bipolar system has two converters
of equal voltage rating connected in series.

11. HOMOPOLAR LINK
 Homopolar system has two or more conductors with
same polarity, usually negative and they always operate
with ground return.
 In the event of fault in one conductor, the whole
converter can be connected to a healthy pole.

13. DRAWBACKS
No transformer for
alternating the voltage
level.
HVDC link is
complicated.
Conversion of AC To DC
is costly.

14. APPLICATION
• Undersea and
under ground
cables.
• Ac network
interconnection
• Interconnecting
asynchronous
system.

15. HVDC offers powerful alternativeto increase
stability of a power system as well as to improve
system flexibilityand loss reduction.
Inthe present times, the increasingnumber of
HVDC transmissionprojects shows the potential
and scope of HVDC.
CONCLUSION