The document discusses Mohd Abdul Sohail's seminar on high voltage direct current (HVDC) transmission. It introduces HVDC, describes the basic principles and components of HVDC systems. The document compares the cost of HVDC to HVAC transmission and lists several advantages of HVDC, such as its ability to transmit electricity over long distances and interconnect separate power grids. It also notes some disadvantages of HVDC, such as higher costs and need for more maintenance of insulators. The objectives of HVDC control systems are to ensure efficient, stable and flexible operation during normal and abnormal conditions.

1. SEMINAR BY MOHD ABDUL SOHAIL.
ROLL.NO.160713734005.from final year

2. Introduction .Introduction .
HVDC link’s.HVDC link’s.
Basic principle’s.Basic principle’s.
Components of HVDC.Components of HVDC.
Cost of HVDC over HVAC.Cost of HVDC over HVAC.
Advantages of HVDC over HVACAdvantages of HVDC over HVAC
Disadvantages of HVDC.Disadvantages of HVDC.
Object’s of control.Object’s of control.
Conclusion.Conclusion.
KEY WORDSKEY WORDS

3. HVDC stands for High Voltage Direct CurrentHVDC stands for High Voltage Direct Current
and is today a well-proven technology employedand is today a well-proven technology employed
for power transmission all over the world.for power transmission all over the world.
HVDC technology is used to transmitHVDC technology is used to transmit
electricity over long distances by overheadelectricity over long distances by overhead
transmission lines or submarine cables.transmission lines or submarine cables.
It is also used to interconnect separate powerIt is also used to interconnect separate power
systems, where traditional alternating currentsystems, where traditional alternating current
(AC) connections can not be used.(AC) connections can not be used.
INTRODUCTIONINTRODUCTION

4. HVDC links can be broadly classifiedHVDC links can be broadly classified
into:into:
Monopolar links :usedMonopolar links :used oneone conducter.conducter.
Bipolar links:usedBipolar links:used twotwo conducters.conducters.
Homopolar links:Homopolar links:twotwo are moreare more conductersconducters

5. BASIC PRINCIPLES
OF
HVDC TRANSMISSION
HVDC systems and FACTS controllers based onHVDC systems and FACTS controllers based on
line-commutated converter technology (LCC)line-commutated converter technology (LCC)

8. Converters:Converters:
 smoothing reactorssmoothing reactors
ElectrodesElectrodes
Harmonic filtersHarmonic filters
Reactive power suppliesReactive power supplies
DC linesDC lines
AC circuit breakers:AC circuit breakers:
Components of HVDCComponents of HVDC
Transmission Systems:Transmission Systems:

10. COST OF HVDC OVER HVAC

11. – CONVENTIONALLY POWER TRANSMISSION IS EFFECTED
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
– CONSIDERING THE DISADVANTAGES OF HVAC SYSTEM
AND THE ADVANTAGES OF HVDC TRANSMISSION ,
POWERGRID HAS CHOOSEN HVDC TRANSMISSION FOR
TRANSFERRING 2000 MW FROM ER TO SR
COMPARISION OF HVAC & HVDC
SYSTEMS

12. Direct current is put to use in common life for driving
our portable devices, UPSs, battery systems and vastly
in railway locomotives.
USE OF DC
DC AS A MEANS OF TRANSMISSIONDC AS A MEANS OF TRANSMISSION
This has been possible with beginning of
High power/ high current capability thyristor.
&
Fast acting computerized controls

13. ADVANTAGES
Technical advantages:
No requirement of reactive power
Practical absence of transmission line length
limitations
No system stability problems
Interconnection of asynchronously operated
power systems
No production of charging current

14. DisadvantagesDisadvantages
Use of converters ,filters etc increases theUse of converters ,filters etc increases the
overall costoverall cost
DC circuit breakers are more expensiveDC circuit breakers are more expensive
HVDC converters have low overloadingHVDC converters have low overloading
capacitycapacity
More maintenance is required for insulatorsMore maintenance is required for insulators
Voltage transformation is possible only on ACVoltage transformation is possible only on AC
sideside

15. OObjectives of Controlbjectives of Control
 Efficient and stable operation.Efficient and stable operation.
 Maximum flexibility of power control withoutMaximum flexibility of power control without
compromising the safety of equipment.compromising the safety of equipment.
 Principle of operation of various control systems.Principle of operation of various control systems.
 Implementation and their performance duringImplementation and their performance during
normal and abnormal system conditions.normal and abnormal system conditions.

16. ConclusionConclusion
HVDC is very important issue in transmission energy.HVDC is very important issue in transmission energy.
Problem of cascade blackout, can be reduced byProblem of cascade blackout, can be reduced by
application of HVDC.application of HVDC.
Very large investments in e.g in China and IndiaVery large investments in e.g in China and India
shows that high-voltage direct current will veryshows that high-voltage direct current will very
important in the future, especially in big, new-industriesimportant in the future, especially in big, new-industries
countries.countries.
Recent studies indicate that HVDC systems are veryRecent studies indicate that HVDC systems are very
reliable.reliable.
The data collected from 31 utilities says that forcedThe data collected from 31 utilities says that forced
unavailability of energy due to the converter station isunavailability of energy due to the converter station is
1.62%.1.62%.

17. If DC is required to be used for transmission
&
since our primary source of power is A.C,
The following are three basic steps:-
1. Convert AC into DC (rectifier)
2. Transmit DC
3. Convert DC into AC ( inverter)

19. Any