cvk

• Oct 6th, 2007

 

In HVDC there are only two conductors and no reactance. So less voltage drop and less line losses.

arunkpkrn

 Profile Answers by arunkpkrn 

• Apr 15th, 2008

 

Additional to above answer, as it is having only 2 conductors, there will be less losses.
It is economic only when the distance of transmission is greater than the critical distane beacause the converter/inverter which is used is of very high rating,which costs heavy.so for lesser distance the this comverters losses will be high which will not be economical.
for more details go through the book  HVDC- By Padiyar.

venky_sastra

 Profile Answers by venky_sastra 

• Dec 28th, 2008

 

HVDC means high voltage DC transmission. Usually when we speak in common terms power p=I*I*R therefore p is propotional to I*I, A high voltage will generally involve low current so as a result the power losses are less. So it has an economic advantage over EHV-AC transmission.

sainathdi

 Profile Answers by sainathdi 

• Aug 16th, 2009

 

HVDC- High Voltage DC Transmission system ,

from the name itself we can say that its a dc transmission system and a dc transmission has two conductors one phase and other neutral. phase conductor is used to transmitt the current from sending end to receiving end, and the nutral conductor is used for the return path of current.

we know that losses in the transmission system is due to resistance (DC & AC ) & impedence drop (only AC)
resistance drop can be minimised using the suitable conductor(since resistance dependence on nature of the conductor) where as the impedence drop in AC is a complicated to minimize due to SKIN effect .

(SKIN EFFECT:when a dc supply is given to conductor, the current flows through utilizing total(surface and inner part) of the conductor and when an ac supply is given to a conductor the current flowing through it concentrates only on the surface of the conductor rather than whole,due to alternating nature of the current . there by increasing drop accros the conductor and losses too.)


 so when using dc mode impedence drop can be avoided and there will be losses in dc too but these losses can be neglected if the transmitting voltage is very high.

so dc transmission mode is efficient and economical for long transmission(>150km) type