Why we don't always use HVDC power distribution system despite of its advantages ove?

[dineshdeshmuk]

Why we don't always use HVDC power distribution system despite of its advantages over normal AC power distribution system ?

thanks

 

[dick_freebird]

The significant disadvantage is that you can't just put a
transformer on a pole and get what you want at the far
end. You need either a genemotor or some kind of
switching power conversion and anything over 1kV puts
you pretty much out of luck for solid state switching
(see 1200 - 1600V devices out there but you have to
derate significantly for overshoot and line abnormalities).

 

[chuckey]

The only HVDC circuit I know is between France and England. The reasons are to allow the import and export of electrical power as the peak useage time will be different times and to decouple the frequency of the two nations grids. See :- https://en.wikipedia.org/wiki/HVDC_Cross-Channel
Frank

 

[hamidrezakarami]

HVDC is very expensive rather than AC transmission systems.

 

[edpalmer42]

It looks like high voltage DC distribution systems are in use all around the world.

https://en.wikipedia.org/wiki/High-voltage_direct_current
https://en.wikipedia.org/wiki/List_of_HVDC_projects

The list includes multiple systems (most in China) that are running at 800Kv!

Ed