| Author |
Message |
davidd31415
Guest
|
 Posted:
Mon Dec 12, 2005 8:34 am Post subject:
DC-DC converter efficiency compared to transformers (for tra |
|
|
Hi,
I've been reading through posts regarding transmission lines and the
pros & cons of using AC or DC but one thing I haven't found much of is
a discussion on is the efficiency of converting DC voltages (stepping
up or down). I realize using high voltage decreases power loss and
that's why we started using transformers & AC back in 1895 at Niagara
Power but I've also read a lot about DC transmission lines that are in
use today, notably the Pacific lines.
How does the efficiency of the DC to DC converters used by the power
companies compare with transformers that would be handling simiilar
amounts of power?
I've read that interconnection and switching are other issues with DC
transmission, could someone explain these, why DC has issues, why AC
doesn't, and what might be done to make DC work? Also, are there any
other serious disadvantages to using DC for transmission now days,
aside from infrastructure changes?
|
|
| Back to top |
|
 |
Figaro
Guest
|
| Posted:
Mon Dec 12, 2005 9:17 am Post subject:
Re: DC-DC converter efficiency compared to transformers (for |
|
|
"davidd31415" <davidd31415@yahoo.com> wrote in message
news:1134354865.016081.319230@g44g2000cwa.googlegroups.com...
| Hi,
|
| I've been reading through posts regarding transmission lines and the
| pros & cons of using AC or DC but one thing I haven't found much of is
| a discussion on is the efficiency of converting DC voltages (stepping
| up or down). I realize using high voltage decreases power loss and
| that's why we started using transformers & AC back in 1895 at Niagara
| Power but I've also read a lot about DC transmission lines that are in
| use today, notably the Pacific lines.
|
| How does the efficiency of the DC to DC converters used by the power
| companies compare with transformers that would be handling simiilar
| amounts of power?
|
| I've read that interconnection and switching are other issues with DC
| transmission, could someone explain these, why DC has issues, why AC
| doesn't, and what might be done to make DC work? Also, are there any
| other serious disadvantages to using DC for transmission now days,
| aside from infrastructure changes?
Post this at: misc.industry.utilities.electric
On the whole, the life-cycle cost (initial cost, operation, maintenance)
of DC transmission is significantly higher than AC transmission.
This is why it is only used when AC transmission becomes technically
unfeasible; for example, very long lines such as the Pacific intertie,
asynchronous transmission, excessive interconnection power angles. |
|
| Back to top |
|
|
neon
Joined: 25 Feb 2006
Posts: 580
|
| Posted:
Sat Feb 25, 2006 3:05 pm Post subject:
|
|
|
transmission ac/ dc big difference. first of all on ac the current can travel along the outside conductor while dc involves the whole cross section of the coductor. now efficiency well all of the USA is ac meaning that we must loose power at the source and loose power at the load. now with electr. conveters we gain some eff. but loose on transmission. tranformers if designed correctly can be as hi as 85% while dc conveters can virtualy approach the 94 97%. the proplem with converters is the tremendous inrush at start up. if somebody is a studend and need a thesys how about estimating what would happen to the USA grid if all PC inverters could start up at the same time. my theory is that the grid would sag and disconnect. that is a terrible thought it never happened yet.
|
|
| Back to top |
|
|
|
|
|
|
FAQ
Memberlist
Register
Profile
Log in to check your private messages
Log in
