Would high voltage DC power grids work the same?

Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
4 replies · 2K views
greypilgrim
Messages
583
Reaction score
45
Hi.

As far as I know, the main reason for using AC in electric power transmission is that voltage can easily be transformed.

If there was a similarly easy way for transforming DC, would power grids work basically the same? To be more specific, how much does AC power transmission rely on the Earth as ground working as a capacitor rather than an ohmic resistor?
 
Engineering news on Phys.org
greypilgrim said:
Hi.

As far as I know, the main reason for using AC in electric power transmission is that voltage can easily be transformed.

If there was a similarly easy way for transforming DC, would power grids work basically the same?

Yes there is a way of transforming DC, but only conceptually so far. See this recent thread.
https://www.physicsforums.com/threads/dc-to-dc-power-transformer.921023/

greypilgrim said:
To be more specific, how much does AC power transmission rely on the Earth as ground working as a capacitor rather than an ohmic resistor?

No. Three phase power systems don't need the ground connection. The currents in the three phases are 120 degrees apart, they add up to zero so ideally there is no need for an Earth return. There are other reasons for neutral to ground earthing, but not to return the power current.
 
greypilgrim said:
To be more specific, how much does AC power transmission rely on the Earth as ground working as a capacitor..

Got a reference for that?