Would high voltage DC power grids work the same?

AI Thread Summary
High voltage DC (HVDC) power grids could function similarly to AC grids if an effective method for transforming DC voltage were developed. Currently, AC is preferred for its ease of voltage transformation and the ability to utilize the Earth as a ground without relying on it as a return path for current. Three-phase AC systems operate with currents that are 120 degrees apart, ideally eliminating the need for an Earth return. The discussion also touches on the concept of single wire earth return (SWER) systems, which utilize the ground in a different capacity. Overall, while DC transformation is conceptually possible, practical implementation remains a challenge.
greypilgrim
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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?
 
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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?
 
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