SOTSOG - EDISON

[marconi]

Edison Lost The War Of Currents, But DC Networks Are Now Making A Big Comeback - GE Reports - https://www.ge.com/reports/power-play-edison-lost-war-currents-dc-networks-now-making-big-comeback/

 

[buzzlightyear]

Have any thing on knitting. The reason I have dropped a few stitches reading this. Lol.

 

[marconi]

Picking up something said in the article I linked to the EF at #1:

What is the problem of using HV alternating current cables in tunnels and underwater and thus a preference for using HV direct current cables instead? Try to work it out for yourself rather than look it up - study the cable below

 

[pc1966]

The sort of message that "Edison was right all along" in relation to modern HV DC is rubbish really, as at the time the choice of AC was far better for the distribution due to its ability to be transformed up and down in voltage to save conductor losses, as well as the much easier task of fault interruption when arcs tend to quench on the zero-crossing of the current.

Edison's main reason for pushing DC was simply down to business as he did not own the patents, etc, relating to AC operations.

HVDC now makes sense for very high power links due to the advances in semiconductors allowing efficient conversion and switching, that was not the case 100 years ago.

 

[Moley]

Things have definately advanced since Edisons days. This is a AC/DC converter station

I doubt he would even recognise the transformer. The spare Tx is on the left. Looks more like a gun turret off a ship.

 

[static zap]

RE Underwater AC issues :
I'm imagining the losses (that sound a bit like a welsh , sheep farming electrician )... Causing unwanted heating as well !

 

[marconi]

Things have definately advanced since Edisons days. This is a AC/DC converter station
View attachment 56943View attachment 56944

I doubt he would even recognise the transformer. The spare Tx is on the left. Looks more like a gun turret off a ship.
View attachment 56945

Is this a line-commutated(thyristor switches) or a voltage-source(transistor switches) converter station? I guess the latter.

 

[Moley]

Haven't got a clue. I don't work on the inverters apart from disconnecting them. I'm on the transformer side of things.

 

[marconi]

Moley: Could you tell us about any special features of that transformer to feed our curiosity? For example a feature of its design or technology or control/protection? How much do they cost to buy?

 

[marconi]

Staticzap:

Oliver Heaviside did some work which will help - the telegrapher's equation - don't get bogged down in the mathematics - just think about the big-picture electrical make-up (as seen at the supply end) of a very long length of the cable I showed you a cross-section of and how it is energised (hint here) by an ac and then a dc current. Do think big scale as if you needed to have a 2000MVA link between a tidal energy farm in Scotland's waters and Bristol.

It would be great if you did the mini-tutorial. Go on - I think you could.