What are these possible heat dissipation tubes?

[phinds]

In the Jan 6 Economist, there is an article about energy ("Britain needs an unprecedented expansion of the electricity grid") headed by this image. I assume that it is part of a power plant but I can't figure out what all those curved tubes are.

First, I thought, maybe heat dissipation but they don't really seem to be designed for that.

Any ideas?

 

[Bystander]

Looks like a movie set to me.

 

[Baluncore]

A HV DC transmission line converter station.

The round tubes are for corona reduction.
Faraday screens that allow cooling air to circulate.

The things inside the blocks could be rectifier diodes, making each vertical stack into a high-voltage 'stick rectifier'. They may also be high-voltage transistors or thyristors, for bidirectional DC to AC inversion.

https://new.abb.com/news/detail/129...-to-boost-integration-of-renewables-in-europe

 

[phinds]

Thanks. So how do they work?

 

[Baluncore]

So how do they work?

How does what specifically work?

Each module in the stack is a switch that handles say 50 kV.
The switches are linked by optic fibres that turn them on and off.

The rounded tubes and surfaces prevent electrical breakdown of the air between modules, by preventing corona discharge from sharp points or thin edges.

Transformer oil immersion of the modules for cooling is avoided, due to the risk of fire. The electronics may be cooled and insulated by SF₆. That may be in the tubes if they are used for cooling, but then I would expect them to be black, not silver.

 

[berkeman]

A HV DC transmission line converter station.

Good thing that worker in the middle has on rubber boots and gloves!

 

[sophiecentaur]

I found a link with the same image in it. A bit more info available but it seems to be (part of?) a 1.4GW inverter for international Power exchange between UK and denmark.
Those tubes are full of AA batteries.

 

[berkeman]

I found a link with the same image in it. A bit more info available but it seems to be (part of?) a 1.4GW inverter for international Power exchange between UK and denmark.

I'm a little slow today, but which way is the energy flowing? Or can it flow in either direction depending on the relative supplies of wind, solar, etc.?

 

[sophiecentaur]

AC with different frequencies / phases each end and a DC link under the sea.No need to sunchronise the two networks and much less loss for DC. Power can be supplied in either direction in an efficient way over hundreds of miles.This has been done for decades buT this is a newer, sexier version.

 

[berkeman]

Oh, so like a high-tech version of the US inter-state power grid connections? Wow.

 

[sophiecentaur]

Oh, so like a high-tech version of the US inter-state power grid connections? Wow.

I remember my Dad describing a system with mercury arc rectifiers as switches in the cross channel (English) to France. Dc transmission was novel in UK at the time. Probably 1960s when UK and France tended to co-operate about things.

 

[Baluncore]

The converter building is still called the "valve hall", because the switching modules used to have gas filled thyratrons. Nowadays, they use SiC IGBTs.

Power semiconductors are not usually operated above about half their breakdown voltage, since when subjected to cosmic rays, they are susceptible to catastrophic failure. That was recognised in 1994, when the reliability of locomotive converters, operating at high altitudes, were compared with those operating underground in salt mines.