Continuing frequency deviation in the Continental European Power System

Re:Continuing frequency deviation in the Continental Europea... by oldcynic on Wednesday March 07, 2018 @08:24AM (#16536148)

Definitely. Dinorwig[0] has the turbine hall built inside a mountain, using a lake in a disused slate quarry. Stop to maximum power in 12s or something similarly ridiculous. They do tours, which I highly recommend if you are in the UK. You go by bus (inside the mountain) to get to the interesting things.

It was also built to be able to do a black start (startup after a total grid outage).

https://en.wikipedia.org/wiki/Dinorwig_Power_Station

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Re:Continuing frequency deviation in the Continental Europea... by gpvos on Wednesday March 07, 2018 @09:15AM (#16536444)

>It was also built to be able to do a black start (startup after a total grid outage).

Aren't all stations?

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Re:Continuing frequency deviation in the Continental Europea... by oldcynic on Wednesday March 07, 2018 @09:38AM (#16536631)

Nope. They have to be able to cope with extreme changes in load, and I think have higher precision of frequency adjustment to pull the rest of the grid into sync.

Some coal plants had gas turbines[0] fitted solely to allow a black start, others a ton of diesel generators. Some plants need power from the grid to kick off - nuclear for instance. Only some percentage of the grid needs cold start capability, and the rest of the grid is bootstrapped from that.

[0] (edit) Think aero engine. Rolls Royce Avons were used at Didcot A, and the industrial Avon is still available after 60 years. That's the same basic engine found in the Hawker Hunter and EE Lightning.

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Re:Continuing frequency deviation in the Continental Europea... by Reason077 on Wednesday March 07, 2018 @10:39AM (#16537084)

I recently got to take a look around a small (~ 4MW) hydro station. Despite this being a tiny contributor to the overall grid, it is apparently a grid/regulatory requirement for them to be able to perform a black start.

For that reason, all the equipment in the generator building ran on 48V DC, supported by a large bank of batteries.

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Re:Continuing frequency deviation in the Continental Europea... by howard941 on Wednesday March 07, 2018 @12:22PM (#16537930)

Additional anecdata: The sensors and controls in distribution substations are also DC although 48VDC is considered the low end in those places where it goes up to over 200V, according to the engineer from a municipal electric company met in an $OFFICE meeting Monday. The guy said they specify flooded lead acids and plan on them lasting 15 years before pre-planned change-outs.

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Re:Continuing frequency deviation in the Continental Europea... by pjc50 on Wednesday March 07, 2018 @11:26AM (#16537438)

In addition to the other answers, large generators usually use externally-energised coils to provide their magnetic field, so they can't generate unless there is already a supply of electricity. Then there's all the peripheral machinery of a power plant such as coal crushers and feeders, pumps, valves and so on.

Somewhere there will be a manual for the unfortunate operators who will have to restart the whole grid in the correct order, relying on the telephone company's backup generators to communicate.

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Re:Continuing frequency deviation in the Continental Europea... by radiowave on Wednesday March 07, 2018 @09:35AM (#16536605)

Larger stations could take a long time (like a day) to start up, as there are trade-offs between start up time and operating efficiency. During that time, you still have to be able to run all the plant equipment - pumps, fans, coal grinders, conveyors, all the monitoring and control equipment. I expect there will be many stations that don't have anywhere near sufficient diesel generator capacity to allow start up without any supply from the grid.

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