9th August 2019 Power Cut - Final Report

[The Other Mike]

Report

Appendicies

--

[The Natural Philosopher]

as good a piece of 'economical with the truth arse covering' as it is possible to get.

Paraphrasing: 'The margins we maintain for these events are about 80% too low when we have a grid full of renewable energy and interconnects'

But we are saying it was just a terribly rare set of events and had nothing to do with renewable energy really'

[Brian Gaff]

I have observed in recent times a new culture of buck passing not seen for many long years. Let me just say this, the public are quite happy to accept somebody made a mistake, as long as it gets fixed. That does not just mean a bland statement of lessons will be learned unless they actually are.

Brian

[charles]

Thank you - an interesting read.

[newshound]

Arse covering or political correctness? Havn't read final report yet but I thought it was a sufficiently rare event to be broadly tolerable.

They've already said elsewhere that they will need to invest more and increase margins as/if renewables grow.

[charles]

The report is written by National Grid. They don't control who generates and by what means - so it's hardly arse-covering.

[The Natural Philosopher]

They are resposnible I think for maintaining the balance and assessing what margins are needed and I think mnaintaining that margin.

[Vir Campestris]

Indeed.

They had ~1Gw of spare capacity, and lost a quarter of that on a CGT station just along from the lightning strike. Well, that sort of thing happens.

The rest of it they lost from a windfarm at the other side of the country. Which is now being reconfigured, so that shouldn't happen again.

As a result of the swings a bunch of small generators (wind farms, solar etc) also shut down. That's by design, and ate a big slice out of that GW they didn't have any more. They should have more margin to cope with that sort of thing, and that will of course reduce the efficiency of the network more.

Then a valve failed at the CGT station, and they had to shut down the rest of the turbines. They'll look into that, it shouldn't happen.

Finally a bunch of trains didn't like the frequency shift, and required a site visit...

Andy

[Tim Streater]

Because they were in the middle of a software update. One might wonder why that was not completed *before* the train is back in service.

[charles]

The trains should have coped with the low frequency. It was within their operating spec.

[charles]

It was the fleet of trains that was in the middle of a software update - not the individual trains.

[Roland Perry]

In message [e-mail]>, at 10:43:54 on Wed, 11 Sep 2019, charles [e-mail]> remarked:

And the update was what made the trains *more* sensitive, not *less*.

[Steve Walker]

Being sensitive I can live with, but why on earth did they need an Engineer to attend a reset each one for what should be an operator reset?

SteveW

[Jim White]

It boils down to Siemens not building units to specification shutting down when the supply frequency dropped below 49Hz for 16 seconds, although the design parameter was 48.5Hz.

Siemens then implemented a software "upgrade" which removed the ability of drivers to undertake a "Battery Reset" on some units - those with the older software could repower, those on the new release needed the attention of technicians - and getting them to the right trains took a long time. These are the dangers inherent with implementing software upgrades on these trains which have not been properly tested.

Jim

[charles]

The word used was 'technician'.

[John Kenyon]

Old version of software - press buttons to reset (driver resets) New version of software - plug laptop into diagnostic port (tech resets)

[Roland Perry]

In message <qledp8$7r8$ [e-mail], at 22:36:39 on Thu, 12 Sep

2019, Steve Walker [e-mail]> remarked:

That's the sensitivity involved. "Something this bad must be investigated by a fitter, not just the driver".

[Tim Streater]

Not when the train stranded and full of passengers.

[charles]

and it's in themiddle of nowhere, so how does the tech get there? and how long does it take?

Mind you I was on an Edinburgh to London train last year which stopped at Berwick and it took nearly an hour to get the brakes released!

[Roland Perry]

In message <130920191504427724% [e-mail], at 15:04:42 on Fri, 13 Sep 2019, Tim Streater [e-mail] remarked:

The software which needs tickling by the fitter doesn't have a concept of "train stranded and full of passengers".

So regardless of the loading, it still needs a fitter.