Complete and utter rubbish... and Unforgivable.
"...our source said, the power control software controlling the multiple feeds into the data centre didn’t get the switch between battery and backup generator supply right at the critical moment – or, potentially, if someone panicked and interrupted the automatic switchover sequence – it could have resulted in both the battery supply and the generator supply being briefly connected in series to the power bus feeding the racks. That would result in the data centre’s servers being fed 480v instead of 240v, causing a literal meltdown."
No. No. NO. Any modern DC has a sequence where the utility feed comes into a box called an ATS (Automatic Transfer Switch). Under normal circumstances, ALL the equipment in the DC is powered from the UPS which is on-line at all times.
The UPS has two roles - maintain the output voltage at a steady 230V to cater for input supply power fluctuations, and to load-balance the input currents across the three supply phases (most modern UPS systems don't care much about output load balancing, though it's good practice to try to balance them to get the most out of the UPS).
On-line UPS systems take the input power feed, convert it to DC to charge the batteries, then they have inverters that take the DC from the battery and convert it into clean AC for the data center. Unless the UPS is in bypass mode for maintenance, this is the case at all times for all modern data center UPS systems.
If the utility feed fails, the ATS detects this and immediately sends a signal to the genset to start the generators.
The UPS should have about 10 minutes of run time with no utility input - this is to cover the start-up of the genset, and if the genset doesn't start, time to send a signal to the servers that they need to do an orderly shutdown (this is done by s/w agents on the servers - signalling normally by IP).
At NO TIME should there be a detectable fluctuation in the power to the data center - all that happens when the input utility supply fails is that the batteries in the UPS are no longer being charged and start to discharge (hence the 10 minute run-time) and the genset starts up..
As soon as the ATS detects that the genset is producing the correct voltages, the utility supply (which has failed anyway) is automatically disconnected from the UPS and the genset output connected in its place - this happens in fraction of a second, automatically, and again, there is NO interruption to the supply to the data center - as the servers are, as always, running off the batteries, not the UPS input supply.
The UPS batteries are now being charged by the genset, and life continues as normal. Normally, gensets spin up and stabilise in a couple of minutes (our one, a 450kW jobbie on the roof, takes under two minutes). The genset should have at least 24 hours of fuel on-site.
When the ATS detects that the utility supply is restored AND STABLE, it disconnects the genset from the input to the UPS and connects the utility supply in its place. After a few minutes of stable running, the genset is switched off.
There is simply NO EXCUSE for a modern (read "last 10 years") DC to lose power the way BA did. Just unforgivable.