27-05-2017, 09:24 AM
In the UK, power companies are olblighted to stick to 50Hz +/- 1%, i.e. 0.5Hz variation is permitted. There are strict rules governing permitted excursions outside these limits, see http://www2.nationalgrid.com/uk/services...-response/ for the simple view...
I'm not entirely sure whether long term frequency stability is still guaranteed - it used to be the case that the generating authorities would correct any daily deviations during the night to keep any synchronous clocks relying on accurate long-term 50Hz for their accuracy correct.
Years ago, nixie clocks, station clocks, time recorders etc. used to rely on the mains for their frequency standard, but that largely changed with Droitwich, MSF Rugby, DCF77 and others. Now of course, it's pretty common to use GPS-disciplined time.
The truth is that there is pretty much no reason to play with the supply/demand numbers for the National Grid in order to maintain long-term 50Hz stability - no-one of any import cares, and it is an expensive exercise.
See http://www.dynamicdemand.co.uk/grid.htm for a bit of fun
I'm not entirely sure whether long term frequency stability is still guaranteed - it used to be the case that the generating authorities would correct any daily deviations during the night to keep any synchronous clocks relying on accurate long-term 50Hz for their accuracy correct.
Years ago, nixie clocks, station clocks, time recorders etc. used to rely on the mains for their frequency standard, but that largely changed with Droitwich, MSF Rugby, DCF77 and others. Now of course, it's pretty common to use GPS-disciplined time.
The truth is that there is pretty much no reason to play with the supply/demand numbers for the National Grid in order to maintain long-term 50Hz stability - no-one of any import cares, and it is an expensive exercise.
See http://www.dynamicdemand.co.uk/grid.htm for a bit of fun
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