Last nights grid

[Dave Liquorice]

Was the grid having fun last night?

Our voltage normally fits within the 235 to 245 range 24/7 but last night the UPS went into voltage trim modes several times, it does this when the input gets above 250v. These were briefly just before

2100 and about 2215, from 0030 to 0230 and 0430 to 0530 (roughly). The voltage plot from the UPS shows a couple of spikes above the allowed upper limit of 253v.

Just wondering if it was a local problem (North Pennines, 33kV feed comes from near Penrith) or more widespread.

[Toby]

Looking at th log on my UPS' at the office, in Kingston upon Thames, Surrey, it looked normal.

Over the last 24 hours it has been between 236v and 248v I cant see anything unusual at the times you say!

[The Natural Philosopher]

Probably there was a gust of wind, and they couldnt turn the coal down fast enough to compensate.:-)

OTOH the period between midnight and 4 a.m. is the lowest consumption period.

By 6 a.m. it's pretty much up t daytime levels tho, where it stays until the 7pm peak before falling back as people switch off and go to bed.