10.5061/DRYAD.Z34TMPGB4
MacKay, Robert
0000-0003-4771-3692
University of Warwick
National Grid frequency trace
Dryad
dataset
2020
National Grid (United States)
https://ror.org/04vdxde73
NIA NGET0161
2020-08-14T00:00:00Z
2020-08-14T00:00:00Z
en
400098 bytes
6
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
The attached dataset provides the GB grid frequency every second for two
hours (02.00-04.00) on 1 September 2015 (at some location that I do not
remember). I used it to test some linear stochastic process models for
the frequency as a function of time. On the 2-hour timescale the trace
fit reasonably well to an Ornstein-Uhlenbeck (OU) process with a decay
time of around 30 minutes. On a shorter timescale, in particular the
first 3 minutes 20 seconds, the trace looked smooth so I fitted it to a
first-order filtered OU process, which gave me time constants of 11
minutes and 1.9 seconds. This was important evidence that a useful model
for power imbalance as a function of time is a filtered white noise.
Furthermore, the power spectrum of the 2-hour trace showed a regime with
slope around -4 for periods shorter than 25 seconds, consistent with being
a first-order filtered OU process, until the Nyquist cutoff at 2 seconds.
The data were publicly available from National Grid
(http://www2.nationalgrid.com/Enhanced-Frequency-Response.aspx) at the
time. I downloaded them. The link is no longer active, so I have made
the data available here. I made no changes.
The data are in an excel file with three columns: date (DD/MM/YEAR), time
(HH:MM:SS), frequency (Hz). A graph is also provided.