8 research outputs found
Comparison of lossless compression schemes for high rate electrical grid time series for smart grid monitoring and analysis
The smart power grid of the future will utilize waveform level monitoring with sampling rates in the kilohertz range for detailed grid status assessment. To this end, we address the challenge of handling large raw data amount with its quasi-periodical characteristic via lossless compression. We compare different freely available algorithms and implementations with regard to compression ratio, computation time and working principle to find the most suitable compression strategy for this type of data. Algorithms from the audio domain (ALAC, ALS, APE, FLAC & TrueAudio) and general archiving schemes (LZMA, Delfate, PPMd, BZip2 & Gzip) are tested against each other. We assemble a dataset from openly available sources (UK-DALE, MIT-REDD, EDR) and establish dataset independent comparison criteria. This combination is a first detailed open benchmark to support the development of tailored lossless compression schemes and a decision support for researchers facing data intensive smart grid measurement
Initial analysis of the impact of the Ukrainian power grid synchronization with Continental Europe
When Russia invaded Ukraine on the 24\textsuperscript{th} of February 2022,
this led to many acts of solidarity with Ukraine, including support for its
electricity system. Just 20 days after the invasion started, the Ukrainian and
Moldovan power grids were synchronized to the Continental European power grid
to provide stability to these grids. Here, we present an initial analysis of
how this synchronization affected the statistics of the power grid frequency
and cross-border flows of electric power within Continental Europe. We observe
faster inter-area oscillations, an increase in fluctuations and changes in the
cross-border flows in and out of Ukraine and surrounding countries as an effect
of the synchronization with Continental Europe. Overall these changes are small
such that the now connected system can be considered as stable as before the
synchronization.Comment: 7 pages, 6 figure
Predicting the power grid frequency of European islands
Modelling, forecasting and overall understanding of the dynamics of the power
grid and its frequency is essential for the safe operation of existing and
future power grids. Much previous research was focused on large continental
areas, while small systems, such as islands are less well-studied. These
natural island systems are ideal testing environments for microgrid proposals
and artificially islanded grid operation. In the present paper, we utilize
measurements of the power grid frequency obtained in European islands: the
Faroe Islands, Ireland, the Balearic Islands and Iceland and investigate how
their frequency can be predicted, compared to the Nordic power system, acting
as a reference. The Balearic islands are found to be particularly deterministic
and easy to predict in contrast to hard-to-predict Iceland. Furthermore, we
show that typically 2-4 weeks of data are needed to improve prediction
performance beyond simple benchmarks.Comment: 16 page
Power grid frequency data base
Frequency time series from many synchronous areas around the world and synchronized data from locations in the Continental European grid
Microscopic Fluctuations in Power-Grid Frequency Recordings at the Subsecond Scale
Complex systems, such as the power grid, are essential for our daily lives. Many
complex systems display multifractal behavior, correlated fluctuations and power
laws. Whether the power-grid frequency, an indicator of the balance of supply
and demand in the electricity grid, also displays such complexity remains a
mostly open question. Within the present article, we utilize highly resolved
measurements to quantify the properties of the power-grid frequency, making
three key contributions: First, we demonstrate the existence of power laws in
power-grid frequency measurements. Second, we show that below one second, the
dynamics may fundamentally change, including a suddenly increasing power
spectral density, emergence of multifractality and a change of correlation
behavior. Third, we provide a simplified stochastic model involving positively
correlated noise to reproduce the observed dynamics, possibly linked to
frequency-dependent loads. Finally, we stress the need for high-quality
measurements and discuss how we obtained the data analyzed here
Open database analysis of scaling and spatio-temporal properties of power grid frequencies
The electrical energy system has attracted much attention from an increasingly diverse research community. Many theoretical predictions have been made, from scaling laws of fluctuations to propagation velocities of disturbances. However, to validate any theory, empirical data from large-scale power systems are necessary but are rarely shared openly. Here, we analyse an open database of measurements of electric power grid frequencies across 17 locations in 12 synchronous areas on three continents. The power grid frequency is of particular interest, as it indicates the balance of supply and demand and carries information on deterministic, stochastic, and control influences. We perform a broad analysis of the recorded data, compare different synchronous areas and validate a previously conjectured scaling law. Furthermore, we show how fluctuations change from local independent oscillations to a homogeneous bulk behaviour. Overall, the presented open database and analyses constitute a step towards more shared, collaborative energy research