diff options
Diffstat (limited to 'ma')
| -rw-r--r-- | ma/Makefile | 1 | ||||
| -rw-r--r-- | ma/safety_reset.tex | 51 |
2 files changed, 46 insertions, 6 deletions
diff --git a/ma/Makefile b/ma/Makefile index e5e2b85..4458082 100644 --- a/ma/Makefile +++ b/ma/Makefile @@ -13,6 +13,7 @@ all: safety_reset.pdf safety_reset.pdf: resources/grid_freq_estimation.pdf safety_reset.pdf: resources/gps_clock_jitter_analysis.pdf safety_reset.pdf: resources/dsss_experiments-ber.pdf +safety_reset.pdf: resources/freq_meas_validation_rocof_testsuite.pdf %.pdf: %.tex %.bib pdflatex -shell-escape $< diff --git a/ma/safety_reset.tex b/ma/safety_reset.tex index c83e8be..6e23651 100644 --- a/ma/safety_reset.tex +++ b/ma/safety_reset.tex @@ -1214,9 +1214,38 @@ with IO contention on the raspberry PI/linux side causing only 16 skipped sample Captured raw waveform data is processed in the Jupyter Lab environment\cite{kluyver01} and grid frequency estimates are extracted as described in sec. \ref{frequency_estimation} using the \textcite{gasior01} technique. Appendix -\ref{grid_freq_estimation_notebook} contains the Jupyter notebook we used for frequency measurement. +\ref{grid_freq_estimation_notebook} contains the Jupyter notebook we used for frequency measurement. In fig.\ +\ref{freq_meas_feedback} we fed back to the frequency estimator its own output giving us an indication of its numerical +performance. The result was \SI{1.3}{\milli\hertz} of RMS noise over a \SI{3600}{\second} simulation time. This +indicates performance is good enough for our purposes. In addition to this we validated our algorithm's performance by +applying it to the test waveforms from \textcite{wright01}. In this test we got errors of \SI{4.4}{\milli\hertz} for the +\emph{noise} test waveform, \SI{0.027}{\milli\hertz} for the \emph{interharmonics} test waveform and +\SI{46}{\milli\hertz} for the \emph{amplitude and phase step} test waveform. Full results can be found in fig.\ +\ref{freq_meas_rocof_reference}. -% TODO comparison against reference measurements? +\begin{figure} + \centering + \includegraphics[width=\textwidth]{../lab-windows/fig_out/freq_meas_feedback} + \caption{ + The frequency estimation algorithm applied to a synthetic noise-less mains waveform generated from its own + output. This feedback simulation gives an indication of numerical errors in our estimation algorithm. The top + four graphs show a comparison of the original trace (blue) and the re-calculated trace (orange). The bottom + trace shows the difference between the two. As we can tell both traces agree very well with an overall RMS + deviation of about \SI{1.3}{\milli\hertz}. The bottom trace shows deviation growing over time. This is very + likely an effect of numerical errors in our ad-hoc waveform generator. + } + \label{freq_meas_feedback} +\end{figure} + +\begin{figure} + \centering + \includegraphics[width=\textwidth]{../lab-windows/fig_out/freq_meas_rocof_reference} + \caption{ + Performance of our frequency estimation algorithm against the test suite specified in \textcite{wright01}. Shown + are standard deviation and variance measurements as well as time-domain traces of differences. + } + \label{freq_meas_rocof_reference} +\end{figure} \section{Channel simulation and parameter validation} @@ -1409,10 +1438,13 @@ indicates SER is related fairly monotonically to the signal-to-noise margins ins \end{figure} \section{Implementation of a demonstrator unit} + %FIXME \section{Experimental results} + %FIXME \section{Lessons learned} + %FIXME @@ -1444,6 +1476,7 @@ managing root keys for other government systems to also manage safety reset keys of safety reset keys do not differ significantly from those for other types of root keys. \section{Practical implementation} + %FIXME \section{Zones of trust} @@ -1490,23 +1523,29 @@ microcontroller providing this type of virtualization on the one hand and the co virtualization on the other hand. Virtualization systems such as TrustZone are still orders of magnitude more complex to correctly configure than it is to simply use separate hardware and secure the interfaces in between. +\chapter{Alternative use of grid frequency modulation} +% FIXME random beacons? funky consensus protocols? proof of knowledge/cryptographic notary service? + \chapter{Conclusion} + %FIXME \newpage \appendix \chapter{Acknowledgements} + %FIXME \newpage \chapter{References} -\nocite{*} +\nocite{*} % FIXME \printbibliography \newpage \chapter{Transcripts of Jupyter notebooks used in this thesis} -\includenotebook{Grid frequency estimation}{grid_freq_estimation} -\includenotebook{Frequency sensor clock stability analysis}{gps_clock_jitter_analysis} -\includenotebook{DSSS modulation experiments}{dsss_experiments-ber} +%\includenotebook{Grid frequency estimation}{grid_freq_estimation} +%\includenotebook{Grid frequency estimation validation against ROCOF test suite}{freq_meas_validation_rocof_testsuite} +%\includenotebook{Frequency sensor clock stability analysis}{gps_clock_jitter_analysis} +%\includenotebook{DSSS modulation experiments}{dsss_experiments-ber} \chapter{Demonstrator schematics and code} |