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TU Delft
Faculty of Electrical Engineering, Mathematics, and Computer Science
Circuits and Systems Group
EE4C03 STATISTICAL DIGITAL SIGNAL PROCESSING
ASSIGNMENT
Estimation algorithm for a Phasor Measurement Unit
1. Context
The incorporation of renewable energy sources into the power grid leads to uncontrolled changes
in the system input and load. Real time monitoring and control is required to balance the
system and maintain the required voltage level and line frequency (50 Hz).
In the mid-1980s the synchronised Phasor Measurement Unit (PMU) was introduced. A PMU
estimates the power system voltage and current phasor (angle and magnitude), frequency and
rate of change of frequency (ROCOF), and sends time-stamped measurement data to a central
location [1]. The IEEE Standard C37.118.1 (2011) and its Amendment (2014) defines the PMU
output and accuracy requirements for both static and dynamic conditions [2].
One of the main operations of a PMU is the high frequency sampling of voltage and current
analog input signals and the calculation of its time-synchronized phasors. The voltage signal is
of the form
x(t) = A(t) cos(2πf0 (1 + 1 )t + 2 ) + 3
In fact, actual 3-phase systems have 3 such signals which are tightly synchronized. Under
steady-state conditions, estimating the phasors is straightforward (e.g. using the DFT), but this
is different under dynamic conditions.
2. Problem
Given the model of the voltage signal, find a suitable estimation algorithm for the instantaneous
synchronized phasors. The implementation may be recursive or adaptive (RLS, Kalman). The
algorithm has to be modeled in matlab. The objective is change detection: what is the earliest
moment you can reliably detect that the frequency has changed from its nominal setting (50
Hz)?
3. Assignment
In a group of 2 students, write a compact essay where you briefly present the problem, consider a
suitable model and a performance measure, develop an (adaptive) model identification algorithm,
and test this on example data. Include your matlab code as an appendix.
The essay typically has 4–10 pages (except for the appendix) depending on the number of graphs.
4. Hints
Conduct a brief literature study to orient yourself on this problem. The paper [2] contains a
description of a measurement setup and several classes of faulty signals.
A data set with PMU synthetic test measurements (simulated data) is available from dipl.ing.
Matija Naglic. This dataset consists of a sequence of events that you can use to develop your
algorithms.
Your algorithm will be tested on another data set where the objective is to detect and classify
dynamic events (line trip, generator trip, load shedding, oscillation) as early as possible.
5. Consultants
Dipl.-ing. Matija Naglic
Intelligent Electric Power Grids
Email: [email protected]
Tel: +31 15 27 88007
Room: LB 03.210
Dr. Marjan Popov
Tel: +31 15 27 86219
Email: [email protected]
Room: LB 03.250
6. Course contact person
Prof.dr.ir. Alle-Jan van der Veen
Email: [email protected]
Room: HB 17.040
References
[1] K.E. Martin e.a., “Exploring the IEEE standard C37.118-2005 synchrophasors for power
systems,” IEEE Tr. Power Delivery, vol. 23, pp. 1805–1811, Oct 2008.
[2] Nhi T.A. Nguyen, M. Popov, and G. Rietveld, “Phasor measurement unit testing in accordance with the IEEE C37.118.2011.1-2011 synchrophasor standard,” IPSI BgD Transactions
on Internet Research, vol. 11, July 2015. ISSN 1820-4503.
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