Using PMU Measurements to Assess Dynamic Line Rating of Transmission Lines

Student thesis: Master thesis (including HD thesis)

  • Sveinn Rúnar Júlìusson
4. term, Energy Engineering, Master (Master Programme)
In this report a dynamic line rating(DLR) model is constructed. The overhead
line which is subject of this report is the BR1 connection which is positioned in
south west Iceland. The model uses measurements from a phasor measurement
unit where from the impedance and admittance of a transmission line is computed.
The impedance and admittance are acquired assuming the line can be
modelled as a ¼-model. A numerical solver is constructed in order to compute
the average height of the conductor using the information about the susceptance
from the PMU measurements. The curve of a overhead line can be described by
the catenary equation which is a hyperbolic function containing information about
horizontal tension, weight per meter of the conductor and the span length. The
horizontal tension decreases with increased conductor temperature and that relationship
is there fore linearised while the weight per meter is kept constant. The
span length varies through out the BR1 connection accordingly. The model is
tested by implementing data from a fixative example where the result indicate that
the equations are implemented correctly. The model is then tested in a case study
using data from the BR1 connection. The result from the case study indicate that
the model is not working properly. A sensitivity analysis is there fore conducted on
the model, proofing that the model is very sensitive to any variation in the current
angle. At last the model is tested by implementing the data of the BR1 connection
in the simulation program DigSilent Powerfactory. By varying the load and the resistance
the value of the susceptance deviates insignificantly. The model is there
fore considered to work properly in theory but as the value of the susceptance is
very sensitive to any variation in the current angle the model is not considered to
be the ideal tool for DLR.
SpecialisationElectric Power Systems and High Voltage Engineering
Publication date4 Jun 2013
Number of pages112
External collaboratorLandsnet
Phd. Electrical Engineer Magni Pálsson
ID: 77194897