الفهرس 
PARAK:TER ESTIMATION PROBLEM
Propertlea of Least Brror Squares Bst1.atesOnly 14 pages are availabe for public view
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Abstract
State estimation is a data processing technique used to assign a value to an unknon system
state variables depending on a set of measurements obtained from the orking system .
In power systems the set of measurements act!ve and reactive power flo , buses voltage . These
measurements are collected state estimator algorithm in the control
consists of lines injection power a and telemetered to
room The state
estimator filters out erroneous measurements and uses the other to obtain the system states .
The traditional state estimators use the classical weighted least squares (WLS) technique which
minimizes the squares of the difference between the measured and calculated values Weighted
least squares technique has many drawbacks ; it produces a poor estimates if the measurements
set is contaminated with bad data or erroneous measurements , and also if the measurements error
does not have a Gaussian distribution .
Other state estimators use the least absolute value technique which minimizes the absolute value
of the difference between the
measured and calculated values ate proposed in the literature ,
these algorithms use the linear programming technique to obtain
the system state estimates . The linear progtamming an iterative algorithm , it needs a great
deal computing time to reach the optimal state estimates
technique of memory
is and
xii
A new technique is proposed and discussed in this thesis to tain the state estimates based on
least absolute value (LAV)
e solution obtained by this algorithm depends on a previous
owledge of the LS esiduals . The new algorithm has the ability detect and reject the erroneous
measurements automatically ring the solution process without any prior knowledge of the
roneous measurements and there locations The new proposed chnique is applied to different
sizes of power systems , 5 , 10 d 14 bus systems , and the results obtained are reported , where
compare between the proposed technique and the well-known WLS
chnique .