This paper has discussed transformer tap pos
ition
estimation with continuous and discrete variables in the context of
three phase distribution state estimation (SE). Ordinal
optimization (OO) technique has been applied to estimate the
transformer tap position for the first time in unbalanced three
p
hase distribution network model. The results on 129 bus system
model have demonstrated that OO method can generate a reliable
estimate for transformer exact tap position with discrete variables
in distribution system state estimation (DSSE) and also in sho
rt
period of time. In this paper the node voltages and power losses
are calculated for 129 bus network. It is also demonstrated that
OO is much faster than other accurate methods such HPSO. The
losses obtained with OO are much accurate. In view of this OO
performs better than WLS as it provides higher accuracy of the
loss calculation. In a distribution network where about 5
-
6% of
electricity generated is lost, accurate estimation of this loss has
significant technical and commercial value. The authors belie
ve
the technique proposed will help realize those benefits.