Abstract:
Power system losses have turned out to be a major challenge for electricity utilities
worldwide and losses in electricity distribution represent dominant part in the overall
power system losses. In the Sri Lankan context, losses in the distribution system are
around 8.5% of gross electricity generation when the total losses in transmission and
distribution amount to 10.5% in 2014. Though this can be viewed as a reasonably
good level, when compared with the power system losses in rest of the developing
countries in the region, country need long strides to reach the levels achieved by the
developed countries. Before formulating strategies for loss reduction, it is essential to
determine the losses at each level. Once losses are segregated, utility can clearly
identify their priorities and launch effective programs to arrest losses.
At present the CEB doesn’t have the data required to calculate the energy loss of the
LV network and has only few basic information. Further collecting LV network data
and calculating the LV loss by modeling the LV network is difficult to be done
practically.
So, the objective of this study was to build a suitable methodology to calculate the
transformer wise energy loss using the available LV network data in CEB to identify
the transformers with high technical energy loss and the areas with higher nontechnical
loss.
In this study, total transformers were divided into 3 groups according to the
consumer mix and 6 sample transformers were selected. Then calculated the
technical power loss of feeders after doing the synergy modeling for the each feeder
that has been selected and a formula was built to calculate the feeder power loss
based on the results obtained. The technical energy loss of each transformer is
calculated after calculating the feeder wise technical power loss of the 20
transformers using the built formula. Based on the results of the 20 transformers a
formula was built to calculate the technical energy loss.
According to the results of this study, the technical energy loss of LV network in
Ratmalana area is 2.6%. and it increases to 3.12%, when lines are consisted with 70
mm2 ABC lines. Further, there are 10% of transformers in this area with technical
energy loss greater than 4% and 50% of the transformers has a value less than 1.5%.
