The sales companies of renewable energy sources
are competing to get on Danish market. The
equipment sold in Denmark must comply with the
standards. However, the standards are subject for
changing with growing new technologies. Therefore,
in some cases the equipment installed 25-30 years
back may not be covered by the new standards
and the new equipment not reflect their large
penetration into the grid. But the DSO task is
to insure safe and stable operation of the network
together with the equipment installed. It can be
done by monitoring the ’health’ of equipment.
The current work investigates the effect of power
electronic based generation and loads on substation
transformer. For this purpose a random substation
were chosen to perform the measurements. The
data gathered during the measurements is used
in the electrical-magnetic-thermal model to assess
transformer temperature. Finally, the interpretation
of the results will be summarized and the guidelines
and recommendations will be provided for DSO.
Keywords: Condition monitoring, Distribution
grid, Distribution transformer, Electrical-Magnetic-
Thermal model