Zusammenfassung
In this paper, the results obtained after monitoring a distribution
transformer during an 18 months period are described and discussed.
The transformer fed several households, each with a grid connected
photovoltaic system, and it was found that the power factor at the
transformer attained unusually low levels. This was due to the fact
that under some conditions, the systems provided a large portion
of the active power demanded by the households, while the grid supplied
all the reactive and distortion powers. The operating temperature
was used as an indicator of the stress on the transformer. The temperature
was at its lowest when the systems were providing the maximum energy
available from the solar cells.
Nutzer