The deregulation of electricity market is a challenge for transmission system operators
all over
the world. The era of the well predictable electrical environment is slowly going
away. Some time ago
those rapid and large exchange program fluctuations that characterize today's European
interconnected
power system were not conceivable. The loop flows that they generate have a severe
impact not only
on the grid of the countries directly involved in the trading but their neighbours
as well. These impacts
are undoubtedly the most observable in the variations of cross-border interface flows.
Foreseeing the
cross-border interface flows may indicate the possibility of congestions and can help
prevent
dangerous operating situations. The Hungarian Transmission System Operator has been
producing
day-ahead forecasts with hourly resolution since 2004. From that time up to now three
different
methods were introduced, each one complementing the other. Historically the first
one relies on a
PTDF (Power Transfer Distribution Factor) based model, the second one utilizes a purely
statistical
algorithm, while the third one is an ancillary method to improve the quality of the
previous two
forecasts. This paper is the detailed description of the aforementioned methods and
the experiences
obtained during the past three years.
