This paper proposes an inflow scenario reduction framework applied in
long-term hydro-thermal scheduling. The strategic management of limited
stored hydro energy in interaction with the electricity system is
defined in long-term hydro-thermal. The Scenario Fan Problem (SFP) is
selected as a long-term hydro-thermal scheduling approach. This approach
is suitable to represent the disaggregated physical representation of
the hydro stations and captures the short-term flexibility of
individual hydropower plants in the long-term scheduling. We develop a
shape-based feature extraction machine learning method to capture the
hydro inflow features. To highlight the performance, we compare the
shape-based method with five alternative clustering methods via the
validation process on a hydro-thermal test case, using in-sample and
out-of-sample data analysis. Our results show that the proposed
framework can significantly reduce the computational time of long-term
hydro-thermal scheduling by around 90\%. Results reveal
that the shape-based feature extraction performs better regarding the
computational time and the expected reservoir volumes. Moreover, this
study demonstrates the possibility of performing long-term hydro-thermal
scheduling at a disaggregated level with detailed topology information
and a small time scale. This provides more opportunities to deal with
the penetration of renewable energy resources in long-term hydro-thermal
scheduling.