Simulations of production costs, flows, and prices are
crucial inputs to generation and transmission planning studies.
To calculate average system performance for many alternatives
over long time periods, it is necessary to simulate large numbers
of hourly combinations of renewable production and loads across
large regions. As this is usually impractical for full network
representations of such systems, aggregation of buses and lines
is desirable. We propose an improved aggregation method for
creating multi-area representations of power systems that yields
more accurate estimates of the quantities required by planners.
The method is based on partitioning the original large system into
smaller areas and making a reduced equivalent for each area.
The partitioning is based on available transfer capability (ATC)
between each pair of network buses. Because ATC depends on
net load conditions, separate partitions are defined for subsets
of similar load and wind conditions, significantly enhancing the
accuracy of optimal power flow solutions. We test the method on
the IEEE 118-bus test system and the Polish 3120-bus system considering
150 load/wind scenarios, comparing the results to those
of admittance-based partitioning methods. Accuracy is improved
with only a negligible increase in simulation time.
IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 30, NO. 1, JANUARY 2015