C. Zhao, S. Dong, C. Gu, F. Li, Y. Song, N. P. Padhy,
"New problem formulation for optimal demand side response in hybrid
AC/DC systems," IEEE Transactions on Smart Grid, In press
【Abstract】This
paper proposes a new problem formulation to simplify the mathematical
representation for a hybrid AC/DC domestic energy system. Instead of building
the formulation from a component level, the new formulation is built at the
whole system level such that all power transfers between AC/DC or DC/AC are
reflected in the AC power drawn from the main grid. This is achieved by
assigning the AC power drawn from the grid as a piecewise function of local DC
power, each slope in the function represents the conversion efficiency, making
it flexible to consider a wide range of conversion efficiencies for different
system components. The new formulation substantially reduces the number of
variables/constraints, improves efficiency modelling accuracy and increases the
search efficacy. The piecewise functions are directly solved by a mixed integer
linear programming (MILP). The performance of the proposed formulation is
illustrated by the hybrid AC/DC energy systems at a primary school in the UK.
The results show that the proposed problem formulation and the MILP solution
method provide an effective optimal control strategy for a mixed AC/DC domestic
energy system in the presence of variable tariffs and differing conversion
efficiency, achieved a cost saving of 24% increase in energy bills compared
with the traditional approach.
【Keywords】Batteries,
Hybrid power systems, Energy management, Optimization, Load modeling,
Reliability
【ISSN】1949-3053
【DOI】 10.1109/TSG.2016.2628040