Hybrid Battery Ultracapacitor Battery-ultracapacitor solar wind
Abstract:
The purpose of this study was to quantify the improvement in the performance of a battery with
the addition of an ultracapacitor as an auxillary energy storage device for solar and wind applica-
tions. The improvement in performance was demonstrated through simulation and modeling. A
ceraolo battery model and a third order ultracapacitor ladder model were implemented in Mat-
lab/Simulink. Sample battery load cycles for solar and wind applications have been obtained
from literature and the corresponding C-rates were quanti ed. The C-rate for the solar load
cycle was found to be 0.3C and 0.2C for the wind load cycle. The performance of the battery-
ultracapacitor system was checked for the sample solar and wind load cycles and compared with
the performance of the battery system without an ultracapacitor. A reduction of 50.5% in bat-
tery RMS currents was found for the solar load cycle and 60.9% for the wind load cycle. This
reduction in battery RMS currents was found to be directly proportional to the ultracapacitor
contribution. Given the low C-rates for the sample load cycles it was deduced that the addition of an ultracapacitor will not signi cantly improve the battery life to justify the high initial costs.
