Abstract
Microgrid, which can be considered as an integration of various
dispersed resources (DRS), is characterized by the number of DRs
interfaced through the power electronics converters. The microgrid
comprising these DRs is often operated in an islanded mode. The droop
control method is traditionally adopted to distribute active and
reactive power among the DRS operating in parallel. However, the
accuracy of distribution of reactive power among the DRS controlled by
the conventional droop control approach is highly dependent on the value
of line impedance, R/X i.e. resistance to reactance ratio of the line,
voltage setting of inverters etc. In this paper, a control strategy has
been presented to improve the reactive power sharing among distributed
generation units in the islanded microgrids. The proposed control method
is based on exerting reactive current injection to correct the output
reference voltage is the common method of droop control. Reactive power
distribution error is reduced by modifying the reference voltage. To
evaluate the performance and effectiveness of the proposed control
strategy, it is implemented on an island microgrid consisting of three
distributed generation units. The simulation results show the proper
performance and efficiency of the proposed method.