  The connection of single-phase microgrids (MG) and loads to three-phase MGs
creates power quality problems such as unbalanced voltage and voltage rise at
the point of common coupling (PCC) of the MGs. In this paper, a modified
reverse droop control (MRDC) scheme in the Energy Storage System (ESS) is
proposed to improve the three-phase PCC voltage quality in multi-microgrids
(MMG). The MRDC consists of a reactive power compensator (RPC) and a voltage
compensator. The controller regulates the reactive power and voltage unbalance
of the MMG by using the reactive power produced by the ESS. The effectiveness
of this proposed scheme is verified in real-time simulation using the Opal-RT
OP5600 real-time simulator. The voltage unbalance factor (VUF) at the PCC is
decreased from 3.6 percent to 0.25 percent, while the reactive power is reduced
significantly at the single-phase load.
