Abstract: In an island microgrid with multiple distributed generations operating in parallel，due to the difference
in impedance of each line，a reasonable control of reactive power can not be achieved using the droop control
strategy． This paper proposes a self-adjusting virtual impedance droop control strategy，which adjusts the virtual
impedance through reactive power and compensates the output voltage difference caused by the impedance
difference without detecting the line impedance parameters，so that the output reactive power of each inverter is
equally distributed or according to the capacity ratio． Using Matlab /Simulink，an isolated island microgrid
simulation model with two distributed generations and parallel operation was built． In two cases，it is verified that
the improved droop control strategy can achieve reactive power sharing and distribution according to capacity
ratio．

Key words: Island microgrid, reactive power sharing, self-adjusting virtual impedance, droop control