In an isolated low-voltage microgrid

the difference of line impedance has a great influence on power distribution and circulation suppression of parallel distributed generation’s（DG） inverter

and cannot reasonably divide the power by traditional droop control. Thus

an improved control strategy that can correct parameters in real time is needed to reduce the effect of impedance differences on power sharing. Firstly

we analyzed the influence of line parameters on the traditional droop control strategy. Furthermore

we proposed an improved Particle Swarm Optimization to improve droop coefficients as follows: the droop part collects line information in real time

at each update cycle is input to PSO module for power deviation and circulation. Then

optimization results were fed back to droop part in real time. Finally

errors of the proposed method were verified by comparing traditional and improved droop errors with MATLAB/Simulink. The results show that the proposed strategy

in the face of different type load and changes of line parameters

can accurately detect its impact on the system

and improve control parameters according to unbalanced states by the proposed method to. Thus

load power is allocated and circulation between DGs’ is suppressed

and no-difference control can be achieved to ensure the stability of microgrid.