Abstract:In view of the mismatching of line impedance between the inverters in the low-voltage inverter parallel system, as well as the failure of the traditional droop control strategy to achieve the accurate equalization of reactive power, thus leading to a large circulating current problem, an improved droop control strategy based on virtual impedance technology has thus been proposed. This control strategy uses the virtual impedance technique to make the equivalent circuit inductive for a realization of the complete power decoupling. Secondly, on the basis of reactive power voltage droop control, the method of voltage compensation is adopted to overcome the failure of the reactive power to be divided equally and the flaw of a large system circulation. The results show that this method can realize the accurate distribution of reactive power, the compensation of the voltage drop caused by virtual impedance, the reduction of the reactive power flow between inverter systems, the acceleration of the dynamic response speed, as well as the improvement of the stability and reliability of the system.