Droop Control Method of Inverter Based on Variable Virtual Impedance

Distributed power supply is typically connected to micro-grid via inverter, it is necessary to solve the problems of power distribution and voltage current stability of inverters. This paper presents a method to solve the problem of power equalization, which uses the deviation between real-time reactive power and given reactive power to adjust the virtual impedance and compensate the line impedance. Then, with the improved droop control, the PI control is introduced in the power control loop, so that the system can adjust adaptively with the operation of the system. The dynamic stability of frequency and voltage is enhanced. Finally, the effectiveness and feasibility of the proposed control strategy are verified by software simulation.