In order to solve the problem of interaction among three-phase parallel inverters

a method is proposed in this paper to analyze the interaction of parallel converters based on the principle of relative gain array. The influence of nonlinear factors is taken into consideration

so that the transfer function model of double closed-loop inverter with additional active damping control is established in the αβ coordinate system

and the equivalent model of LCL inverter parallel system based on droop control is constructed. Combined with the principle of relative gain array

the degree of interaction among parallel inverters is analyzed

and the relevant laws of interactive operation of parallel system are revealed. Finally

the model of multiple three-phase inverters grid-connected system is built on the Matlab/Simulink

and the correctness of theoretical analysis and the effectiveness of interaction analysis method are verified by simulations and experiments. The research results show that the interaction degree of multi three-phase grid-connected inverters is mainly affected by the system operating frequency

filter capacitance value and the number of parallel inverters. This method can be adopted to quantitatively analyze the degree of interaction among inverters

and provide experience for optimal design of inverter control system and improvement of power quality of parallel inverter system.