Grid-connected current control of micro inverter based on ANN inverse model

The flyback type grid-connected micro inverter has received much attention because of its simple structure and electrical isolation characteristics. However, due to the nonlinear characteristics of the flyback converter, a large amount of harmonic currents are generated during the operation process. In this paper, an inverse control method is proposed to improve the grid current quality of flyback type micro inverter. The mathematical model of the inverter is established by small signal method, and the major factors affecting the grid-connected current are discussed. Then inverse model of the system is established by ANN method and the inverse control method is proposed. Simulation results indicate that compared with conventional PID control method, the presented method could effectively reduce the harmonic content of grid-connected current.

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