Research on Photovoltaic Grid-connected Control of Z Source Inverter Based on Active Disturbance Rejection Technology

In the grid-connected system of pv power generation z-source inverter, double closed-loop control is adopted for the z-source inverter with outer capacitor voltage loop and inner current loop. In order to solve the problem of high starting impulse voltage of capacitor in Z source inverter, an active disturbance rejection control algorithm is introduced into the outer loop of capacitor voltage, and an active disturbance rejection controller is designed to stabilize the capacitor voltage during starting. The Z source inverter based on active disturbance rejection control is combined with LCL filter, and the parameters are optimized by fuzzy control. The inner current loop composing of filter capacitor current and grid-side grid-connected current adopts PI algorithm to reduce the harmonic distortion rate of grid-connected current and improve the grid-connected current quality. The feasibility and effectiveness of the proposed method are verified by the simulation experiment, which realizes the maximum power tracking of photovoltaic power generation.