PREDICTIVE CONTROL METHOD AND SYSTEM OF GRID-CONNECTED CONVERTER BASED ON STRUCTURALLY ADAPTIVE EXTENDED STATE OBSERVER

A predictive control method of a grid-connected converter based on a structurally adaptive extended state observer (ESO) is provided. The method includes: obtaining data of a grid current and a grid voltage and converting the data to data in a dq coordinate system; calculating a selected voltage vector based on a voltage in the dq coordinate system; adaptively inputting the current in the dq coordinate system to a parallel ESO, a cascade ESO, or a hybrid cascade-parallel ESO, so as to obtain a current predicted current value and estimated total disturbance; carrying out a two-step grid current prediction based on the current predicted current value, the estimated total disturbance and the selected voltage vector; and taking minimizing a cost function as a control target, so as to obtain an optimal voltage vector based on a two-step grid current prediction result, and carrying out switching control of the grid-connected converter.