In practical applications

the stability and interference suppression performance of the grid-connected inverter

using the traditional robust H∞ control method

are often affected by the weak grid characteristics of the power grid. In order to enhance the adaptability of grid-connected inverters to grid impedance changes

this paper presents an improved H∞ control method for grid-connected inverters which is suitable for weak grids. A single-phase grid-connected inverter is used as an example to establish a robust H∞ control model for a grid-connected inverter under a weak grid and to prove that the weak grid characteristics will cause the system parameter

control input parameter and interference input parameter are perturbed

which affects the stability and interference suppression performance of the system. In order to overcome the influence of weak grid characteristics and improve the stability and interference suppression performance of the system

an improved H∞ control method for grid-connected inverter in weak power grid is proposed. In this method

indirect control is introduced to dynamically adjust the voltage of the common connection point and to eliminate the parameter perturbation of the control system

which makes the grid-connected inverter adaptable to the weak grid. Finally

the rationality and validity of the theoretical analysis and the improved H∞ control method are verified by the experiments.