Seamless Transitions Between Grid-Following and Grid-Forming Control: A Novel Switching Method

In order to adapt to the complex working environments of the power grid, the grid-connected inverters need to seamlessly change the control strategy according to the different conditions. However, the transition may pose some sudden changes on the references of the inner control loops as well as the outer control loops like power loop or voltage loop, which results in distorted voltages and currents or even the risk of ensuring a safe operation. In order to solve this problem, this paper proposes a smooth switching method between grid-following and grid-forming control in grid-connected mode. Time-domain simulations are done in Matlab/Simulink to verify the effectiveness of the proposed control method, showing it works appropriately. Finally, an experimental prototype is established to verify the practical effectiveness of the proposed method.