Power Decoupled VSG Based on Full-State Feedback for Better Dynamic Performance and Improved System Robustness

Grid-forming control is widely used in distributed generation to improve the stability of grid-connected units and provide support to the power grid. However, due to the coupling between active and reactive power in transmission lines, the active and reactive power control loops in grid-forming control influence each other, leading to a decline in system stability. This paper analyzes the mechanism of active and reactive power coupling, as well as the adverse effects of power coupling on grid-forming control. A full-state feedback power decoupling control is proposed as an auxiliary controller to eliminate the impact of power coupling on grid-forming control. Simulation and experimental results show that the proposed control method can eliminate power coupling, improving the system's dynamic performance and robustness.