Sequence Impedance Modeling of the Matching Control and Comparison with Virtual Synchronous Generator

In this paper, sequence impedance modeling is carried out for a grid-forming control based on matching inverter and synchronous generator dynamics. The outer grid-forming control provides a voltage reference for the inner cascaded voltage and current control, which are defined in stationary reference frame. The impedance model is analytically derived by applying linearization, validated by time-domain simulations in MATLAB/Simulink and is subsequently compared to a more common type of grid-forming control. The paper shows that both control concepts, although apparently being different, show equal small signal dynamics. Moreover, the small signal impedance of the matching control is experimentally validated, using a power-hardware-in-the-loop laboratory setup.