A Cascaded Power Controller for Robust Frequency Ride-Through of Grid-Forming Converters

The aim of this paper is to present a grid-forming (GFM) control strategy with a novel active-power loop (APL) structure facilitating limitation of active power while providing maximum available inertial support. This is achieved by decou-piing the synchronization duties of the APL from the inertial support. The latter is provided by calculating an active-power reference through a dedicated inertia-emulation loop (IEL), which is connected in cascade with the APL. The effectiveness of the proposed method is demonstrated through time-domain simulations including frequency transients of varying size and unbalanced operating conditions.