Transient Energy Shaping Strategy for Grid‐Forming Converters Based on the Port‐Hamiltonian Framework

ABSTRACT In converter‐based grids (CBGs) without support from the main grid or synchronous generators, grid‐forming converters (GFMs) are responsible for sustaining frequency and voltage stability. However, disturbances or load variations frequently lead to frequency and voltage deviations, and the operating point (OP) of GFM may not align with the desired stable state. Under severe faults, current‐limiting actions may be triggered, potentially leading to instability. This paper proposes a Port‐Hamiltonian (PH) framework‐based control strategy to optimise steady‐state operation and improve transient stability. A PH model of a GFM under VSG control is first derived, including its energy function and the stability region boundary imposed by current‐limiting constraints. Interconnection and damping assignment passivity‐based control (IDA‐PBC) is then employed to shape the system energy so the OP becomes the minimum of the energy function, while a PH‐structured integrator compensates for steady‐state frequency and voltage deviations. Leveraging PH structural properties enables unified modelling, stability analysis, and controller design, while simplifying the proof of closed‐loop stability. Finally, simulations on an IEEE 9‐bus CBG system validate the proposed method: the GFM tracks the desired equilibrium, avoids current‐limiting activation during faults, and returns to the pre‐fault OP with superior transient performance compared to the original uncontrolled case.