Stability Assessment of an IBR-based LFC System Using Grid-Forming (GFM) Inverter Control

The shift in electrical power generation is inevitable as inverter-based resources (IBRs) are increasingly integrated into the utility grid. However, the integration of these low-inertial IBRs presents challenges in maintaining the frequency stability of the grid. The grid-connected inverters operating in grid-following (GFL) mode control their output through a phase-locked loop (PLL). Since GFL inverters do not actively regulate voltage and frequency, their ability to provide ancillary support to the grid is limited. These limitations have led to the development of grid-forming (GFM) control techniques, which allow inverters to function similarly to synchronous generators. Unlike GFL inverters, GFM inverters actively regulate their frequency output, enabling them to support system frequency while accommodating changes in load demand. The present study explores implementing GFM inverter control in a single-area load frequency control (LFC) system comprising thermal, solar, and electric vehicle (EV) sources. The required model is developed and analyzed using MATLAB Simulink®. The magnetotactic bacteria optimization (MBO) technique is employed to optimize the controller gains for the LFC and GFM control loops of the proposed power system model. The simulation results indicate that the integration of GFM inverters enhances the frequency and overall stability of the power system.