DOI
10.5703/1288284318525
Description
This paper presents an adaptive gain tuning approach to enhance frequency stability in islanded microgrids consisting of diesel generators and grid-forming (GFM) inverters. Although GFM inverters provide voltage and frequency regulation capabilities, their interaction with diesel generators can introduce dynamic challenges such as reduced system inertia and frequency deviations during load transients. Existing studies have focused on small-signal modeling and damping methods but often overlook data-driven techniques for improving transient stability under varying diesel-to-GFM power ratios and inverter droop settings. To address this gap, this work investigates frequency stability behavior across different diesel and inverter power rating ratios and analyzes the impact of droop gain variations on transient response. A stability margin function is developed using polynomial surface fitting, based on which an adaptive gain tuning algorithm is designed to dynamically adjust inverter droop parameters for improved system performance. The proposed method is validated on an islanded microgrid test system modeled in MATLAB/Simulink and Typhoon HIL, demonstrating enhanced frequency stability and resilience during load disturbances
Adaptive Droop Control Gain Tuning of Grid-Forming Inverters for Stability Enhancement of Diesel-plus-Battery Islanded Microgrids
This paper presents an adaptive gain tuning approach to enhance frequency stability in islanded microgrids consisting of diesel generators and grid-forming (GFM) inverters. Although GFM inverters provide voltage and frequency regulation capabilities, their interaction with diesel generators can introduce dynamic challenges such as reduced system inertia and frequency deviations during load transients. Existing studies have focused on small-signal modeling and damping methods but often overlook data-driven techniques for improving transient stability under varying diesel-to-GFM power ratios and inverter droop settings. To address this gap, this work investigates frequency stability behavior across different diesel and inverter power rating ratios and analyzes the impact of droop gain variations on transient response. A stability margin function is developed using polynomial surface fitting, based on which an adaptive gain tuning algorithm is designed to dynamically adjust inverter droop parameters for improved system performance. The proposed method is validated on an islanded microgrid test system modeled in MATLAB/Simulink and Typhoon HIL, demonstrating enhanced frequency stability and resilience during load disturbances