Dynamic Modeling and State Feedback Control for Enhancing Small Signal Stability in Islanded Microgrids with Diesel Generator Frequency Damping

Microgrids face significant challenges due to the stochastic behavior of distributed energy resources, which may excite low-damped oscillatory modes and compromise stability. This paper develops a unified small-signal model of an islanded microgrid and proposes a state-feedback controller (SFC) as a power system stabilizer (PSS) to enhance low-frequency damping in the diesel generator subsystem. The controller and inverter control parameters are tuned using a genetic algorithm (GA). Numerical results show that the proposed approach increases the damping ratio of the dominant electromechanical mode from ۰.۰۳ to ۰.۱۸ (a six-fold improvement) and reduces rotor-speed overshoot by nearly ۶۰% under a ۱۰% disturbance. Time-domain simulations further confirm a ۷۰% reduction in settling time for rotor-angle deviations. These results demonstrate that the optimized SFC significantly improves electromechanical damping and strengthens the small-signal stability margin of the islanded microgrid.

کلیدواژه ها:

Islanded microgrid ، small-signal stability ، state-feedback controller ، Power System Stabilizer ، genetic algorithm ، diesel generator dynamics