Dynamic droop control in microgrid for stability enhancement considering RES variation

In this paper, small signal stability analysis of a hybrid Microgrid (MG) considering RES variations is addressed. As wind speed or solar irradiance fluctuates, active power output from DGs might vary significantly. Hence, the power sharing scheme would change considerably. Dynamic droop-gain control is proposed to deal with the RES change and maintain the stability of MG. The proposed control method provides adjustable power sharing strategies to manage RES fluctuation and ensure frequency and voltage regulation of each DGs. Eigenvalues analysis and time domain simulation suggest that at high wind speed and solar irradiance the damping ratio of critical modes and dynamic performance of DG units defer significantly. As the dynamic droop controller implemented, the damping performance and stability margin of the hybrid MG were improved in different operating condition, ensuring stable MG operation in most of RES conditions.