Voltage Stability at PCC in Islanded System using Droop Control Technique

Maintaining voltage stability in low-voltage grids with multiple inverter-interfaced sources is essential, particularly in autonomous microgrids lacking support from the main distribution network. This study proposes a droop control strategy for an islanded hybrid microgrid integrating solar photovoltaic (PV), wind, and an ideal DC voltage source, designed to regulate frequency and voltage at the point of common coupling (PCC) through reactive power adjustment. The system's performance was analyzed using MATLAB Simulink under variable load conditions. Results indicate that the droop controller stabilizes voltage within 0.28 seconds under baseline conditions. Upon application of a nonlinear load at 1 second, the controller re-stabilizes the voltage by 1.16 seconds, and after load disconnection at 2 seconds, stabilization is achieved by 2.23 seconds. These findings demonstrate the droop controller's effectiveness in maintaining power quality and voltage stability in the face of load fluctuations and renewable source variability. The proposed approach shows potential for reliable operation in independent microgrid applications.