Hybrid SFS and Q-f Islanding Detection Method for inverter-based DG

Sandia Frequency Shift (SFS) Islanding Detection Method (IDM) has been widely applied to inverter-based distributed generators due to its small Non-Detection Zone (NDZ). The NDZ of the SFS is highly depends on its design parameters. In this paper, a new hybrid islanding detection method has been introduced, which is based on SFS and Q-f droop curve methods. The optimal SFS configuration is calculated by using instability criterion of phase angle and Bacterial Foraging Algorithm. The results are verified on MATLAB / Simulink environment.