A Hybrid Islanding Detection Technique using Voltage Positive Feedback and Frequency Deviation in GFM based Microgrid

This paper introduces a grid forming(GFM) inverter equipped with a hybrid islanding detection method which combined the positive feedback(PF) of the point of common coupling(PCC) voltage based active method used and the frequency deviation as a passive method. The proposed algorithm is implemented inside the GFM voltage controller. Furthermore, a frequency deviation threshold is addressed based on a theoretical approach in order to relieve continuous disturbance injection. This hybrid method doesn't undergo a non-detection zone(NDZ) and, an additionally, a continuous operation of the microgrid is achieved. Moreover, the proposed algorithms can distinguish islanding phenomenon against load switching during grid connected mode. The results are evaluated by simulations using ATPdraw software.