A New Slip Mode Frequency Shift Islanding Detection Method for single phase grid connected inverters

This paper presents a new slip mode frequency shift islanding detection method (SMS IDM). This new method uses a non-sinusoidal function for drifting the inverter phase angle. The Non-Detection Zone (NDZ) of the SMS IDM with sinusoidal function has been calculated and it has been shown that if the quality factor and/or the resonance frequency of the load changes during the inverter operation time, SMS IDM with sinusoidal function fails to detect islanding for a specific range of variation. It is shown in the paper that SMS IDM with the new function has a smaller NDZ area compared to the SMS IDM with sinusoidal function. Simulation and experimental results verify the results of the proposed new method.