Performance and Analysis of Islanding Detection Method by using Sandia Frequency Shift for Solar Grid Tied Inverter
This paper analysis of Islanding is the continued operation of the inverter when the grid has been removed intentionally, by accident or by damage. In other words, if the grid has been removed from the inverter, then the inverter should stop supplying power to the grid. All anti-islanding methods can be categorized as being passive or active. In passive methods, usually the grid voltage and grid frequency are monitored, and if either deviate outside of their defined operating range, the inverter will switch off. Active methods, on the other hand, will inject a small disturbance signal and then monitor the response to determine if islanding has occurred. In the event that the local load resonates near the operating frequency before the grid was removed, the inverter will see a small change in active and reactive power, and will not be able to detect that the grid has shut down. This is known as an island condition and is a Non-Detection Zone (NDZ) for the inverter. All passive methods have a large NDZ, while active methods have a relatively small NDZ.
Keywords - Disturbance observer (DOB), estimation of grid voltage and phase angle, Distributed generation (DG), Grid tied inverter, Islanding Detection.