A Performance Analysis of Active Anti-Islanding Methods Based on Frequency Drift

In Grid-Tied Distributed Generation systems (GTDG), the islanding phenomena is a fundamental subject, since it can possibly lead to safety hazards for the line workers during maintenance and damage to equipment. Therefore, it is required that GTDG have anti-islanding techniques, which can be passive and/or active. This paper focuses on the computational implementation of three active anti-islanding techniques based on the frequency drift of the injected current of the inverter. These methods are the Classic Active Frequency Drift (AFD), AFD with Positive Feedback (AFDPF) and AFD with Pulsating Chopping Factor (AFDPCF). For the tests carried out, was considered a PV system of 1 kWp using a VSI inverter, evaluating the time for detecting the islanding, the NDZ size and the THDi caused by the anti-islanding method. The AFDPCF proved to present reduced NDZ, the SFS performed the faster islanding detection and both presented reduced THDi , for all the analyzed cases.