- 2014 IEEE. Anti-islanding detection is essential for grid connected inverter to avoid substantial safety accident. Many Anti-islanding methods available nowadays are proposed based on ideal grid and load conditions. Then most of them have weaknesses as high sensitivity to grid distortion in grid-connection state. This will certainly limit their wide application in some aspects. Active Frequency Drift (AFD) and Reactive power variation method (RPV) are two promising active anti-islanding detection methods. In this paper, the performance of these two methods under various extreme conditions are considered and compared, including different grid distortion conditions, different loading conditions. Test results are given by means of figures and tables to show clearly the final conclusion.