Improved Active Frequency Drift Anti-Islanding Detection Method

Since passive anti-islanding detection have largely blind spots, easily fluctuation and so on shortcomings, moreover active frequency drift have Some drawbacks too.For example distortion of current and fluctuation of active power injecting into grid associated with islanding detection.a based on variable active power improved active frequency drift anti-islanding detection method is proposed.The technology acquired chopping fraction of active frequency drift through adding variable active power into offset.So as to achieve positive feedback of voltage frequency at the point of common coupling in islanding state and realize anti-islanding function.Under normal circumstances injected power quality into grid has improved greatly, and ensure that the less pollution to the grid.The simulation and experimental results show that the anti-islanding detection methods not only improve detected speed of anti-islanding detection, but also to ensure have better power quality that the injected into the grid