A novel active anti-islanding protection scheme for grid-interactive roof-top solar PV system

This paper proposes a novel active anti-islanding scheme for inverter fed roof-top solar PV generation connected to LT distribution grid with unbalanced non-linear loads. The method is based on creating a perturbation in the system using positive feedback and d-q implementation algorithm. The conventional passive anti-islanding schemes fail to detect islanding during power balancing conditions, but the novel active anti-islanding controller ensures that the voltage (or frequency) at the point of common coupling (PCC) is automatically driven beyond the threshold preset values. This proposed scheme has been tested in the presence of non-linear loads and development has found faster islanding detection compared to the existing methods. Further, the islanding conditions are simulated and accurately verified on real time.