Investigation of the impact of positive feedback anti-islanding controls on dynamics of motor load

Positive feedback anti-islanding controls are designed within the inverter controllers to facilitate the islanding detection for the inverter-based distributed generation (DG). These anti-islanding controls, however, can have influence on the dynamics of DG systems. This paper investigates the impact of the positive feedback anti-islanding controls on the small-signal stability of the grid-connected inverter-based DG system with motor load. The small-signal model of the investigated DG system is developed and the sensitivity analysis is conducted based on the small-signal model. The analysis results show that the strong positive feedback gain of the anti-islanding controls will reduce the capacity of the DG motor load.