Dynamic modeling of inverter-based distributed generators with voltage positive feedback anti-islanding protection

This paper presents three models for dynamic analysis of inverter-based distributed generators equipped with voltage positive-feedback anti-islanding protection. The models analyzed are: the switched model, where the switches are represented in details, the average model, where the switches and signal generators are replaced by controlled voltage sources, and the small-signal model, where the average model is linearized. This small-signal model can be used for design purposes. The small-signal model is confronted with the nonlinear average model through time domain simulations and presents accurate dynamic behavior. The model introduced is suitable for computational analysis of stability impact of positive feedback controls, dynamic interactions between multiple controls, non-detection zones evaluation and other grid connection studies in distribution systems with this kind of distributed generation.