2017 Volume 137 Issue 7 Pages 546-554
This paper describes a mechanism and its countermeasure of a hunting phenomenon caused by an anti-islanding scheme using a frequency feedback method of photovoltaic generation. It is known that the hunting phenomenon occurs when large PVs are connected to the end part of a long distributed transmission line, and it was observed in some experiments and simulations. But the hunting mechanism hasn't been clarified yet. The authors describe the hunting mechanism theoretically using a linearized model and a detailed model, and then check it by Nyquist plot and Y-ho simulation. The hunting is induced by a frequency positive feedback between power system and reactive power injected by the anti-islanding scheme. A simple and effective countermeasure is to add a first-order time delay to the signal of reactive power.