H. Mohammadzadeh Niaki - School of Electrical and Computer Engineering University of Tehran Tehran, Iran
s Afsharnia - School of Electrical and Computer Engineering University of Tehran Tehran, Iran

This paper investigates the effect of load imbalance on the performance of the islanding detection methods (IDMs). A new analytical technique is proposed and the mathematical equations are presented. The proposed method is based on the calculation of the equivalent quality factor and resonant frequency of the unbalanced load. Validity of the proposed technique is proved by the extensive simulations. It is demonstrated that the imbalance can bring the load operating point inside (outside) the non-detection zone (NDZ) of the IDM, while it is outside (inside) the NDZ in balanced condition. Moreover, the sensitivity study is carried out and it is concluded that the effect of load imbalance level depends on the imbalance distribution between three phases and the configuration of unbalanced load.

Distributed generation; islanding detection; unbalanced load; sensitivity study