A sequence perturbation based islanding detection for distributed generation with periodic code matching.

Islanding detection is a significant technical barrier to the distributed generation (DG) industry. When islanding occurs, the inverter current of DG has a strong correlation with load voltage of DG. With respect to the correlation, this paper proposes an islanding detection method (IDM) based on periodic matching of the sequence perturbation. In this periodic code matching detection method, a periodic sequence is introduced to perturb the inverter current amplitude. The IDM can be achieved by calculating periodic matching degree between the islanding detection coefficient and the sequence. The influence on IDM imposed by sequence characteristics and load variation is also discussed in this paper. According to IEEE Std. 1547, an islanding detection model is designed and simulated in this paper. The simulation and experiment results indicate a strong ability to anti-harmonic noise when the 1-0 non-zeroing sequence with six bits is selected as the perturbation sequence. The proposed method introduces little damage to grid. In the normal range of voltage and frequency, this method can detect the islanding of DG reliably and effectively even if load varies. [ABSTRACT FROM AUTHOR]