Passive Island Detection Method Based on Sequence Impedance Component and Load-Shedding Implementation

Active islanding detection techniques majorly affect power quality due to injected harmonic
signals, whereas passive methods have a large non-detection zone (NDZ). This article presents a new
method based on the resultant sequential impedance component (RSIC) as a new approach to island
detection with zero NDZs. The abrupt variable in the conventional impedance approach was replaced
by the RSIC of the inverter in this method. When the measured value exceeds the threshold range,
islanding is detected by monitoring the variations in the RSIC at the point of common coupling (PCC).
For proper power utilization in the identified islands, a priority-based load-shedding strategy is also
recommended and implemented in this article. Its efficacy was verified in a wide range of real-world
settings. It offers superior stability in various non-islanding (NIS) scenarios to prevent accidental
tripping. The proposed method advantages include a cheap cost, the simplicity of implementation,
independence from the number and type of distributed generation (DG) units connected, and no
power quality effects. Compared to other methods reported in the literature, the obtained detection
times illustrate that the proposed method is superior