Analysis and optimization of active frequency drift islanding detection method

Unintentional islanding of distributed generation (DG) cause negative impacts on distribution systems and must be detected within acceptable durations. To certify the anti-islanding performance of DG systems, IEEE Std. 929-2000 [1] issued a standardized test procedure to distinguish an inverter with an adequate anti-islanding technique from those without. Lab testing is an effective way to judge the anti-islanding performance, although the process is time costing and any little mistake (like poor tuned RLC load) may mislead the judgement. This makes anti-islanding schemes comparison difficult. Non-detection zone (NDZ) is an effective performance index to evaluate anti-islanding schemes. This paper proposes a novel NDZ mapping method that set up relations between NDZ and IEEE Std. 929-2000 testing requirement. It maps the NDZ into load space that characterized by "power quality" and load capacitance. Based on the NDZ plot, not only the dominate factors that influence anti-islanding protection performance can be identified, but also optimized parameter setting of the anti-islanding schemes can be deduced, that helps to achieve the "non-islanding inverter" as well as least potential adverse impact on power quality.