Parameter Optimization of Active Frequency Drift Islanding Detection Method

Anti-islanding protection is mandatory feature for grid-connected inverters. Desired islanding detection method not only can detect islanding within acceptable duration,but also require it has less adverse impact on power quality. The performance of islanding detection method is usually subject to anti-islanding strategy and parameter setting. The paper analyzes non detection zone(NDZ) of active frequency drift(AFD) and active frequency drift with positive feedback(AFDPF) . Based on analysis the relationship between NDZ and feedback gain of AFDPF is deduced,which can be expressed as a mathematics equation and gives range for feedback gain to guarantee anti-islanding protection. The calculation is simple and accurate,thus can be taken as a good guideline in AFDPF parameters setting.