Anti-Islanding Calculator

Calculate anti-islanding detection thresholds and trip times per IEEE 1547 for grid-tied inverters.

Input Parameters

Results

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Power Imbalance
kW
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Voltage Shift
%
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Frequency Shift
Hz
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Required Trip Time
s
Note: IEEE 1547-2018 requires inverters to cease energizing within 2 seconds of grid loss. Active anti-islanding (AFD/SFS) is standard.

Reference

Power Imbalance = P_inverter − P_load Voltage Shift % = (Imbalance / P_load) × 100 Frequency Shift = f_nom × (Imbalance / (P_load × 10)) IEEE 1547: Trip within 2s, or 0.16s if V > 120%