Hybrid Method for Islanding Detection of Distributed Generators in LV Distribution Networks

Islanding problem of DG-s in distribution network (DN) comes with development and implementation of renewable energy sources (RES) as distributed generator (DG). This research introduces new hybrid method for islanding detection of DC/AC inverter based DG in low voltage (LV) DN. Proposed technique is combination of active and passive technique: frequency change at given moment and rate of change of RMS voltage. Proposed method heavily exploit sinusoidal function interpolation due to Fourier transformation when Gibbs phenomenon occurs. To prove its effectiveness several test conducted based on different active load conditions and multiple DGs. Simulation results shows precision with allowed impact on power quality according to standard EN 50160. Proposed method shows good results as in low power consumption regime thus in high power regime. Hybrid method gives non detection zone (NDZ) smaller than individual islanding detection hybrid methods of frequency and under voltage based by combining those techniques as active and passive.