Figure 13 The simulation output of AFD for
Frequency=50.4 Hz, Cf=0.0504 Detection time, t=0.1005 s and load VPCC
stop at t=0.0.1672 s
Despite, the active methods have small NDZ, but unfortunately it leads
to decreasing power quality of the system. In addition to, these methods
may change the magnitude of the output for the inverter either frequency
or current. Although, there are some active methods can detect islanding
without decreasing power quality, it will require using many controllers
that will increase the complexity for the implementation and more
expensive than the other local techniques [32,33 ,34 ,35 ,36 ,37 ,38
,39 ,40]. AI detection techniques are explained in detail in the rest
of this subsection.