Disturbances just visible are said to have a flicker severity
factor of Pst = 1 The flicker emissions, Pst and Plt may also be
estimated with the coefficient and factors, cf( Ψ
k, va ) and
kf( Ψ
k) obtained from the measurements, which are usually
provided by wind turbine manufacturers.
The flicker emissions from a wind turbine installation
should be limited to comply with the flicker emission limits. It
is recommended [3] that Plt≤0.50 in 10-20 kV networks and
Plt≤0.35 in 50-60 kV networks are considered acceptable.
However, different utilities may have different flicker
emission limits. The assessments of the flicker emissions are
described below.