IEC 61000-4-15 specifies a flickermeter which can be used
to measure flicker directly [12]. The flicker measurement is
based on the measurements of three instantaneous phase
voltages and currents followed by using a “flicker algorithm”
to calculate the Pst and Plt. where Pst is the short term flicker
severity factor and measured over 10 minutes, and the long
term flicker severity factor Plt is defined for two hour periods.
The flicker assessments can also be conducted with simulation
method