Influence of Sampling Rate on Flicker Assessment by IEC Flickermeter Built-In AMI Energy Meters

The
$P_{st}$
indicator is one of the parameters used in the power quality evaluation. The International Electrotechnical Commission (IEC) flickermeter with a complex signal chain structure is used for
$P_{st}$
measurements. The occurrence of
$P_{st}$
values greater than the limit value indicates the occurrence of flicker severity caused by voltage fluctuation. This article presents the analysis of the influence of the sampling rate on
$P_{st}$
measurement results. For analysis purpose, the analytical model of the IEC flickermeter signal chain has been prepared, considering the sampling rate of input voltage. Based on the prepared model, the possible effects of incorrect sampling rate selection in
$P_{st}$
measurements have been presented. The model test results have been compared with laboratory measurement results for two advanced metering infrastructure energy meters with built-in IEC flickermeter. The obtained laboratory measurement results indicate the occurrence of aliasing for tested energy meters, which causes
$P_{st}$
measurement disturbance.