Flicker Standard

[CKent]

I've read a technical article indicating the allowable Short term flicker severity should be 1.0 and the long term flicker severity should be 0.8. Short term is measured over 10 minutes while long term is suppose to be derived from 2 hours of the short term flicker. Does this 1.0 and 0.8 values refer to the % limit normally being implemented by utilities for voltage flicker? What does the standards (ANSI & IEC) say?

CK

 

[Humble2000]

Utilities use IEC curves to check the flicker severity, in that curve the percentage of voltage variation over the period of time is measured. Flicker measurment is discussed in IEC and IEEE standards.
Pst and PLt are used to indicate flicker severity, the method described in IEC and IEEE are somewhat different( f=50 and f=60 in filter design).
search Google for related articles and curves.

 

[ozmosis]

Here is an interesting overview to the IEC standards concerning Flicker:

http://www.lpqi.org/lpqi_archive_co...86975_905_905_CONTRIBUTE_PATH_514-flicker.pdf

 

[ozmosis]

I think I sent the wrong link. This is probably more relevant to your question:

http://www.lpqi.org/lpqi_archive_co...32662547_818_818_CONTRIBUTE_PATH_5_2_3_lo.pdf