duration for CBEMA curve

[danielle_brandon]

What's the real definition for duration for CBEMA curve? Is it the period from the starts of disturbance till it dies out? Or is it the period when the disturbance exceeds per unit voltage? Pls help. Need to complete my fyp. Thanks a lot!

 

[pqtest]

Re: duration for CBEMA curve

Hello-

Not sure if you were aware of this, but CBEMA is now ITIC. ITIC explains the curve and how to apply it in a white paper posted on their site:

http://www.itic.org/technical/iticurv.pdf

Mark

 

[danielle_brandon]

Re: duration for CBEMA curve

yes. I know about this. But i m not sure about the definition of 'duration of the disturbance'.

 

[pqtest]

Re: duration for CBEMA curve

Hello-

"Duration" starts at the beginning of the disturbance.

When the disturbance exceeds the PU, that (potentially) is the equipment malfunction zone regardless of duration.

May I ask what the topic of your project is? Like FIPS Pub 94, the ITIC curve is interesting, but in my opinion no longer has any real relevance in the power quality world. The only ones who seem to use it are the manufacturers of PQ analyzers- allowing you to plot recorded events against the curve.


Mark

 

[danielle_brandon]

Re: duration for CBEMA curve

thanks for your reply. I m working on detection, classification n analysis of power system transients.

 

[rich000]

Re: duration for CBEMA curve

Every UPS manufacturer cares about the curve, although all UPS's typically operate and transfer within a tiny portion of the curve.