Current Zero Crossing -Simply What It Means?

[ThePunisher]

Hi all, the simplest understanding I have in regards to the term zero current crossing in short circuits, is that this where the asymterical current waveform of one phase crosses the x-axis of the current waveform. In terms of determining the required CB interrupting time (and contact parting time), this is based on how long would all asymetrical phase currents crosses the zero x-axis, in ms or in cycles. When a breaker is connected to a generator, the generator X/R is high that the zero crossings are delayed, such that a CB with longer contact parting time is required. Is my dumb understanding and "layman" definition, good enough?

 

[7anoter4]

I think you are right. According to the following article:
Breaking Capability of a SF6 Circuit Breaker for Short Circuits Close to a Generation Unit with
Delayed Current Zero Crossing

http://ipstconf.org/papers/Proc_IPST2011/11IPST027.pdf

ch. D. Measure Against Long Arcing Time
it seems to me , one has to delay the opening of circuit breaker in order to decrease the arcing time.