Quote from smart:
Taking a measure of v and i at time t is pointless in power engineering,
Generally, Yes -cf
for p does not exist where Δt=0.
That's the part that is just not true. p is a rate. And by definition a rate is an instantaneous measure - unless you want to use RMS values (for V and I) and get an average power over one period.-cf
Yes, you can call it the vi product. And you can assign the unit measure volt-ampere to it. However, by implicit definition, you cannot call it power (p).
I'm not going to use Noetic Science definitions. I'm going to stick with IEEE 100 concepts. Yes, it is power - cf
Anyway, I have no idea who even brought up the idea of limiting ourselves to instantaneous measures of a single point in time, but that is simply not the case.
As I recall, that was you - remember back to your insistent discussions of impedance varying from zero to infinity depending on what part of the V-I waveform the cycle was in. - cf
I've never even run across anyone (other than here) that would confine their defintion of instantaneous to a single point in time when discussing power engineering.
This one completely baffles me. Yes it is rare that one uses concepts on instantaneous power in power engineering. However there is no definition of "instantaneous" other than being confined to a single point in time. As Bes has said over and over, (paraphrased), "that's what instantaneous means - at a single point in time." -cf
Additionally, we basically use the term "instantaneous" to distinguish between DC-equivalent, single-value measures from measures that continually varying through expiration of time. Summarily, doing so is within the bounds of conventional concepts and calculations.
Huh? -cf