Hi, My name is Gary Raposa and I’m an Application Engineer here at Keysight Technologies. Today,
I want to talk to you about our IntegraVision Power Analyzer, model number PA2201A. And
specifically, I want to focus on the AC power disturbance measurement capability that’s
built into this product. It can show AC waveforms just like an oscilloscope – the voltage,
the current, and the power. And we’ll take a look at that in just a moment here. First,
I want to show you that what I’ll be testing is this DC power supply. It’s a 200-watt
power supply, 20 volts, 10 amps. In fact, it’s running at 20 volts and 10 amps right
now. The 10 amps is flowing into one of our electronic loads and the AC input from this
DC power supply is coming from one of our AC sources here down on the bottom. All of
these things are available from Keysight as well. In fact, I’ll be using our AC source
here – this is a 6813B – in order to create the power disturbances that I’ll be showing
you here today. Now, we’ll be measuring power disturbances on this DC power supply
but the product that you will be designing will also potentially be subjected to power
disturbances because no AC line is perfect. It could be thunderstorms could create surges,
there could be a sag in voltage, there could be a dropout in AC cycles, there could be
a brownout, there could be noise on the lines. So, all different power line disturbances
could be on the line that your product is plugged into and you just want to make sure
that your product behaves well when it’s subjected to those types of power disturbances.
So, we’ll be doing those measurements with the Power Analyzer. Now again, this PA2201A
is a two-channel analyzer. Each channel has voltage input and current inputs, and it calculates
the power from the voltage and current inputs. So, the top screen, the top part of the screen
here is showing the voltage waveforms. The middle part is showing the current and the
bottom is showing the power. Yellow is the AC input voltage, the AC input current, and
the AC input power. This is also a touch screen, so it’s very easy to change anything on
here. I can go to anything on here and it works just like an oscilloscope. I can change
the time per division. I can change the volts per division here very simply; the voltage
is up and down. If I switch over to the current, I can change the amps per division, and of
course I can go to the power and change the power per division here as well. So, let’s
take a quick look at a surge of voltage and see how our power supply output behaves when
subjected to a surge of AC input voltage. So, let’s take a look at what happens when
a surge of voltage, AC input voltage, occurs on the AC input of the DC power supply. We’re
going to see what happens to the DC output. So first, now it’s running and it’s triggering
off of the AC input. On the back of here, there are external input triggers. So, I’ve
got the AC source set up to send a trigger signal, when I create the surge with the source,
to trigger the IntegraVision Power Analyzer. So, let me make sure this is paying attention
to the right trigger. I go to Trigger, Source – from Voltage 1, I’m going to say external.
So, now it will look for the external trigger on the back. And I’m going to clear this
display and we’re going to get a single sweep here. I’ve got this set up with my
computer to program the AC source to do a single surge up. If I hit the button here
and see if we capture that. Well, there it is. So, the yellow waveform on the top is
the surge of voltage, as you can see, and the green waveform also on the top is a disturbance
in the DC output. So, there is a disturbance that occurred as a result of that surge of
voltage. You can even still see the current and the power and what happens to the current
and the power when that surge occurs also. Now, I want to run that again. I’m going
to change this display and let’s make it so we look only at the voltage, because that’s
really what we’re interested in. There’s various displays we have to choose from here.
So, right now I pick just the voltage. I’m going to repeat the surge and see if we can
capture that. Again, there it is. The voltage is surging up and after the surge is done
and the voltage comes back to a nominal value is when the disturbance occurs. So, I’m
going to stop this so it doesn’t accidentally sweep here. And you’re going to see, I can
also use the touch screen to zoom in on this part of the waveform here. If I hit that,
and hit horizontal waveform zoom, we get even a better view of what that surge really looks
like. I can zoom even further on that if I really want to. We can undo those zooms if
we want to take a look at it from here as well. So, it’s very capable product, very
useful in taking a look at power disturbances. And in this particular case, we saw that the
output voltage is affected by a surge and then back down to nominal. So, let’s take
a look at one other power disturbance. Actually, we’ll look at a sag next. Once again, we’ll
take a look at a sag in the AC input voltage and see how the output performs. Again, I’m
producing the sag with our AC source and my computer control here. Let’s see if we’re
set up to go. Yup, so there’s the sag in voltage goes from about 120 volts down to
about 98 volts. And you can see again, the yellow is the AC input. The green is the DC
output and you can see that there’s a disturbance on the output. Once again, I can kind of zoom
in on that with this if I want to take a closer look. And I can get even closer with it zooming
in further and take a look at what the output does and undo those if I want. But again,
we see that the DC output of this power supply is affected by a sag in voltage. Now, this
sag is beyond the AC input limits of the supply. I did that on purpose to create some type
of an output disturbance. We’ll try another one here. We’ll do next a cycle dropout
to see what happens with an AC cycle dropout. So, let’s take a look at how the output
performs when subjected to a single cycle dropout, so a single cycle on the AC line
will disappear and we’ll see what the green output waveform does. So, I’ve got my computer
program set to do that. And I’ll hit the Start Transient, and we’ll see what happens
here. Yup, so as you can see, the single cycle disappeared, the yellow AC input. And the
green is the output, set at 20 volts, 10 amps. And AC-coupled here, we’ve got one volt
per division, so the voltage dropped about one division, two divisions, almost two and
a half divisions. It dropped about 2.5 volts and came back within – this is 10 milliseconds
per division, so we can actually measure how much that dropped by turning the cursors on.
I can move those up and down with the cursor knob here. I can put this down around the
bottom of that peak and we can see on the side here – let’s see, take a moment just
to find that on here. Oh, sorry that’s on the voltage of Channel 1, so we’ll change
it to the voltage of Channel 2. That will make much more sense. And now, I can put that
over here and I got yeah, about -2.4 volts is the transient for the output voltage on
a single cycle dropout. Okay now, so here’s another really interesting AC power disturbance
we can capture on a single shot basis. So, we can look at the AC inrush current of that
DC power supply. So, once again I have my program set up to just go from zero volts
up to an AC input. And I’m going to do that right now. The AC should come on. It was sitting
at zero and it went up and you can see this peak of inrush current that flows in. In fact,
again we can turn the cursors on to measure that and move that up and down with this knob.
And see that that peak of inrush current, this is out of about 5 amps per division,
so 5, 10, 15, 20, 25, 30 and yeah, sure enough 29.9 amps it says on there. So, you can very
easily capture a single shot with the IntegraVision Power Analyzer to see what the inrush current
is. Let’s take a look at one last waveform on the IntegraVision Power Analyzer. And this
is really interesting one also. This is the I^2t rating measurement. So, I^2t is a rating
on a fuse. Well, let’s get it on a screen first and then I’ll talk more about it in
just a moment. So, I’m going to start a transient that will get the AC inrush current
in there again. So, there’s the AC inrush on my DC power supply. So, this is just amps
and now I can turn the math on – turning the math on – and I’ve got the math set
up here to do this I1 times I1, so that’s I^2. An then I have another function of math
that is the integral of the first math function, so that’s the integral of I^2. So, that
means it’s I^2t, so this will be a measurement now of I^2t. So, let me take this measurement
again, start this transient. And we’ll actually see the purple waveform appear here, which
is the math function. And that’s our I2t measurement. Let me just move this down a
little bit, let’s see 1.5 amps sounds like a good place for the offset. And the scale
is 500 milliamps squared seconds per division. So, we’ve got about one, two, three, four,
five divisions and half an amp squared second per division. So 5 – that’s about 2.5
amps squared seconds is the peak here. Now, what is again that measurement? Fuses have
two ratings: they have the main rating for the fuse and the AC input fuse on this power
supply happens to be a three-amp fuse. But it also has an I2t rating of 38 amps squared
seconds. So, this is way, way below that and in no danger of blowing that fuse due to this
peak of current that’s much, much higher than the three-amp rating. But it’s there
just for a short time. So again, for people who are familiar with amps squared seconds
ratings on fuses, you’ll know that this is a very, very useful measurement and very
easy to make with the IntegraVision Power Analyzer. So, we’ve seen today how the Keysight
IntegraVision Power Analyzer is able to show you how your product will behave as a result
of AC disturbances that are on the line. In this case, we took a look at one of our DC
power supplies. We took a look at how the output behaves when subjected to a surge in
voltage, to a sag in voltage, to cycle dropouts, to also we saw what happened with the AC inrush
current, and even an I^2t measurement at the very end here. So, I hope you can see how
this product can help you design your products and help you make them as immune as possible
to power line disturbances, to help satisfy your customers.