Ed:
I agree with all your points, but you have to understand Tom Simpson is
convinced that the suppression they installed resolved the issue. He's
said that it's virtually impossible for the optimizers or any other
components in the system to continue to cause RFI at this point.
The only way to convince him that the noise is still present is to
either cover the panels or remove them since there's no other way to
shut the system down completely during the day.
The other alternative is that he stays late to witness the system shut
down at sundown.
Tony -K2MO
On 9/28/2020 4:28 PM, Hare, Ed W1RFI wrote:
< That has yet to be determined Ed. Tom Simpson (SE engineer) believes the RFI
could be caused by the solar panels themselves which he said has happened in the
past.>
If that were the case, and I and a number of EMC engineers here are skeptical,
the noise would almost certainly just be a broadband hiss.
And removing all of the panels at once would stop the entire system from
generating noise, just like covering them up would do, and the optimizers would
not be seeing anything resembling normal, so it is hard to even guess what they
would do, although shutting down completely would be a good failsafe design..
-----Original Message-----
From: Tony <73guddx@gmail.com>
Sent: Monday, September 28, 2020 4:24 PM
To: Hare, Ed W1RFI <w1rfi@arrl.org>; Rfi List <rfi@contesting.com>
Subject: Re: [RFI] Question Regarding Variations In Solar Panel RFI?
Ed:
This is no different from the noise change that occurs when the sun goes down,
so all it really does is demonstrate that the noise is coming from some part of
the system.
That's correct. The reason my neighbor and I had to resort to covering the
panels was to show that the system was still generating RFI after the chokes
were applied to the optimizers. Solar Edge insisted that the chokes had
resolved this issue and we proved otherwise.
The only way to completely shut down the system during the day is to cover the
panels.
By the description here, the first major noise source, the optimizers, seems to
have been corrected.
That has yet to be determined Ed. Tom Simpson (SE engineer) believes the RFI
could be caused by the solar panels themselves which he said has happened in
the past.
This idea of guessing or theorizing what component is causing the noise could
have been resolved a long time ago if Solar Edge would agree to disconnect the
ALL panels from the system and probe each component to see which one is causing
the RFI.
I've been at the site each time SE has worked on the system and they've NEVER
removed all the panels at once. This would, at the very least show that there's
a problem with the panels and or optimizers.
I'm hoping that yourself or perhaps Paul can convince Tom Simpson to do so when
he visits the site. If not, we're just going around in circles.
Tony -K2MO
On 9/28/2020 3:13 PM, Hare, Ed W1RFI wrote:
<We were able to isolate the noise from the solar panels and associated
electronics by covering the panels and seeing it disappear.>
This is no different from the noise change that occurs when the sun goes down,
so all it really does is demonstrate that the noise is coming from some part of
the system.
By the description here, the first major noise source, the optimizers, seems to
have been corrected. The inverter noise appears to still be present. This is
an area that Paul and Solar Edge are investigating and working on, so let's
give that a bit of time to develop. Paul owns the system, and he is qualified
to work on it, so when they come up with possible ideas, he is able to do the
work without having to coordinate with a neighbor.
-----Original Message-----
From: RFI <rfi-bounces+w1rfi=arrl.org@contesting.com> On Behalf Of
Tony
Sent: Monday, September 28, 2020 2:55 PM
To: Cianciolo, Paul, W1VLF <pcianciolo@arrl.org>; Rfi List
<rfi@contesting.com>
Subject: Re: [RFI] Question Regarding Variations In Solar Panel RFI?
Paul:
The RFI on the home AC lines is identical to the RFI generated by the Solar
Edge system. I can't tell you if it's induced or directly injected onto the A/C
lines but it's there.
More importantly, the RFI on the AC lines disappears when the system shuts down
either by covering the solar panels with tarps or when the system automatically
shuts down at night.
Here's what we know for certain after months of testing and observation:
1. The inverter and optimizers produce a distinct noise of their own.
2. The noise disappeared completely when we covered the solar panels with tarps.
3. The noise reappears when we removed the tarps.
4. The noise appears at sunrise and disappears at sundown.
5. We were able to isolate the noise from the inverter by shutting it off and
seeing the spikes disappear.
6. We were able to isolate the noise from the solar panels and associated electronics by covering
the panels and seeing it disappear.
Solar Edge recently replaced the inverter on the 18th of August and I recorded
the event from start to finish. What it showed was that the inverter spikes
disappeared while the inverter was removed from the system and then re-appeared
once the new inverter was installed and activated.
I'll post the link to the time lapse video I recorded ASAP.
Good to hear from you Paul. Let me know if you need further information.
Tony -K2MO
On 9/28/2020 10:23 AM, Cianciolo, Paul, W1VLF wrote:
Tony,
Regarding your statement below:
"We found high levels of RFI on the A/C lines throughout my neighbor's home and
that's likely the case with all Solar Edge installations .............since there are no
chokes between the mains and inverter."
It is the last part that I take issue with. See the attached photo.
This is the EMI filter on the SE inverter on my house. Also see the
attached PDF, look under page 3 COMPLIANCES you will find part 15B
They could not legally connect these to a residential AC line if it
were not part 15b compliant. In addition I have a Corcom 25fc10
installed at my home. See the data sheet and response curves here.
http://www.farnell.com/datasheets/1430489.pdf
The filter makes a barely detectable change in the any received RFI I have from
the SE system.
What needs to happen here is to determine, the source of the RFI first, not
the radiating elements. In the past you have mentioned that even with the
inverter off, not producing power, you still had the interference. In fact you
had covered the panels and the RFI went away.
With that in mind here are a couple of sources, or generators, and not he
radiating element that I cab confirm in my testing.
1) The inverter itself. The original inverters SE used had an
internal switching frequency of roughly 18 KHz and thus harmonics
were found every 18 KHz
2) The HD wave inverters operate at roughly 50 KHz and thus you can see
harmonic energy at 50 KHZ intervals Other manufacturers that I have worked
with use 39 KHZ .
It is difficult to switch, in my case 6.5 Kilowatts of power in a box 12" x 12" by
8"
3) The original optimizers as we all know had a serious 200 KHz problem. In
the next version, as I have in my installation that problem has been rectified.
4) This leaves the fact that the current optimizers, the SP350? I believe? may
still generate some noise in the non-power generating state. I am pretty sure
you sent me a video or photo comparison that Randy, sorry I forget his call at
the moment, but he did bench test on a non-power generating optimizer.
In that video, you showed the spectral waveforms looking similar I believe?
I don't think the inverter is the cause of your issues at that this point. The
exact radiation mechanism of the RFI from your neighbors SE system is still
unknown.
I also do not see the noise issue you have, as you previously described at my
house. The again I only have a 275' open wire fed dipole that I tune on all HF
bands 200 feet away from house. I don not have a multielement beam design for
20 meters.
To me it would make the most sense to concentrate on the specific device
generating your noise based on the RF signature.
73,
Paul Cianciolo, W1VLF
ARRL EMC Engineer
ARRL - The national association for Amateur RadioT
225 Main Street, Newington, CT 06111-1400 USA
Telephone: (860) 594-0392
FAX: (860) 594-0259
Email: w1vlf@arrl.org
World Wide Web: www.arrl.org
-----Original Message-----
From: RFI <rfi-bounces+pcianciolo=arrl.org@contesting.com> On Behalf
Of Tony
Sent: Friday, September 25, 2020 6:23 PM
To: Rfi List <rfi@contesting.com>
Subject: [RFI] Question Regarding Variations In Solar Panel RFI?
All:
The reports I've read suggest that the strength of interference caused by solar
panel systems can vary from one installation to the next EVEN when the distance
to the source is similar. That variation could be attributed to radiating
conductors tied to the system such as the house wiring.
We found high levels of RFI on the A/C lines throughout my neighbors home and
that's likely the case with all Solar Edge installations since there are no
chokes between the mains and inverter.
Given those facts, would a large home with long runs of un-shielded Romex
produce higher levels of interference compared to a smaller home with shorter
runs? Or does the resonance of the wiring play more of a role than length and
number of runs?
It's an oversimplification, but it seems logical to consider what's connected
to system and not just the system itself.
Tony -K2MO
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