<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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