[RFI] SolarEdge Finds New Source of Solar System RFI

[Tony]

Tony:

I asked if they were sure about their findings and the answer I got was 
that they were still seeing RFI with the system turned off and the array 
disconnected and disassembled. I'm assuming disassembled means they 
removed the optimizers from the panels.

They found that the noise dropped significantly after they applied 
ferrites to the panels, but I'm not sure if they tested a stand-alone 
panel with and without chokes or if they ran the test with the system 
completely reassembled and turned on. I'll asked that question the next 
time I speak with them.

The engineer mentioned the diode theory as well. If there is ambient RF 
exciting the panel diodes, is it possible that it would come from the 
inverter?

Tony -K2MO



On 6/2/2019 8:51 AM, Tony Brock-Fisher wrote:
> Tony et al-
>
> This sounds pretty hard to believe to me. The panels normally contain 
> no active circuitry, so it's hard to see how they could be generating 
> RFI.
>
> The panels may have a series diode. Additionally, the cells themselves 
> are really, really large diodes. The only thing I can think of is that 
> they could be getting excited by high ambient RF, and then rectifying 
> that RF to produce harmonics or possibly cross modulation products.
>
> I have an AM BC station that is less than a mile, line of sight, from 
> my QTH. During the day they transmit at 44kW. I have tons of RF all 
> over the place, and it does cause lots of products with other BC 
> stations and AC line modulated direct-diode supplies.
>
> Just my opinion here...
>
> -Tony, K1KP
>
> On 6/1/2019 5:59 PM, Tony wrote:
>> All:
>>
>> I recently spoke with an engineer from SolarEdge who said that they 
>> discovered a previously unknown source of RFI which turned out to be 
>> the solar panels themselves. They found that the panels were 
>> producing noise while physically disconnected from the system at a 
>> few installations.
>>
>> They are now working with the panel manufacturers Hanwha and Trina to 
>> determine why a certain batch of their panels are producing RFI. The 
>> goal is to locate installations with the defective panels and replace 
>> them.
>>
>> Cumulative RFI from multiple panels is apparently enough to cause 
>> serious RFI and may be the reason why my neighbors installation still 
>> makes noise during?? the day while the system is turned off. It could 
>> also be the reason why the choking the Optimizers had little effect.
>>
>> Tony -K2MO
>>
>>
>>
>