[RFI] Growing RFI problem from SolarEdge systems

Jim Brown jim at audiosystemsgroup.com
Sun Nov 12 15:27:41 EST 2017

On 11/12/2017 12:07 PM, Mike Kirkland wrote:
> Actually the FCC has proved turning the system off is ineffective at
> eliminating the interference and the system must be disassembled.

Interesting -- the question is, HOW and WHAT was turned off? There are 
(at least) two components/functions of solar power systems that can 
generate RFI. One is charge regulation, which prevents batteries from 
being overcharged. Another is power inversion from DC to AC.  In both 
cases, it is failure to suppress the generation and radiation of RF 
components of pulsed currents and rectangular waves. It is quite well 
known that excessively fast rise times, poor circuit design, and poor 
wiring/installation techniques increase the strength of these components 
and cause them to be radiated.

If, for example, inverters were turned off but charge regulators were 
still functioning, they could still be generating noise.

Another possibility is that improper bonding by the installation company 
might be causing noise present on the mains power system to be radiated.

QST published an interesting piece a few years ago detailing the heroic 
efforts required to suppress a really bad system.

73, Jim K9YC

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