[TowerTalk] Solar Microinverters/RFI

[Cox, Norman R.]

   I have a small PV array that I use for testing microinverters.  This past year, the microinverter under test failed after 2 years of service due to a lightning glitch.  I thought I would try an inexpensive (imported) microinverter someone was selling on eBay.  It generated so much RFI, you could hear it all over the neighborhood!  I returned it for a refund.


    Apparently, they manufactured these units with no filtering.  The idea was to not only reduce the cost, but to eliminate the tantalum capacitors that are one of the weak links in the converter.  Their aim was to be able to claim higher reliability.  In the instructions, they mentioned that you would have to furnish you own line filters.


   I have an SMA string inverter out at my farm, and it is very well engineered.  However, I have not done any measurements for RFI.


Good luck,


Norm

KE0ZT