question

josegiron avatar image
josegiron asked

ESS with generator, AC Coupled Fronius, risk of damage generator.

Do you have an idea, how to solve the risk to damage the generator in an ESS system, when the grid fails, batteries are low but CCGX starts generator for backup. Fronius with MG is AC coupled in the output of the Quattros, if Sun comes suddenly and AC2 input relay from generator is closed Fronius could feed back. Do you have an idea to solve this risk? or there is not such a risk to damage the generator? I can not change frequency in the generator it is 60Hz (stable).

ESS
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2 Answers
Kevin Windrem avatar image
Kevin Windrem answered ·

Just a guess but ESS instructions indicate using AC1 for the generator and setting the input source to Generator in the CCGX

I'd assume from that that there would be no feed-in to AC1/generator.

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petajoule avatar image
petajoule answered ·

Having continuous woes attaching ANY generator to a 3p Quattro system (which has a Fronius-fed AC-arm), I can confirm that the Fronius constantly pushes significant current INTO the/any generator. Or - to be more precise - the Quattros happily shovel that current through to AC1-in.

So for all (failed so far) tests where we try to get some electrons from a generator, we have to turn off the Fronius to have at least a chance of the generator working for a few seconds.

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