Article 705

[iwire]

That's not necessarily true. I have gotten a Sunny Boy/Sunny Island system to operate with a generator acting as the grid. You cannot use just a generator, or at least it's not advisable because without a battery buffer to prevent backfeeding of the generator you can blow up the generator, but in the above scenario the Sunny Island can be in paasthrough mode with the Sunny Boy accepting the generator as the grid.

Is that strictly a grid interactive or not?

 

[GoldDigger]

Is that strictly a grid interactive or not?

A very good question of terminology. The SunnyBoy is a strictly grid interactive inverter with the addition of an algorithm to reduce its output power as the reference frequency rises rather than shutting down when it hits a tolerance value. But no way other than that to tell a POCO grid from a local reference signal from either
SI or generator.
Adding the SunnyIsland makes the combination a hybrid system which can operate in off grid mode when there is no AC reference input to the SI.
But in the situation described it is acting more like a pure hybrid system with a "grid"which is not as clean as it normally sees. There is no protection against excess production trying to backfeed the generator as there is with systems with two different AC inputs.
What would you call it?

 

[iwire]

What would you call it?

Not strictly a grid interactive system which is what I was talking about and what the OP very likely has.

 

[ggunn]

Is that strictly a grid interactive or not?

The Sunny Boy is. It accepts the generator waveform as grid in the scenario I described. I read your comment to mean that there was something about the AC waveform from a generator that made a GT inverter not see it as grid. That is what I said was not necessarily true.

Whether such a system is what the OP has or not (I think not) is irrelevant to the point I was trying to make.

 

[iwire]

I read your comment to mean that there was something about the AC waveform from a generator that made a GT inverter not see it as grid. That is what I said was not necessarily true.

And yet it is true unless the unit is designed to run on a generator as GD explained.

 

[ggunn]

And yet it is true unless the unit is designed to run on a generator as GD explained.

By "unit" if you mean the GT inverter in and of itself, I'd say again not necessarily. While it is true that Sunny Boys have the capacity to throttle back their output in response to frequency munging by a Sunny Island, that isn't happening when the Sunny Island is in pasthrough mode using the generator as grid. In that state of the system The Sunny Island is transparent; the Sunny Boy nether knows or cares whether the AC it is seeing comes from the grid or the genny. The generator is driving the AC bus and the SI is charging the batteries from the AC bus, providing enough load to the SB that it doesn't backfeed the generator.

Theoretically, anyway, you could put any GT inverter in place of the SB and it would work... sort of. The difference would be that the GT inverter would merely turn off when the SI shifts the frequency when the batteries are full and the SI is controlling the AC bus (i.e., inverting from battery power - the genny is off) rather than gracefully throttling back.