Can Growatt Inverter do this?

fafrd

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Can anyone point me to a document that says enphase is using their PLC to control the inverter output similar to what 1741/CA21 requires? What little I have seen it looks like the enphase only uses the PLC for data gathering, not control.

BTW: I agree that something like the enphase PLC could be a better way to control AC coupled inverters.......
I believe that one active member on the Forum has an Enphase solution (HKRD?). Most of what I (think I) know about what Enphase is doing I learned from exchanging posts with him.

Any ‘walled garden’ hybrid solution that only works to support certain AC-coupled features if you are using their specific Microinverters and their specific brain/controller (whether the battery or the hybrid inverter) is likely to be based on proprietary PLC communication rather than a less-reliable open standard…
 

Ampster

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Can anyone point me to a document that says enphase is using their PLC to control the inverter output similar to what 1741/CA21 requires?
I am only speculating that there has to be some internal firmware that that takes the frequency or voltage shift and translates that into a signal to reduce output. I have never observed this response but I have often wondered if every micro reduces output or if only certain ones drop off to create a reduction of output in total.
 

FilterGuy

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I am only speculating that there has to be some internal firmware that that takes the frequency or voltage shift and translates that into a signal to reduce output. I have never observed this response but I have often wondered if every micro reduces output or if only certain ones drop off to create a reduction of output in total.
If the control is strictly on frequency shift, then I have to believe all of them would be acting totally independent and any difference in when they turn on or off would be due to minor build differences and therefore negligible.

If there is some kind of handshaking over a PLC, the algorithm could be arbitrarily complex and some could stay on while others shut off, but I am not sure that kind of complexity would add any overall value so my *guess* is they all ramp down together.
 

fafrd

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I am only speculating that there has to be some internal firmware that that takes the frequency or voltage shift and translates that into a signal to reduce output. I have never observed this response but I have often wondered if every micro reduces output or if only certain ones drop off to create a reduction of output in total.
It is certainly not any kind of coordinated reduction across micros (there is no communication between them).

1/ Master changes grid frequency to reduce power generation.

2/ Each and every Microinverter independently decides how to modulate its power output in response to the modified frequency (some not at all, such as my older-generation Microinverters).

3/ if power generation has reduced too much, master backs-off on frequency shift, if generation still too high, master further increases frequency shift.

4/ Once a ‘just right’ frequency is settled on (or frequency ‘saw tooths’ around a ‘just right’ average frequency) where generation matches load, that continues until there is a change in load (or a drop in generation).
 

fafrd

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I found this description of the Enphase AC-coupled backup power solution: https://enphase.com/sites/default/f...e_System_Planning_Guide_Tech_Brief_NA_0_0.pdf

It’s cute, but clearly a walled garden (only functions in an all-Enphase solution set).

They don’t explicitly state the technology they are using to communicate with the Microinverters, by the only way to ‘block’ power line communication is through use of a filter, so this statement is pretty much proof Enphase is relying on PLC for their (proprietary) walled-garden solution:

‘• When multiple Envoys exist on site, a power line filter must be installed to prevent cross domain communication.’

Each ‘domain’ is the equivalent of an independent local area network.

You can also see in figures 6 and 7 that the Enphase solution includes CT sensors connected to the Envoy both to monitor consumption and generation.

The AC-coupled storage is superfluous to how the architecture actually works and I believe it’s just a matter of time before we see open systems supporting similar capability…
 
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