Deye inverters and external electronic meters.

[shadowmaker]

Not sure about crossy's area but where I am we have outages fairly regularly it's the whole reason my wife's actually ok with the idea of solar.

I have automatic transfer switch (which I use only manually, but can be automated if wanted) to change my GTIs between GEN port AC coupled/LOAD port parallel. If there is elongated outage (rare here, but who knows when the next one occurs) it's just a flip of switch and GTIs start working if batts not full already.

For me it's my big consumption and doubled/tripled energy prices here. I didn't ask permission from wife before doing this as I reckon asking after is much easier...

 

[ThaiTaffy]

I would have thought that even Thailand can handle 2 milli-Watt hours a day

Meh smarty pants but tbh I'm not so sure I might be even correct on that the voltage drop some days at peak times was getting very close to cut-off point for my inverters ups mode.

 

[crossy]

I didn't ask permission from wife before doing this as I reckon asking after is much easier...

"It's easier to ask forgiveness than it is to get permission" - Admiral Grace Hopper!

 

[ThaiTaffy]

didn't ask permission from wife before doing this as I reckon asking after is much easier...

Not sure about crossy but even though I pay for half of our life, by law everything is pretty much in my wife's name. I also made(some might say the silly decision) to marry an extremely wealthy independent individual rather than a typical supporting Thai wife so most of my decisions have to be vetoed by her but on the plus side I'm a clumsy idiot so having someone to say "your great idea is idiotic" can be pretty helpful.

 

[shadowmaker]

Here's how nicely GTIs are working on my system:


So what is happening is that my four identical strings are producing something like 4 x 3,2kW =12,8kW. At the same time my loads seem to be zero as my GTIs are taking care of that. Actually my loads are 12,8kW - 8,3kW =4,5kW. The point here is that normally I should be only capable of charging my batts with ~3,2kW produced by this Deye but it seems I can actually use all four inverters combined power now to do that instead exporting that extra power to grid. GEN port "Micro Inv Input" is ticked, but as one can see my GTIs are not AC coupled and thus making 0W according screen.

 

[timselectric]

Here's how nicely GTIs are working on my system:
View attachment 227443

So what is happening is that my four identical strings are producing something like 4 x 3,2kW =12,8kW. At the same time my loads seem to be zero as my GTIs are taking care of that. Actually my loads are 12,8kW - 8,3kW =4,5kW. The point here is that normally I should be only capable of charging my batts with ~3,2kW produced by this Deye but it seems I can actually use all four inverters combined power now to do that instead exporting that extra power to grid. GEN port "Micro Inv Input" is ticked, but as one can see my GTIs are not AC coupled and thus making 0W according screen.

Not AC coupled through the gen port.
But still AC coupled, through the load port.

 

[shadowmaker]

Not AC coupled through the gen port.
But still AC coupled, through the load port.

So GRID port shares busbar with LOAD port? Really don't mind if it does as I don't care if it's called AC coupling or not, just want it to work. And now it works really nice.

 

[timselectric]

So GRID port shares busbar with LOAD port? Really don't mind if it does as I don't care if it's called AC coupling or not, just want it to work. And now it works really nice.

Yes
Grid-tied inverters only work when AC coupled to a source.
Whether that is the utility grid or a micro grid.
The Deye will still frequency shift control it (when off grid).
It just can't shut it down completely if needed. (Gen port can)
And the Deye can track its production through the gen port.
But not on the load port.

 

[shadowmaker]

Yes
Grid-tied inverters only work when AC coupled to a source.
Whether that is the utility grid or a micro grid.

I understand GTIs need certain frequency area or they shut down. I would have expected that without grid they shut down as they are connected to GRID port not LOAD/GEN. Also they have been shutting down before when there has been few outages already. Back then, although they were connected exactly the same way (through GRID port), Deyes couldn't use exporting power to charge up my batts. That happened to much later time and I suspected that was because of some altered settings (Don't know what exactly I changed).

The Deye will still frequency shift control it (when off grid).
It just can't shut it down completely if needed. (Gen port can)

That doesn't sound all that good. So where is power going if my batts are full? At the moment my setup doesn't provide ANY backup power during outage so power can't go to my loads. We have talked this before but for others reading this the reason is that my Deyes are connected parallel BUT without comms and without comms it's not safe to use them parallel off-grid without balancing base frequency (provided by grid).

Is there any power coming in even if GTIs stay on??? I mean power is always drawn from the panels not pushed. If there's no demand there should be no production?

And the Deye can track its production through the gen port.
But not on the load port.

That doesn't bother me. If I want I can get production numbers from my GTIs but the main thing is that I can now utilise all four inverters to charge up my batts and when batts are full GTIs continue working and selling their power to grid. I want this done safely without braking things though.

 

[timselectric]

I would have expected that without grid they shut down as they are connected to GRID port not LOAD/GEN.

I missed that part.
With only the GTI's connected to the grid port, they shouldn't function.
I'm not sure how they are.

Is there any power coming in even if GTIs stay on??? I mean power is always drawn from the panels not pushed. If there's no demand there should be no production?

Grid-tied inverters don't operate based on loads drawn.
They set the load for the panels to produce.
They run at max production at all times. (Unless frequency is shifted from normal)
They will assume that they are connected to a utility grid that can accept all that they can give.

 

[shadowmaker]

I missed that part.
With only the GTI's connected to the grid port, they shouldn't function.
I'm not sure how they are.

My GTIs have been connected this way (parallel through GRID port) for a year or so at first. Back then they did shut down in case of outages, but they also didn't contribute batt charging at all. Then I decided to try AC coupling and connected GTIs through GEN port but also left original connection through GRID port in place with ATS between them so I can change it back with a flip of switch (using ATS manually). With AC coupling through GEN port GTIs charged my batts up to full and then disconnected. At that point I needed to flip ATS to connect GTIs back to being just parallel to my Deyes through GRID port to get them going and producing power to the utility grid. That was annoying. At some point I noticed that my Deyes were somehow capable to utilize GTIs extra power and only extra power to charge my batts even they were connected through GRID port and this is how they have been connected since (2-3 months now). There hasn't been any outages lately so I don't know how they will behave but I would guess they will shut down. I really don't know what settings I have changed as for a year GTIs were connected this way but didn't contribute batt charging at all. It is like my Deyes can now detect there's extra power available (export power) through CT meter and decides automatically to use grid charge up to a point that they still never use utility power. My system is working really nice now but would be nice to know how it is possible as I haven't seen this kind of behaviour mentioned here before or anywhere else including manual.

Grid-tied inverters don't operate based on loads drawn.
They set the load for the panels to produce.
They run at max production at all times. (Unless frequency is shifted from normal)
They will assume that they are connected to a utility grid that can accept all that they can give.

Always learning something new. But then probably forgetting it soon...

 

[timselectric]

If connected on grid side (grid port) and grid is also providing the power source.
Then yes, they should help with battery charging, as long as grid charging is selected. But no frequency shift control, as the grid is the source.
And when grid is lost, they will shut down.
I thought that you were saying that you only had the GTI's connected to the grid port (without grid). Which is why I said that it should not work.

 

[shadowmaker]

...they should help with battery charging, as long as grid charging is selected...

This. But how do you select "automatic grid charge, only when there is excess CT power available"??? I mean there is no such setting in manual. You can set grid charge/amperage and use TOU settings to enable it, but then it is a set value. It will charge using utility power if there is no excess power available. Mine doesn't use utility power at all, only excess. Of course I can use utility power to charge my batts if I want, but then I need to enable it at TOU settings. My TOU settings for grid charge are all off.

I mean my current system works like it was engineered in Deye program. Like someone already thought that maybe there are setups with additional GTIs in the same system and it would be nice if one could use their power to charge batts too plus use CT reading as arbitary line so that utility power is not used if so wanted. That's fine but there is no mention of this in manual, at least I haven't found it. Also haven't read anything like this here on the forum even there seem to be lots of people using hybrids with GTIs. I don't know how I did manage to enable this feature but I know it wasn't on for the first year or so. Maybe it's ordinary thing but I just have missed it and managed to enable it by accident.

These cheapo shitty Chinese Deyes keep surprising me. Positively at least so far.

 

[timselectric]

The only way that the Deye can know if there is excess power on the grid side, is with the CT's. (Placed between the grid and GTI's)
"Export to CT" is the setting, I believe.

 

[shadowmaker]

The only way that the Deye can know if there is excess power on the grid side, is with the CT's. (Placed between the grid and GTI's)
"Export to CT" is the setting, I believe.

Yes, that is setting I'm almost always using unless I want to backfeed grid when spot prices are high. Deye knows line between import/export because of CTs located just after utility meter. But there is still no setting for "automatic grid charge, only when there is excess CT power available". At least I haven't heard anyone saying there is. For the first year I was also using "Zero Export to CT" but then if my GTIs were making excess power it went straight backfeeding grid and Deyes were not able to use that excess to charge batts. That means some settings must have been altered lately as otherwise my system hasn't altered in any way. I might need to just try and change one setting at time to see if I can spot what is enabling this. I just don't want to loose this as now it works much better than the whole last year.

 

[timselectric]

Hopefully I will get my Deye up and running, this winter.
Then I will know more about how to make it work in different scenarios.
I just haven't had time to build the middle section of my system, yet.
And I don't want to play with it on the grid, at all.