What's the best way to limit/down regulate the current (A) output from the inverter in PV*SOL?

[Jimmy]

Say that I have a 20 ampere main fuse in the house and I want to use an inverter that can output a little more than that.

 

Do I use the "Maximum Feed-in Power Clipping" under AC Mains, if so how precisely does that work. What's the difference between clipping at the inverter or at the feed in point? And what does it mean when it says that it's clipping "% of PV power"?

 

Can I use the displacement factor instead? How does that work?

 

Or is it perhaps easier to create a new (copy of an) inverter which has the desired AC output?

 

Also, someone broke the upload file size by a factor of 1000 (max size 14.85kB) so I can't upload screenshots. 

 

 

[Johan]

When I need this I often use the "Maximum Feed-in power clipping function.

If it is the best sollution I am not 100% sure about it, in my oppinion it should be easier to just give a maximum grid feed-in current.

[developer_mh]

Hi Jimmy,

the "Maximum Feed-in Power Clipping" lets you limit the power at either the feed-in point or at the inverter output to a percentage of the installed PV power (STC). If you have PV modules with a total STC of 10 kWp installed and you set the power clipping to 70% percent at the inverter, everything above 7 kW (AC) will be cut off. Actually, if you limit the power at the inverter output, the exceeding power will not be cut off, but instead another point on the I-V characteristics of the modules is chosen so that the power limit is not hit.

If you choose to clip at the feed-in point, the inverter can still output power to its own limit, say 10 kW. Then electrical appliances or a battery system or an electric vehicel can be supplied, and only after that, before feeding in the surplus PV power into the grid, we check if the power clipping limit is reached. If so, we cut the excess off. If the PV is outputting 10 kW (AC), and the consumers draw 5 kW at the same time, the grid feed-in would only be 5 kW, so no clipping would occur.

If you want to limit to an AC current of 20 A, you would have to calculate the resulting power depending on the grid voltage. On a one-phase 230 V grid you can get 4.6 kW over a 20 A fuse. If you have 10 kWp of PV power installed, you would enter 46 % "Maximum Feed-in Power Clipping" at the feed-in point.

Hope that helps, kind regards,

Martin

[developer_mh]

On 12/15/2021 at 3:48 PM, Jimmy said:

Also, someone broke the upload file size by a factor of 1000 (max size 14.85kB) so I can't upload screenshots. 

This is because your attachment quota is nearly full. You'll need to delete older attachments or messages in order to upload new ones.

[Jimmy]

Thanks for the thorough explanation Martin, it helps a lot!

Regarding the attachment quota, I suspect that you have that mainly as a spam guard. Could you consider raising mine or perhaps making the quota dependent on contributor rank? I really don't want to delete any of my attachments as that would lower the quality of the posts and comments that I've made that might be useful for others in the future when searching through topics.  

 

Kind regards

[Eriic]

Hello regarding using the power clipping of PV-power at the feed in point. Say I wish to limit a 100kW inverter and about 110kwp to 50% to make sure the fuse is not overloaded. Is it possible to see hos much energy (preferably in kWh) or the amount of times that it limits the inverter? 
Trying to find out how much energy is lost due to 80A fuse and limiting the export. 

in the documentation or in hourly values report somewhere?
Thanks  

[developer_fw]

Hi Eriic,

this is probably not exactly what you are looking for, but instead of limiting the current, via Project Options > AC Mains > Maximum Feed-in Power Clipping it is possible to set a limitation for the percentage of your PV power:

After simulating with clipping, there are several ways to have a look into how the results are affected:

I hope this helps.

Best regards,
Frederik