Export Limitation and Maximum Feed in power clipping

[seshyd]

Hi all,

I've tried searching in the forum on this subject and nothing quite answers my particular question.

We have a site that is 1680 kW DC and it has a grid export limitation of 485 kW. The site has an average load of 700 kW through the year. 

We are trying to model in PVSOL to show the correct annual yield of the PV considering this 485 kW export limitation. When we select power clipping at the 'feed-in point' the results simulation shows no difference to the kWh/kWp or PR of the solar generation. This is despite calculating down regulation of approximately 60,000 kWhs through the year.

Since in practice the limitation to the grid is don't by derating the inverter in real time, surely we should see a production reduction?

If we select power clipping at the inverter, then PVSOL simply caps inverter production to 485 kW at all times and this is obviously not the desired result we are looking to simulate.

 

Does this mean we are correct that we need to select power clipping at feed in point, however we need to subtract the down regulation total from the annual production manually so that we can esitmate annual PV yield correctly?

[developer_mh]

Hi seshyd,

On 6/1/2023 at 9:55 PM, seshyd said:

Since in practice the limitation to the grid is don't by derating the inverter in real time, surely we should see a production reduction?

This is correct in the real world, yes. However, in PV*SOL the simulation of the clipping mechanism at the feed-in point is not conducted by a derating in the inverter directly, so the PV energy production and thus the PR are not affected. We have chosen this way in order to avoid additional feedback loops in the simulation, which would have lead to a significant increase of simulation time.

On 6/1/2023 at 9:55 PM, seshyd said:

Does this mean we are correct that we need to select power clipping at feed in point, however we need to subtract the down regulation total from the annual production manually so that we can esitmate annual PV yield correctly?

Yes, correct!

Kind regards,

Martin