string configuration

[garf]

Greeting,

I have a project where we design based on CSI PV 665Wp and Huawei 330KTL inverter.

The 330KTL inverter has 6 MPPT with 28 inputs.

Total DC power is about 45MWp and AC power is 30MWac.

So I have total 2,114 strings x 32PV per string, distribute to 100 unit of inverters.

When I configure like the following, the DC:AC ratio is 1.5. The inverter power is slightly undersized, but PVsyst still allow to simulate.

If we divide 2,114 strings to 100 inverters. Each inverter will have 21.14 strings. 

But in actual, we can't have 21.14 strings per inverter. So I need to have 86 inverters with 21 strings x 32PV per string; and 14 inverters with 22 strings x 32PV per string.

When I configure this way, Pvsyst says inverter power is undersized, and not allow to simulate.

 

So, in this case does it mean 45MWp to 30MWac is not achievable? or what setting I need to change? anyone can share your view? thanks in advance

 

[Michele Oliosi]

On 1/26/2023 at 6:53 AM, garf said:

Each inverter will have 21.14 strings. 

PVsyst will not calculate like that. PVsyst will simulate the following:

On 1/26/2023 at 6:53 AM, garf said:

need to have 86 inverters with 21 strings x 32PV per string; and 14 inverters with 22 strings x 32PV per string

The reason for the difference between warning in one case and error in the other is that (for the warnings only) PVsyst in the first case does only a rough evaluation using the total Pnoms, it doesn't separate the two types of inverter.
If you still want to proceed, you can change the threshold for activation of the error. It is found in the project settings, you can increase the value 3% to a higher value.

[garf]

1 hour ago, Michele Oliosi said:

PVsyst will not calculate like that. PVsyst will simulate the following:

The reason for the difference between warning in one case and error in the other is that (for the warnings only) PVsyst in the first case does only a rough evaluation using the total Pnoms, it doesn't separate the two types of inverter.
If you still want to proceed, you can change the threshold for activation of the error. It is found in the project settings, you can increase the value 3% to a higher value.

I see... Got it... thanks for advice