String Configuration PVsol - MPPTs and Polystrings

[Emile]

Hi Team Valentin Software,

For some inverters, MPPT trackers can accept more than one string (usually 2). PVsol doesn't usually indicate this when the inverter is selected. In the Configuration menu if I select for example a Huawei SUN2000-20KTL-M2, I get two sections to fill, MPPT1 and MPPT2.

For MPPT1, two strings can be inputted. One of those strings is going to be connected straight to the first input (lets name it input MPPT1a) and for the other input (MPPT1b) I want to connect two strings using a Y(or T)-Connector.

This separation between input a and b for every MPPT does not exist in PVsol, which leads me to the question, how can I achieve this separation using the options that are already present in the software? Polystringconfiguration is also not an accurate solution here to this problem.

I wanted to attached two models in this inquiry. The first is made with 20KW inverters with T-branch connectors and the other is with 15KW inverters without any T-branch connectors. I see very little difference in the yearly production for those two models, which cannot be true. The files are too big to be attached here unfortunately.

Your feedback here would be much appreciated. 

[Emile]

This is the model with 20 KW inverters with T-connectors

Autobedrijf Rick Van Lierop (20KTL met Y Connectors zonder begrenzing 80A).pvprj

[developer_mo]

Hi Emile,

thank you for your posts and sorry for my late reply.

On 5/28/2024 at 9:31 AM, Emile said:

This separation between input a and b for every MPPT does not exist in PVsol, which leads me to the question, how can I achieve this separation using the options that are already present in the software?

We took a look at the 20 kW project that you posted. If I understand it correctly, it's about the warnings that PV*SOL issues for this configuration. Is that correct?
Warnings do not mean that the system must not be built in this way, but indicate that increased losses may be expected.

The losses could be reduced by using a third inverter, but this would then lead to higher acquisition costs. With three of the 20 kW inverters, we were able to increase the specific annual yield by 1.91 kWh/kWp. Although the clipping losses are lower with the addition of a third inverter, the third inverter is hardly worthwhile.

On 5/28/2024 at 9:31 AM, Emile said:

The first is made with 20KW inverters with T-branch connectors and the other is with 15KW inverters without any T-branch connectors. I see very little difference in the yearly production for those two models, which cannot be true.

I also simulated the project with the SUN2000 15KTL-M2, which reduced the specific annual yield to 812 kWh/kWp. This seems plausible to me due to the higher clipping losses.

Please feel free to contact me again if this does not answer your question.

Kind regards

Mikio