Inverter overloading (eg 5-10%)

[tecnun]

We are considering upgrading 6th version. For us it is important this issue: We are ABB distributors and almost every inverter can supply more power than the nominal value. In our country it is not restricted. So, when we simulate, there are more losses considered regarding the moments when the potential generation exceeds nominal values. Is there in the newer versions a way to set a value over nominal for this extra generation (when you characterize inverter parameters)? In 5th version this parameter (maximum power) is only informative, it does not take it into account on simulations.

Thanks in advance

Jose

[André Mermoud]

I don't understand what you mean.

In the version 5, as in the version 6, the maximum power of the inverter is obviously taken into account in the simulation process: the excess energy will appear as "Overload Loss".

Plese see Can I define a system with Highly undersized inverter ?

[tecnun]

I mean that, in my opinion, it is a good practice to undersize inverter power (to a moderate extend), bcs as time goes by, the PV power diminishes bcs of natural degradation and the efficiency of an inverter is higher when it is fully charged. I have conducted several studies for 25-35 years and the initial loss (excess) is leveled by the 6th-7th year...next years yield is relatively positive. Sometimes local regulations dont help too much to my idea, as inverter has to apply a limit (exactly to nominal values) --> Potential production over that limit is loss. But some inverters, as you know, allow a margin of kW over nominal values (depending on temperature of operation). In version 5 you cannot apply this extra yield but i am not sure if in the newer this is possible.

Thanks in advance, BR Jose.

[André Mermoud]

Since the version 6.27, it is possible to specify a Maximal Power value (PMax), which may be higher than the PNom value when the inverter's temperature is sufficiently low.