Inverter startup voltage matching

[ChrisSolarTinkerer]

Please can you explain how the minimum inverter startup voltage is stored and used in PVsyst to ensure that the specified string lengths of a given module are long enough?

For example, I'm running a simulation with a Ginlong 20kW 'Solis-20K'. The inverter datasheet states that it's startup voltage is 350V and its operation MPP range is 200-800V. When I select a typical 60 cell module, the design screen states that my allowable string length is 8-23. The minimum string length of 8 is using the min MPP value of 200, but I think it should be using the 350V startup voltage. On that basis, the minimum string length would be 14.

I realise the startup voltage is only used each morning and then the working voltage can reduce down to 200, but I'm surprised the 350V startup voltage isn't mentioned anywhere.

I'd appreciate any assistance you can provide.

Thanks,

Chris.

[André Mermoud]

PVsyst doesn't manage the minimum starting voltage specified by some few manufacturers.

Usually this is below the VmppMin and I don't understand well the mechanism.

In your case of a value far above the VmppMin, we can understand that when the array is not operating, it is at Voc, not Vmpp, so that this constraint is perhaps less important.

However, please ask the manufacturer for details about this behaviour.