kamomeno68 Posted December 19, 2013 Share Posted December 19, 2013 Quick question about Voltage Threshold. I assume this item reflects inverter losses incurred when the input voltage to the inverter drops below its minimum dc operating voltage. In a real-world installation, I can see how this scenario would arise. Object shading could knock out a number of modules in a string, for example, which would drop the string voltage below the min inverter operating voltage, or you could have row-to-row shading on modules in landscape which would engage bypass diodes which would also drop the string voltage below the min inverter operating voltage. In the PVsyst model, however, I'm having trouble seeing when this will occur. For extremely high temperatures, maybe, but not as a result of shading. I have run two models which are identical in every respect other than the row-to-row spacing. Flat roof, single rows in landscape, near shadings defined "according to strings, 100% electrical effect". The wider row-to-row spacing shows 0% "loss due to voltage threshold", while the narrower spacing shows 0.2% "loss due to voltage threshold". With this near shading definition, it seems to me object or row-to-row shading would never result in a low string voltage - as soon as a shadow hits the string, it is considered 100% lost. I've tried running a number of different test models, just trying to better understand this loss factor, but the results aren't intuitive to me. Can you offer some insight into this loss factor? Thank you. Link to comment Share on other sites More sharing options...
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