Search documents

Browse topics

Document details

DC Cables Sizing and PV Modules Protection on PV Farms
I. Gal
Cost Reduction, Sizing, Module, PV Farm
PV Systems
Subtopic: Large PV Power Plants and Distributed PV: System Aspects and Grid Connection
Event: 27th European Photovoltaic Solar Energy Conference and Exhibition
Session: 5AV.1.43
4006 - 4008
ISBN: 3-936338-28-0
Paper DOI: 10.4229/27thEUPVSEC2012-5AV.1.43
0,00 EUR
Document(s): paper


To prevent fires on PV farms, DC cables have to be sized correctly and PV modules must be protected against reverse currents due to short circuits. But one feature specific to PV installations is that short circuit currents, which depend on the irradiance, may be permanent, as to low to make the protections quickly melt or trip. The difficulty in sizing cables and protections is that several different rules exist. A lot of standards are still emerging, and some of them, like the French standard UTE C 15-712-1 are more accomplished. However, they all agree on the logical fact that the PV module and cable protection has to be defined first, and then after the cable current-carrying capacity and cross-sectional area according to that protection. The first aim of this article is to clarify the different DC cable and parallel strings sizing rules, to reach a safe installation. However, a PV installation must be safe AND remain profitable; indeed cables account for a large part of installation costs! The second objective of this paper is to show in what way cross-sectional areas can be reduced by optimizing calculation, and how the number of strings in parallel on one protection can be increased on large solar farms.