Life Monitoring Tool of Insulated Cables in Photovoltaic Installations

A photovoltaic installation is exposed to extreme ambient conditions due to solar radiation, humidity, wind, and thermal stresses. A comprehensive design of its power system could follow two complementary strategies: one consisting in the adoption of special components and the other one consisting in an adequate installation of standard components providing a continuous control of its operation life cycle. At this aim, this paper suggests to subdivide the dc wiring system in a final distribution to the panels with high stress exposition, wired by special solar cables, and a main distribution as much as possible with an installation avoiding the stress exposition, wired by normal cables. This paper introduces a thermal aging model for the cables that allows one to define an aging criterion and a life monitoring tool. The tool evaluates and monitors the real thermal aging of the main wiring system and could be integrated in the supervisory system.