Reliability assessment of high-concentration photovoltaic trackers

Ten years of accelerated reliability test data for trackers used in high-concentration photo-voltaic power systems have been generated, collected and analyzed. The life test plan was developed based on potential failure modes of the tracker hardware, which are dominated by wear-out mechanisms. The number of units on test and the test duration are based on a 2-pa rameter Weibull distribution. The data collected include motor currents, voltages, temperatures and vibrations for gears and bearings. Time-based and frequency-based analyses are both used to assess reliability. Equations used to help identify degrading bearings and gears were based on vibration frequency analysis. The results show both wear-in and wear-out mechanisms. Hardware times-to-failure distributions and tracker reliability estimates were developed.