Investigation of the Effect of Operating Conditions on Reliability of DC-link Capacitors in Microgrids

This paper considers a microgrid system where the impact of different non-ideal operating conditions on the reliability of the DC-link capacitor in three phase inverter systems is investigated. Rather than focusing on the lifetime of the capacitor, its failure rate is investigated and deemed a valuable indicator of the system's reliability. The thermal modeling of the capacitor is investigated as well is its importance in evaluating the failure rate of the capacitor. The study shows that unbalanced conditions has a particularly detrimental effect on the DC-link reliability. Nonlinear loads may have small effects as long as they do not adversely affect the power factor.