Abstract
DC-link capacitors are reliability-critical components in a photovoltaic (PV) inverter. Typically, the lifetime of a DC-link capacitor is evaluated by considering the voltage and hot-spot temperature of the capacitor under the specific operating condition of the PV inverter. However, the output of the PV inverter is determined by solar irradiation and ambient temperature, which vary with the seasons; accordingly, the hot-spot temperature of the capacitor also changes. Therefore, the mission profile of the PV system should be considered to effectively evaluate the reliability of the DC-link capacitor. In this study, the reliability of the DC-link capacitor of a three-level NPC inverter is comparatively analyzed with and without considering the mission profiles of the PV system, where two mission profiles recorded in Arizona and Iza are considered. The accumulated damage of the DC-link capacitor is calculated based on the lifetime model by analyzing its thermal loading. Afterward, a reliability evaluation of the DC-link capacitor is performed at the component level and then at the system level by considering all capacitors by means of Monte Carlo analysis. Results reveal the importance of performing a mission-profile-based reliability evaluation during the design of high-reliability PV inverters to achieve the target reliability performance.
| Translated title of the contribution | Comparative Reliability Analysis of DC-link Capacitor of 3-Level NPC Inverter Considering Mission-Profiles of PV Systems |
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| Original language | Korean |
| Pages (from-to) | 535-540 |
| Number of pages | 6 |
| Journal | 전력전자학회 논문지 |
| Volume | 27 |
| Issue number | 6 |
| DOIs | |
| State | Published - 2022 |