Description
This is a two-part thesis.Part-I:
This work investigated the long-term reliability of a statistically significant number of two different commercial module-level power electronics (MLPE) devices using two input power profiles at high temperatures to estimate their reliability and service life in field-use conditions. Microinverters underwent a period of 15,000 accelerated stress hours, whereas the power optimizers underwent a period of 6,400 accelerated stress hours. None of the MLPE devices failed during the accelerated test; however, the optimizers degraded by about 1% in output efficiency. Based on their accelerated stress temperatures, the estimated field equivalent service life approximated using the Arrhenius model ranges between 24-48 years for microinverters and 39-73 years for optimizers, with a reliability of 74% and a lower one-sided confidence level of 95%. Furthermore, using the Weibull distribution model, the reliability and service lifetimes of MLPE devices are statistically analyzed. MLPE lifetimes estimated using Weibull slope and shape parameters with a 95% lower one-sided confidence level indicate a similar, or possibly exceeding, the 25-year lifetime of the associated photovoltaic (PV) modules. Part–II:This study investigated the impact of the hotspot stress test on glass-backsheet and glass-glass modules. Before the hotspot testing, both modules were pre-stressed using 600 thermal cycles (TC600) to represent decades of field-exposed modules experiencing hotspot effects in field-use conditions. The glass-glass module reached a hotspot temperature of nearly 200°C, whereas the glass-backsheet module's maximum hotspot temperature was almost 150°C. After the hotspot experiment, electroluminescence imaging showed that most of the cells in the glass-glass module appeared to have experienced significant damage. In contrast, the stressed cells in the glass-backsheet module appeared to have experienced insignificant damage. After the sequential stress testing (hotspot testing after TC600), the glass-glass module degraded by nearly 8.3% in maximum power, whereas the glass-backsheet module experienced 1.3% degradation. This study also incorporated hotspot endurance in fresh (without being subjected to prior TC600) glass-glass and glass-backsheet modules. The test outcome demonstrated that both module types exhibited marginal maximum power loss.
Details
Title
- Module Level Power Electronics and Photovoltaic Modules: Thermal Reliability Evaluation
Contributors
- Afridi, Muhammad Zain Ul Abideen (Author)
- Tamizhmani, Govindasamy (Thesis advisor)
- Kiaei, Sayfe (Thesis advisor)
- Bakkaloglu, Bertan (Committee member)
- Flicker, Jack (Committee member)
- Arizona State University (Publisher)
Date Created
The date the item was original created (prior to any relationship with the ASU Digital Repositories.)
2023
Subjects
Resource Type
Collections this item is in
Note
- Partial requirement for: Ph.D., Arizona State University, 2023
- Field of study: Electrical Engineering