Date of Completion


Embargo Period



Peter Luh; Yaakov Bar-Shalom; Shengli Zhou

Field of Study

Electrical Engineering


Master of Science

Open Access

Open Access


This thesis reviews the methods for evaluating the reliability of large PV systems and techniques for quantifying the impacts of PV interconnection on distribution system reliability. In addition, a comparative study is performed to evaluate the seasonal condition-dependent risk performance of central-inverter and string-inverter grid-tied PV power systems. Major contributions include: 1) risk analysis of seasonal impacts for string and centralized PV systems. Seasonal sensitivities of PV system risks to system structures, temperature variation, solar insolation, and capacitor equivalent series resistance are analyzed; and 2) the incorporation of the effect of operational conditions and the aging failure model into the PV system risk analysis. The PV panel aging effect, over a time span of 25 years, is incorporated to the reliability model. The risk performance is then analyzed with respect to the number of PV strings, PV panel failure rate and inverter repair time. The effectiveness of the proposed method has been validated on two real-life 20kW grid-connected PV systems. Application of the proposed method to actual large PV systems can provide valuable information to manage PV system risks, to choose better PV system design options, to develop better maintenance strategies, and thus to realize maximum benefit of photovoltaic power. Finally, future research trend for the emerging Giga-PV power systems is identified and discussed.

Major Advisor

Peng Zhang