Modeling and Simulation of the Longtime Behavior and Fatigue Failure of Photovoltaic Modules under Desert Environment

During operation, the PV modules undergo thermomechanical loadings because of the continuous temperature variations. This cyclic load causes fatigue failure. The constituent of the PV module which is more prone to failure due to fatigue is the copper interconnect, the role of which is to electrically and mechanically link PV cells in series. This higher probability of the failure is due to comparatively smaller size of the copper interconnect with respect to other constituents of the PV module. Also, a PV module is composed of different layers stacked together, each with different material properties. Therefore, in this work, to be used in finite element (FE) analysis, the material models have been defined as realistic as possible. This ensures that we can make sound judgments on the stress-strain variations obtained through a FE analysis. Using this stress-strain variation, we then estimate the life of the PV module based on the fatigue life of the copper interconnects. The choice of specific material models opted in this work, for each layer, is justified through various validations. It has been shown that for fatigue analysis, it is a must to use kinematic hardening models, rather than the isotropic hardening models.