Reliability Evaluation of Smart Meters under Degradation-Shock Loads Based on Phase-Type Distributions

To address the problem that high-reliability and long-life complex products are susceptible to coupled fault mechanisms, and to address the challenge of constructing a macro fault behavior model for reliability evaluation, the reliability of a smart meter based on a Phase-Type (PH) distribution under a degradation-shock load is examined. This reliability assessment method considers the impacts of environmental stress and lightning shock on a smart meter. The performance degradation process caused by environmental stress is described by a Wiener model, which is converted into a representation of a PH distribution in a subsequent step. A lightning impulse can cause performance degradation or direct failure of a smart meter. The arrival time of the lightning, the magnitude of the lightning, and the damage caused by the lightning are analyzed separately, and then, the obtained model is expressed in the form of a PH distribution. Finally, a reliability evaluation model of a smart meter based on the PH model under a degradation-shock load is established. The accuracy of the model is verified by comparing the model results with Monte Carlo simulation results.